Full PDF - The Bone & Joint Journal

Canadian Orthopaedic Association (COA)
Canadian Orthopaedic Research Society (CORS)
Canadian Orthopaedic Residents’ Association (CORA)
Whistler, British Columbia, Canada: 3–6 July 2009
President: Dr. Peter O’Brien
Correspondence should be addressed to CEO Doug C. Thomson. Email: doug@canorth.org
CORS PAPER SESSION 1:
CARTILAGE AND MUSCLE
1. INFLAMMATION CAUSES MUSCLE
INJURY IN COMPARTMENT SYNDROME:
AN EXPERIMENTAL STUDY
Abdel-Rahman Lawendy 1 , David W. Sanders 2 ,
Aurelia Bihari 3 , Amit Badhwar 3
1
University of Western Ontario; 2 Victoria
Hospital, London Health Sciences Centre;
3
Lawson Health Research Institute
Purpose: Compartment syndrome is a limb-threatening
complication of skeletal trauma. Both ischemia and
inflammation may be responsible for tissue necrosis
in compartment syndrome (CS). In this study, normal
rodents were compared with neutropenic animals to
determine the importance of inflammation as a mechanism
of cellular damage using techniques of intravital
videomicroscopy (IVVM) and histochemical staining.
Method: Forty Wistar rats were randomised. Twenty
animals served as a control (group C). Twenty rats were
rendered neutropenic using cyclophosphamide (250mg/
kg) (group N). Animals were anaesthetised with 5 %
isoflurane. Elevated intracompartmental pressure was
induced by saline infusion into the anterior hindlimb
compartment and maintained at 30–40 mmHg for 0,
15, 45 or 90 minute time intervals. Following fasciotomy,
the EDL muscle was analyzed using IVVM to
quantify tissue injury, capillary perfusion, and inflammatory
response.
Results: The proportion of injured cells decreased in
group N compared to group C at all time intervals
of EICP (p0.05).
Conclusion: This study demonstrates the importance
of inflammation as a cause of injury in compartment
syndrome. There was a 50% decrease in injury in neutropenic
animals compared to controls after 90 minutes
of elevated intracompartmental pressure. Microvascular
perfusion analysis demonstrated a time-dependent
decrease in capillary perfusion in both neutropenic
and control animals. Blocking of the inflammatory
response via neutropenia was protective against tissue
injury. These results provide evidence toward a potential
therapeutic benefit for anti-inflammatory treatment of
elevated intra-compartmental pressure.
2. CHONDROITINASE ABC AND ACUTE
ELECTRICAL STIMULATION ARE
BENEFICIAL FOR MUSCLE REINNERVATION
AFTER A SCIATIC NERVE TRANSECTION IN
RAT
Frédérick-Charles Cloutier, Dominique Rouleau,
Eric Beaumont, Michael Atlan * , Pierre H.
Beaumont
Hôpital Sacré-Coeur de Montréal; *France
Purpose: Nerve re-generation and functional recovery
are often incomplete after a peripheral nerve lesion. The
aim of this study was to determine if the injection of
chondrotinase ABC at the lesion site, one hour of electrical
stimulation, and the combination of these treatments
at the time of repair are effective in promoting
nerve regeneration and muscle re-innervation.
Method: A complete right sciatic nerve section was done
on 32 female Sprague-Dawley rats. End-to-end microsuture
repair was performed and fibrin glue was added.
Five groups were studied: 1- Sutures and Fibrine glue
(S+F), 2- S+F and chondrotinase ABC, 3- S+F and electrical
stimulation, 4- S+F and chondrotinase and electrical
stimulation, 5 uninjured nerve. Video kynematic,
EMG, muscle strengh and axonal count were used to
asses nerve recovery at 150 days post-repair.
Results: Side video kinematics was performed and a
larger excursion of the hip-ankle-toe angle during walking
was showed in groups 2, 3, and 4. (p

244 COA/CORS/CORA
cells within the MSC population. It is also present on
chondrocytes and is thought to play a critical role in cartilage
matrix generation and homeostasis. We hypothesized
that a CD44+ purified subpopulation of MSCs will
possess enhanced chondrogenic potential and be more
suitable for articular cartilage regeneration.
Method: Bone marrow aspirates were collected from
orthopaedic patients undergoing iliac crest bone grafting.
Human MSCs were isolated and cultured using
standard techniques. Flow cytometry was utilized to
identify the cell surface antigens characteristic of the
MSC population. FACS was utilized to isolate the CD44
positive cells based on antigenic recognition, generating
a CD44 positive population and a CD44 negative population.
To confirm the multilineage potential of the isolates,
defined media and culture conditions were utilized
to differentiate both groups into osteocytes, adipocytes
and chondrocytes. Real time polymerase chain reaction
was utilized to quantify and compare the essential markers,
collagen II, collagen I and aggrecan, in the stem cell
derived chondrocytes. The CD44 enriched and CD44
depleted populations were compared.
Results: The cells isolated possessed a cell morphology
and surface antigen profile consistent with a MSC
population. In addition, both experimental groups demonstrated
multipotent ability. Real time PCR analysis
of the chondrogenic cells demonstrated that the CD44
positive population expressed collagen II and aggrecan
at a significantly higher level than the CD44 negative
population.
Conclusion: To date no group has successfully identified
a relationship between a MSC subpopulation and the
multipotent progenitors responsible for generating cartilage.
This work demonstrated that there are MSC subpopulations
with different potential for chondrogenic
expression and represents an important step towards
identifying MSC subpopulations with enhanced cartilage
formation potential.
5. MECHANISM OF DECREASED
EXPRESSION OF TYPE X COLLAGEN
IN HUMAN MESENCHYMAL STEM
CELLS CULTURED ON NITROGEN-RICH
PLASMA POLYMERS: IMPLICATION OF
CYCLOOXYGENASE-1
Fackson Mwale 1 , Hong Tian Wang 2 , Pierre-Luc
Girard-Lauriault 3 , Michael R. Wertheimer 3 , John
Antoniou 1 , Alain Petit 2
1
McGill University; 2 Lady Davis Institute; 3 École
Polytechnique
Purpose: Recent evidence indicates that a major drawback
of current cartilage and intervertebral disc (IVD)
tissue engineering is that human mesenchymal stem cells
(MSCs) from osteoarthritic patients rapidly express
type X collagen (COL10A1), a marker of late-stage
chondrocyte hypertrophy associated with endochondral
ossification. We recently discovered that a novel
atmospheric-pressure plasma-polymerized thin film substrate,
named “nitrogen-rich plasma-polymerized ethylene”
(PPE:N), is able to inhibit COL10A1 expression
in committed MSCs. However, the cellular mechanisms
implicated in the inhibition of COL10A1 expression by
PPE:N surfaces are unknown.
Method: Human mesenchymal stem cells (MSCs) were
obtained from aspirates from the intramedullary canal
of donors (60-80 years of age) undergoing total hip
replacement for osteoarthritis. Bone marrow aspirates
were processed and MSCs were cultured on commercial
polystyrene (PS control) and on PPE:N surfaces in the
presence of different kinases and cyclooxygenase inhibitors
for 3 days. Total RNA was extracted with TRIzol
reagent (Invitrogen, Burlington, ON) and the expression
of COL10A1, cyclooxygenase-1 (COX-1), and 5-
lipoxygenase (5-LOX) genes was measured by real-time
quantitative RT-PCR.
Results: Results showed that a non-specific inhibitor of
cyclooxygenases reduced the expression of COL10A1.
In contrast, inhibitors of protein kinases stimulated
the expression of COL10A1. Furthermore, potent and
selective inhibitors of COX-1 and 5-LOX also reduced
the expression of COL10A1. However, COX-2 and 12-
LOX inhibitors had no significant effect on the expression
of COL10A1. COX-1 gene expression was also
decreased when MSCs were incubated on “S5” PPE:N
surfaces. Interestingly, MSCs did not express 5-LOX.
Conclusion: PPE:N surfaces suppress COL10A1
expression through the inhibition of COX-1 which is
directly implicated in the synthesis of prostaglandins.
The decreased expression of COX-1 and COL10A1 in
human MSCs cultured on PPE:N is therefore in agreement
with the induction of the osteogenic capacity of
rat bone marrow and bone formation by systemic or
local injection of PGE2 in rats. However, PGE2 and
other prostaglandins inhibited COL10A1 expression in
chick growth plate chondrocytes. This suggests that the
effect of prostaglandins on COL10A1 expression may
be cell-specific or may be dependent on pre-existing
patho-physiological conditions.
6. HYPOXIC REGULATION OF
CHONDROCYTE DIFFERENTIATION AND
ITS APPLICATION TO CARTILAGE REPAIR
Richard C. Smith, Brenton Short, Paul W.
Clarkson, Bassam A. Masri, Michael Underhill
UBC
Purpose: Chondral injuries of the knee are commonly
seen at arthroscopy, yet there is no consensus on the most
appropriate treatment method. However, untreated cartilage
injury predisposes to osteoarthritis contributing to
pain and disability. For cell-based cartilage repair strategies,
an ex-vivo expansion phase is required to obtain
sufficient numbers of cells needed for therapy. Although
recent reports demonstrated the central role of oxygen
for the function and differentiation of chondrocytes,
little is known of the effect of physiological low oxygen
concentrations during the expansion of the cells and
whether this alters their chondrogenic capacity.
Method: Initial studies of chondrocyte expansion were
performed in mature mice, with cells expanded at
either atmospheric oxygen tension (21%) or 5% 02 in
monolayer cultures. Chondrogenic differentiation was
subsequently assessed via micromass culture. Having
determined that oxygen tension influences murine chondrocyte
expansion and differentiation, similar studies
were conducted using adult human chondrocytes taken
from knee arthroplasty off-cuts, with mRNA expression
of select genes involved in the chondrogenic program
analyzed by q-PCR.
Results: Cellular morphology was improved in hypoxic
culture, with a markedly more fibroblastic appearance
seen after greater than 2 passages in 21% O2. Micromass
cultures maintained in hypoxic conditions demonstrated
stronger staining with Alcian blue, indicating stronger
expression of cartilaginous glycosaminoglycans. Collagen
type II mRNA expression was two-fold higher in cells
expanded at 5% as compared to expansion at 21% O2.
Micromass cultures grown at 21% O2 showed up to a
twofold increase in the tissue content of glycosaminoglycans
when formed with cells expanded at 5% instead of
21% O2. However, no differences in the mRNA expression
or staining for collagen type II protein were observed
in these micromass cultures. Hypoxia (5% O2) applied
during micromass cultures gave rise to tissues with low
contents of glycosaminoglycans.
Conclusion: In-vivo, chondrocytes are adapted to a
hypoxic environment. Taking this into account, applying
5% O2 in the expansion phase in the course of cellbased
cartilage repair strategies, may result in a repair
tissue with higher quality by increasing the content of
glycosaminoglycans.
7. THE MOLECULAR MECHANISMS OF
COMPARTMENT SYNDROME
Greg W. McGarr, David W. Sanders, Amit
Badhwar
Lawson Health Research Institute
Purpose: Compartment syndrome is a severe complication
of skeletal trauma. Intravital microscopy (IVVM)
has demonstrated an inflammatory response to compartment
syndrome (CS). The molecular mechanisms
underlying this inflammatory response are unknown.
The purpose of this study was threefold. First, a broad
inflammatory cytokine profile was examined to determine
the molecules responsible for white cell recruitment.
As well, skeletal muscle expression of white cell
adhesion molecules including P-Selectin, E-Selectin,
Mac-1 and ICAM-1 were examined to assess the extent
of white cell activation in target tissues. Finally, skeletal
muscle apoptosis was measured to determine the magnitude
of cell death.
Method: Normal and neutropenic rats were randomised
to either compartment syndrome or control groups. CS
Animals were treated with 45 minutes of elevated intracompartmental
pressure (EICP) of the hindlimb. Fasciotomy
was then performed, followed by 60 minutes
of reperfusion. Control animals experienced no EICP.
Blood was collected from carotid arterial lines used for
pressure monitoring. Skeletal muscle tissue samples were
collected from the EDL following reperfusion. Blood
samples were obtained from carotid arterial lines and
skeletal muscle was collected following reperfusion. A
Multiplex assay was used to examine serum levels of 24
proinflammatory cytokines/chemokines. Skeletal muscle
mRNA levels of P-Selectin, E-Selectin, Mac-1 and
ICAM-1 were evaluated using real-time PCR. Finally,
skeletal muscle apoptosis was measured by DNA laddering
and a caspase-3 assay.
Results: Neutropenic CS animals demonstrated a continuous
increase in TNF-alpha levels, peaking at 700+/-
350pg/ml by 60 minutes of reperfusion. TNF-alpha
values for other groups did not increase. A 104-fold
increase in ICAM-1 mRNA levels was observed in neutropenic
CS rats while other groups showed no significant
increase. There was no significant increase in any
group for P-Selectin, E-Selectin, or Mac-1.
Conclusion: This study is the first to attempt to describe
the molecular inflammatory response in CS. Neutropenic
CS animals demonstrated an upregulation in TNFalpha
and ICAM-1 mRNA levels. This likely represents
an attempt to generate an inflammatory response in
the neutropenic animals. Additional data at incremental
timepoints is necessary to further characterize the
molecular mechanisms. However, both TNF-alpha and
ICAM-1 appear to be important in the mechanism of
inflammatory activation in compartment syndrome.
8. INSIGHTS INTO MESENCHYMAL STEM
CELL DIFFERENTIATION TO ADULT
CHONDROCYTES -HUMAN FACILITATIVE
GLUCOSE TRANSPORTERS (SLC2A
PROTEINS)? A NEW GENERATION OF
PHYSIOLOGICAL MARKERS
Andrei R. Manolescu, David Cinats, Charles
Secretan, Deborah O’Neill, Chris Cheeseman,
Keith Bagnall, Nadr M. Jomha
University of Alberta
Purpose: Differentiation of BM-MSCs into adult chondrocytes
represents a complex physiological mechanism
and full characterization of each individual stage
through which the BM-MSC differentiate into adult
chondrocytes is not yet understood.The physiological
micro-environment of the chondrocytes is intensely
hypoxic which triggers over-expression SLC2A proteins
(GLUTs) in their membranes as a compensatory mechanism
for energy production within the glycolytic cycle.
Method: We cultured and differentiated BM-MSC, and
adult chondrocytes in hypoxic (5% O2 tension) and
normoxic (20% O2) conditions. Within this cell populations
we screened for the presence of the 12 GLUT
genes as well as quantification of the variation of the
12 GLUTs gene translation by simple pcr and rt-pcr.
The expression profile of the GLUT proteins was investigated
using western blot analysis and immunohistochemistry.
Functional characterization of the GLUTs
expressed in the different cell populations was carried
out by the means of radio-isotope labeled hexose fluxes
done accordingly to the substrate specificity and kinetic
properties particular to each SLC2A isoforms.
Results: Our data showed that the functional genotype
and phenotype of the adult chondrocyte and hypoxic
BM-MSC comprised an extensive expression of fructose-transporting
GLUTs as opposed to the glucoseonly
transporting isoforms expression in normoxic
J BONE JOINT SURG [BR] 2011; 93-B:SUPP III

COA/CORS/CORA 245
BM-MSC. The flux data showed clear similarities in
functional GLUT profiles between BM-MSC cultured in
hypoxic conditions, adult chondrocytes. Investigation
of the uptake of a panel of five individual sugars (glucose,
fructose, 2-deoxy-gluose, 3-orthomethyl-glucose
and galactose) in these cellular populations under both
hypoxic and normoxic conditions and in the presence
and absence of Cytochalasin B (a GLUT1-specific inhibitor)
showed that SLC2A class II transporters (GLUTs 5,
7, 9 and 11) play a more important role in the uptake of
sugars by the normal hypoxic chondrocytes when compared
to the ubiquitously-expressed GLUT1.
Conclusion: Use of this approach allows the correct
culturing conditions to be identified that would select
for those chondrocyte precursors from the total BM-
MSC population that would have the best potential for
producing viable articular cartilage. In addition, specific
substrates for GLUTs isoforms could be used for physiologic,
non-invasive and real time imaging of cartilage,
BM-MSC and cartilage autograft by means of Positron
Emission Tomography.
9. THE EFFECT OF REMAINING AT
CONFLUENCE ON THE CHONDROCYTIC
PHENOTYPE
Krishna Maragh, Jenn Bater, Charles Secretan,
Keith M. Bagnall, Nadr M. Jomha
University of Alberta
Purpose: Current techniques for articular cartilage
repair remain sub-optimal. The best technique involves
the introduction of cultured chondrocytes into the
injury site. Experimental results of current chondrocyte
culture and expansion techniques (passaging) have
shown phenotypic alteration resulting in fibroblastlike
cells. Therefore, treatment methods that propose
the transplantation of cultured chondrocytes might be
transplanting fibroblast-like cells instead of chondrocytes.
This experiment explored the difference in genetic
expression of chondrocytes left at confluence compared
to chondrocytes that were passaged as performed in current
culture techniques. It was hypothesized that chondrocytes
left at confluence would maintain their collagen
I and collagen II gene expression over time.
Method: Fresh normal human articular cartilage was
collected from deceased donor patients. The matrix was
digested and the chondrocytes were plated in monolayer
to create two groups. The first group was cultured and
passaged 2? at confluence seven times. The second group
was cultured at confluence and left for seven weeks,
with medium changes every 3-4 days without passaging.
At weekly intervals RNA was extracted from cells in
both groups and analyzed with real time PCR, probing
specifically for the genes responsible for the production
of collagen I, collagen II, aggrecan, and GAPDH. This
was done in duplicate.
Results: Collagen II gene expression was maintained
over seven weeks in cells left at confluence but was
decreased in passaged cells. Collagen I gene expression
decreased over seven weeks in cells left at confluence,
but remained the same in passaged cells. Aggrecan gene
expression remained the same in both groups.
Conclusion: Current culture and expansion techniques
that employ passaging (as used in clinical scenarios)
result in significant alterations in gene expression that
are inconsistent with the current definition of a “chondrocyte”.
Culturing chondrocytes at confluence can
produce gene expression more similar to native chondrocytes
but even these cells have expression of collagen
type I that should not be present in chondrocytes. The
results of this study suggest that further investigation is
required to develop chondrocyte culture and expansion
techniques that minimize the de-differentiation of chondrocytes
by maintaining collagen II gene expression and
eliminating/preventing collagen I gene expression.
CORS PAPER SESSION 2: BONE
10. AN IN-VIVO EVALUATION OF THE
EFFECT OF A HYDROXYAPATITE COATING
WITH AND WITHOUT THE USE OF BMP-7
ON EXTRACORTICAL BONE BRIDGING
USING A CANINE SEGMENTAL DEFECT
MODEL
Neil Saran, Robert É. Turcotte, Renwen Zhang*
McGill University Health; *Stryker Orthopaedics
Purpose: Extracortical bone bridging and ingrowth
have been shown to reduce stresses on the stem and
cement mantle of tumor endoprostheses. The purpose
of this study was to assess the effect of bone morphogenetic
protein 7 (BMP-7) delivered by Peri-Apatiteâ
(PA, Stryker Orthopaedics) hydroxyapatite coating on
porous segmental replacement prostheses.
Method: Eighteen mature mongrel canines were
implanted with unilateral segmental replacement prostheses
made of a cobalt-chromium (Co-Cr) alloy and coated
with two layers of sintered Co-Cr alloy beads (diameter
600 to 800mm). The control group consisted of a plain
porous coated segmental prosthesis without any PA coating.
Group 2 consisted of a PA-coated segmental prosthesis
coated with buffer solution. Group three consisted of
a PA-coated segmental prosthesis loaded with rhBMP-7
(Stryker Biotech) in a buffer solution carrier. Group 1
had the implant only. Group 2 had the buffer solution
evenly applied to the porous coat and group 3 had 2.9
mg of BMP-7 in liquid buffer solution evenly applied.
The canines were allowed to fully bear weight without
restrictions. The femurs were retrieved at twelve weeks
for radiographic and histologic analysis.
Results: Gross and radiographic data of the retrieved
specimens showed that all six PA-coated implants augmented
with BMP-7 had complete bone bridging; only
one of the PA-coated implants and only two of the plain
porous implants were completely bridged. There was
a greater percentage of bone apposition for the BMP-
7 augmented PA-coated group compared to both the
plain (p=0.0026) and the PA-coated (p=0.0001). There
was no difference in bone formation or bone apposition
between the plain and PA-coated groups. Histology
revealed greater depth of bone ingrowth in the BMP-7
augmented PA-coated group as compared to the plain
(p

246 COA/CORS/CORA
13. EFFECT OF THE HVEGF TRANSFER ON
ENDOGENOUS VEGF MRNA EXPRESSION
IN A RAT OSTEOBLAST OR FIBROBLAST
CULTURE MODEL
Claire Li, Ru Li, Michael D. McKee, Emil H.
Schemitsch
University of Toronto
Purpose: Vascular Endothelial Growth Factor (VEGF)
plays an important role in promoting angiogenesis and
osteogenesis during fracture repair. Our previous studies
have shown that cell-based VEGF gene therapy accelerates
bone healing of a rabbit tibia segmental bone defect
in-vivo, and increases osteoblast proliferation and
mineralization in-vitro. The aim of this project was to
examine the effect of exogenous human VEGF (hVEGF)
on the endogenous rat VEGF messenger RNA (mRNA)
expression in a cell-based gene transfer model.
Method: The osteoblasts were obtained from the rat
periosteum. The fibroblasts were obtained from the rat
dermal tissue. The cells were then cultured to reach 60%
confluence and transfected with hVEGF using Superfect.
Four groups were: 1) osteoblast-hVEGF, 2) fibroblasthVEGF,
3) Osteoblasts alone, and 4) Fibroblasts only.
The cultured cells were harvested at 1, 3 and 7 days
after the transfection. The total mRNA was extracted
(TRIZOL); both hVEGF and rat VEGF mRNA were
measured by reverse transcriptase- polymerase chain
reaction (RT-PCR) and quantified by VisionWorksLS.
Results: The hVEGF mRNA was detected by RT-PCR
from transfected osteoblasts after three days of gene
transfection. The hVEGF mRNA expression in transfected
fibroblasts increased exponentially at days 1, 3 and
7 after the transfection. We compared the endogenous
rat VEGF mRNA expression level of the osteoblasts or
fibroblasts that were transfected with hVEGF with the
cells without the transfection. The hVEGF transfected
osteoblasts had a greater rat VEGF mRNA expression
than the non-transfected osteoblasts. Furthermore,
when hVEGF was transfected to the rat fibroblasts, the
endogenous mRNA expression level measured was also
greater than that from the non-transfected fibroblasts.
Rat VEGF mRNA expression increased in the first three
days of the hVEGF transfection, but the expression level
was reduced at Day 7.
Conclusion: These results suggest that cell-based hVEGF
gene therapy enhances endogenous rat VEGF mRNA
expression in both osteoblasts and fibroblasts.
14. VASCULAR ENDOTHELIAL GROWTH
FACTOR REGULATES OSTEOBLAST CELL
DEATH IN OSTEOPOROTIC VERTEBRAL
FRACTURE
John Street 1,2 , Brian Lenehan 1,2 , Charles G.
Fisher 2 , Marcel Dvorak 2
1
University College Cork, Ireland; 2 UBC
Purpose: Apoptosis of osteoblasts and osteoclasts regulates
bone homeostasis. Vertebral osteoporotic insufficiency
fractures are characterised by pathological rates
of osteoblast apoptosis. Skeletal injury in humans results
in ‘angiogenic’ responses primarily mediated by vascular
endothelial growth factor(VEGF), a protein essential for
bone repair in animal models. Osteoblasts release VEGF
in response to a number of stimuli and express receptors
for VEGF in a differentiation dependent manner. This
study investigates the putative role of VEGF in regulating
the lifespan of primary human vertebral osteoblasts
(PHVO) in-vitro.
Method: PHVO were cultured from biopsies taken at
time of therapeutic vertebroplasty and were examined
for VEGF receptors. Cultures were supplemented with
VEGF(0–50ng/mL), a neutralising antibody to VEGF,
mAB VEGF(0.3ug/mL) and Placental Growth Factor
(PlGF), an Flt-1 receptor-specific VEGF ligand(0–100
ng/mL) to examine their effects on mineralised nodule
assay, alkaline phosphatase assay and apoptosis. The
role of the VEGF specific antiapoptotic gene target BCl2
in apoptosis was determined.
Results: PHVO expressed functional VEGF receptors.
VEGF 10 and 25 ng/mL increased nodule formation
2.3- and 3.16-fold and alkaline phosphatase release 2.6
and 4.1-fold respectively while 0.3ug/mL of mAB VEGF
resulted in approx 40% reductions in both. PlGF 50ng/
mL had greater effects on alkaline phosphatase release
(103% increase) than on nodule formation (57%
increase). 10ng/mL of VEGF inhibited spontaneous and
pathological apoptosis by 83.6% and 71% respectively,
while PlGF had no significant effect. Pretreatment with
mAB VEGF, in the absence of exogenous VEGF resulted
in a significant increase in apoptosis (14 versus 3%).
BCl2 transfection gave a 0.9% apoptotic rate. VEGF 10
ng/mL increased BCl2 expression four fold while mAB
VEGF decreased it by over 50%.
Conclusion: VEGF is a potent regulator of osteoblast
life-span in-vitro. This autocrine feedback regulates survival
of these cells, mediated via the KDR receptor and
expression of BCl2 antiapoptotic gene. This mechanism
may represent a novel therapeutic model for the treatment
of osteoporosis.
15. CHARACTERIZATION OF RAT AND
MOUSE FORELIMB COMPRESSION MODELS
FOR STUDIES OF WOVEN BONE REPAIR IN
RESPONSE TO FATIGUE DAMAGE
Thomas Karakolis, Gregory R. Wohl
McMaster University
Purpose: Bone fatigue damage can lead to stress fractures
and may play a role in fragility fractures. The rat
forelimb compression model has been used to examine
biological responses and gene expression associated with
woven bone repair after fatigue damage. Development a
similar mouse model would enable the use of genetically
modified mice to study molecular mechanisms associated
with bone repair.
Method: Following approval from our Central Animal
Facility, forelimbs of male retired breeder C57BL/6 mice
and Sprague Dawley rats (n=31 each) were loaded in
axial compression across the carpus and olecranon. First,
both forelimbs (postmortem, n=6 each) were monotonically
loaded to determine failure load. Next, both forelimbs
of animals (postmortem, n=5 each) were loaded
cyclically to sub-fracture load (67% of monotonic load
for mice, 55% for rats) until fatigue failure. Following
analysis of fatigue displacement histories, right forelimbs
(post-mortem, n=10 each) were loaded cyclically to a set
displacement short of the expected failure displacement
(mice–30%; rats–55%). Non-loaded left forelimbs served
as controls. Three-point bending tests were performed on
the ulnae; mechanical properties were compared between
fatigued and non-loaded limbs. Finally, right forelimbs
(n=10 each) were cyclically loaded in anaesthetised (2.5%
isofluorane) animals to 30% (mice) and 55% (rats) of
failure displacement. Animals recovered for seven days;
microCT imaging and three-point bend tests were performed
on the ulnae.
Results: Ultimate forelimb failure loads were 5.63 ±
0.47 N (mouse) and 57.1 ± 5.8 N (rat). Measured from
the 10th cycle, fatigue failure occurred at displacements
of 1.68 ± 0.21 mm (mouse) and 2.96 ± 0.22 mm (rat). In
three-point bending, fatigue damaged ulnae failed at significantly
lower loads versus control (mouse -51.6%; rat
-32.1%). After seven days healing, bone cross-sectional
area was significantly greater (microCT) and mechanical
properties partially recovered (-13.8% versus control).
Conclusion: Rat and mouse forelimb fatigue loading
models have been developed to induce repeatable
bone damage. Observed differences in fatigue behaviour
necessitated different loading parameters between
models. Following seven days of healing, recovery of
mechanical strength accompanied woven bone formation
(demonstrated by microCT). Further work will
compare the biological, woven bone, response between
the mouse and rat forelimb models.
16. THE EFFECT OF INTRAMEDULLARY
REAMING ON A DIAPHYSEAL BONE
DEFECT OF THE TIBIA
Paul R. T. Kuzyk, John E.D. Davies, Emil H.
Schemitsch
University of Toronto
Purpose: The purpose of this study was to relate the
extent of reaming to bone formation occurring around
a critical sized defect in the tibia.
Method: Eleven canines were allocated into 2 groups:
empty (N=5) or iliac crest autograft (N=6). All tibiae
were reamed to 7.0 mm and fixed with a 6.5 mm statically
locked intramedullary nail after creation of an 8.0
mm diaphyseal defect. The extent of reaming of the
canal was dependent on the cross-sectional area of the
tibia as all tibiae were reamed to 7.0 mm. Fluorescent
markers were given at different times: calcein green (6
weeks), xylenol orange (9 weeks), and tetracycline (11
and 14 weeks). Animals were sacrificed at 15 weeks and
perfused with a barium compound. Radiography, Micro
CT, brightfield microscopy and fluorescent microscopy
were used for analysis.
Results: Bone and vasculature volume within the defect
were reported as a percentage of the total volume of
the defect. Linear regression analysis of percent bone
volume (dependent variable) and canal area (independent
variable) provided a Pearson correlation coefficient
of 0.925 (p=0.025) for the empty group and 0.244
(p=0.641) for the autograft group. Linear regression
analysis of percent vasculature volume (dependent variable)
and canal area (independent variable) provided a
Pearson correlation coefficient of 0.784 (p=0.117) for
the empty group and -0.146 (p=0.783) for the autograft
group. Bone formation at osteotomy sites was defined
as the distance from the original osteotomy site to the
tip of newly formed bone. Linear regression analysis of
bone formation at the osteotomy sites (dependent variable)
and canal area (independent variable) provided a
Pearson correlation coefficient of 0.132 (p=0.832) for
the empty group and -0.937 (p=0.006) for the autograft
group. Bone formation rates were reported as the distance
between the fluorescent labels. Bone formation
rate was less within the endosteum, cortex and periosteum
with extensive reaming in empty samples.
Conclusion: Our results suggest that the acute management
of tibia fractures with bone defects should involve
limited reaming. This does not apply when the defect is
autografted. Limited reaming may be defined by the crosssectional
area of the tibia in ratio to that of the reamer.
17. USE OF CO-REGISTERED HIGH-
RESOLUTION COMPUTED TOMOGRAPHY
SCANS BEFORE AND AFTER SCREW
INSERTION AS A NOVEL TECHNIQUE FOR
BONE MINERAL DENSITY DETERMINATION
ALONG SCREW TRAJECTORY
Marlis Sabo, Steven I. Pollmann, Kevin R. Gurr,
Christopher Bailey, David W. Holdsworth
University of Western Ontario
Purpose: Bone mineral density (BMD) is an important
factor in the performance of orthopaedic instrumentation
both in and ex-vivo, and until now, there has not existed
a reliable technique for determining BMD at the precise
location of such hardware. This paper describes such a
technique using cadaveric human sacra as a model.
Method: Nine fresh-frozen sacra had solid and hollow
titanium screw placed into the S1 pedicles from a posterior
approach. High-resolution micro-computed tomography
(CT) was performed on each specimen before and
after screw placement. All images were reconstructed
with an isotropic spatial resolution of 0.308 mm, reoriented,
and the pre-screw and post-screw scans were registered
and transformed using a six-degree rigid-body
transformation matrix. Once registered, two points,
corresponding to the center of the screw at the cortex
and at the screw tip, were determined in each scan.
These points were used to generate cylindrical regions of
interest (ROI) with the same trajectory and dimensions
as the screw. BMD measurements were obtained within
each of the ROI in the pre-screw scan. To examine the
effect of artefact on BMD measurements around the
J BONE JOINT SURG [BR] 2011; 93-B:SUPP III

COA/CORS/CORA 247
titanium screws, annular ROI of 1 mm thickness were
created expanding from the surface of the screws, and
BMD was measured within each in both the pre- and
post-screw scans.
Results: The registration process was accurate, with
an error of 0.2 mm. Four specimens were scanned five
times with repositioning, and error in BMD measurements
was ± 2%. BMD values in the cylindrical ROI
corresponding to screw trajectories were not statistically
different from side to side of each specimen (p = 0.23).
Artefact-related differences in BMD values followed an
exponential decay curve as distance from the screws
increased, approaching a low value of approximately 20
mg HA/cc, but not disappearing completely.
Conclusion: CT in the presence of metal creates artefact,
making measured BMD values near implants unreliable.
This technique is accurate for determination of
BMD, non-destructive, and eliminates the problem of
this metal artefact through the use of co-registration of
a pre- and post-screw scan. This technique has applications
both in-vitro and in-vivo.
18. TREATMENT OF FRACTURE NON-
UNION USING RECOMBINANT BMP-7:
SINGLE CENTRE EXPERIENCE
Inder Gill, Vinod Kolimarala, Richard
Montgomery
James Cook, University Hospital, Middlesbrough,
UK
Purpose: To analyse the results of the use of Recombinant
Bone Morphogenic Protein (BMP-7) for treatment
of fracture nonunions at our institution.
Method: From 2001 to 2006, 23 patients with fracture
non-union were treated with BMP-7 for bone healing.
There were 14 male and nine females. The mean age of
patients was 45 years (Range 21-76 yrs). There were 11
femoral, nine tibial and three humerus fractures. There
were four open injuries. The average number of operations
before BMP-7 insertion was 2.5 (Range 0-6). The
mean time between the injury and BMP insertion was
52 months (Range 5-312). Nine (40%) patients had
previous autologous bone graft inserted without union.
4 patients had BMP-7 insertion on its own. In another
4 patients it was mixed with allograft. In the rest of 15
patients BMP-7 was mixed with autologous bone graft. 2
patients needed BMP-7 insertion on 2 separate occasions.
In all except 1 patient the original fixation of the fracture
had to be revised using various appropriate methods.
Results: All the fracture went on to unite within an average
of seven months (Range 4-16). There were no complications
from the use of BMP-7.
Conclusion: Use of recombinant BMP-7, bone graft and
stable fixation lead to fracture union in all our patients.
We believe that the use of BMP-7 improved the chances
of fracture healing in persistent non-unions and it is safe
and easy to use.
CORS PAPER SESSION 3:
MECHANICS AND MATERIALS
19. EXAMINATION OF RADIOGRAPHIC
FEATURES AND LURCH; A MEASURE OF
ASYMMETRIC GAIT, AMONG PATIENTS
AWAITING TOTAL HIP ARTHROPLASTY
Kyle A. R. Kemp, Michael J. Dunbar, Lori A.
Livingston, Allan Hennigar
Dalhousie University
Purpose: Despite their inclusion within clinical practice,
standardized radiographs may not accurately project an
individual’s level of function and mobility. The purpose
of this study is to examine the potential relationship
between established radiographic features and lurch; a
functional measure of asymmetric gait, in a group of
patients who will receive total hip arthroplasty (THA).
Method: Thirty-two patients (16 females, 16 males) identified
as hip replacement candidates were recruited, with
a mean age of 57.0 years. Lurch was obtained using the
Walkabout Portable Gait Monitor (WPGM); a wireless,
tri-axial accelerometry device. The independent variables
were comprised of the Kellgren-Lawrence Scale, and a
collection of standard radiographic features, as adopted
by the American Academy of Orthopaedic Surgeons
(AAOS), the National Institutes of Health (NIH), and the
World Health Organization (WHO). Radiographs were
blinded, and the surgeon completing the rating scale was
unaware of patient’s lurch values. Age-adjusted regression
analyses were used to examine the potential association
between each radiographic feature and lurch.
Results: Increased amounts of lurch (i.e. functional
impairment) were independently associated with higher
Kellgren-Lawrence Scale scores (p=.047), increased Joint
Space Narrowing in the mid-portion of the joint (zone
2; p=.004), the presence of acetabular wear (p=.045),
an increased severity of subchondral femoral head cysts
(p=.004), and higher surgeon-rated Visual Analog Scale
scores for overall severity of joint degeneration (p=.008).
Lurch was not significantly associated with the remaining
10 features which were examined. Further analyses
revealed that lurch was not significantly associated with
certain demographic factors, including sex, Body Mass
Index, and co-morbid health conditions.
Conclusion: Although the Kellgren-Lawrence scale was
associated with an objective measure of gait, our results
indicate that other radiographic features may provide
a more accurate prediction of gait performance among
this patient population. As lurch appears to be a robust
objective measure of physical impairment, which is
unaffected by BMI and co-morbidities, we believe that
portable triaxial accelerometers can likely be used to
conveniently collect objective gait data. This functional
data may be used to supplement clinical efforts to screen
and prioritize appropriate hip arthroplasty patients.
20. MOTION-BASED JOINT COORDINATE
SYSTEMS FOR THE ELBOW: A NEW
METHOD FOR REDUCING VARIABILITY OF
FLEXION KINEMATICS
Louis M. Ferreira, Graham J.W. King*, James A.
Johnson
University of Western Ontario; *St. Joseph’s
Health Care
Results: Repeatability of creating motion-based JCS
was less than 1 mm and 1º in all directions. The interspecimen
standard-deviations of position and orientation
measurements were smaller for the motion-based
than for the anatomy-based JCS in every direction and
for every specimen (p

248 COA/CORS/CORA
23. IMAGE-BASED NAVIGATION IMPROVES
THE POSITIONING OF THE HUMERAL
COMPONENT IN TOTAL ELBOW
ARTHROPLASTY
Colin P. McDonald, James A. Johnson, Terry M.
Peters*, Graham J.W. King
St. Joseph’s Health Care London; *Robarts
Research Institute
Purpose: This study evaluated the accuracy of humeral
component alignment in total elbow arthroplasty. An
image-based navigated approach was compared against
a conventional non-navigated technique. We hypothesized
that an image-based navigation system would
improve humeral component positioning, with navigational
errors less than or approaching 2.0mm and 2.0°.
Method: Eleven cadaveric distal humeri were imaged
using a CT scanner, from which 3D surface models
were reconstructed. Non-navigated humeral component
implantation was based on a visual estimation of the
flexion-extension (FE) axis on the medial and lateral
aspects of the distal humerus, followed by standard
instrumentation and positioning of a commercial prosthesis
by an experienced surgeon. Positioning was based
on the estimated FE axis and surgeon judgment. The stem
length was reduced by 75% to evaluate the navigation
system independent of implant design constraints. For
navigated alignment, the implant was aligned with the
FE axis of the CT surface model, which was registered
to landmarks of the physical humerus using the iterative
closest point algorithm. Navigated implant positioning
was based on aligning a 3D computer model calibrated
to the implant with a 3D model registered to the distal
humerus. Each alignment technique was repeated for
a bone loss scenario where distal landmarks were not
available for FE axis identification.
Results: Implant alignment error was significantly lower
using navigation (P

COA/CORS/CORA 249
and by rotating the cups, such that a 900 abduction
angle and a 00 anteversion angle were achieved. The
grid used was divided to quadrants, and subdivided into
radial thirds of the average rim radius. The correspondence
of left and right density maps was investigated by
comparing the average bone density in corresponding
zones and across the population.
Results: High bone densities were found around the roof
of the acetabulum aligning with the femoral mechanical
axis during standing. The highest average bone density
were found to be the superior and posterior walls of
the acetabulum, corresponding to regions 8, 9, and 12
compared to other regions of the acetabuli (P

250 COA/CORS/CORA
32. COMPARISON BETWEEN CT-
TOMASD AND CT-OAM FOR ASSESSING
OSTEOARTHRITIC AND NORMAL TIBIAE
James D. Johnston*, Bassam A. Masri, David R.
Wilson
*University of Saskatchewan; UBC
Purpose: Subchondral cortical and trabecular bone mineral
density (BMD) may increase and/or decrease during
different stages of osteoarthritis (OA) disease progression.
2D in-vivo imaging studies examining direct associations
between increased proximal tibial BMD and
knee OA offer conflicting results, which may be due to
the inherent limitations of 2D BMD imaging tools. Our
objective was to compare existing and novel 3D imaging
techniques for distinguishing subchondral bone properties
in OA and normal cadaveric tibiae.
Method: Eight intact cadaver knees from five donors
(4M:1F; age: 77+/-10) were repositioned and scanned
three times using QCT (0.5mm isotropic resolution,
0.15mSv dosage). BMD was assessed using 1) computed
tomography absorptiometry (CT-OAM) which uses
maximum intensity projections to assesses peak density
values within subchondral bone, and 2) our novel computed
tomography topographic mapping of subchondral
density (CT-TOMASD) technique, which uses surface
projections to assess both cortical and trabecular bone
density at specific depths from the subchondral surface.
Average BMD at normalized depths of 0-2.5mm, 2.5–
5.0mm, and 5.0-10mm from the surface were assessed
using CT-TomasD. Regional analyses were performed
consisting of: (1) medial/lateral (M/L) BMD ratio, and
(2) BMD of a 10mm diameter core identified as having
the maximum regional BMD. Each bone was assessed
for OA using a modified-KL scoring system: Normal
(mKL=0); Early-OA (1-2); and Late-OA (3-4).
Results: OA was identified in four compartments of
three tibiae (1 late OA+valgus, 1 late OA+varus, 1 early
OA+neutral). Larger density differences between OA
and normal knees were noted using CT-TOMASD compared
with CT-OAM. CT-TomasD demonstrated that
the two knees with late OA demonstrated M/L BMD
ratios differing by more than 3.4 SD compared with
normals, with peak cores higher than normals across
all depths. The knee with early OA and neutral alignment
demonstrated M/L ratios less than normals while
core differences were highest proximally, with density
becoming lower than normals with increasing depth.
Conclusion: CT-TomasD demonstrated larger differences
between OA and normal subjects when compared
with CT-OAM differences. This may be due to CT-
OAM primarily assessing peak density within the thin
subchondral cortical endplate; a region demonstrating
fairly uniform peak densities within a limited range.
33. IN VITRO ACTIVITY OF FUSIDIC
ACID AND VANCOMYCIN IN PMMA
BONE CEMENT FOR THE TREATMENT
OF METHICILLIN-RESISTANT
STAPHLYOCOCCUS AUREUS
Fay Leung, Clive P. Duncan, Helen Burt, John
Jackson
UBC
Purpose: This study investigates the synergistic use of
fusidic acid with vancomycin, and linezolid in polymethylmethacrylate
(PMMA) cement for the treatment
of orthopedic MRSA and MRSE infections. Alone, Vancomycin
is typically eluted in limited quantities from
cement. The purpose of this study was to 1) combine FA
and Vancomycin, and Linezolid alone in PMMA cement
and characterize antibiotic elution, and 2) to improve
drug release using polyethylene glycol (PEG) and NaCl
in PMMA cement.
Method: Standardized 1g pellets of Palacos cement were
manufactured containing Vancomycin and FA or Linezolid
at increasing concentrations in three batches: without
additive, with increasing concentrations of PEG,
and with increasing concentrations of NaCl. The pellets
were incubated in phosphate buffered saline and sampled
at regular intervals. Drug analysis was performed
with high pressure liquid chromatograpy.
Results: Total drug release at 2.5% loading of Vancomycin
alone was 0.84% and of FA was 2.35%. Linezolid
showed comparable release profiles. Vancomycin and
FA combined yeilded Vancomycin release of 6.2% and
FA of 8.4%. The addition of 30% PEG increased release
of Vancomycin and Fusidic Acid by six-fold. The addition
of 18% NaCl increased total Vancomycin release
by 11-fold but had no effect on FA release.
Conclusion: Linezolid, Vancomycin and FA can be combined
in PMMA and have favorable release profiles.
The addition of PEG and NaCl dramatically increases
the release of antibiotics, with the exception of FA and
NaCl. These strategies may be useful in the management
of MRSA/MRSE infections.
34. PREVALENCE OF CAM TYPE FAI
MORPHOLOGY IN 200 ASYMPTOMATIC
VOLUNTEERS
Paul-Edgar Beaulé, Kalesha Hack, Gina DiPrimio,
Kawan Rakhra
University of Ottawa
Purpose: A growing body of literature confirms that
idiopathic OA is frequently caused by subtle, and often
radiographically occult, abnormalities at the femoral
head-neck junction or acetabulum that result in abnormal
contact between the femur and acetabulum. This
condition, known as femoroacetabular impingement, is
a widely accepted cause of early OA of the hip. MRI is
the imaging modality that is most sensitive in detecting
cam morphology. There is currently little published data
regarding the prevalence of abnormalities of the femoral
head-neck junction in patients without hip pain or previous
hip pathology. The primary aim of this project is
to examine the incidence of cam morphology in a population
without hip pain or pre-existing hip disease using
non-contrast MRI.
Method: Two hundred asymptomatic volunteers underwent
magnetic resonance imaging targeted to both hips.
Subjects were examined at the time of MRI to document
internal rotation of the hips at 90 degrees flexion
and to assess for a positive impingement sign. The mean
age was 29.4 years (range 21.4-50.6); 77.5% were Caucasian
and 55.5% female. The Nötzli alpha angle was
measured on oblique axial images through the middle of
the femoral neck for each hip. A value greater than 50
degrees was considered consistent with cam morphology.
Measurements were performed independently by
two musculoskeletal radiologists.
Results: Twenty-six percent of volunteers had at least
one hip with cam morphology: 20% had an elevated
alpha angle on either the right or the left side, and 6%
had bilateral deformity. The average alpha angle was
42.6 degrees on the right (SD=7.9) and 42.4 degrees
on the left (SD=7.7). Internal rotation was negatively
correlated with alpha angle (p55.5 on the Dunn view and Pincer impingement was
defined by the presence of either acetabular retroversion
or coxa profunda. Statistical analysis was done using
the two tailed paired t-test, chi-square test and intraclass
correlation coefficient. Odds Ratios were calculated
using conditional logistic regression.
Results: Eighty-eight patients (77.8%) had bilateral
deformity and 27% had symptoms in both hips. Mean
α angles were higher for bilateral impingement deformity
than for the impingement side only when unilateral
deformity was present (72.10 versus 64.50, p

COA/CORS/CORA 251
37. HIP ARTHROSCOPY MAY CAUSE
CHONDROLYSIS
Javad Parvizi, Orhan Bican, Kevin Bozic * , Chris
Peters †
Rothman Institute; * University of California;
†
University of Utah
Purpose: Hip arthroscopy has been used at an increasing
frequency over the last few years. Majority of patients
undergoing hip arthroscopy are young and active individuals
who seek definitive therapy for a painful hip condition
and wish to avoid undergoing a hip replacement.
Although relatively successful, complications following
hip arthroscopy occur. This multi-institutional study
presents a worrisome and previously unrecognized complication
of hip arthroscopy, namely chondrolysis that
lead to accelerated development of end-stage arthritis.
Method: Using the computerized database in each
institution, patients undergoing total hip arthroplasty
between 1999-2008 who had received hip arthroscopy
prior to arthroplasty were identified. 39 patients were
identified to have undergone at least one hip arthroscopy
on the affected hip prior to arthroplasty. There
were21 female and 18 male patients. The mean age of
patients at the time of hip arthroscopy was 45.9 years.
Data regarding demographics, comorbidities, preoperative
diagnosis, number of previous procedures, and the
details of the surgical procedure were compiled. Radiographs
were evaluated.
Results: The median time from arthroscopy to arthroplasty
was 14.8 months (range 2.2 months to 7 years).
Fourteen patients (35%) underwent THA within 12
months of a previous hip arthroscopy and in nine of
these patients the indication for hip arthroscopy was
labral tear debridement. These patients despite having
none to minimal arthritis at the time of arthroscopy
developed accelerated arthritis within a year that necessitated
hip replacement.
Conclusion: Hip arthroscopy can cause accelerated
degenerative arthritis of the hip in some patients. We
believe the subset of our patients who developed arthritis
so early after hip arthroscopy may have suffered
chondrolysis and/or chondral injury during the arthroscopy
that resulted in progressive and aggressive arthritis
of the hip within 12 months. Hip arthroscopy should
be reserved for a select group of patients. All measures
to minimize the possibility of chondrolysis and/or chondral
injury should be exercised.
COA/CORS COMBINED PAPER SESSION 5:
SPINE/TRAUMA
38. BIOMECHANICAL CHARACTERIZATION
OF CERVICAL SPINE DISLOCATION IN AN
INNOVATIVE SPINAL CORD INJURY (SCI)
MODEL
Qingan Zhu, Jie Liu, Tim Bhatnagar, Wolfram
Tetzlaff, Thomas Oxland
UBC
Purpose: Recent studies have shown differences in short
term spinal cord pathology between spinal column
injury mechanisms, such as contusion and fracturedislocation.
Such differences may exist at longer time
points, and thus survival studies are needed in the dislocation
models. A more in-depth characterization of the
dislocation model is needed for development of a mildmoderate
cervical spine dislocation model in a rat that is
suitable for survival studies. Specifically, our objective in
this study was to determine the dislocation displacement
that produces initial spinal column failure in a Sprague-
Dawley rat model and to validate a consistent injury at
the desired dislocation in-vitro and in-vivo.
Method: For the dislocation model, the dorsal ligaments
and facets at C4-C5 were removed to mimic the
type of posterior element fracture and ligament injury
commonly seen in a bilateral fracture-dislocation. C3
and C4 were clamped together and held stationary
while the clamp holding C5 and C6 was connected to
an electromagnetic actuator and displaced dorsally to
produce the injury while force and displacement were
recorded. Twenty-eight isolated cervical spine specimens
of Sprague-Dawley rats were used to determine dislocation
displacement at initial spinal column failure. The
C4-C5 segment sustained dislocation (>3mm) injury
at 0.05mm/s (n=11), 100mm/s (n=4) and 1000mm/s
(n=13). Initial spinal column failure was defined at with
maximum force during the dislocation. A dislocation
displacement of 1.4mm was applied to 7 isolated specimens
and 4 anesthetized rats at 430mm/s. The spinal
column failure was inspected up to 3 days after injury,
as well as hemorrhage of spinal cord in-situ.
Results: The dislocation displacement at in-vitro spinal
column failure was 0.95mm±0.32 and not significantly
different among specimens at the three dislocation
speeds. Under a dislocation displacement of 1.4mm,
rupture of the C4-C5 disc occurred in all in-vitro
(0.67mm±0.38) and in-vivo (0.65mm±0.17) cases. SCI
hemorrhage at epicenter was observed in 3 of 4 cases.
Conclusion: The initial spinal column failure in an innovative
SCI model occurs at displacement between 0.65mm
and 0.95mm. Dislocation displacement of 1.4mm results
in spinal column failure consistently and SCI hemorrhage,
and may be suitable for survival studies.
39. MAVERICK TOTAL DISC REPLACEMENT
IN THE LOWER LUMBAR SPINE ADJACENT
TO A LONG SPINAL FUSION: AN IN VITRO
BIOMECHANICAL STUDY OF KINEMATICS
Qingan Zhu, Claire Jones, Tim Schwab,
Chad Larson, Eyal Itshayek, Lawrence Lenke,
Washington University; Peter Cripton
UBC
Purpose: A long spinal fusion across the thoracolumbar
region is sometimes applied in scoliosis. Adjacent level
degeneration below these constructs has been documented.
Treatment with an artificial disc replacement
below the fusion has been proposed to prevent degeneration
there. There is currently little data detailing the
expected biomechanics of this situation. The objective
of this study was to evaluate range of motion (ROM)
and helical axis of motion (HAM) changes due to oneand
two-level Maverick total disc replacement adjacent
to a long spinal fusion.
Method: A multidirectional flexibility testing protocol
with compressive follower preload was used to test seven
human cadaveric spine specimens (T8-S1). A continuous
pure moment ±5.0 Nm was applied in flexion-extension
(FE), lateral bending (LB) and axial rotation (AR), with
a compressive follower preload of 400 N. The motion
of each vertebra was monitored with an optoelectronic
camera system. The test was completed for the intact
condition and after each surgical technique: (1) T8-L4
fusion and facet capsulotomy at L4-L5 and L5-S1; (2)
L4-L5 Maverick; (3) L5-S1 Maverick. Maverick total
disc replacement and fusion with the CD Horizon
system was performed. Repeated measures ANOVA
was used to analyze changes in ROM and HAM of the
L4-L5 and L5-S1 segments.
Results: Following L4-L5 Maverick replacement, L4-
L5 ROMs tended to decrease slightly (on average from
6.2°±2.8° to 5.1°±3.8° in FE, 1.1°±1.1° to 0.9°±0.5° in
LB and 1.3°±0.9° to 1.0°±0.6° in AR). With two-level
Maverick implantation, L5-S1 ROMs tended to increase
slightly in FE (from 6.6°±2.6° to 7.1°±3.9°), and to
decrease slightly in LB (from 1.5°±0.9° to 1.0°±0.3°) and
AR (from 1.5°±1.5° to 1.1°±0.6°), compared to the fused
condition. As a trend, HAM location shifted posteriorly
in FE and AR, and inferiorly in LB following Maverick
replacement. However, neither ROM nor HAM at these
two segments showed any significant change due to the
implantation of one-or two-level Maverick total disc
replacement in any of the three directions.
Conclusion: The present results suggested that lower
lumbar segments with Maverick disc replacement exhibited
intact-like kinematics in both extent and quality of
motion.
40. CERVICAL SPINAL MOTION THAT
WOULD OTHERWISE BE SAFE, CAN
CAUSE SPINAL CORD COMPRESSION IN A
STENOTIC SPINE
James C. Boak, Philippe Gedet, Marcel Dvorak*,
Stephen Ferguson*, Peter Cripton
UBC; *University of Bern
Purpose: The average age of people suffering spinal cord
injuries in many countries is shifting toward an older
population, with a disproportionate number occurring
in the spondylotic cervical spine. These injuries
are typically due to low energy impacts, such as a fall
from standing height. Since a stenotic spinal canal (a
common feature of a spondylotic cervical spine) can
cause myelopathy when the spine is flexed or extended,
traumatic flexion or extension likely causes the injury
during the low energy impact. However, this injury
mechanism has not been observed experimentally.
Method: To better understand this injury mechanism an
in-vitro study, using six whole cervical porcine spines,
was conducted. The following techniques were combined
to directly observe spinal cord compression in a
stenotic spine during physiologic and super-physiologic
motion:
• A radio-opaque surrogate cord, with material properties
matched to in-vivo specimens, replaced the real
spinal cord.
• Sagittal plane X-rays imaged the surrogate cord in the
spine during testing.
• Varying levels of canal stenosis were simulated by a
M8 machine cap screw that entered the canal from
the anterior by drilling through the C5 vertebral
body.
• Pure moment loading and a compressive follower
load were used to replicate physiologic and superphysiologic
motion.
Results: Initial results show that a stenotic occlusion that
removes all extra space in the canal in the neutral posture,
without compressing the cord, can lead to spinal
cord compression within physiologic ranges of flexion
and extension. The spinal cord can also be compressed
during slightly super-physiologic flexion and extension
with only 25% canal occlusion. Physiologic loads and
motions in the same spines did not cause cord compression
when canal occlusion was 0%.
Conclusion: These results support the hypothesis that cervical
spinal canal stenosis increases the risk of spinal cord
injury because spinal cord compression was observed
during motions and loads that would be safe for a nonstenotic
spine. These results are limited primarily due to
the use of a porcine spine. However, this new stenosis
model and experimental technique will be applied to invitro
human spine specimens in future work.
41. THE POSITIVE EFFECTS OF POLY-N-
ACETYL GLUCOSAMINE ON HUMAN
INTERVERTEBRAL DISC CELL METABOLISM
IN VITRO
Deepthi Gorapalli 1,2 , Albert J.M. Yee 1,2 , Aiguo
Zhang 1 , Marina Demcheva 3 , Cari Whyne 1,2 ,
J. Vournakis 3 , A. Seth 1
1
Sunnybrook Health Sciences Centre, 2 University
of Toronto, 3 Marine Polymers Technologies Inc
Purpose: There is interest in biologic strategies that can
potentially treat degenerative disc disease (DDD). A new
deacetylated derivative of a marine diatomic glycosaminoglycan
(DEAC) was developed and incorporated
into two sulphated hydrogel formulations; Gel 1 and
2. These materials were proposed to have a reparative
effect on damaged tissue. Biochemical studies were conducted
using primary human disc cell (HDC) cultures.
Method: HDCs were isolated from surgical specimens
by sequential enzymatic digestion (pronase and collagenase).
Time-course in-vitro studies were conducted
on cell cultures treated with DEAC, Gel 1 or Gel 2 (28
day period). Proteoglycan content (alcian blue), cellular
viability/proliferation (MTT assay), and type collagen
II, aggrecan expression (RT-PCR, immunohistochemistry)
was assessed.
Results: When compared to controls, the DEAC, Gel 1
and 2 treated HDC groups showed significant increases
J BONE JOINT SURG [BR] 2011; 93-B:SUPP III

252 COA/CORS/CORA
in proteoglycan content as early as day 12. The greatest
effect was observed with Gel 1 (78.4±1.9 fold greater
optical density compared to control, p < 0.05). The
amount of proteoglycan quantified on DEAC treated
HDCs on day 28 was 27.7±0.09 times higher than
control (p

COA/CORS/CORA 253
necrosis versus apoptosis to cellular injury. Existing
studies have only considered indomethacin administration
prior to induction of compartment syndrome.
The purpose of this study was to determine the effect
of timing of indomethacin administration on muscle
damage in compartment syndrome, and to assess apoptosis
as a cause of tissue demise.
Method: Twenty-four Wistar rats were randomized to
elevated intracompartmental pressure (EICP) for either
45 or 90 minutes (30mm Hg). In the 45 min group,
indomethacin was withheld (group 1), given prior to
induction of EICP (group 2) or given 15 min prior to
fasciotomy (group 3). In the 90 min group, indomethacin
was withheld (group 4) or provided 30 or 60 minutes
prior to fasciotomy (groups 5 and 6). Intravital
microscopy and histochemical staining assessed capillary
perfusion, cell damage and inflammatory activation
within EDL muscle. Apoptosis was assessed using
ELISA staining for caspase-3. Groups were compared
with one-way ANOVA (p

254 COA/CORS/CORA
51. CEMENTED AND CEMENTLESS TOTAL
HIP ARTHROPLASTY: RESULTS OF A
RANDOMISED CONTROLLED TRIAL AT 17
TO 21 YEARS FOLLOW-UP
Keegan Au*, Kristoff Corten † , Robert B. Bourne † ,
Cecil H. Rorabeck † , Andreas Laupacis ‡ , Li Ka
Shing ‡
*London Health Sciences Centre; † University
Hospital, University of Western Ontario;
‡
Knowledge Institute of St. Michael’s Hospital
Purpose: A randomised controlled trial comparing fixation
of a Mallory-Head prosthesis for total hip arthroplasty
(THA) with and without cement was performed
with average 19 years (range 17-21 years) of continuous
follow-up.
Method: Two hundred and fifty patients were randomised
to undergo THA using either a Mallory-Head
THA prosthesis designed to be inserted with cement or
one designed for cementless insertion. Both patients and
those involved in outcome assessment were blinded to
the type of implantation. Patients were followed yearly
after the first post-operative year for outcomes including
mortality, revision arthroplasty, and health-related quality
of life assessment scores.
Results: Primary THA was performed with cement
in 124 patients and without cement in 126 patients.
Mean age at the time of surgery was 64 years, and 48%
were female. During the period of review, there were
78 (31%) deaths in the cohort, and 75 (30%) patients
underwent revision surgery. Kaplan-Meier survivorship
analysis revealed significantly increased revision rates in
cemented compared with cementless THA using failure
of either component (p=0.01) or femoral component
(p

COA/CORS/CORA 255
approach=140.0, p=0.053). The cup abduction angle
(CA) was slightly different between the two groups (MI
RAH 42.5°, lateral approach=39.2°, p=0.03). More
patients had cup abduction angles in the 45°-55° range
(p=0.009) in the MI HR group but none had a cup angle
over 55° of abduction in either group. On the femur
side, component positioning was comparable.
Conclusion: Based on our early results, the anterior-
Hueter approach is a reasonable alternative to more
extensile surgical approaches. Like any MI approach to
hip surgery, great care has to be taken not to put the
cups too vertical. Further long-term studies as well as
comparisons to other approaches such as the posterior
approach will determine if the anterior approach can be
recommended for hip resurfacing.
56. COMPUTER NAVIGATED HIP
RESURFACING: AN EVALUATION OF
ACCURACY AND LEARNING CURVE
Michael Olsen, Edward T. Davis*, James P.
Waddell, Emil H. Schemitsch
St. Michael’s Hospital, *Royal Orthopaedic
Hospital, Birmingham, UK
Purpose: Hip resurfacing is a technically demanding
alternative to total hip arthroplasty. Placement of the
initial femoral guidewire utilizing traditional mechanical
jigs may lead to preparatory errors and a high degree
of variability in final implant stem-shaft angle (SSA).
Intra-operative computer navigation has the potential
to decrease preparatory errors and provide a reliable
method of femoral component placement. The current
study evaluated the accuracy and learning curve of 140
consecutive navigated hip resurfacing arthroplasties.
Method: Between October 2005 and May 2007, 140 consecutive
Birmingham Hip Resurfacings were performed
on 132 patients (107 male, 25 female). The mean age of
the cohort was 51.2 years (range 25-82). Indications for
surgery included osteoarthritis (n=136) and avascular
necrosis (n=4). Pre-operative templating was performed
using digital AP unilateral hip radiographs. Neck-shaft
angles (NSA) were digitally measured and relative
implant stem-shaft angles planned. The central guidewire
was drilled and verified intra-operatively using an imageless
navigation system. Implant stem-shaft angles were
assessed using 3 month post-operative radiographs.
Results: Pre-operative templating determined a mean NSA
of 132.2 degrees (SD 5.3 degrees, range 115-160). The
planned SSA was a relative valgus alignment of 9.5 degrees
(SD 2.6 degrees). The post-operative SSA differed from the
planned SSA by 2.5 degrees (SD 1.9 degrees, range 0-8).
The final SSA measured within ±5 degrees of the planned
SSA in 89% of cases. Of the remaining 11% of cases, all
measurements erred in valgus. No cases of neck notching
or varus implant alignment occurred in the series. The
mean navigation time for the entire series was 18 minutes
(SD 6.6 minutes, range 10-50). A learning curve was
observed with respect to navigation time, with a significant
decrease in navigation time between the first 20 cases and
the remainder of the series. There was no evidence of a
learning curve for implant placement accuracy.
Conclusion: Imageless computer navigation shows
promise in optimizing preparation of the femoral head
and reducing the introduction of mechanical preparatory
factors that predispose to femoral neck fracture.
Navigation may afford the surgeon an accurate and
reliable method of femoral component placement with
negligible learning curve.
COA PAPER SESSION 7:
TRAUMA LOWER EXTREMITY 1
57. EVEN UNDISPLACED FRACTURE NECK
OF FEMUR CAN RESULT INTO POOR
OUTCOME DEPENDING ON ASSOCIATED
CO-MORBIDITES: A STUDY OF AO
CANNULATED SCREWS DONE IN 315
PATIENTS
Vishal Upadhyay, Ajay Sahu*, Charalambos P.
Charalambous, N. Harshawardena, Heath P.
Taylor, Mark Farrar
Poole General Hospital, UK; *Stepping Hill
Hospital, UK
Purpose: The aim of this study was to analyze the outcome
of AO cannulated screws for undisplaced fracture
neck of femur and find out the correlation in outcome
with respect to co-morbidities in a general trauma unit
in UK.
Method: A retrospective study was conducted using
data from electronic patient record,clinical coding
information,clinic letters and GP’s. 315 patients who
underwent AO screws for fracture neck of femur during
2000 to 2004 were included. We looked into age, place
of living, classification, mechanisn of injury, comorbidities,
mobility before fracture, allergy, addictions,
whether patient was anticoagulated, delay for theatre
with reasons, length of stay in hospital, complications
and treatment for complications. We assessed reasons
for other admissions later on, need and type of another
operation, consequently developed comorbidities,
patient getting fracture of other side and its treatment,
time and cause of death if happened?
Results: There were 81 males and 234 females in the
study. Mean age of patients was 72 years (range 50-96
years). Non-union occurred in 19 patients (6%) and
avascular necrosis occurred in 49 patients (15.5%).
Reoperation with an arthroplasty was required in 69
patients (21.9 %). The incidence of avascular necrosis
with internal fixation at 1 year was 31 (9.8%). Fifty-one
(16%) patients died in 2 year period. The age, walking
ability of the patient, and associated co-morbidities
were of statistical significance in predicting fracture
healing complications. We correlated our complications
with comorbidities and found them more in patients
with end-stage renal failure, steroid intake, osteoporosis
and diabetes mellitus etc.
Conclusion: The rate of fracture healing complications
and reoperations in patients with undisplaced fractures
was high in our series with two year follow up. It was
even higher in patients with age greater than 80 years
and some specific comorbidities. We should also consider
co-morbidities and age before deciding for internal
fixation rather than only the fracture configuration
(Treat patient not the X-rays). Outcome is multifactorial
and depends on many predictive factors. Each patient
should be evaluated carefully and we should treat the
physiological age and not the chronological age.
58. A STUDY ANALYSING THE OUTCOME
OF AO CANNULATED SCREWS FOR THE
FRACTURE NECK OF FEMUR IN PATIENTS
WITH DIABETES MELLITUS
Vishal Upadhyay, Ajay Sahu, Ravi Mahajan*,
Heath Taylor, Mark Farrar
Poole Hospital NHS, Trust, UK; *Royal
Bournemouth Hospital NHS Trust, UK
Purpose: The aim of the study was to analyze the outcome
of AO cannulated screws for fractures neck of
femur in patients with Diabetes mellitus.
Method: Sixty-two patients aged 50 years or more (17
males & 45 females) who underwent AO screws for
fracture neck of femur over seven years (1999–2005)
and followed-up for a minimum of two years formed
the study population. A retrospective review of data
from electronic patient record (EPR), clinical coding,
clinic & GP letters was made. Age, residential placement,
Garden’s classification of fracture, mode of injury,
associated other co morbidities, pre-admission mobilisation
status, allergies, addictions and anticoagulation
status details were collected.
Results: The mean age of patients was 67 years (range
52–96 yrs). Eleven patients died in two years time.
Forty-one patients were less than 75 years of age and 21
patients were more than 75 years of age. All the patients
more than 75 years of age had undisplaced intracapsular
fractures. Thirteen patients were type I and 49 patients
were type II diabetic. Non-union and avascular necrosis
occurred in nine (17%) & 13 (26%) patients respectively.
Revision surgery in the form of total hip replacement or
hemiarthroplasty were performed in 21 (41%) cases. The
incidence of avascular necrosis following osteosynthesis
at one year was 14%. Age, control of diabetes, postoperative
complications, pre-fracture mobilization status
etc. Complications like wound infection were more principally
in patients who had poorly-controlled diabetes.
Conclusion: Patients with diabetes mellitus have metabolic
bone disease due to vasculitis. This increases the
risk of complications associated with fracture fixation
such as non-union, cut-through and avascular necrosis
(AVN). The complications and revision surgery rate
was high in patients with displaced fractures and with
poorly controlled diabetes. Comorbidities like diabetes
and patient’s age were also strong predictors of healing
in addition to fracture configuration. Looking at very
high complication and re-operation rate, our recommendation
in patients with diabetes is primary hemiarthroplasty
irrespective of femoral head displacement, if
there age is more than 75 years.
59. HIP FRACTURE COMPLICATIONS AND
30-DAY MORTALITY OUTCOMES WITHIN
ACUTE CARE IN CANADA FROM 2001–02
TO 2003–04
Gisele M. Carriere, Pierre Guy*
Statistics Canada; *UBC
Purpose: Decubitus ulcers and post-operative infections
significantly impact patients` outcome and resource utilization.
The purpose of this study is to report incidence
of post-surgical infection, decubitus ulcer and associations
to 30-day in-hospital mortality among elderly
Canadians admitted for hip fracture.
Method: Statistics Canada`s national Health Person-
Oriented Information database of linked acute care
hospital discharges was queried for fiscal 2001–02,
2002–03, 2003–04 creating a cohort of 67,434 hip fracture
patients aged 60+. Demographics, comorbidities
(enhanced Charlson Index), fracture type and treatment
were used in logistic regression models to report odds
ratios for outcomes.
Results: Women were 76% of the cohort, median age
was 82 yrs. Decubitus ulcer was detected in 2.3% of
hip fracture patients. Increased risk was indentified
for trochanteric fractures (OR 1.14, p< .05), dementia
(OR 1.25, p< .05) and increasing age (OR: 1.02,
p

256 COA/CORS/CORA
60. PERCUTANEOUS REDUCTION AND
FIXATION OF ACETABULUM FRACTURES IN
ELDERLY PATIENTS
Joshua Gary, Kelly Lefaivre*, Frank Gerold,
Michael Hay † , Charles M. Reinert, Adam J. Starr
UTSW; *UBC; † UTS
Purpose: Acetabular fractures in elderly patients are
difficult problems with various treatment options. Our
institution treats many of these patients with percutaneous
acetabular fixation. We reviewed medical records
and contacted patients to determine the rate of conversion
to total hip arthroplasty.
Method: Our institutional trauma database was searched
for all patients age 60 and older who had been treated
with percutaneous screw fixation for an acetabular fracture.
Seventy-nine consecutive patients (80 fractures)
were identified. Medical records were examined to obtain
peri-operative and follow-up information regarding the
hospital course and conversion to total hip arthroplasty.
A survivorship anaylsis was created with conversion to
total hip arthroplasty as the censored event, and standard
Kaplan-Meier curves were constructed. Five categorical
variables were used to test for differences in survival of
the native hip: age, sex, simple versus complex fracture
pattern, closed versus limited open reduction, and occurrence
of a medical complication.
Results: Seventy-five fractures had adequate clinical
follow-up with a mean of 3.9 years (range 0.5 – 11.9
years). Average blood loss was 69 cc and there were no
postoperative infections. 19/75 (25%) were converted
to total hip arthroplasty at a mean time of 1.4 years
after the index procedure. Survivorship analysis demonstrated
a cumulative survival of 65% at 11.9 years
of follow-up. There were no conversions to arthroplasty
beyond 4.7 post-operatively. There were no statistically
significant associations between conversion to
arthroplasty and age, sex, closed versus limited open
reduction, simple versus complex fracture pattern, and
occurrence of a medical complication.
Conclusion: Percutaneous fixation is a viable treatment
option for patients age 60 or greater with acetabular fractures.
Rates of conversion to total hip arthroplasty are
comparable to other treatment methods and if conversion
is required, soft tissues are preserved for future surgery.
61. MODIFIED STOPPA APPROACH FOR
ACETABULAR FRACTURES OF THE
ELDERLY PATIENT
G. Yves Laflamme, Benoit Benoit, Stéphane Leduc,
Jonah Hébert-Davies*
Hôpital du Sacré-Coeur; *Université de Montreal
Purpose: The age of patients presenting with acetabular
fracture has increased over the last ten years. Older
patients tend to have patterns involving the anterior
column with comminution of the quadrilateral plate.
Our goal was to investigate the appropriateness of
open reduction and internal fixation using the modified
Stoppa approach for geriatric acetabular fractures.
Method: A retrospective review of patients over the age
of 60 having presented to an academic level I trauma
center over the course of four years. Twenty patients
were identified and treated using the modified Stoppa
approach with plating of the quadrilateral surface.
Patients were evaluated clinically using both SF-36 and
Harris Hip Score. Records and radiographs (using criteria
described by Matta) were reviewed retrospectively.
Results: All patients were followed for a minimum
of two years with no lost at follow-up. Mean age for
patients at time of intervention was 68 years. Average
blood lost was 800cc and surgical time was 130 minutes
(range, 55-210). There was one traumatic injury
to the obturator nerve and two patients were noted to
have temporary weakness of the hip adductors postoperatively.
Average Harris Hip Score and the SF-36
were improved significantly (p

COA/CORS/CORA 257
65. ENDSTAGE ARTHRITIS FOLLOWING
TIBIA PLATEAU FRACTURES: 10 YEAR
FOLLOW UP
Ramin Mehin, Peter O’Brien, Penny Brasher,
Henry M. Broekhuyse, Piotr Blachut, Robert N.
Meek, Pierre Guy
UBC
Purpose: Problem: Tibia plateau fractures may lead to
end-stage post-traumatic arthritis that requires reconstructive
surgery. The incidence of this problem is
unknown but has been estimated at 20–40% by studies
that were limited by small sample sizes, potential followup
bias, and the limitations of using radiographic arthritis
as a chosen outcome (not correlated to function). The
use of administrative data bases to follow the care of a
large number patients for robust end points such as surgery,
offers an opportunity to address these limitations.
Purpose: to determine the minimum ten year incidence
of post-traumatic arthritis necessitating reconstructive
surgery following tibia plateau fractures.
Method: We queried our prospectively collected Orthopedic
Trauma Data base to identify operatively treated
patients with tibia plateau fractures. These cases were
cross-referenced with the data from our Province’s
administrative health database and tracked over time
for the performance of reconstructive knee surgery.
Each individual’s exposure/follow-up period was limited
by end of health plan coverage on record or date of
death from vital statistics data. The minimum follow-up
was ten years.
Results: Between 1987 and 1994, 378 patients with a
tibia plateau fracture were treated at our institution.
The average age was 46 years (SD=18, range 14-87),
while 56% of patients were males. Seventeen out-of-
Province residents were excluded, along with forty-six
others whose “Medical Services Plan” numbers could
not be identified. Of which seven were WCB patients
and one who was affiliated with the military. The study
cohort therefore consisted of 311 patients with 314 tibia
plateau fractures. Four individuals (1.3%) we treated
tibia plateau fractures have required reconstructive knee
surgery for end-stage post-traumatic knee arthritis at 10
years. Of these 3 of 4 were type VI fractures and 1 of
4 was open.
Conclusion: Patients who require surgical treatment of
tibia plateau fractures may be counseled on their longterm
risk of requiring reconstructive knee surgery for
endstage knee arthritis based on a clinical study. Based
on our findings, the proportion of those who have
required a total knee surgery, ten years following their
injury, is lower than previously published.
66. OSTEOTOMY FOR FEMORAL OR TIBIAL
SHAFT MALUNION IN PATIENTS WITH
END-STAGE OSTEOARTHRITIS OF THE
KNEE
Arvindera Ghag, Pierre Guy, Peter J. O’Brien,
Henry M. Broekhuyse, Robert N. Meek, Piotr A.
Blachut
UBC
Purpose: Femoral and tibial shaft malunion may predispose
to knee osteoarthritis but may also pose a problem
for knee reconstruction; malposition of total knee
prostheses being a known cause of early failure. Limb
realignment may prove to be beneficial prior to proceeding
with arthroplasty. The purpose of this study was to
evaluate the outcome and effect of shaft osteotomy prior
to total knee arthroplasty (TKA).
Method: A search of the trauma database between 1987
and 2006 was conducted. Twenty-two osteotomies were
performed on 21 patients with femoral or tibial shaft
malunion who had been considered for TKA. Mean
age at osteotomy was 54 years and mean follow-up 86
months. Time intervals between surgical procedures and
Knee Society scores were calculated. Patients were surveyed
regarding pain relief and functional improvement.
Results: Femoral osteotomy improved mean Knee Society
knee scores from 47 to 76 and function scores from
34 to 61. Tibial osteotomy improved knee scores from
53 to 82 and function scores from 28 to 50. Four osteotomies
were complicated by nonunion and required
further intervention. Osteotomy subjectively improved
pain and function for a mean of 56 months. Femoral
and tibial shaft osteotomy delayed TKA in 45% (10
cases) for a mean period of just over 6.5 years (89 and 73
months for femoral and tibial osteotomy respectively).
Pre and post Knee society scores were: Femur: knee 56
to 88, function 41 to 72; Tibia: knee 65 to 85, function
25 to 57. One TKA was revised after 11 months due to
valgus malalignment and was complicated by a wound
infection. There were no other infections or wound
complications. The procedure additionally relieved pain
and improved function in the remaining 12 joints, not
yet requiring arthroplasty.
Conclusion: Femoral and tibial shaft osteotomy may
delay and possibly avoid TKA, relieve pain and improve
function in patients who present with malunion and
end-stage knee arthritis. The complication rate and clinical
results of TKA following shaft osteotomy appear
to be similar to primary TKA.This treatment strategy
should be considered in younger patients with post traumatic
osteoarthritis where significant femoral or tibial
deformity is present.
COA PAPER SESSION 8:
RECONSTRUCTIVE UPPER EXTREMITY 1
67. ASSOCIATION BETWEEN THE UPWARD
MIGRATION INDEX AND FUNCTIONAL
AND QUALITY OF LIFE OUTCOMES IN
ARTHROSCOPIC ROTATOR CUFF REPAIR
Peter Lapner, Emilio Lopez, Felipe Pereira, Salah
Elfatori, David Simon
University of Ottawa
Purpose: The upward migration index (UMI) is a useful
radiographic parameter for assessment of disorders of the
rotator cuff. Utility of the UMI as a prognostic indicator
for outcome following cuff repair has not been previously
studied. The objective of this study was to determine if
an association exists between the pre-operative UMI and
the improvement in clinical and quality of life outcome
scores following arthroscopic rotator cuff repair.
Method: Patients with a full thickness tear of the rotator
cuff who underwent an arthroscopic repair of the
cuff were selected for review. Eighty-four patients were
included in the series. Mean patient age was 55 (range 25-
78). The UMI was measured by MRI, and patients were
divided into three groups: < 1.25 (GROUP A), 1.25-1.35
(GROUP B) and > 1.35 (GROUP C). Outcome variables
were the non-weighted Constant-Murley score, ASES and
the WORC assessed at baseline, 6 month and 12 months
post-operatively. The paired t-test was used to carry out
comparisons in follow up and one-way ANOVA was
used to carry out comparisons between groups.
Results: There were 9 patients in group A, 33 in group
B and 42 in group C. The improvement in scores from
baseline to 1 year were as follows: ASES; 21.1 (A),
32.6 (B), and 38.4 (C); Constant 21.4 (A) 19.8 (B), and
24.2 (C) and WORC 31.9 (A), 42.7 (B), and 44 (C).
Statistically significant improvements were observed
in all groups in all outcome measures from baseline to
6 months and from 6 months to 1 year. Although the
differences were not statistically significant (p>0.05),
a trend toward greater improvement in outcomes was
observed with higher upward migration indices.
Conclusion: A lower UMI was associated with less
improvement in functional and quality of life outcomes
following arthroscopic rotator cuff repair, although
these differences were not statistically significant.
Patients with a low UMI demonstrated a significant
improvement in functional and quality of life scores
following surgery. In isolation, a low UMI should not
represent a significant contraindication to treatment by
arthroscopic rotator cuff repair.
68. DOES PHYSICAL EXAMINATION OF THE
SHOULDER PREDICT PATIENT-REPORTED
FUNCTIONAL OUTCOME IN PATIENTS
WITH PREVIOUS PROXIMAL HUMERUS
FRACTURES?
Gerard Slobogean, Akin Famuyide, Vanessa
Noonan, Peter J. O’Brien
UBC
Purpose: To quantify how well the physical examination
of the shoulder predicts patient-reported functional
outcome in a cohort of patients with previous proximal
humerus fractures.
Method: Potential subjects were identified from a recent
study cohort of proximal humerus fracture patients
treated within the past six years. The cohort consisted
of all fracture types and treatment modalities. Participants
underwent a focused physical examination of
their injured shoulder containing the components of the
Constant-Murley shoulder score: range of motion for
forward flexion, abduction, internal rotation, external
rotation, and abduction strength measured by an IsoBex
muscle strength analyzer. Participants also completed
the following patient-reported functional outcome questionnaires:
Disabilities of Arm, Shoulder, Hand (DASH),
American Shoulder and Elbow Surgeons Standardized
Shoulder Assessment Form (ASES), Simple Shoulder
Test (SST), and Oxford Shoulder Score (OSS). Forwardand
backward-stepwise linear regression was used to
assess the relationship between the functional outcomes
and the physical exam measurements.
Results: Thirty-one subjects with a mean age of 70 ±
8 years participated. Sixteen patients were previously
treated with ORIF and 15 were treated with sling
immobilization. The mean physical examination measures
were: flexion 117° ± 31°, abduction 117° ± 37°,
internal rotation 7° ± 2°, external rotation 7° ± 4°, and
strength 6 ± 5 Newtons. The mean functional outcome
scores were: DASH 21 ± 19, ASES 82 ± 17, SST 8 ± 3,
and Oxford 20 ± 8. Using linear regression, adjusted
R-squared statistics suggest components of the physical
exam can explain 38% of the Oxford, 50% of the
DASH, 58% of the SST, and 70% of the ASES variance.
Abduction strength was a significant predictor for all
functional outcomes. Combinations of flexion, abduction,
or internal rotation were also significant predictors
depending on the outcome instrument being modeled.
Conclusion: Physical exam of the shoulder accounts for
differing amounts of patient-reported functional outcome
variance. Abduction strength is the most consistent
predictor of functional outcome within this cohort
of proximal humerus fracture patients.
69. IMPACT OF COMPENSATION CLAIMS
ON SURGICAL OUTCOME IN PATIENTS
WITH ROTATOR CUFF RELATED
PATHOLOGIES
Richard M. Holtby, Helen Razmjou, Iona
MacRitchie
Holland Orthopaedic and Arthritic Centre
Purpose: There is controversial information on recovery
of patients with compensable injuries. The purpose of this
matched case-control study was to examine the impact of
an active compensation claim following a work-related
shoulder injury on reporting disability as measured by subjective
and objective outcomes at 1 year post-operatively.
Method: Data of 506 consecutive patients who had undergone
a decompression or rotator cuff repair were reviewed.
One hundred and fourteen patients were on compensation
related to their shoulder problems. Patients were matched
with a historical control group (patients without a compensation
claim) based on age (4 age groups:

258 COA/CORS/CORA
each group, 42 patients (58%) had undergone a fullthickness
repair and 65 (61%) had surgeries related to
impingement syndrome. Paired and independent t-tests
showed that both groups improved significantly regardless
of their claim status. However, the compensation
group had a significantly lower level of improvement
than the non-compensation group. An analysis of covariance
which adjusted for pre-operative differences in
disability scores showed that an active claim was indeed
a strong predictor of follow up scores.
Conclusion: This is the first study that has used a
matched case-control design to control for potential
confounding factors in injured worker population. Our
results indicate that although patients with work-related
injuries demonstrate a lower level of recovery, they still
benefit from surgery.
70. CONTACT PRESSURES AND
GLENOHUMERAL TRANSLATIONS
FOLLOWING SUBACROMIAL
DECOMPRESSION: HOW MUCH IS
ENOUGH?
Patrick Denard, Timothy Bahney, Robert M. Orfaly
OHSU
Purpose: Determine the ideal form of subacromial
decompression.
Method: Six cadaveric shoulders with intact rotator
cuffs (RTC) underwent “smooth & move (SM),” limited
acromioplasty with coracoacromial ligament (CAL) preservation,
and CAL resection. Glenohumeral translation
was measured in four directions utilizing electromagnetic
spatial sensors. Peak RTC pressure was measured during
arm abduction utilizing pressure film sensors.
Results: Anterosuperior translation was unchanged
after SM or acromioplasty, but increased from 2mm at
baseline to 4mm following CAL resection with the arm
at 300 abduction (p=0.03). There were no significant
changes in other directions of translation following any
procedure. In neutral humeral rotation RTC pressure
was unchanged after SM (p=1.00). Pressure decreased
64% after a limited acromioplasty (p=0.04), and 72%
after CAL resection (p=0.03). There was a trend towards
increased abduction at which peak pressure occurred
following CAL resection (760 compared to 620;p=0.11)
In external rotation, RTC pressure decreased 26%
following SM, 52% after limited acromioplasty, and
64% after CAL resection, but values were not statistically
changed (p=0.52, p=0.08, and p=0.06). Similarly,
abduction angle at which peak pressure was reached
increased but was statistically insignificant after SM
(720; p=0.75), limited acromioplasty (750; p=0.11),
and CAL resection (790; p=0.08). In internal rotation,
RTC pressure decreased 32% following the SM, 59%
following the limited acromioplasty, and 58% following
CAL resection, but none reached statistical significance
(p=0.52, p=0.26, p=0.17). Abduction angle of peak
pressure was unchanged after SM (670; p=0.63) and
limited acromioplasty (670; p=0.63), but increased following
CAL resection (620 vs. 790; p=0.04).
Conclusion: A CAL resection leads to increased anterosuperior
instability. “Smooth and move” or acromioplasty
can safely be performed without increasing
translation. Rotator cuff pressure did not significantly
decrease after SM. Rotator cuff pressure was significantly
decreased to a similar degree following a limited
acromioplasty or a CAL resection. A limited acromioplasty
with preservation of the CAL may offer the greatest
decrease in cuff pressures without the undesirable
effect of increased translation. However, statistical
significance was affected by high anatomic variability.
Therefore, the choice between “smooth & move” and
acromioplasty to decrease contact pressure is likely best
to be individualized based on acromial morphology.
71. THE EFFECT OF POSTERIOR CAPSULAR
TIGHTNESS ON PRESSURE IN THE
SUBACROMIAL SPACE
Peter Lapner, Philippe Poitras, Othman Ramadan,
Stephen Kingwell, Donald Russell*
University of Ottawa; *Carleton University
Purpose: Subacromial impingement syndrome is a painful
condition which occurs during overhead activities as
the rotator cuff is compressed between the greater tuberosity
and the acromion. Unrecognized secondary causes
of impingement syndrome may lead to treatment failure.
Posterior capsular tightness, believed to alter shoulder
joint kinematics, is often cited as a secondary cause but
scientific evidence is lacking. The objective of this study
was to evaluate the effect of posterior capsular tightness
on pressure in the subacromial space.
Method: Ten fresh-frozen cadaver shoulder specimens
were mounted on a custom testing apparatus. With the
scapula fixed, the deltoid and cuff muscles were loaded
statically with a constant ratio to elevate the humerus
in the scapular plane under physiologic loading conditions.
For each treatment (intact capsule, 1cm and 2cm
plication), pressure in the subacromial space and glenohumeral
kinematics were recorded during elevation. The
treatment order was randomly assigned to each specimen.
Peak pressure and translation of the humeral head center
were compared using a repeated measures ANOVA.
Results: Peak subacromial pressures (mean±sd) were similar
between treatment groups: 345±152 kPa, 410±213
kPa and 330±164 kPa for the intact, 1cm and 2cm plication
respectively (p>0.05). No significant differences were
found for superior or antero-posterior translations of the
humeral head at the peak pressure position (p>0.05).
Conclusion: Posterior capsular tightness, as a sole variable,
did not contribute significantly to increased pressure
in the subacromial space or to increased anterior
or superior humeral head translation during abduction.
Clinically, posterior capsular tightness may occur in
association with impingement syndrome but may not
play a significant role in causation.
72. CONTACT AREA, CONTACT PRESSURE
AND LOAD-FAILURE OF 3 ROTATOR CUFF
REPAIR METHOD: A BIOMECHANICAL
ANALYSIS
Frédéric Balg, Josianne Lepine, Nicolas Huppe,
Eve Langelier, Denis Rancourt
Université de Sherbrooke
Purpose: Comparer la technique de réparation de la
coiffe des rotateurs par haubanage tendineux en simple
rangée aux techniques transosseuse et double-rangée par
rapport à la surface et la pression de contact à l’interface
tendon-os, et la force de rupture.
Method: Pour tester la pression et la surface de contact,
les techniques de réparation ont été faite sur 2 spécimens
cadavériques (tête humérale et sus-épineux) chaque. Un
film Prescale pressure-sensing a été interposé entre les
tendons et l’os pendant 2 minutes avec une tension de
120N sur les tendons. Les films ont été numérisés pour
l’analyse avec le logiciel ImageJ. La force de rupture a été
testé sur un modèle Sawbones d’humérus proximal. Des
tendons synthétiques en fibre de nylon et polyesther dans
du silicone ont été créés pour les propriétés d’un tendon
proportionnellement à la rigidité du Sawbones. La force
a été appliquée à 135° jusqu’à rupture sur 2 montages
par technique de réparation. La suture transosseuse
utilisait 2 fils Orthocord dans 2 tunnels transosseux. La
suture double rangé a été faite avec 2 ancres Spiralok
médialement et 2 ancres Versalok latéralement avec des
fils Orthocord. Le haubanage tendineux a été fait avec 2
ancres Panalok RC latéralement dans la zone corticale.
Results: La surface de contact du haubanage de 17mm2
était significativement plus basse que de la suture transosseuse
à 48mm2 (p=0.002) et double-rangée à 86mm2
(p=0.001). La différence entre transosseux et double
rangée était significative (p=0.029). La pression de contact
du haubanage de 0.353MPa était significativement
plus basse que de la suture transosseuse à 0.441MPa
(p=0.002) et double-rangée à 0.567MPa (p=0.003). La
différence entre transosseux et double rangée était significative
(p-0.029). La force de rupture du haubanage
de 106N était significativement plus basse que de la
suture transosseuse à 249N (p=0.03) et double-rangée
à 316N (p=0.04). La différence entre transosseux et
double rangée n’était pas significative.
Conclusion: Le haubanage tendineux ne reproduit pas
l’empreinte anatomique du sus-épineux sur la grande
tubérosité ni une pression de contact adéquate en plus
d’avoir une force de rupture plus faible. Malgré son coût
plus élevé, la suture par double rangée est supérieure à la
technique transosseuse ou simple rangée.
73. PATIENT REPORTED ACTIVITIES
AFTER SHOULDER REPLACEMENT:
HEMIARTHROPLASTY VERSUS TOTAL
SHOULDER ARTHROPLASTY
Peter Zarkadas*, Thomas Throckmorton, Diane
Dahm, John Sperling, Robert Cofield
*Lions Gate Hospital; Mayo Clinic
Purpose: The indication to perform a total shoulder
arthroplasty (TSA) versus a hemiarthroplasty is guided
by a patient’s intended level of activity after surgery. It
is unclear what activities patients actually perform following
shoulder replacement, therefore, the purpose of
this study was to compare the self-reported activities of
patients following either a TSA or hemiarthroplasty.
Method: Two groups of 75 patients each, following
TSA or hemiarthroplasty, were matched for a variety
of demographic variables. A mailed activity questionnaire
asked patients to report their level of pain,
motion, strength, and a choice of 70 different activities.
Reported activities were classified as high (i.e. tennis) or
low (i.e. fishing) demand, and categorized as household
(i.e. cooking), yard work (i.e. gardening), sporting (i.e.
golf), or musical (i.e. piano).
Results: Ninety-six (64%) patients completed the survey,
50 in the TSA group (27F:19M, avg. 53.2 yrs), and 46
in the HA group (29F:21M, avg. 53.5 yrs). Pain was
not different between groups (3.6/10 TSA: 3.9/10 HA),
yet a significant difference was reported in forward flexion
(145° TSA: 120° HA, P

COA/CORS/CORA 259
6 weeks, and 3, 6, 12, 18, and 24 months. The primary
endpoint was the WOOS score at 2 years.
Results: One hundred and sixty-one patients were
consented and randomized for the study. There were
80 patients in the cemented and 81 patients in the
uncemented group. At baseline, the groups were alike
with regards to demographics and baseline evaluations.
The WOOS scores at post-operative intervals of
12, 18 and 24 months showed a significant difference
(p=0.009, 0.001, 0.028 respectively) in favour of the
cemented group. The cemented group also had better
strength (3 m p=0.038, 12 m p= 0.036, 18 m p=0.051,
24 m p=0.053) and forward flexion (6m p=0.031, 12
m p=0.04). As expected, the operative time was significantly
less for the uncemented group (C = 2.26h +/-.63;
U = 1.69h +/- 1.9, p= 0.03).
Conclusion: These findings provide the first evidence
that cemented fixation of the humeral head provides
better quality of life, strength and ROM than uncemented
fixation. This was a Tier 1 Project of the JOINTs
Canada group.
75. BONY INCREASED-OFFSET REVERSE
SHOULDER ARTHROPLASTY (BIO RSA):
A BIOLOGLIC SOLUTION TO SCAPULAR
NOTCHING, PROSTHETIC INSTABILITY
AND LIMITED SHOULDER ROTATION
Ryan Bicknell*, Pascal Boileau, Yannick
Roussanne, Nicolas Brassart, Chris Chuinard
*Queen’s University; University of Nice
Purpose: We hypothesized that lateralization of the RSA,
with a glenoid bone graft taken from the osteotomised
humeral head, would prevent those problems without
increasing torque on the glenoid component by keeping
the center of rotation within the glenoid. The objectives
of this study were to describe the results of the first 12
patients that underwent a bony increased-offset RSA
(BIO RSA).
Method: Thirty-six shoulders in 34 consecutive patients
with cuff tear arthritis (mean age 72 years, range 52-
86 years) received a BIO RSA, consisted of a RSA
incorporating an autogenous humeral head bone graft
placed beneath the glenoid baseplate. A baseplate with a
lengthened central peg (+25 mm) was inserted in the glenoid
vault, securing the bone graft beneath the baseplate
and screws. All patients underwent clinical and radiographic
(computed tomography) review at a minimum
1-year follow-up.
Results: All patients were satisfied or very satisfied and
all had no or slight pain. Mean active elevation increased
from 72° to 142° (p

260 COA/CORS/CORA
concerns identified by PSI-P. This analysis will guide us
in the development of a new and more comprehensive
instrument for evaluating ankle outcomes following
fusion or replacement.
79. PREFERENCE-BASED QUALITY OF LIFE
IN END-STAGE ANKLE ARTHRITIS, TOTAL
ANKLE ARTHROPLASTY, AND ANKLE
ARTHODESIS
Gerard Slobogean, Alastair S.E. Younger, Carlo
A. Marra, Kevin J. Wing, Murray J. Penner, Mark
Glazebrook*
UBC; *Dalhousie University; On Behalf of the
Canadian Orthopaedic Foot and Ankle Society
Purpose: To describe the pre- and one-year post-operative
preference-based, health related quality of life (health
state values) among a cohort of subjects with end-stage
ankle arthritis treated with total ankle arthroplasty or
ankle arthrodesis. This short-term study is not intended
to compare the efficacy of arthoplasty and arthrodesis.
Method: The Short-Form 36 (SF-36) was prospectively
completed by subjects enrolled in the Canadian Orthopaedic
Foot and Ankle Society Multicentered Ankle
Arthritis Outcome Study between 2003 and 2005. Preference-based
quality of life was assessed pre-operatively
and at one-year post-procedure using health state values
(HSVs) derived from the SF-36 transformation described
by Brazier (SF-6D). The SF-6D scores are anchored at
1.0 (full health) and at 0 (death). Basic patient demographic
and treatment information was also collected.
The decision to perform arthroplasty or arthrodesis was
made by the attending surgeon.
Results: Two hundred four of the 214 eligible subjects
had complete preoperative SF-36 data to allow transformation
to SF-6D values. One-year follow-up was
available for 114 of the participants. The mean age at
surgery of the included subjects was 58.9 +/- 13.3 years.
Of the patients with one-year follow-up, 56% were male
and 59% had received total ankle arthroplasty. These
demographics did not differ from the original preoperative
cohort. The mean SF-6D score among all subjects
with end-stage ankle arthrosis was 0.66 (95% CI 0.65
– 0.68). At one-year, the mean HSVs of the total ankle
arthroplasty and ankle arthrodesis groups were 0.73
(95% CI 0.71 – 0.76) and 0.73 (95% CI 0.70 – 0.75),
respectively. The reported pre-operative scores describe
health states below normative data for the US population
(0.76 +/- 0.01 for females, ages 55-64).
Conclusion: These are the first available HSVs for a
cohort of patients with end-stage ankle arthritis treated
with total ankle arthroplasty or ankle arthrodesis. These
data demonstrate an improvement in preference-based
quality of life following ankle arthroplasty or arthrodesis.
At one-year follow-up, patient reported HSVs
approach age-matched US norms.
80. RSA RESULTS FOR AN UN-CEMENTED
MOBILE-BEARING TOTAL ANKLE
ARTHROPLASTY SYSTEM
Andrea Veljkovic, Jason Fong, Allan Henigar,
David R. Wilson, Michael J. Dunbar, Mark
Glazebrook
Dalhousie University
Purpose: Radiostereometric Analysis (RSA) is used to
measure migration and inducible displacement (ID) of
orthopedic implant devices to allow early prediction
of implant failure (eg. Aseptic loosening). Total Ankle
Arthroplasty (TAA) is used for the treatment of endstage
ankle arthritis. First generation TAA implant have
meet with widespread failures while some second generation
TAA implants are showing improved results. In
this study RSA is used to evaluate the biomechanical
properties of a new third generation TAA implant in an
attempt to set a standard for the biomechanical evaluation
on TAA implants in-vivo.
Method: Patients undergoing TAA were enrolled consecutively
(n=12; 7 males; mean age=59 years; mean
BMI=29) and had 8 markers (0.08mm) inserted in both
the tibia and talus during surgery. Standing, weightbearing
RSA exams were performed at 3 and 6 months
and compared to concurrent supine exams to determine
component ID.
Results: For tibial components: at six months the components
had translated posteriorly (0.3mm±0.5) and
proximally (0.5mm±0.2), tilted into varus (0.5°±1.3),
and tilted posteriorly (0.4°±0.8). The magnitudes of
ID for the tibial components were moderate (mean <
0.2mm and 0.5°, standard deviation < 0.3mm and 2.2°
in each direction). For talar components: at six months
the components had translated distally (0.28mm±0.35),
rotated internally (0.21°±1.32) and tilted posteriorly
(0.15°±0.90). There was varus/valgus tilt measured in
the talar components but there was no consistent direction
of migration (0.03°±1.4). At six months the magnitudes
of ID for the talar components were small (mean
< 0.1mm and 0.25°, standard deviation < 0.2mm and
0.6° in each direction).
Conclusion: An RSA methodology has been established
to predict stability.
81. ACHILLES INSERTIONAL
TENDINOPATHY TREATED BY A
POSTERIOR MIDLINE APPROACH: A SAFE
PROCEDURE
Stéphane Leduc*, Michael P. Clare † , Scott
Swanson, Arthur K. Walling
*Université de Montréal; † Florida Orthopaedic
Institute; Florida Orthopaedic Institute
Purpose: Insertional calcific Achilles tendinosis is a painful,
frequently disabling, condition. The longitudinal
and radial alignment of the angiosomes of the posterior
region of the leg makes a straight posterior midline
approach logical. The safety of the posterior midline
approach and the outcome of a central tendon splitting
approach associated with a Strayer procedure to treat
this condition was evaluated.
Method: A retrospective review of a consecutive cohort
of a single surgeon was performed. All patients had
failed conservative treatment and all patients were primary
cases. Forty-seven patients (48 heels) were treated
over a 11-year period for chronic insertional Achilles
tendinosis. All patients underwent a midline posterior
splitting approach, debridment of the bursae, resection
of the haglund deformity, partial Achilles detachment,
debridement, reinsertion with bone anchor associated
with a proximal gatrocnemius recession (strayer procedure)
through a second midline incision. The average
age was 59 years old (39-75), co-morbidities included
four smokers and one diabetic patient. The average followup
was 54 months (15-144). All patients answered
pre-op and latest follow up AOFAS questionnaire, satisfaction
rate and complications were reviewed.
Results: Satisfaction rate was 100%. AOFAS score
improved significantly from 59 (36-80) preop to 97 (90-
100) at the latest follow-up. Complications included
one superficial infection and one sural nerve paresthesia.
There were no major complications.
Conclusion: Achilles insertional tendinopathy treated by
a posterior midline approach is a safe and reliable procedure.
The procedure was associated with high patient
satisfaction rate and excellent outcome.
82. OPENING-WEDGE VERSUS
PROXIMAL CHEVRON OSTEOTOMY
FOR HALLUX VALGUS WITH INCREASED
INTERMETATARSAL ANGLE
Peter Copithorne, Timothy R. Daniels*, Mark
Glazebrook
Dalhousie University; *University of Toronto;
Purpose: For patients with moderate to severe hallux
valgus with increased intermetatarsal angle, correction
with a proximal first metatarsal osteotomy is indicated.
The purpose of this study is to compare the opening-wedge
osteotomy of the proximal first metatarsal the proximal
chevron osteotomy in the treatment of moderate to severe
hallux valgus with increased intermetatarsal angle.
Method: This prospective, randomized, multi-centered
study is being conducted at three centers in Canada.
Approximately 75 adult patients with hallux valgus
are being randomized to either the proximal metatarsal
opening-wedge osteotomy with plate fixation or the
proximal chevron osteotomy. Patient functional scores
using the SF-36, American Orthopaedic Foot and Ankle
Society (AOFAS) forefoot metatarsophalangeal interphalangeal
score and Visual Analogue Scale (VAS) for
pain, activity & patient satisfaction, are assessed prior
to surgery and 3, 6, 12 and 24 months. Surgeon preference
is being evaluated based on a questionnaire and
actual surgical times. Radiologic measurements (intermetatarsal
angle correction, hallux valgus angle correction,
sagital talus-first metatarsal (Meary’s) angle,
metatarsal length and union) will also be assessed.
Results: Preliminary results demonstrate that patients
who undergo the opening-wedge osteotomy have less
pain at 3 months (ave.VAS pain reduction 2.9, SE±1.0)
than those with the chevron (ave. VAS pain reduction
2.4, SE±1.2). VAS for activity demonstrates greater
improvements with the chevron osteotomy at 3 months
(0.8, SE±0.8) versus the opening-wedge (0.1, SE±1.0).
AOFAS scores improve on average 18.3 (SE±8.6) with
the opening wedge compared to 20.8 (SE±7.4) with
the chevron at 3 months. Average hallux valgus angle
correction for opening-wedge and chevron osteotomies
are 11.0 degrees (SE±2.5) and 19.0 degrees (SE±3.1)
respectfully. Average intermetatarsal angle correction
for opening-wedge and chevron osteotomies are 6.5
(SE±1.3) and 4.3 (SE±1.7) respectfully. Both procedures
are effective at maintaining metatarsal length. The
opening-wedge osteotomy takes on average 60.9 minutes
(SE±3.9) to complete compared to 69.1 minutes
(SE±5.1) for the chevron ostetotomy. Surgeon response
to the new opening-wedge osteotomy is favorable.
Conclusion: Opening-wedge and proximal chevron
osteotomies have comparable pain, function and radiographic
outcomes. Opening wedge osteotomy is technically
less demanding and requires less surgical time.
83. RELATION TIBIO-PERONIERE DISTALE
SUR VUE FLUOROSCOPIQUE LATERALE
Benoit Benoit, Stéphanie Grenier, G. Yves
Laflamme, Dominique Rouleau, Stéphane Leduc
Université de Montreal
Purpose: Lors de la réduction chirurgicale des fractures
de la cheville avec instabilité syndesmotique, le
chirurgien se fie généralement sur les vues de mortaise
et antéro-postérieure. Toutefois, une subluxation ou
luxation antérieure du péroné par rapport au tibia distal
peu survenir et passer inaperçu (trois exemples cliniques
prouvés par CT Scan post-opératoire), spécialement lors
de la pose de vis syndesmotique(s). La présente étude a
pour but d’établir la relation radiologique précise sur
une vue latérale fluoroscopique entre les tibia et péroné
distaux qui permettra au chirurgien de confirmer en
peropératoire que l’articulation tibio-péronière distale
est bel et bien réduite.
Method: Les chevilles normales de trente volontaires
sans antécédent de traumatisme ou de maladie de
la cheville ont été imagées sous une vue latérale fluoroscopique
parfaite, avec un Mini C-Arm. Les images
ont été analysées et comparées entre elle afin d’établir
une relation radiologique fiable et reproductible entre le
tibia et le péroné distaux.
Results: Dans les trente cas, il y avait intersection du
milieu de la cicatrice physaire et du cortex antérieur du
péroné. Cette relation a été trouvée statistiquement significative.
Conclusion: La réduction chirurgicale parfaite de
l’articulation tibio-péronière distale peut être confirmée
avec une vue latérale fluoroscopique de la cheville. Le
cortex antérieur du péroné doit toucher le milieu de la
cicatrice physaire.
J BONE JOINT SURG [BR] 2011; 93-B:SUPP III

COA/CORS/CORA 261
84. OPERATIVE VERSUS NON-OPERATIVE
TREATMENT OF ACHILLES TENDON
RUPTURES: A RANDOMISED CONTROLLED
TRIAL
Kevin Willits, Nicholas G.H. Mohtadi*, Crystal
Kean, Dianne Bryant, Annunziato Amendola †
The University of Western Ontario; *University of
Calgary; † University of Iowa
Purpose: The purpose of this randomised controlled
trial was to compare outcomes of operative and nonoperative
management of Achilles tendon ruptures.
Method: Patients with acute complete Achilles tendon
ruptures were randomised to receive open suture repair
followed by graduated rehabilitation or graduated rehabilitation
alone. The primary outcome measure was rerupture
rate. Assessments at three and six months, and
one and two years included a modified Leppelhati score
(no strength data), range of motion, calf circumference,
and isokinetic strength at one and two years. We report
the two year findings.
Results: Two centres randomized 145 patients (118 males
and 27 females), mean age 40.9±8.8 years (22.5 – 67.2)
to operative (n=73) and non-operative (n=72) treatment.
Fourteen were lost to follow-up. Re-rupture occurred in
three patients in both groups. The mean modified Leppelhati
score (out of 85) was 78.2±7.7 in the operative
group and 79.7±7.0 in the non-operative group, which
was not significant (-1.5 95%CI -6.4 to 3.5, p=0.55).
Mean side-to-side difference in plantar flexion and calfcircumference
in the operative group was -2.0±3.2° and -
1.4±1.2cm, and in the non-operative group -0.9±3.0°and
-1.6±1.8cm respectively. Mean isokinetic plantar flexion
strength was 62.4±24.2 for the operative and 56.7±19.3
for the non-operative group, which was not significant
(5.7, 95%CI -3.1 to 14.5, p=0.20). There were a greater
number of serious adverse events in the operative group,
including pulmonary embolus in one patient, deep vein
thrombosis in one and deep infections requiring irrigation
and debridement in three.
Conclusion: This study suggests that non-operative
management of Achilles tendon ruptures utilizing an
accelerated rehabilitation programme may produce
comparable results with fewer adverse events.
85. TO ASSESS MODERATE-TERM
OUTCOMES OF SILASTIC JOINT
REPLACEMENTS OF THE FIRST
METATARSOPHALANGEAL JOINT
Vishal Upadhyay*, Ravi H. Mahajan, Ajay Sahu,
Usman Butt, Amir Khan, Rakesh B. Dalal
*Poole General Hospital, UK; Stepping Hill
Hospital
Purpose: To assess moderate-term outcomes of silastic
joint replacements of the first metatarsophalangeal
joint.
Method: The thirty-two patients (37 feet) that had silastic
implants inserted were reviewed at an average of 2 years
and 4 months (ranging 7 months to 5 years and 4 months).
The mean patient age was 63 years. These patients
answered a subjective questionnaire, had their feet examined
clinically and radiographically and a pre-operative
and post-operative AOFAS score was calculated for each.
Results: The follow-up assessment revealed that every
patient described that their pain had decreased after surgery
and 17 feet (46%) were completely pain free. There
was a significant improvement in patients’ subjective pain
scores after surgery (t value =

262 COA/CORS/CORA
89. TOTAL KNEE ARTHROPLASTY: DOES A
DIFFERENCE BETWEEN GENDERS EXIST?
Camilo Resterpo, Javad Parvizi, Peter F. Sharkey,
Aidin Eslam Pour, Craig T. Haytmanek, Nathan
Roberts, Richard H. Rothman
Rothman Institute
Purpose: Recently an orthopedic manufacturer has introduced
a gender specific knee design implying that there is
a substantial anatomical difference between the genders.
If such concept is true then TKA prosthesis implanted
in the female population over the last decades, by definition,
must have suboptimal outcome when compared
to the male patients. The purpose of this study was to
examine the functional outcome, the incidence of complications,
and the need for revision between the two
genders receiving the same knee design.
Method: The study selected a matched group of 150 men
and 250 women undergoing TKA at our instituion. The
patients were matched for age, BMI, pre-op diagnosis,
comorbidities, race, mode of fixation, and the type of
implant. Other demographic, surgical, and medical factors
between the two genders were similar. Both pre-op
and post-op functional scores were compared between
the two groups. Pre-op and post-op radiographic images
were assessed for implant fit.
Results: There was a significant improvement in functional
outcome as measured by Knee Society score,
WOMAC, and SF-36 for all patients. The improvement
in functional outcome was not different between
the two groups. The incidence of complications, reoperations,
and need for revision between the two genders
was also not significantly different.
Conclusion: Total knee arthroplasty continues to be
an effective surgical procedure. Both genders appear
to enjoy relief of pain and improvement of function
equally. Based on this retrospective study the use of nongender
specific knee prosthesis did not seem to result in
suboptimal outcome in female patients. There appears
to be little merit in introduction of gender specific knee
designs when previous non-gender specific prosthesis
appeared to function well in both genders.
90. THE RELATIONSHIP BETWEEN
BODY HABITUS AND LEPTIN IN A KNEE
OSTEOARTHRITIS POPULATION
Rajiv Gandhi, Mark Takahashi, Khalid Syed, J
Roderick Davey, Nizar N. Mahomed
University of Toronto
Purpose: Synovial fluid (SF) leptin has been shown to
have an association with cartilage degeneration. Our
objective was to examine the relationship between different
measures of body habitus and SF leptin levels in
an end stage knee osteoarthritis (OA) population.
Method: Sixty consecutive patients with knee OA were
surveyed prior to surgery for demographic data. Body
habitus was assessed with the body mass index (BMI),
waist circumference (WC) and waist-hip ratio (WHR).
SF and serum samples were analyzed for leptin and
adiponectin using specific ELISA. Non-parametric correlations
and linear regression modeling was used to
identify the relationship between the measures of body
habitus and SF leptin levels.
Results: Females had greater levels of leptin than males
in both the serum and SF. Significant correlations were
found between SF leptin levels and BMI and WC (R2
0.44 and 0.38 respectively, p< 0.05). Regression modeling
showed that female gender and WC were independent
predictors of a greater SF leptin level independent
of age, BMI, and presence of diabetes.(p

COA/CORS/CORA 263
compartmental knee arthroplasty (UKA) and total knee
arthroplasty (TKA) are all viable options. Gait analysis
is one tool available to clinically assess knee kinematics,
and may prove to be a good way of predicting functional
outcomes of these different surgical procedures.
The purpose of this study was to compare the knee
kinematics, function, and quality of life of patients that
underwent either a medial opening wedge HTO, UKA,
or TKA for primary medial compartment OA.
Method: A matched prospective cohort study of patients
between the ages of 45 and 65 who had undergone an
HTO, UKA, or TKA for primary medial compartment
knee OA was undertaken over a 3-year period. Primary
outcome measures were gait variables, namely knee
adduction moments, as measured through gait analysis.
Secondary measures included quality of life (WOMAC),
functional performance tests (six minute walk and timedup-and-go),
self-reported functional ability (LEFS), and
general health (SF-36). Gait and functional performance
tests were evaluated preoperatively and at 6, 12, and
24 months postoperatively. Self-reported quality of life,
function and general health were assessed preoperatively
and at 3, 6, 12, and 24 months post-operatively.
Results: Twenty HTOs, 19 medial UKAs, and 17 TKAs
were matched for Kellgren-Lawrence grade of medial
OA, age at surgery, and body mass index. Significant
differences were observed between the three groups in
step length and peak adduction moments at 24 months.
Significant differences were observed in preoperative
WOMAC pain and function scores, KOOS pain scores,
and LEFS, but no significantly different outcome measures
were observed postoperatively. Lateral Blackburne-Peel
and modified Insall-Salvati ratios were the
only significant radiographic differences observed
between groups at 24 months.
Conclusion: To our knowledge, no gait analysis study
exists comparing the medial opening wedge HTO to
UKA or TKA. The results of this study suggest that most
gait variables except step length and knee adduction
moments are similar between groups. Moreover, except
for patellar height, there were no major functional or
radiographic differences between these groups.
95. OUTPATIENT UNICOMPARTMENTAL
KNEE ARTHROPLASTY WITH FEMORAL
NERVE BLOCK
Geoffrey Dervin, Holly Evans, Susan Madden,
Peter R. Thurston
University of Ottawa
Purpose: Unicompartmental replacement for medial
compartment arthrosis of the knee has become popular
with eligible patients because of the shortened recovery
time, decreased tissue damage and easier future revision.
Contemporary multimodal anesthesia has added
the potential to safely perform this as outpatient surgery
reducing inpatient bed burden. We describe our initial
pilot experience with this approach.
Method: The first 25 patients who fulfilled the criteria
developed underwent same day surgery for unicompartmental
arthroplasty for medial (19) or lateral (3) compartment
replacement with either the Oxford knee (20)
or the Uniglide (2). All patients were treated with an
indwelling femoral nerve catheter supplied by Ropivacaine
through a constant release pump (Stryker) which
was discontinued at 48 hours. Home care support was
made available in first 72 hours by way of RN and
physiotherapy visits and mandatory use of walker or
crutches for the first 48 hours.
Results: Patients in this cohort were universally very satisfied
with the model of post-op care as described and
particularly pleased to avoid a hospital stay. Eighty percent
of those who were offered this model chose it. The
use of narcotic oral medication was consistently about
50% less than that observed to similar inpatients treated
without catheter, and eight patients had complete opioid
sparing experience. There were no complications related
to the catheter, in particular serious falls or longer term
neurologic sequelae. The clinical results were very good
and equal to those who were in patients.
Conclusion: Outpatient unicompartmental replacement
can be performed safely recognizing the decreased surgical
trauma and pain stimuli associated with UKR and a
relatively younger and healthier cohort screened for this
alternative. These patients are amongst the most satisfied
with their perioperative course and all would do the
same again if given the chance. Other models of analgesia
could be considered, though the catheter does seem
to have a large opioid sparing effect that likely contributed
to patient well being and satisfaction.
96. MINIMAL INCISION SURGERY AS A RISK
FACTOR FOR EARLY FAILURE OF TOTAL
KNEE ARTHROPLASTY
Robert L. Barrack*, R. Stephen J. Burnett † , C.
Lowry Barnes‡, Derk Miller*, John C. Clohisy*,
William J. Maloney §
*Washington University Department of
Orthopaedic Surgery; † Division of Orthopaedic
Surgery, Victoria BC Canada; ‡ University of
Arkansas Department of Orthopaedic Surgery;
§
Stanford University Department of Orthopaedic
Surgery
Purpose: A study was undertaken to determine the current
prevalence of revisions of total knee arthroplasty
(TKA) following minimal incision surgery (MIS) and to
compare revisions of MIS TKA procedures to revisions of
TKA performed following a standard surgical approach.
Method: A consecutive series of revision TKA performed
at three centers by five surgeons over a three
year time period was reviewed. Revisions performed
for infection and re-revisions were excluded. Review of
clinical and radiographic data determined incision type,
gender, age, time to revision, and primary diagnosis at
time of revision.
Results: Two hundred and thirty-seven first time revision
TKAs were performed of which 44 (18.6%) had
been a MIS primary TKA and 193 (81.4%) had been a
standard primary TKA. Patients with MIS were younger
(62.1 years versus 66.2 years, p=.02). There was a trend
towards a higher percentage of females in the MIS
group (75% versus 63%), although this difference was
not significant (p=0.12). Most striking was the difference
in time to revision which was significantly shorter
for the MIS group (14.8 months versus 80 months,
p

264 COA/CORS/CORA
egories were reviewed for each patient. Sacral fractures
were graded based on severity. The age, ISS, and six categories
of AIS were recorded for each patient. A statistical
analysis was performed to test the associations between
fracture characteristics and injury severity.
Results: All patients but three had one or more rami
fractures, and all but two had a sacral fracture. Of the
98 anterior sacral injuries, there were nine (9.2%) buckles,
39 (39.8%) simple fractures, and 50 (51.0%) comminuted
fractures. Of these 98 anterior sacral injuries,
47 (48.0%) were complete, passing through the sacrum
and exiting the posterior cortex. Increasing severity of
anterior sacrum fracture was associated with the presence
of a complete sacral fracture (p value 3mm gap). Post-operative
measurement of step and gap by CT scan were 1.2 mm
(SD) and 2.3 mm (SD) respectively. Using CT scans, eight
patients were found to have either an inadequate reduction,
intra-articular hardware or retained fragments.
Computed tomography demonstrated 2 times more step
and gap compared to plain radiographs.
Conclusion: Post-operative CT was found to be more
sensitive than plain radiographs to assess the quality of
acetabular fracture reduction. Plain radiographs detected
only 1 out of 8 cases where further operative intervention
may have been beneficial. Given the consequences
of missing an unacceptable reduction, intra-articular
hardware, or retained intra-articular fragments, it is
recommended that all fractures should be assessed postoperatively
with CT unless the patient is not a candidate
for further surgery for reasons independent of reduction
quality. The benefits of post-operative CT imaging in
acetabular fractures likely outweigh the cost and radiation
exposure associated with its use.
102. THE EFFECT OF FEMORAL NECK
CUT, CABLE TENSION AND MUSCLE
FORCES ON THE STABILITY OF GREATER
TROCHANTER REATTACHMENT
Kajsa Duke, G. Yves Laflamme*, Yvan Petit
École de Technologie Superieure; *Hôpital du
Sacré-Coeur de Montreal;
Purpose: Greater trochanter reattachment is frequently
accomplished using cable grip type systems. There is a
relatively high failure rate for these systems, the mechanisms
of which are unclear. One possible source of
instability could be femoral neck cut location. Another
concern is the effect of variability in cable tension. The
objective is to create a femur implant model which
allows for variation in cable tension, common muscle
forces and the placement of the femoral neck cut in
order to analyse trochanter fragment fixation.
Method: A finite element model (FEM) of a femur with
simulated greater trochanter osteotomy (30º) was combined
with the femoral component of a hip prosthesis
and a greater trochanter reattachment system with 4
cables (Cable-Ready®, Zimmer). A total of 18 simulations
were modeled in a full factorial design using three
independent variables; cable tightening (178N, 356
N and 534 N), muscle forces (rest, walking and stair
climbing) and femoral neck cut (10 mm and 15 mm
above the lesser trochanter). Displacement of the fragment,
in terms of both gap and shear components, as
well, stress in the bone were investigated.
Results: The location of the femoral neck cut reduced
contact surface area by 20% and had the largest influence
on displacement (0.24 mm). Pivoting of the fragment
was observed with a maximum gap (0.38 mm) and
maximum total displacement (0.41 mm) at the bottom of
the fragment. This was observed during stair climbing,
while the cables were tightened to 177.9 N and with the
femoral neck cut at 10 mm. Increased tightening of the
cables provided no significant reduction in fragment displacement.
However, higher cable tension significantly
increased the stress in the bone (8 MPa and 26 MPa for
cable tension of 178 N and 534 N respectively).
Conclusion: Placement of the femoral neck cut closer
to the lesser trochanter significantly increased fragment
displacement. Preservation of the contact surface area is
recommended. Excessive cable tightening did not reduce
fragment movement and only exacerbated bone stress.
Caution must be used to not over tighten the cables.
This model can be used to test and compare the performance
of new implant designs.
103. PROGNOSTIC BASELINE FACTORS FOR
PREDICTING RE-OPERATIONS IN PATIENTS
WITH TIBIAL SHAFT FRACTURES
Sprint Investigators*, Emil H. Schemitsch
*McMaster University; St. Michael’s Hospital/
University of Toronto
Purpose: Accurate prediction of re-operation following
tibial nailing may facilitate optimal patient care. We
recently completed the SPRINT trial, a large, multicentre
trial of reamed versus non-reamed intramedullary
nails in 1226 patients with tibial shaft fractures.
Using the SPRINT data, we conducted an investigation
of baseline and surgical patient characteristics to
determine if they are associated with increased risk of
re-operation within one year.
Method: Using multivariable logistic regression analysis,
we investigated 15 characteristics for association with
increased risk of re-operations. Because the primary
SPRINT analysis found that reamed nailing reduced
events in patients with closed but not open fractures, we
considered both open and closed as well as treatment
status in our model.
Results: We found an increased risk of re-operation in
patients with a high energy mechanism of injury (odds
ratio, OR=1.57, 95% CI 1.05 to 2.35), stainless steel
versus titanium nail (OR=1.52, 95% CI 1.10 to 2.13),
fracture gap (OR=2.40, 95% CI 1.47 to 3.94) and
post-operative weightbearing (OR=1.63, 95% 1.003 to
2.64). Open fractures increased the risk of re-operation
in patients who received a reamed nail (OR=3.26, 95%
CI 2.01 to 5.28) but not in patients who received a nonreamed
nail (OR=1.50, 95% CI 0.92 to 2.47). Patients
with open fractures who had either wound management
without any additional procedures, or delayed primary
closure, had a decreased risk of re-operation when
compared to patients who required subsequent reconstruction
(respectively, OR=0.18, 95% CI 0.09 to 0.35;
OR=0.29 95% CI 0.14 to 0.62).
Conclusion: To ensure optimal patient care surgeons
should consider the characteristics identified in our
analysis to reduce risk of re-operation.
104. REVISION OF PROVISIONAL
STABILIZATION IN PILON FRACTURES
REFERRED FROM OUTSIDE INSTITUTIONS
David Barei, Michael Gardner, Sean Nork,
Stephen Benirschke
Harborview Medical Center
Purpose: Pilon fractures demonstrate complex osseous
and soft tissue injury. Protocols involving immediate
tibial reduction and external fixation, with or without
J BONE JOINT SURG [BR] 2011; 93-B:SUPP III

COA/CORS/CORA 265
fibular fixation, then delayed definitive fixation result
in decreased complications. Our purpose was to evaluate
the treatment course of pilon fractures provisionally
stabilised at outside institutions and subsequently transferred,
focusing on the incidence and reasons for revision
procedures, and subsequent complication rates.
Method: An institutional trauma database was retrospectively
reviewed, demonstrating 668 pilon fractures
treated at our institution between 2000-2007. Of these,
39 patients with 42 fractures had a temporising surgical
procedure prior to referral. Demographics, injury characteristics,
reason for revision, and subsequent complications
were determined. Clinical follow-up averaged
60 weeks (range, 1 to 281).
Results: Mean age was 41 years (range, 18-78). Twentytwo
fractures (52%) were open; 38 (90%) demonstrated
a fractured fibula. Referral occurred an average of 5.8
days (range, 1-20) after initial stabilization. Pre-transfer
fixation was revised in 40 fractures (95%). Reasons
for revision included tibial malreduction (33 fractures,
83%), fibular malreduction (4 fractures, 10%), pins in
the proposed incision (5 fractures, 13%), or loose pins
(3 fractures, 8%). Of the 34 fractures with distal pins, 24
(71%) required revision for pin malposition, loosening,
drainage, talar placement, or extraosseous placement.
Late complications occurred in 14 fractures (33%),
including deep infection in 10 (24%), and non-union in
3 (7%). Twenty-three patients (55%) required additional
procedures following definitive fixation, including 9 soft
tissue coverage procedures and 3 amputations.
Conclusion: The majority of patients with pilon fractures
treated with provisional stabilisation followed by referral
to our institution required revision prior to definitive
fixation. This resulted in many avoidable additional procedures,
and a higher complication rate than recent contemporary
controls. The authors recommend that, when
possible, the initial and definitive management of these
injuries be performed at the accepting institution.
105. ORIF OF HIGH-ENERGY PILON
FRACTURES: VIOLATING THE 7-CM SKIN
BRIDGE RULE
Geoffrey Wilkin*, Steven Papp, Wade Gofton,
Allan Liew
*Queen’s University; University of Ottawa
Purpose: The purpose of this study was to review our
results in patients with pilon fractures treated with
ORIF in which surgical planning involved multiple skin
incisions, ensuring that the distance incisions overlapped
was less than the distance between them. We hypothesized
that soft-tissue complications would be minimal
despite incisions placed 85% of cases. In contrast, there was a statistically
significant association between a Weber C fracture
and older age and the presence of a SIMPLE PM fracture.
These factors being potentially “protective” from
joint comminution.
Conclusion: We have defined and quantified the PM
articular lesions which require anatomic reduction
and fixation, beyond what has been published. We
have defined clinical and radiographic criteria which,
because higly associated with COMPLEX lesions, could
1) prompt surgeons to order further imaging (CT) to
better delineate the lesion, and 2) draw his/her attention
to potentially malaligned fragments at the time surgery.
COA PAPER SESSION 12: ONCOLOGY
107. CORE NEEDLE BIOPSY IS HIGHLY
ACCURATE IN DIAGNOSING BONE AND
SOFT-TISSUE TUMOURS
Piya Kiatisevi*, Torsten Nielsen, Malcolm Hayes,
Peter L. Munk, Amy E. LaFrance, Paul Clarkson,
Bassam A. Masri
*Lerdsin General Hospital, Bangkok, Thailand;
UBC
Purpose: Core needle biopsy is increasingly accepted for
the diagnosis of bone and soft-tissue tumours. Advantages
over open biopsy include reduced morbidity, time
and cost; however diagnostic accuracy remains a concern.
Our objective was to assess and compare the diagnostic
accuracy of core needle, open, and fine needle biopsies.
Method: We reviewed 286 cases collected in a prospective
database between 2004 and 2007. Of these, 229
had core needle, 32 open, and 25 fine needle biopsies.
230 had soft-tissue lesions, 56 had bone lesions. The
results of these biopsies were compared to the final
resection diagnosis for accuracy and, where inaccurate,
any effects on management.
Results: Ninety-two percent of the core needle, 100% of
the open and 72% of the fine needle biopsies had adequate
tissue to make a diagnosis. Of the adequate specimens,
the accuracy of core/open/fine needle biopsy was
96%, 97% and 94% for determining malignant versus
benign; of the correctly identified malignant lesions
97%, 100% and 80% were accurate for histological
grade; and 79%, 84%, 59% for histological subtype.
Conclusion: Core needle biopsy yields diagnostic results
comparable to open biopsy for determining malignancy
and grade in bone and soft-tissue tumours. Fine needle
biopsy has a high inadequate sampling rate and should
not be used for diagnosing bone and soft-tissue tumours.
Given the reduced cost and morbidity associated with
core needle biopsies we believe they should be used
routinely for diagnosis where possible, and open biopsy
reserved for situations where an inadequate specimen is
obtained or core biopsy is not feasible.
108. GAMMA PROBE GUIDED SURGERY
FOR BENIGN BONE TUMOURS: SURGICAL
RESULTS WITH AVERAGE FOLLOW-UP OF 5
YEARS
Nanjundappa S. Harshavardhana, Brian J.C.
Freeman*, Alan C. Perkins † , Ujjwal K. Debnath
Queen’s Medical Centre; *Royal Adelaide
Hospital; † University of Nottingham;
Purpose: Intra-op localisation of small nidus in Osteiod
osteoma and Osteoblastomas is often difficult resulting in
failed excision with persistent pain. We report two year
follow-up results of the efficacy and reliability of using an
intra-operative gamma probe in conjunction with fluoroscopy
to aid resection in primary and revision surgeries.
Method: Eight patients (6M; 2F) with a diagnosis of
osteoid osteoma (7) and osteoblastoma (1) were seen
at our centre. The mean age at presentation was 20.9
years (9–31y). The tumour was localised to cervical (2),
thoracic(4) and lumbar (2) posterior elements. All had
back or neck pain of varying duration with a mean of 20
months (6-48mo). Three patients had failed treatments
including CT-guided radiofrequency ablation in one and
surgical excision under fluoroscopy in two. No case had
previously utilised an intra-op gamma probe for localisation.
All patients had work-up with plain X-rays, CT,
MRI and 99 m Technetium bone scan to identify and
localise the lesion. A pre-requisite for use of intra-op
gamma probe was a positive pre-op bone scan. On the
day of surgery, 600 MBq Tech HMDP (hydroxy-methylene-di-phosphate)
was administered IV 3 hours prior
to surgery. Fluoroscopy was used to confirm anatomical
level, permanent mark made on skin and area exposed
surgically. A 5 mm cadmium telluride (Cd Te) probe
(which converts gamma radiation into electrical signal)
and rate meter were used to scan the area containing
lesion and counts per second(cps) recorded. The tumour
nidus was then excised and cps from tumour bed and
excised specimen recorded.
Results: The mean follow-up was 5.85 years (2–12.3y).
The mean cps for osteoid osteoma pre-excision was
203.8 (60-515), which fell to 72.5 (10-220) post-excision.
The cps reduced from 373 to 40.5 post-operatively
for Osteoblastoma. Complete excision was recorded
every time and all patients reported characteristic disappearance
of pre-operative pain. All had discontinued
analgesic medication and returned to normal activity by
three months. All patients were followed-up regularly
when they filled NDI, ODI and SF-36.
Conclusion: Gamma probe guided surgical excision
facilitates accurate localisation of lesion, is less invasive
and most importantly confirmation of complete excision
of the tumour nidus consistently every time.
J BONE JOINT SURG [BR] 2011; 93-B:SUPP III

266 COA/CORS/CORA
109. LOCAL RECURRENCE OF SOFT TISSUE
SARCOMA FOLLOWING PRIMARY TUMOUR
MANAGEMENT BY MUSCULOSKELETAL
ONCOLOGY TEAMS
Sarantis Abatzoglou, Abdurahman Adoubali*,
Cindy Wong, Marc Isler, Robert É. Turcotte
McGill University Health; *Hopital Maisonneuve-
Rosemont
Purpose: Management of local recurrence (LR) remains
unclear. Optimal management of primary tumour by
specialised teams minimises this risk. However, previous
treatments may impact on the available options when
LR is encountered. We thus studied the outcome of this
population with recurrent STS.
Method: Retrospective review was carried based on our
prospective sarcoma databases. DFSP and ALT were
excluded. Among 618 primarily managed STS we found
35 cases of local recurrences (5.7%). Median f-up after
LR was 14 mos (0-98).
Results: Twenty were female. Mean age was 54 (Range
15 – 92). 22 involved lower limb, 11 upper limb and 2
the trunk. Mean delay from original surgery was 23 mos
(3-75) and the mean size of LR was 4.7 cm (0.4-28.0
cm). Primary tumours were superficial in 4 and deep in
31 while recurrences were found superficial in 8 and deep
in 26. Most frequent histology was MFH 8, Leiomyosarcoma
6, Liposarcoma, synovial sarcoma and MPNST had
4 each. 84% were high grade. Only 23 showed no metastatic
disease at time LR was diagnosed. All 5 pts without
initial RT got RT for their LR. 7 pts with therapeutic level
of RT to the primary tumour got full course of RT as well
for their LR. 11 did not undergo surgery. 6/18 who had
initial RT underwent amputation as opposed to 0/6 who
did not. Trend to amputate was for younger age, deep
and large tumour and previous RT. Ultimatly, 21(60%)
locally recurrent tumours showed metastatic disease; 6
prior diagnosis of LR, 6 concomitantly and 9 after with
an average delay of 17 months (1-24). 6 pts developed
additional local recurrences.
Conclusion: Although infrequent local recurrence correlates
with impaired outcome. Albeit challenging, limb salvage
and additional radiotherapy remain possible despite
optimal multi modality management of the initial tumour.
110. SURGICAL MANAGEMENT OF
RECURRENT GIANT CELL TUMOUR
OF LONG BONES. A LONG-TERM
RETROSPECTIVE STUDY
Frank M. Klenke, Doris E. Wenger, Carrie Y.
Inwards, Franklin H. Sim
Mayo Clinic
Purpose: Giant cell tumor (GCT) of bone is a rare,
usually benign, primary skeletal lesion. The disease’s
clinical course may be complicated by local recurrence
subsequent to surgical treatment or the development of
benign pulmonary metastases. Intra-lesional curettage is
the standard treatment of primary GCT of bone. However,
the value of intralesional procedures in recurrent
GCT has not been well established.
Method: Forty-six patients with recurrent GCT of long
bones treated between 1983 and 2005 were followed
retrospectively. Minimum follow-up was three years;
mean follow-up was 11.1 (±4.8) years.
Results: Wide resections were performed in 18 patients.
Intralesional, joint preserving procedures were performed
in 28 patients. Subsequent recurrence occurred
in nine patients (20%). Wide resection was performed
if joint salvage was not achievable due to expansion of
the tumor. Reconstructions following wide resection
included arthroplasty (n=4), osteoarticular allograft
(n=3), APC (n=1) and fibular autograft reconstruction
of the wrist (n=3). Amputations were performed in two
patients. Patients undergoing wide resections for local
recurrence had a significantly smaller risk of subsequent
recurrence as compared to patients treated with intralesional
surgery (6% versus 32%, hazard ratio: 0.28,
p

COA/CORS/CORA 267
Musculoskeletal Tumor Society (MSTS) 1987 scores
demonstrated one excellent, 4 good, and 5 fair results.
MSTS 1993 scores averaged 71.4 ± 17.2 percent and
Toronto Extremity Salvage Scores (TESS) averaged 61.7
± 21.8. There were no significant differences between
the functional scores for patients with femoral or sciatic
nerve resections (P=1.0).
Conclusion: Femoral nerve resection appears more
morbid than anticipated. The falls to which patients were
prone, even years after surgery, subject them to ongoing
long-term risks for fractures and other injuries. Nervespecific
functional outcomes should be considered when
counseling patients prior possible resection of the femoral
nerve for involvement by a soft tissue sarcoma.
114. IMMEDIATE TISSUE TRANSFER MAY
BE SUPERIOR TO PRIMARY WOUND
CLOSURE IN INTERNAL HEMIPELVECTOMY
PROCEDURES
Arvindera Ghag, Kyle Winter, Erin Brown, Amy E.
LaFrance, Paul Clarkson, Bassam A. Masri
UBC
Purpose: Resection of pelvic sarcoma with limb preservation
(internal hemipelvectomy) is a major undertaking.
Resection requires large areas of soft-tissue to be
removed. Because of wound complications, we manage
these defects with immediate tissue transfer (ITT) at
the time of resection when a large defect is anticipated.
This study compares the outcomes of ITT with primary
wound closure (PWC).
Method: Twenty patients undergoing 22 separate procedures
(1995-2007) were identified in our prospectively
maintained database. Demographics, tumour type,
operative data and complications, and functional scores
(MSTS-1993, TESS) were collected.
Results: Twelve defects were managed with ITT, nine
with pedicled myocutaneous vertical rectus abdominis
(VRAM) flaps (one received double VRAM flaps due to
the large defect), two with tensor fascia lata (TFL) rotation
flaps (one augmented by local V-Y advancement,
the other with gluteus maximus rotation flap) and one
received latissimus dorsi free tissue transfer. Four wound
complications necessitated operative intervention in this
group: two debrided VRAM flaps went on to heal and
the two TFL flaps required revision: one to VRAM
flap and the other to a latissimus dorsi free flap which
ultimately suffered chronic infection and hindquarter
amputation was performed. Ten defects were managed
with PWC, and 5 wound complications occurred, all
five suffered infection, one developed hematoma and
one dehisced. One wound resolved with debridement,
two healed after revision to pedicled gracilis and gluteus
maximus myocutaneous flaps. Two patients were converted
to hindquarter amputation due to chronic infection.
Functional scores were collected on 8 of 12 living
patients, at time of writing. The mean TESS scores were
83 and 73 in the ITT and PWC groups. Five patients in
the ITT and 3 in the PWC group were deceased.
Conclusion: Soft-tissue closure following pelvic sarcoma
resection remains a difficult challenge, and our experience
reflects that. There were fewer wound complications
(33% v 50%) and slightly better function with ITT
than PWC, but this was not statistically significant due
to the small size of our study. Although small, this study
suggests ITT should be considered whenever a large soft
tissue defect is anticipated.
115. SINGLE DOSE ANTIBIOTIC
PROPHYLAXIS FOR LOWER LIMB
ARTHROPLASTY
Inder Gill, Ajay Malviya, Scott Muller, Mike Reed
Northumbria Healthcare NHS Trust, UK
Purpose: To assess the infection rate following Lower
Limb Arthroplasty using single dose gentamicin antibiotic
prophylaxis compared to a traditional three doses
of cephalosporin.
Method: All patients undergoing Total Hip and Knee
replacements over six months (October 2007 to March
2008) at three participating hospitals were prospectively
followed to assess perioperative infection rates
using Surgical Site Surveillance(SSI) criteria. All patients
received single dose antibiotic prophylaxis using intravenous
Gentamicin 4.5mg/kg. This was compared with
previous data collected over a 6 month period (Jan to
Mar 2007 and Oct to Dec 2005) from the same hospitals
using 3 doses of Cefuroxime 750mg. Return to
theatre data was collected independently after introduction
of gentamicin to compare with previous data. The
change in creatinine level postoperatively was also measured
in a selected group of patients.
Results: Four hundred and eight patients underwent
Total Hip Replacements (THR) and 458 patients Total
Knee Replacements (TKR) during the study period. This
was compared with 414 and 421 patients who underwent
THRs and TKRs respectively during a previous
six month period. SSI was detected in 9 THRs(2.2%)
and 2 TKRs(0.44%) in the study group as compared
to 13 THRs(3.1%) and 12 TKRs(2.9%) in the control
group. The infection rates in THRs were not significantly
different between the 2 groups(p value–0.52)
but were significantly reduced in the study group for
TKRs(p value–0.005). The rate of Clostridium difficile
infection was reduced within the hospital with the use
of gentamicin, although other measures to reduce its
incidence were also introduced. The return to theatre
was 1.64%(23/1402) after introduction of Gentamicin
as compared with 1.05%(21/2005) [p value–0.092]
before this. This was a cause for concern although not
significant. The day1 postoperative creatinine level
increased by more than 30 units in 6% of patients on
Gentamicin.
Conclusion: This study shows that the use of single dose
prophylaxis using Gentamicin is effective for Lower
Limb Arthroplasty. However, be wary of increased rate
of return to theatre and the rise in creatinine level following
use of gentamicin. Further period of evaluation
and study is needed before it is recommended for routine
use in present or modified form.
COA PAPER SESSION 13:
SPORTS UPPER EXTREMITY
116. ARTHROSCOPIC TREATMENT
OF MULTIDIRECTIONAL SHOULDER
INSTABILITY IN ATHLETES: A
RETROSPECTIVE ANALYSIS OF 2 TO 5 YEAR
CLINICAL OUTCOMES
Randy Mascarenhas*, Champ L. Baker † , Alex J.
Kline ‡ , Anikar Chhabra § , Mathew Pombo ‡ , James
P. Bradley ‡
University of Manitoba; † Hughston Sports
Medicine; ‡ University of Pittsburgh; § Canyon
Orthopaedics
Purpose: There are few reports in the literature detailing
the arthroscopic treatment of multidirectional instability
of the shoulder. The purpose of this study was to evaluate
the results of arthroscopic methods in the treatment
of athletes with symptomatic multidirectional instability
of the shoulder.
Method: Forty patients (43 shoulders) with multidirectional
instability of the shoulder were treated via
arthrscopic means and were evaluated at a mean of
33.5 months post-operatively. The mean patient age
was 19.1 years (range 14 to 39). There were 24 male
patients and 16 female patients. Patients were evaluated
with the ASES and WOSI scoring systems. Stability,
strength, and range of motion were evaluated with
patient-reported scales.
Results: The mean ASES score postoperatively was 91.4
out of 100. The mean WOSI post-operative percentage
score was 91.1 out of 100. Ninety-one percent of
patients had full or satisfactory range of motion, 98%
had normal or slightly decreased strength, and 86% of
patients were able to return to their sport with little or
no limitation.
Conclusion: Arthroscopic methods can provide an effective
treatment for symptomatic multidirectional instability
in an athletic population.
117. GENERALIZED LIGAMENTOUS LAXITY
AS A PREDISPOSING FACTOR FOR PRIMARY
ANTERIOR SHOULDER DISLOCATION
Jaskarndip Chahal, Tom McCarthy, Jeff Leiter*,
Daniel B. Whelan †
University of Toronto; *Pan Am Clinic, University
of Manitoba; †St. Michael’s Hospital
Purpose: To determine whether generalized ligamentous
laxity is a predisposing factor for primary traumatic
anterior shoulder dislocation in young, active patients.
Method: Prospective case series with age and sex
matched controls. The Hospital Del Mar Criteria was
utilized to measure generalized ligamentous laxity. Fiftyseven
(n=57) consecutive individuals (age

268 COA/CORS/CORA
lar to previous reports, and resulted in improved HRQL
and shoulder ROM. The WOSI score was better able
to detect problems in HRQL related to instability than
either the ASES or Constant score.
119. DOES THE WESTERN ONTARIO
SHOULDER INSTABILITY (WOSI) INDEX
DISTINGUISH BETWEEN OPERATIVE
AND NON-OPERATIVE PATIENTS WITH
SHOULDER INSTABILITY: A CASE-CONTROL
STUDY
Nicholas G.H. Mohtadi, Jocelyn N. Fredine,
Heather N. Hannaford, Denise S. Chan, Treny M.
Sasyniuk*
University of Calgary; *LifeMark Health
Purpose: Shoulder instability is a common problem
affecting patients in their most active years resulting in
an impact on their quality of life. The WOSI is a validated,
disease-specific (shoulder instability) evaluative
quality of life measure. It has not been tested for its ability
to discriminate between those who require surgical
care and those who do not. The purpose of this study
is to determine if the WOSI can discriminate between
surgical and non-surgical patients and between patients
with different types of shoulder instability.
Method: Sixty patients with a confirmed diagnosis of
shoulder instability were included as cases. Twenty
had documented multidirectional instability requiring
surgery: Group 1 Surgical MDI – 20 patients had
documented recurrent traumatic anterior dislocations
requiring surgery: Group 2 Surgical Anterior – 20
patients were first time anterior dislocators who were
followed for a minimum one year who had no further
recurrences and did not require surgery: Group 3 Non-
Surgical First Time Anterior – The cases were compared
to 60 age and gender matched control patients with no
history of shoulder problems: Group 4 Control – WOSI
scores were analyzed using a one-way ANOVA.
Results: The WOSI scores were as follows: Group 1
Surgical MDI- mean 30.5 (95% CI 23.1-37.8); Group 2
Surgical Anterior- mean 39.8 (95% CI 33.1-46.5); Group
3 Non-Surgical First time Anterior- mean 76.2 (95%
CI 66.4-86.0) and Group 4 Control- mean 96.6 (95%
CI 95.8-97.4). Based on the 95% Confidence Intervals,
there were statistically significant differences between the
two surgical groups (Group 1 Surgical MDI and Group 2
Surgical Anterior) compared to the non-surgical patients
(Group 3 Non Surgical First Time Anterior) and the controls
(P=0.000). There is a trend to discriminate between
the two surgical groups (P=0.079).
Conclusion: The WOSI Index clearly discriminates
between surgical and non-surgical patients with shoulder
instability, and the control population with normal
shoulders. There is a trend to discriminate between MDI
and recurrent anterior traumatic dislocators.
120. THE UNSTABLE PAINFUL SHOULDER
(UPS): AS A CAUSE OF PAIN FROM
UNRECOGNIZED INSTABILITY IN THE
YOUNG ATHLETE
Ryan Bicknell*, Chris Chuinard, Scott Penington,
Frédéric Balg, Pascal Boileau
*Queen’s University; University of Nice
Purpose: Shoulder pain in the young athlete is often a
diagnostic challenge. It is our experience that this pain
can be related to a so-called “unstable painful shoulder”
(UPS), defined as instability presenting in a purely painful
form, without any history of instability but with anatomical
(soft tissue or bony) ‘roll-over’ lesions. The objectives
are to describe the epidemiology and diagnostic criteria
and to report the results of surgical treatment.
Method: A prospective review was performed of 20
patients (mean age 22 ± 8 years). Inclusion criteria: a
painful shoulder and “roll-over lesions” on imaging or
at surgery. Exclusion criteria: a dislocation/subluxation;
associated pathology; previous shoulder surgery.
Results: Most patients were male (60%), athletes (85%)
and involved the dominant arm (80%). All patients
denied a feeling of instability and only complained
of deep, anterior pain. Most had a history of trauma
(80%). All patients had rehabilitation without success
and 30% had subacromial injections. All had to stop
sports. Most (85%) had anterior or inferior hyperlaxity.
All had pain with an anterior apprehension test and
relieved by relocation test. ‘Roll-over’ lesions included:
labrum detachment (90%), capsular distension (75%),
HAGL lesion (10%), glenoid fracture (20%) or Hill-
Sachs (40%). Time from symptoms to surgery was 25
± 23 months. All patients had arthroscopic treatment.
Mean follow-up was 38 ± 14 months. Eighteen patients
(90%) were very satisfied/satisfied. None had pain at
rest, but one (5%) had pain with apprehension test.
There was no change in elevation, external or internal
rotation (p>0.05). There were no cases of instability.
Rowe and Duplay scores improved (p

COA/CORS/CORA 269
to 57.1 days (p < 0.01). ROM increased in both groups
non-significantly from pre-op to 3 months follow up in
the study group.
Conclusion: The results of this study show that the
fibrin-PRP clot enhances the healing of the labrum to
the glenoid. We have significantly fewer failures, less
pain, quicker time to discharge, and faster functional
recovery. By suturing a fibrin-PRP clot between the
labrum and glenoid, recovery and healing of the tear
occurs quicker and more reliably.
124. INJURY OF THE SUPRASCAPULAR
NERVE DURING ARTHROSCOPIC REPAIR OF
SUPERIOR LABRAL TEARS: AN ANATOMIC
STUDY
Holman Chan, Martin Bouliane, Lauren Beaupré
University of Alberta Hospital
Purpose: Due to its proximity to the glenohumeral joint,
the suprascapular nerve may be at risk of iatrogenic nerve
injury during arthroscopic labral repair. Our primary objective
is to evaluate the risk of suprascapular nerve injury
during standard drilling techniques utilized in arthroscopic
superior labral repairs. Secondarily, we evaluated the correlation
between this risk and scapular size.
Method: Forty-two cadaveric shoulders were dissected
to isolate their scapulae. A surgical drill and guide
was used to create suture anchor holes in 3 locations
in the superior rim of the glenoids as typically done in
arthroscopic superior labral repairs. The orientation
of these drill holes correspond to common shoulder
arthroscopic portals. The suprascapular nerve was then
dissected from the suprascapular notch to the spinoglenoid
notch. The presence of drill perforations through
the medial cortex of the glenoid vault was recorded
along with the corresponding hole depth and distance
to the suprascapular nerve.
Results: Medial glenoid vault perforations occurred in
8/21(38%) cadavers with a total of 18/126(14%) perforations.
The suprascapular nerve was in line of the drill
path in 5/18(28%) perforations. Female specimens and
smaller scapulae had a statistically higher risk of having
a perforation (p

270 COA/CORS/CORA
total laxity of 11.2 ± 1.5. There was no significant effect
of sequential olecranon excision on elbow kinematics
or stability with the elbow in the vertical or horizontal
positions. The elbows became grossly unstable after
resection of greater than 75% of the olecranon.
Conclusion: A progressive increase in the varus-valgus
laxity of the elbow was seen with sequential excision
of the olecranon. Laxity of the elbow was increased
with excision of 75% of the olecranon, likely due to
the loss of the bony congruity and attachment site of
the posterior band of the medial collateral ligament.
Gross instability resulted when 87.5% or greater was
removed, likely due to damage to the anterior band of
the medial collateral ligament as it inserts on the sublime
tubercle of the ulna. Rehabilitation of the elbow
with the arm in the dependant position should be considered
following excision of the olecranon; varus and
valgus orientations should be avoided. The contribution
of the olecranon to elbow stability may be even more
important in patients with associated ligament injuries
or fractures of the elbow.
129. PROXIMAL ULNAR ANATOMY:
IMPORTANCE OF THE DORSAL
ANGULATION (PUDA)
Dominique Rouleau*, George Athwal, Kenneth
J. Faber
*Hôpital Sacré-Coeur de Montréal; University of
Western Ontario
Purpose: Recognition of the proximal ulna dorsal angulation
(PUDA) is important for anatomic reduction
of proximal ulnar fractures or osteotomies, especially
when using newer straight precontoured proximal ulnar
plates. The purpose of this study was to characterize the
PUDA in 50 patients with bilateral elbow radiographs.
Method: Bilateral elbow radiographs (100 radiographs)
were magnified four times using commercial software.
The PUDA was measured from the intersection of lines
tangent to the subcutaneous border of the olecranon and
the proximal ulnar shaft. The olecranon tip-to-apex distance
of the PUDA was also measured. Three orthopaedic
surgeons independently examined the radiographs
and intra/inter-observer reliability was calculated using
Intra-Class-Correlation (ICC).
Results: A PUDA was present in 96% of radiographs.
The average PUDA was 5.7° (range, 0°to14°). The
Pearson Correlation coefficient for a side-to-side comparison
was 0.86(p

COA/CORS/CORA 271
programs and other cost containment measures in
orthopaedic surgery.
134. THE 80 HOUR WORK WEEK: IMPACT
ON RESIDENT SURGICAL EXPOSURE AND
NATIONAL IN-TRAINING EXAM SCORES
John M. Froelich, Joseph C. Milbrandt, D.
Gordon Allan*
Southern Illinois University School of Medicine;
*Orthopaedic Center of Illinois
Purpose: The current study examines the impact of the
80-hour work week on the number of surgical cases performed
by PGY2 – PGY5 Orthopedic residents. We also
evaluated Orthopaedic In-training Exam (OITE) scores
during the same time period.
Method: Data were collected from the ACGME
national database for 3 academic years prior to and 5
years after July 1, 2003. CPT surgical procedure codes
logged by all residents three years prior to and five years
following implementation of the 80-hour work week
were compared. The average raw OITE scores for each
class obtained during the same time period were also
evaluated. Data were reported as the mean ± standard
deviation (SD) and group means were compared using
independent t-tests.
Results: No statistical difference was noted in the
number of surgical procedure codes logged prior to or
after institution of the 80-hour week during any single
year of training. However, an increase in the number
of CPT codes logged in the PGY-3 year after 2003 did
approach significance (457.7 vs. 551.9, p=0.057). There
was a statistically significant increase in total number of
cases performed (464.4 vs. 515.5 p=0.048). No statistically
significant difference was noted in the raw OITE
scores before or after work hour restrictions for our
residents or nationally.
Conclusion: We found no statistical difference for each
residency class in the average number of cases performed
or OITE scores. We also found no statistical difference
in the national OITE scores. Our data suggest that the
impact of the 80 hour work has not had a detrimental
effect in these two resident training measurements.
135. THE CANADIAN ORTHOPAEDIC
MEDICOLEGAL CLIMATE: GLOBAL
WARMING OR ISOLATED COOLING?
Carol R. Hutchison, Claude Martin*
University of Calgary; *Canadian Medical
Protective Association
Purpose: Litigation continues to be a concern in orthopaedic
surgery despite suggestions on how to contain
liability. The purpose of this study was to characterize
orthopaedic litigation in Canada from 1997-2006.
Method: This study reviewed all closed claims reported
to the Canadian Medical Protective Association (CMPA)
for 1997-2006 in which orthopaedic surgeons were
named. There were 11,983 closed legal actions involving
CMPA members (> 73,000 physicians), and 1,353
involved orthopaedic surgeons. A careful review of
closed legal actions is a recognized tool for risk identification,
assessment and management. The CMPA identifies
any critical incidents within the closed legal files. A
critical incident is defined as any omission or commission
in the evaluation or management which led to the
problem(s) that triggered the legal action. Each closed
legal action can have more than one critical incident.
Results: Performance, diagnostic and communication
issues were the most frequently identified problems.
These three areas account for 55% of the critical incidents
identified. Performance related issues accounted
for 395 critical incidents (29%). Diagnostic issues,
including deficient histories and general evaluations,
were identified in 281 cases (21%). Communicationrelated
critical incidents included those concerning
informed consent. The lack of informed consent was
a common allegation, proven in 71 cases. In 439 cases
(32%) there was no identifiable critical incident for the
orthopaedic surgeon involved. Seventy-eight per cent of
patients experienced minor or no disability and 22%
experienced major disability or death. Events related
to tibia trauma and knee arthroscopy formed the two
major categories of claims. Patient care areas of high
risk include the operating room and outpatient clinic.
Overall, 31% of legal actions against orthopaedic surgeons
had outcomes in favour of the plaintiffs, compared
with 33% of all CMPA members’ claims.
Conclusion: Although the likelihood for an orthopaedic
surgeon to be sued in Canada has decreased over the last
10 years, the percentage of legal cases resolved in favour
of plaintiffs has remained stable. Performance-related
deficiencies, delays in diagnosis, and failures in communication
represent areas of high medico-legal risk. Suggestions
for risk management are provided to further
decrease adverse events and the medico-legal risks for
Canadian orthopaedic surgeons.
COA PAPER SESSION 15: SPINE 1
136. PREOPERATIVE PREDICTORS FOR
POSTOPERATIVE CLINICAL OUTCOME IN
LUMBAR DISCECTOMY
Yangmin Zeng, Travis Marion, Pamela Leece,
Eugene Wai*
University of Ottawa, Faculty of Medicine;
*University of Ottawa, Division of Orthopaedic
Surgery
Purpose: Persistent radiculopathy secondary to lumbar
disc herniation is a common problem that greatly compromises
quality of life. In North America, lumbar
discectomies are among the most common elective surgical
procedures performed. There is still much debate
about when conservative or surgical treatments should
be offered to patients. Although the related literature is
comprehensive, there are limited systematic reviews on
the prognostic factors predicting the outcome of lumbar
discectomy. The purpose of this review is to define the
preoperative factors predicting clinical outcome after
lumbar discectomy.
Method: We conducted a computerized literature search
using Ovid Medline and the Cochrane Central Register
of Controlled Trials. We included randomized controlled
trials or prospective studies dealing with lumbar
disc surgery. The preoperative predictors had to be
clearly identified and correlated with outcome measures
in terms of pain, disability, work capacity, analgesia
consumption, or a combination of these measures. We
assessed the articles as high or low quality studies using
the Newcastle-Ottawa Quality Assessment Scale, and
summarized the results of High Quality Studies.
Results: A total of 39 articles were included. The two
most prominent negative predictors were Workers’
Compensation status and depression according to 6
studies. Poor predictors reported in 4 articles were
female gender, increasing age, and prolonged duration
of leg or back pain. Lower education level, smoking,
and higher levels of psychological complaints were
negative predictors in 3 articles. A positive Lasègue sign
was a positive predictor in 7 articles. Absence of back
pain, positive patient expectations, and higher income
were good prognostic factors in 3 studies. Patients with
contained herniations did worse than those who had
uncontained disc extrusions and sequestrations according
to 4 studies. The level of herniation was not a predictive
factor in 7 studies.
Conclusion: Workers’ Compensation, depression, greater
back versus leg pain, increasing age, female gender, contained
herniations, and prolonged symptoms predict
unfavourable postoperative outcomes after lumbar discectomy.
Positive Lasègue sign, higher income, uncontained
herniations, and positive patient expectations
predict favourable postoperative outcomes. The level of
herniation is not an established prognostic factor. The
results of this review provide a preliminary framework
for patient selection for lumbar disc surgery.
137. PRE-OPERATIVE CT IMAGING OF THE
CROSS-SECTIONAL AREA OF PERISPINAL
MUSCULATURE AS A PREDICTOR OF
POSTERIOR LUMBAR FUSION SURGERY
OUTCOMES
Travis E. Marion, Yangmin Zeng, Eugene Wai*
University of Ottawa, Faculty of Medicine;
*University of Ottawa, Division of Orthopaedic
Surgery
Purpose: Perispinal core muscle strength has been theorized
to be an important component in the pathogenesis
of back pain. Recent research has demonstrated a
strong association between preoperative perispinal musculature,
adjusted for fatty infiltration and prospective
outcomes and improvements in back pain in patients
undergoing lumbar laminectomy without fusion. The
purpose of this study is to determine if a similar relationship
exists in patients undergoing elective posterior
lumbar fusion and decompression (PLFD) surgery.
Method: A retrospective observational study of prospectively
collected outcomes data was conducted in
which pre-operative function and patient variables of
those undergoing PLFD were derived from a functional
status questionnaire and medical records. ImageJ Digital
Imaging Software was utilized to measure the total
(CSA) and percentage of fatty infiltration of the psoas,
multifidus, and erector spinae muscles in pre-operative
L4 axial CT images. Pre-operative and post-operative
lateral images were evaluated for degree of post-operative
adjacent level degeneration. Follow-up consisted of
a functional status questionnaire. Outcomes measured
were improvements in back pain, leg pain, and Oswestry
disability scores.
Results: Twenty-three patients were analyzed with a
mean follow-up of 2 years (range 1 – 5 years). Outcomes
improved following surgery. There were strong to moderate
correlations between percentage of fat in the preoperative
posterior spinal muscles and improvements
in leg pain (r = 0.63, p = < 0.001) and improvements
in back pain (r = 0.41, p = 0.05). There was a moderate
trend towards greater adjacent level degeneration (r
= 0.37, p = 0.1) in patients with higher percentage of
fat in the pre-operative posterior spinal muscles. There
was a strong relationship between greater adjacent level
degeneration and pre-operative disability as measured
by the Oswestry (r = 0.62, p = 0.03).
Conclusion: The results demonstrate that a potential
relationship exists between pre-operative fatty infiltration
of posterior perispinal muscles and post-operative
outcomes, and adjacent level degeneration following
lumbar fusion surgery. This suggests that perispinal
muscle atrophy and conditioning may play a role in
these outcomes. Results may be used for prognostication,
surgical candidate selection, and interventional
strategies.
138. CAUDAL EPIDURAL STEROID
INJECTIONS FOR LUMBO-SACRAL
RADICULAR PAIN… DOES IT REALLY MAKE
A DIFFERENCE?
Girish N. Swamy, Lynn DeLoughery,
Rajendranath Bommireddy, Zdenek Klezl, Denis
Calthorpe
Derbyshire Royal Infirmary
Purpose: The management of radicular pain due to
lumbar or sacral nerve root compromise remains controversial.
Caudal epidural steroid injections are widely
employed although there is little hard evidence to confirm
their efficacy. This empirical treatment still remains
a matter of personal choice and experience. To investigate
the clinical effectiveness of caudal epidural steroid
injections (CESIs) in the treatment of sciatica and
to identify potential predictors (clinical subgroups) of
response to CESIs.
Method: Prospective study. All patients with corresponding
radicular pain received a course of three caudal epidural
steroid injections, two weeks apart. All patients
reviewed at three months interval in a dedicated epidural
follow up clinic and one-year postal and telephonic
follow-up. Exhaustive epidural database maintained.
VAS scores documented both axial and limb pain for
J BONE JOINT SURG [BR] 2011; 93-B:SUPP III

272 COA/CORS/CORA
actual and comparative analysis. ODI and HADS were
recorded prior to treatment, at three months follow-up
and one year. Main outcome measures: The primary
outcome measure was the Oswestry Disability Questionnaire
(ODQ). The Visual analogue score (VAS) and
the Hospital Anxiety and Depression Scores (HADS)
were also employed in all cases.
Results: In the largest single series to date, we report
on 928 consecutive patients, with three months followup
and 354 patients with 12 months follow-up. Fiftyeight
percent were females, 24% smoked and 4.1% had
ongoing litigation due to their pain. The mean age was
56 years with BMI ranging from 17 to 50 (mean=28).
Ten (0.6%) patients required subsequent surgical intervention
due to disc herniation.The mean VAS, ODI and
HADS improved significantly at three months and oneyear
results were encouraging.
Conclusion: Significant improvement in both axial and
limb pain in the short and intermediate terms achieved
facilitating onward referral for physical therapy. Subgroups
predicting poor outcome are identified. Positive
primary care feedback encourages further recruitment.
139. THE TREATMENT OF LUMBAR
INTERMITENT NEUROGENIC
CLAUDICATION USING THE XSTOP IPD
DEVICE: A PROSPECTIVE CINICAL AND
FUNCTIONAL OUTCOME STUDY
Bernard E. Rerri, Temilolu O. Opadele*
Brantford General Hospital; *McMaster
University, Hamilton
Purpose: Lumbar spinal stenosis is the most common
indication for spine surgery in the elderly. XStop IPD is
an attractive alternative to traditional laminectomy or
laminectomy with fusion as it avoids a longer procedure
and anaesthesia with significantly less blood loss. The
purpose of this study is to prospectively evaluate clinical
outcomes, complications and functional evaluation of
symptom severity, physical function and patient satisfaction
following XStop IPD procedure
Method: Preoperative and postoperative clinical data as
well as SF 36, visual analog scale and Roland Morris
questionnaire data collected on 16 consecutive patients
over 60 years undergoing XStop IPD at L3-4 and L4-
5 levels or both levels. All patients had symptomatic
lumbar spine stenosis with intermittent neurogenic claudication.
Evaluations were made pre-operatively and
post-operatively at 3, 6, 12 and 24 months. All patients
had clinical radiographic data as well as data on visual
analog scale SF 36 and the Roland Morris back questionnaire.
Results: Patients ages ranged from 58 to 86 years with
an average age of 74.25 years. In 75 percent of patients
there were two or more significant co-morbidities with
18.75 percent requiring 2 level surgery. Four of the 16
patients had lumbar degenerative scoliosis with cobb
angle less than 25 degrees. 50.25% the patients had
grade I spondylolisthesis. No patient had previous spine
surgery. In 31.25 percent of patients there was a history
of diabetes. BMI ranged from 20 to 40. Seventy
five percent of patients were discharged home within 24
hours. Ninety percent of patients reported relief of their
leg pain at their first follow up visit within two weeks
of the surgery.There were no significant complications.
One-year follow up in six patients demonstrated
improvements in VAS, Roland Morris criteria and SF 36
while the remaining patients have up to nine months of
follow-up clinical data.
Conclusion: We present our early results of this prospective
study. There were significant improvements in
functional outcomes. We therefore recommend the use
of XStop IPD for elderly patients with multiple co-morbidities
suffering from symptomatic lumbar spine stenosis
with neurogenic claudication.
140. UNDERSTANDING PATIENT AND
PHYSICIAN PREFERENCES FOR SURGERY
ON THE DEGENERATIVE LUMBAR SPINE
S. Samuel Bederman*, Nizar N. Mahomed, Hans
J. Kreder, Warren J. McIsaac † , Peter C. Coyte ‡ ,
James G. Wright
*Department of Orthopaedic Surgery, University
of California, San Francisco; Division of
Orthopaedic Surgery, University of Toronto;
†
Department of Family and Community Medicine,
University of Toronto; ‡ Department of Health
Policy Management and Evaluation, University of
Toronto
Purpose: Surgery for degenerative lumbar spinal conditions
offers tremendous benefit for patients with moderate/severe
symptoms failing non-operative treatment.
There is little appreciation among referring family physicians
(FPs) on factors that identify the ideal surgical
candidate. Differences in preferences between patients
and physicians leads to wide variation in referrals and
impedes the shared decision-making process. Our purpose
was to identify the dominant clinical factors influencing
patient, FP, and surgeon preferences for lumbar
spinal surgery.
Method: We used conjoint analysis, a rigorous method
for eliciting preferences, in a mailed survey to all orthopaedic
and neurosurgeons, a random sample of FPs,
and patients in Ontario to determine the importance
that respondents place on decisions for lumbar spinal
surgery. We identified six clinical factors (walking tolerance,
duration of pain, pain severity, neurological symptoms,
typical onset, and dominant location of pain) and
presented 16 hypothetical vignettes to participants who
rated, on a six-point-scale, their preference for surgery.
Data were analyzed using random-effects ordered probit
regression models and relative importance of each clinical
factor was reported.
Results: We obtained responses from 131 surgeons, 202
FPs, and 164 patients. We demonstrated that despite
wide variations in overall responses, all six clinical factors
were highly associated with surgical preference
(p

COA/CORS/CORA 273
clinical results in carefully selected patients. The radiographic
assessment confirmed preservation of movement
at the replaced disc during flexion and extension
of the lumbar spine.
143. PROSPECTIVE RANDOMISED
CONTROLLED STUDY COMPARING A DBM-
CASO4 COMPOSITE GRAFT AND BONE
MARROW ASPIRATE WITH AUTOLOGOUS
ILIAC CREST BONE GRAFT IN ONE-
LEVEL AND TWO-LEVEL LUMBAR AND
LUMBOSACRAL SPINAL FUSIONS
David I. Alexander, William M. Oxner, Alex M.
Soroceanu, Adrienne Kelly, Donna Shakespeare
Dalhousie University
Purpose: The current gold standard for spinal arthrodesis,
autologous bone graft harvested from the iliac crest,
has several disadvantages including donor site morbidity,
blood loss, delayed wound healing, and increased
operative time. Our study explores a Demineralized
Bone Matrix-Calcium Sulfate(DBM-CaSO4) composite
graft with autologous bone marrow aspirate (BMA),
and compares it to autologous iliac crest bone graft in
lumbar and lumbosacral spinal fusions.
Method: A total of 80 patients were recruited for the
study and randomised, via a computer-generated randomisation
schedule, to autologous iliac crest bone graft
(control) or DBM-CaSO4 composite graft with BMA
(study) groups. Patients were evaluated at three-months,
six-months, 12-months and 24-months post-operatively
with questionnaires to evaluate clinical outcome
(Oswestry disability questionnaire (ODI), visual analogue
pain scales (VAS), and validated SF-36) and with
posteroanterior and lateral x-rays of the spine to evaluate
radiological outcome.
Results: At 24-months post-operatively, there were no
statistical differences seen between the two groups based
on the clinical outcomes measured. Average ODI values
were 27.19 for the control group versus 22.68 for the
study group (p > 0.05). The average back VAS pain for
the control group was 3.50 versus 3.51 for the study
group (p > 0.05). The SF-36 score was 89.22 for the control
group versus 91.56 for the study group (p > 0.05).
The average operative time was 115.7 minutes for the
control group versus 104.2 minutes for the study group
(p: 0.014). Average calculated blood loss was 571.9 cc for
the control group versus 438.2 cc for the study group (p:
0.025). The Lenke score was 1.92 for the control group
versus 2.66 for the study group (p: 0.004).
Conclusion: At two year follow-up, radiographic fusion
was slightly higher in the ICBG. However, clinical outcomes
were equivalent in both groups. Moreover, the
DBM-CaSO4 and BMA composite graft offered the
advantages of decreased blood loss and shorter operative
time. Therefore, the DBM-CaSO4 and BMA composite
graft represents a viable alternative to autologous
iliac crest bone graft in carefully selected patients undergoing
spinal arthrodesis.
144. VERTEBRAL FRACTURE RISK AND
TOKUHASHI SCORE VALIDATION IN
PATIENTS WITH METASTATIC BREAST
CANCER
John Townley, Cari Whyne*, Michael R.
Hardisty*, Liying Zhang, Mark Clemons † , Albert
J.M. Yee ‡
University of Toronto; *Sunnybrook Health
Sciences Centre, Toronto; † University Health
Network, Toronto; ‡ University of Toronto Spine
Program, Toronto
Purpose: To identify local and systemic risk factors
for the development of pathologic fractures and determine
the value of the Tokuhashi Score in patients with
known asymptomatic lytic spinal metastases secondary
to breast cancer.
Method: A prospective cohort study was carried out
on 51 patients with lytic spinal metastases secondary
to breast cancer identified as having either purely lytic
or mixed disease. The Tokuhashi Score, developed to
estimate life expectancy for patients with symptomatic
spinal metastases being considered for surgery, was calculated
for each of the 51 patients. The score consists of
six parameters each of which is rated from 0-2. Initial
and follow up CT images and pain and function data
were obtained every four months for one year. A final
review of patient charts was performed two years later
to determine if each patient was still alive.
Results: Tumour burden was predominantly blastic and
mixed rather than lytic. There was no progression of
lytic tumour burden over the 12-month period, however
there was progression of blastic tumour load. Eleven
compression fractures occurred in seven patients; no
burst fractures occurred during the study. No correlation
between tumour burden (lytic, blastic or both) and
risk of fracture was found. A weak correlation between
bone mineral density and length of time elapsed from
diagnosis of metastatic disease and fracture risk was
found. Pain and functional data results were not related
to tumour load. Tokuhashi score did correlate with survival,
however actual survival in our population was
far longer than that found in previous studies. Negative
progesterone status was found to be negatively associated
with life expectancy.
Conclusion: Metastatic vertebral disease in breast cancer
patients has a predominantly blastic and mixed appearance
with current pharmacologic therapies. Pathologic
fracture risk appears to be more related to bone mineral
density than tumour burden in this population.
Tokuhashi score does correlate with life expectancy in
patients with relatively asymptomatic spinal metastases.
Having a progesterone receptor negative tumour has a
significantly negative impact on life expectancy.
145. VALIDATION OF THE ENNEKING
ONCOLOGIC CLASSIFICATION IN THE
MANAGEMENT OF PRIMARY TUMOURS OF
THE SPINE: A COHORT STUDY
Davor D. Saravanja, Charles G. Fisher, Marcel
Dvorak, Michael Boyd*, Paul Clarkson †
CNOSP; *Hongbin Zhang, Research Institute;
†
Orthopaedic Surgery
Purpose: Oncologic management of primary bone
tumors of the spine is inconsistent, controversial and
open to individual interpretation. Tumor margin violation
intraoperatively increases local recurrence and mortality.
The purpose of this study is to determine whether
applying Enneking’s principles to the surgical management
of primary bone tumors of the spine significantly
decreases local recurrence and/or mortality.
Method: A prospective and retrospective multicenter
Cohort Study: Inclusion of patients undergoing en
bloc or intralesional resection of primary tumors of the
spine at four separate quaternary care centers, between
January 1994 and January 2008. Patients were staged,
using the Enneking system, prior to surgery and baseline
demographic and surgical variables were recorded. Outcomes
measured were disease local recurrence, or death.
The results were statistically analyzed for significance.
Results: One hundred-fifty patients with primary tumors
of the spine were recruited. Average age was 47.0 (range
8 to 83). Sixty-two patients were identified to have local
recurrence. A statistically significant decrease in local
recurrence (p=0.0001) was observed in favor of en bloc
resection. In patients with local recurrence there was a
significant increased risk of mortality, (p

274 COA/CORS/CORA
Median urine Co(mg/day): 0.44(poly), 4.55(28mm),
5.42(36mm)). (Median serum Cr(mg/L): 0.17(poly),
1.29(28mm), 0.91(36mm). Median erythrocyte Cr(mg/
L): 1.10(poly), 1.10(28mm), 1.20(36mm). Median urine
Cr(mg/day): 0.27(poly), 1.92(28mm), 2.02(36mm)).
Conclusion: Both cobalt and chromium ion measurements
were significantly elevated in the blood and urine
of the patients randomized to receive the metal-on-metal
bearings at all time intervals. There were no differences
seen between the 28mm and 36mm metal-on-metal
bearings, keeping all other variables identical. The
larger diameter bearing therefore provides the potential
clinical advantages of improved range of motion and
stability, while providing a similar metal ion profile.
While reduced wear is seen with larger diameter metalon-metal
bearings in-vitro, we could not demonstrate a
reduction in blood or urine metal ion levels in-vivo.
148. RANDOMISED CONTROLLED
TRIAL COMPARING METAL ON METAL
VERSUS METAL ON POLYETHYLENE
ARTICULATION IN THA
Rajeshkumar Kakwani, Chris Wainwright,
Gautam Tawari, Shankar Kashyap, A. Roysam,
A. Nanu
Gateshead Heathcare
Purpose: A single blind prospective randomised controlled
trial comparing the Metal-on-polyethylene articulation
with the metal-on-metal articulation in THA.
Method: The clinical and radiological findings of the
consecutive patients who were enrolled in the RCT at
the participating centres were recorded prospectively.
The clinical evaluation was performed with the Harris
scoring system as well as the Oxford Hip Scoring Sheet.
The computer randomised option was revealed to the
operative surgeon only after the patient was anaesthetised,
during the recruitment period (June 1998 to July
2004). Of the total of 378 patients, 2 died prior to the
final review and 63 were lost to follow-up. The final
study group contained 315 patients, with 159 patients
in the metal-on-polyethylene group and 156 patients in
the metal-on-metal group.
Results: The indication for the hip arthroplasty for
majority (309 patients) was primary osteoarthritis. The
average age at the time of the surgery was 68.2 years
and the average duration of follow-up was 85 months
(42-115). There was an improvement of the Oxford hip
scores from an average of 37 per-operatively to 16 postoperatively.
The Harris hip scores also improved from
an average of 47.0 pre-operatively to 87.3 post-operatively.
The patient groups were statistically similar with
respect to age, sex and duration of follow-up, and the
final outcome scores revealed no statistical difference
between the two groups.
Conclusion: The clinical results obtained with the use of
the articulation are comparable to those obtained by the
metal-on-polyethylene articulation encouraging the use
of this alternative bearing surface.
149. RECONSTRUCTION OF ACETABULAR
HIP BIOMECHANICS WITH SURFACE
REPLACEMENT ARTHROPLASTY
Kristoff Corten, Ward Bartels*, Guy Molenaers,
Jos Vander Sloten*, Paul Broos, Johan Bellemans,
Jean-Pierre Simon
University Hospital Leuven; *Catholic University
Leuven
Purpose: Precise biomechanical reconstruction of the
hip joint by a hip arthroplasty is essential for the success
of this procedure. With the increasing use of surface
replacement arthroplasty (SRA), there is a need for
better understanding of the key factors that influence
the anatomical and the biomechanical parameters of the
resurfaced hip joint. The goal of this study was to examine
the influence of SRA on the vertical and horizontal
offset of the hip.
Method: Twenty-one hips from 12 embalmed cadavers
were resurfaced with a Birmingham Hip resurfacing.
The thickness of the acetabular bone was measured pre-
and post-reaming in 6 acetabular zones. Radiographs
were taken before and after the procedure with a scaling
marker. For statistical analysis, the paired Student’s T-
test with a confidence interval of 95% and a significant
p-value of p

COA/CORS/CORA 275
revised for recurrent infection. Currently no patients are
suspected of having a recurrence of infection.
Conclusion: Retention of a well-fixed femoral cement
mantle during two-stage revision for infection and subsequent
in-cement reconstruction is safe with a cure rate
of 93%. Advantages include a shorter operating time,
reduced loss of bone stock, improved component fixation
and a technically easier second stage procedure.
153. ACETABULAR REVISIONS USING
ANTI PROTRUSION (ILIOISCHIAL)
CAGE AND TRABECULAR METAL CUP
CONSTRUCTS FOR SEVERE ACETABULAR
BONE LOSS ASSOCIATED WITH PELVIC
DISCONTINUITY? PRELIMINARY RESULTS
WITH 1 TO 6 YEARS FOLLOW-UP
David Backstein, Yona Kosashvili, Oleg Safir,
Dror Lakstein, Matthew MacDonald, Allan E.
Gross
Arthroplasty Division, University of Toronto
Purpose: Pelvic discontinuity associated with bone loss
is a complex challenge in acetabular revision surgery.
Reconstruction with anti protrusion cages, Trabecular
Metal (Zimmer, Warsaw, Indiana) cups and morselized
bone (Cup-Cage) constructs is a relatively new technique
used by the authors for the past 6 years. The purpose
of the study was to examine the clinical outcome
of these patients.
Method: Thirty-two consecutive acetabular revision
reconstructions in 30 patients with pelvic discontinuity
and bone loss treated by cup cage technique between
January 2003 and September 2007 were reviewed.
Average clinical and radiological follow up was 38.5 ±
19 months (range 12 – 68, median 34.5). Failure was
defined as component migration > 5mm.
Results: In 29 (90.6%) patients there was no clinical or
radiographic evidence indicative of loosening at latest
follow up. Harris Hip Scores improved significantly
(p0.05). We found
a deep infection rate of 3.1% in the ALBC group and
2.2% in the PBC group (p=0.27). Adjusted analysis
showed that ALBC was not predictive of a lower infection
rate at 1 year (p=0.84).
Conclusion: ALBC did not reduce the incidence of deep
infection following primary TKA at 1 year follow up.
Further studies are needed to define any high risk groups
for which ALBC might be beneficial.
158. METABOLIC SYNDROME AND THE
INCIDENCE OF DEEP VEIN THROMBOSIS
FOLLOWING TOTAL KNEE ARTHROPLASTY
Rajiv Gandhi, Fahad Razak, Peggy Tso, J
Roderick Davey, Nizar N. Mahomed
University of Toronto
Purpose: Metabolic syndrome (MS) is defined as central
adiposity, elevated fasting glucose, hypertension, and dyslipidemia
defined as high triglyceride and low high-density
lipoprotein (HDL) cholesterol. MS is associated with
a systemic proinflammatory and prothrombotic state. We
asked if patients with MS undergoing total knee arthroplasty
(TKA) have an increased risk for symptomatic
deep vein thrombosis at 3 months follow-up (DVT).
Method: 1,460 consecutive patients were reviewed
from our joint registry undergoing primary, unilateral
TKA between the years of 1998-2006. Demographic
variables of age, gender, comorbidity, and education
were retrieved. Metabolic syndrome (MS) was defined
as body mass index above 30 kg/m2, diabetes, hypertension,
and hypercholesterolemia. Logistic regression
was used to examine the relationship of MS on the
incidence of DVT.
J BONE JOINT SURG [BR] 2011; 93-B:SUPP III

276 COA/CORS/CORA
Results: The overall incidence of symptomatic DVT was
4.4% (65/1460). Patients with MS had an increased incidence
of DVT as compared to those without MS(15.5%
vs 3.4%). Adjusted analysis showed that MS increased
the risk of symptomatic DVT by 3.2(95% CI [1.0,15.4],
p=0.04) times compared to those without MS.
Conclusion: Hospital protocols developed for prophylactic
anti-coagulation following TKR should give special
consideration to patients with MS.
159. THE RECORD4 STUDY: ORAL,
ONCE-DAILY RIVAROXABAN COMPARED
TO SUBCUTANEOUS, TWICE-DAILY
ENOXAPARIN FOR PREVENTION OF
VENOUS THROMBOEMBOLISM AFTER
TOTAL KNEE REPLACEMENT
William D. Fisher 1 , Michael Gent 2 , Bruce L.
Davidson 3 , Michael R. Lassen 4 , Louis M.
Kwong 5 , Fred D. Cushner 6 , Paul A. Lotke 7 , Frank
Misselwitz 8 , Tiemo J. Bandel 8 , Alexander G.G.
Turpie 2
1
McGill University Health Centre; 2 McMaster
University; 3 Weill Cornell Medical College;
4
Hoersholm Hospital; 5 Harbor-UCLA
Medical Center; 6 Insall Scott Kelly Center for
Orthopaedics and Sports Medicine; 7 University
of Pennsylvania Medical Center; 8 Bayer Health
Care AG
Purpose: Venous thromboembolism (VTE) after major
orthopaedic surgery remains an important clinical
problem. Convenient, oral antithrombotic agents that
are both effective and safe could improve adherence
to guidelines for VTE prophylaxis. Recently, the focus
has been on the development of oral agents that target
a single step in the coagulation cascade and Factor Xa
is a pivotal step. Rivaroxaban is an oral, direct Factor
Xa inhibitor. Four international phase III trials (the
RECORD programme) were undertaken to investigate
the safety and efficacy of once-daily rivaroxaban for
thromboprophylaxis after major orthopaedic surgery.
The results of RECORD3 showed that rivaroxaban
was more effective than enoxaparin 40 mg once daily
after total knee replacement (TKR), with a 48% risk
reduction in VTE and all cause mortality. RECORD4
was designed to determine the efficacy and safety of 10
mg rivaroxaban od compared to 30 mg bid enoxaparin
after total knee replacement (TKR).
Method: This study randomized 3148 patients to either
rivaroxaban (10 mg od started 6–8 hours after surgery)
or enoxaparin (30 mg bid s.c. started 12–24 hours after
surgery) for 10–14 days. The primary efficacy outcome
was the composite of asymptomatic deep vein thrombosis
(DVT) detected by mandatory, bilateral venography
and symptomatic DVT, non-fatal pulmonary embolism
(PE), and all-cause mortality up to day 13±4. Secondary
outcomes included major VTE (composite of proximal
DVT, non-fatal PE, and VTE-related death) and symptomatic
VTE. Safety outcomes included on-treatment
major and non-major bleeding.
Results: Rivaroxaban provided a 31% relative risk
reduction in the incidence of the primary efficacy outcome
when compared to enoxaparin (6.9% vs 10.1%,
respectively; p=0.012). The corresponding rates for
major VTE were 1.2% and 2.0%, respectively (p=0.124)
and for symptomatic VTE were 0.7% and 1.2%, respectively
(p=0.187). There were no significant differences
in bleeding incidence observed between rivaroxaban
and enoxaparin (major bleeding: 0.7% vs 0.3%, respectively,
p=0.110; clinically relevant non-major bleeding:
2.6% vs 2.0%, respectively, p=0.279).
Conclusion: Rivaroxaban 10 mg od is the first oral
thromboprophylactic agent to significantly reduce the
incidence of VTE after TKR compared to enoxaparin
30 mg bid, with a similar, low rate of bleeding.
160. ALIGNMENT TO ACCP PROPHYLAXIS
GUIDELINES AND VTE OUTCOMES IN THR
AND TKR PATIENTS
Rita Selby 1 , Bijan Borah 2 , Heather McDonald 3 ,
Joe Henk 2 , Mark Crowther 4 , Phil Wells 5
1
Division of Hematology, University of Toronto;
2
i3Innovus, Eden Prarie, USA; 3 Bayer Inc.,
Canada; 4 Department of Hematology, St. Joseph’s
Healthcare, Hamilton, Canada; 5 Division of
Hematology and Clinical Epidemiology, Ottawa
Health Research Institute/University of Ottawa
Purpose: A retrospective database analysis was conducted
to a) determine the extent to which the American
College of Chest Physicians (ACCP) guidelines for
VTE prophylaxis are followed after total hip replacement
(THR) and total knee replacement (TKR) and b)
evaluate the incidence of VTE for patients receiving and
not receiving prophylaxis according to ACCP guidelines
(‘ACCP’ and ‘non-ACCP’, respectively).
Method: A claims database associated with a large US
health plan was linked to the Premier database, which
provides details of in-patient medication use. Patients
≥18 years undergoing TKR/THR and enrolled in
the health plan 90 days before and 90 days following
discharge from hospitalization (or until death) were
included. Patients were considered to have received
ACCP-guideline prophylaxis if they: a) received
LMWH, fondaparinux, or VKA following surgery b)
initiated prophylaxis within one day of surgery (for
THR patients) and c) were prescribed prophylaxis
for a minimum of ten days, or until the occurrence of
major bleeding, VTE, or death. In addition, the number
of DVTs and PEs occurring in ACCP and non-ACCP
patients was recorded.
Results: Of the 30,644 eligible patients from the health
plan, 3,497 patients were linked to the in-patient database.
Except for geographic indicators, there were no
significant differences in demographics or baseline comorbidities
between those included and excluded from
the final study sample. Of the 3,497 linked patients,
1,395 (40%) received ACCP prophylaxis. The number
of DVTs occurring in the ACCP and non-ACCP groups
were 28 (2.01%) and 79 (3.76%), suggesting that non-
ACCP patients were almost twice as likely as ACCP
patients to have a DVT (p=0.0521). The number of PEs
occurring in the ACCP and non-ACCP groups were 2
(0.14%) and 25 (1.19%), respectively, suggesting that
non-ACCP patients were 8.5 times more likely than
ACCP patients to experience a PE (p15 and/or flexion

COA/CORS/CORA 277
163. MINIMALLY-INVASIVE TOTAL
KNEE ARTHROPLASTY: POTENTIAL
COMPLICATIONS BASED ON A LARGE
SINGLE-SURGEON COHORT REVIEW
Michael G. Zywiel, Peter M. Bonutti*, Slif D.
Ulrich, Mike S. McGrath, Michael A. Mont
Rubin Institute for Advanced Orthopaedics;
*Bonutti Clinic
Purpose: Minimally-invasive total knee arthroplasty has
generated tremendous recent interest, but there have
been reports of complications resulting from these new
techniques. However, most studies have less than one
year follow-up and are anecdotal in their results. The
purpose of this study was to retrospectively evaluate a
series of 1,000 consecutive minimally invasive total knee
arthroplasties, to describe the clinical and radiographic
complications of this technique, to determine whether
complication rates changed with experience, and finally
to compare complication rates to a match group operated
by the same surgeon.
Method: Clinical and radiographic data were reviewed
for the first 1,000 consecutive minimally-invasive knees
(820 patients) performed by a single surgeon with a
minimum 2 year post-operative period. All patients
were operated using the mid-vastus approach, with a
mean incision length of 10 cm (range, 8 to 13 cm). Nine
patients were lost prior to 2 year follow-up, leaving 990
knees (811 patients) in this report with annual followup.
After determining overall results, data was stratified
into 100-knee groups to determine whether complication
rates changed over time. Finally, complication rates
were compared to a matched group of 50 knees operated
by the same surgeon.
Results: There were a total of 45 clinical complications
(4.5%), including 20 (2.0%) manipulations under
anesthesia, 12 (1.2%) arthroscopies for painful crepitus,
4 (0.4%) component changes, and 3 (0.3%) spacer
changes. There were 3 (0.3%) impending radiographic
failures. Stratification of results showed a complication
rate of 6% over the first 200 knees, and 1% over
the subsequent 800 knees. In comparison, the matched
group had a complication rate of 4% over mean followup
of 3 years (range, 2 to 4).
Conclusion: This large series with minimum two year
follow-up describes many of the long-term complications
of this technique. Additionally, this large series
suggests that high volume knee surgeons may require
as many as 200 minimally invasive arthroplasties before
achieving optimum proficiency with this technique.
Nonetheless, comparison to a matched group suggests
that even with this learning curve, complication rates
need not increase markedly during this period if surgeons
remain attentive to the potential complications
associated with minimally invasive techniques.
164. INCIDENCE OF SPINAL EPIMORPH
RELATED COMPLICATIONS IN TOTAL
JOINT ARTHROPLASTY
Aaron Bigham, James J. Howard, Sugantha
Ganapathy
University of Western Ontario
Purpose: Spinal epimorph is commonly used as part of
multimodal analgesia for patients undergoing total joint
arthroplasty. Patients who receive spinal epimorph are
at risk for certain post- operative complications. The
purpose of this study was to determine the incidence of
complications in patients undergoing total joint arthroplasty
with administration of spinal epimorph compared
to patients undergoing the same procedure who did not
receive spinal epimorph as part of their analgesia.
Method: A retrospective chart review of 72 patients in
which two age, sex and procedure matched groups were
compared for differences in known spinal epimorph complications.
One group received spinal epimorph as part
of their analgesia while the comparative group did not
receive spinal epimorph but rather continuous infusion
of local analgesia. Data extraction involved foley and
oxygen usage, documented nausea/vomiting and puritis,
associated risk factors and complications such as prostate
disease and urinary tract infections, and secondary outcome
measures such as Gravol and Benadryl usage.
Results: Comparison of the two well-matched groups demonstrated
that patients who received spinal epimorph had
increased rates of foley insertion (p=0.0026), foley duration
(p=0.015), oxygen usage (p=0.0053), documented
puritis (p=0.0006) and Benadryl usage (p=0.0053). Trends
towards increased nausea/vomiting (p=0.17), antiemetic
use (p=0.16) and urinary tract infections (p=0.15) were
seen in the spinal epimorph group, although these differences
did not reach statistical significance.
Conclusion: The use of spinal epimorph as part of an analgesia
protocol surrounding total joint arthroplasty is associated
with increased complications and patient discomfort
when compared to patients who received continuous local
infiltrative analgesia. Further research is needed to determine
if alternate modes of analgesia provide adequate pain
relief when compared with spinal epimorph and thus provide
suitable alternatives with less complications.
COA PAPER SESSION 18:
SPORTS LOWER EXTREMITY
165. RETURN TO SPORT FOLLOWING
SINGLE-BUNDLE ACL RECONSTRUCTION:
PATELLAR TENDON AUTOGRAFT VERSUS
HAMSTRING AUTOGRAFT
Randy Mascarenhas*, Michael Tranovich † , Eric J.
Kropf, James Irrgang, Freddie H. Fu, Christopher
D. Harner
*University of Manitoba; † Lake Erie College of
Osteopathic Medicine; University of Pittsburgh
Purpose: This study sought to examine return to sports
in athletes younger than 25 following ACL reconstruction
with either patellar tendon (PT) or hamstring (HS)
autografts using a matched-pairs case-control experimental
design.
Method: Twenty-three matched pairs were obtained
based on gender (56.5% Female), age (18.3±2.5yrs PT
vs.17.6±2.6 HS), and length of follow-up (4.7±2.1yrs
PT vs. 4.2±1.6 HS). All patients reported participating
in very strenuous (soccer, basketball etc.) or strenuous
(skiing, tennis etc.) sporting activity 4-7 times/ week
prior to their knee injury. Outcomes other than return to
play included the IKDC, SAS, ADLS, SF-36, knee range
of motion, laxity, and hop/jump testing.
Results: Most patients in both groups were able to participate
in very strenuous or strenuous sporting activity
at follow-up [18 (78.3%) PT vs. 19 (82.6%) HS]. However,
only 13 (56.5%) of the patellar tendon subjects
and 10 (43.5%) of the hamstrings patients were able to
return to pre-injury activity levels in terms of frequency
and type of sport (p=.63). Hamstrings patients showed
higher ADLS (p

278 COA/CORS/CORA
168. SOCCER AND ACL RECONSTRUCTION
IN TEENAGE GIRLS
Krish Maragh, Lauren Beaupré, Allyson Jones,
David Otto
University of Alberta
Purpose: Females are at greater risk for anterior cruciate
ligament (ACL) injury than males. Soccer may be a significant
risk factor for ACL injury in adolescent females.
ACL injury has significant consequences, including early
onset of osteo-arthritis. The purpose of the study was
to determine a) the number of ACL reconstruction surgeries
performed on females between the ages of 13-
18 inclusive in the Capital Health (CH) region from
December 2000 to November 2005, and b) those due to
soccer injuries. Secondly, we describe factors relating to
the mechanism of injury.
Method: Utilizing regional administrative data, we
performed a standardized chart review and telephone
interviews with female adolescents who underwent
ACL reconstruction in the aforementioned time period.
Information gathered included: a) Age at reconstruction
procedure. b) Indoor versus outdoor soccer playing
surface. c) Level of play and frequency of participation.
The Alberta Soccer Association provided the number of
registrants in indoor and outdoor seasons over the same
time period.
Results: 2,824 ACL reconstruction operations were performed
between December 2000 and November 2005.
Reconstructions in females took place at an earlier age
than in males. There were 266 ACL reconstructions in
256 adolescent females, of which 253 charts were available
for review. One hundred and eleven (44%) knees
were injured during soccer play. Seven patients with
eight ACL reconstructions who injured their ACL playing
soccer could not be located. ACL injuries occurred
during indoor soccer in 52 (51%) cases despite higher
registration in outdoor soccer during the same timeframe.
77 (74%) subjects played competitively and 81
(79%) subjects played two or more times/week.
Conclusion: Approximately 10% of ACL reconstructions
were performed on adolescent females. Nearly
50% of ACL injuries occurred during soccer play, with
a similar number seen in indoor versus outdoor play.
Study limitations include the use of administrative data
to assess the number of ACL reconstructions rather than
ACL injuries. An awareness of the propensity of knee
injuries in female soccer players is important. With the
increased participation of young females in soccer and
the serious lifelong implications of ACL rupture, prevention
and training should be improved to lower the
incidence of injury.
169. RELIABILITY OF TUNNEL ANGLE
IN ACL RECONSTRUCTION: FREE HAND
VERSUS MECHANICAL GUIDE TECHNIQUE
Jeff Leiter, Nevin de Korompay, Lindsey
MacDonald, Carling MacDonald, Warren G.
Froese, Peter B MacDonald
Pan Am Clinic
Purpose: The increasing number of ACL reconstructions
has led to the introduction of new techniques irrespective
of the fact optimal tunnel angle placement has yet to
be established. Improper tunnel angle placement is associated
with a variety of complications including graft
failure. The purpose of this retrospective study was to
compare the reliability of tibial tunnel angles produced
by two experienced surgeons using a free hand method
or mechanical guide (HowellTM 65° Tibial Guide).
Method: Tibial tunnel angles in the coronal and sagittal
planes were determined from anteroposterior and lateral
radiographs, respectively, taken at 2 to 6 months
postoperatively. Fifty-two sets of digital radiographs
were analyzed (free hand = 28, mechanical = 24) with
the knee in full extension 100 cm from the beam source.
Tunnel angle measurements were calculated using NIH
ImageJ software. Each angle was measured by two
investigators on three separate occasions with minimum
7 days between each analysis.
Results: There was a significant difference (p 0.75) to
moderate (0.75 –0.40), respectively.
Conclusion: Tibial tunnel angles in the coronal plane
produced with a mechanical guide are more accurate
than those drilled free hand when the intended angle
of placement is 65°. The method used to measure tibial
angles in this study was reliable within and between
investigators. Further research will be conducted to
investigate the correlation between tunnel angle placement
and patient outcome measures.
170. THE OTTAWA TREATMENT PROTOCOL
FOR SEPTIC ARTHRITIS FOLLOWING ACL
RECONSTRUCTION
Emilio Lopez-Vidriero, Olufemi R. Ayeni, Tracy
Rupke, Ahmad Bin Nasser, Donnald Johnson
University of Ottawa
Purpose: To present our clinical and quality of life
outcomes after one year treatment with our protocol
including graft retention.
Method: Seventeen of 1, 847 patients who underwent
ACL reconstruction surgery were identified as infected
following retrospective chart review in our institution
(University of Ottawa) from 1995 to 2005. Mean age
was 37 years old (range 18-56). Gender ratio was 14
male/ three female. Laterality 13 left/ four right knees.
The diagnosis was achieved by clinical suspicion and
serum markers (ESR, CPR, WBC) followed with aspiration
and culture of intraarticular liquid. After that,
our treatment protocol included IV antibiotics (empiric
and culture guided) and knee arthroscopy performing
debridement and lavage with 12L of saline irrigation
as well as graft retention when possible. Clinical and
Radiographic data were collected at a minimum of
one year follow-up (IKDC, KT-1000, Lysholm, SF-12,
Tegner, Cybex Strength testing).
Results: The Incidence of septic arthritis following ACL
reconstruction was 0, 92%. Bacteriology results were as
follows: seven staphylococcus aureus, four Propionibacterium
acnes, one Klebsiella oxytoca, five no growth.
The time from ACL reconstruction to first symptoms of
infection was 37 days (range 4-63). The time from symptoms
to arthroscopic debridement was 5, 5 days (range
0-33). Serology markers were as follows: ESR mean 69
(range 23-128), CPR 136 (50-387), WBC 10.3 (6-15).
The average follow up was 41 months (range 12-85).
Sixteen of 17 grafts were retained after 1.53 procedures
per patient. Antibiotic treatment lasted 5.2 weeks on
average. The average clinical outcomes were: Lysholm
77 (44-98), IKDC 74 (46-95), Quadriceps strength 71
% of non operative side, and Hamstrings strength 70 %
of non operative side, KT -1000 side to side difference
1 mm (-3 to 4). Degenerative radiological changes were
noted in three patients. Two later repeat reconstructions
occurred due to instability (11,1%). No delayed recurrence
of infection was noted.
Conclusion: ACL reconstruction is a safe procedure
being the incidence of septic arthritis in our series of 0,
92%. Our protocol of treatment is clinically effective
and allows for a stable knee in 88, 9% of the patients
avoiding the appearance of a delayed infection.
171. AUTOMATIC CLASSIFICATION OF 3D
KINETIC DATA OF HEALTHY AND ACL
DEFICIENT PARTICIPANTS
Alexandre Fuentes*, Neila Mezghani, Nicola
Hagemeister, Jacques A. de Guise
*Université de Montreal; École de Technologie
Superieure
Purpose: Gait analysis has become an innovative
approach to assess the biomechanical adaptations due to
an ACL injury. However, interpreting the large amount
of data collected often requires an expert. Therefore,
there is a need to develop an automatic method capable
to distinguish kinetic pattern of an ACL deficient
patients from an asymptomatic population.
Method: 26 ACL deficient patients and 30 asymptomatic
participants took part in a treadmill gait analysis.
3D ground reaction forces (vertical, medio-lateral and
anterior-posterior) were collected using the ADAL 3D
treadmill. Features were extracted from the 3D ground
reaction forces as a function of time and then classified
by the nearest neighbour rule using a wavelet decomposition
method. The classification method was tested on
our data base of 56 participants.
Results: The proposed classification method obtained
an accuracy of 90%. The classification accuracy per
class was higher for the ACL deficient group allowing
classifying correctly 25 out of 26 ACL deficient patient.
25 out of the 30 asymptomatic participants were properly
classified.
Conclusion: This study shows that an automatic objective
computer method could be used in a clinical setting
to help diagnose an anterior cruciate ligament injury
during a gait analysis evaluation. Future studies should
apply this method on a larger database including data
from patients with other musculoskeletal pathologies to
help diagnose other injuries.
172. A SURVEY STUDY REGARDING THE
NATURAL HISTORY AND TREATMENT OF
ANTERIOR CRUCIATE LIGAMENT INJURY
AMONG MEMBERS OF THE CANADIAN
ORTHOPAEDIC ASSOCIATION
Sheila McRae, Jaskarnip Chahal, Jeff Leiter, Peter
B. MacDonald, Robert Marx*
Pan Am Clinic; *Hospital for Special Surgery
Purpose: To describe the current practices and opinions
of members of the Canadian Orthopaedic Association
(COA) pertaining to anterior cruciate ligament (ACL)
reconstruction.
Method: All orthopaedic surgeon members of the COA
residing in Canada were sent an email invitation to take
part in a survey via an internet-based survey manager.
Expanding on a previously published survey (Marx
et al., 2003), the current survey was comprised of 30
questions regarding the natural history of ACL-injured
knees, surgical and post-surgical treatment choices, and
success of the surgery. Clinical agreement was defined
as greater than 80% agreement in choice of response
option.
Results: Two hundred and eighty-three surgeons
(49.3%) responded to the survey. Responses of the 143
surgeons (50.5%) who indicated they performed ACL
reconstruction in the last year are presented. Clinical
agreement with respect to surgical technique was demonstrated
with respect to only three practices – ipsilateral
graft harvest (100%), single incision approach (86.1%),
and manual graft tensioning (81.6%). In terms of natural
history, the only area of agreement was that hamstring
and quadriceps strength affects function in ACL
deficient knees (92%). Although less than the clinical
agreement threshold, a majority of surgeons indicated
their preference for semitendinosis-gracilis autograft
(73%), transtibial versus anteromedial portal for establishment
of the femoral tunnel (65 versus 29%), notchplasty
(65% only with impingement) and promotion of
full weight-bearing and range of motion immediately
post-surgery (72.1 and 74.8%, respectively). The most
frequent surgeon-reported complications were tunnel
widening (9.8%) and graft failure (4.4%). A greater
proportion of high-volume surgeons used a manual tensioning
device intra-operatively and permitted earlier
return to sport (p

COA/CORS/CORA 279
173. MANAGEMENT OF MULTIPLE
LIGAMENT INJURED KNEE: A SURVEY OF
CURRENT PRACTICE IN CANADA
Robert G. McCormack, Rafael Martinez, Tom
Herschmiller*, Kian Chung †
UBC; *University of Sidney; † University of
Singapore
Purpose: Treatment of knee dislocations remains challenging
and controversial. Several strategies for the management
of multiple ligament knee injuries have been
described and there are multiple unresolved questions.
These include the indications for surgery, repair versus
reconstruction, surgical timing and graft selection. The
aim of this survey was to identify areas of agreement
and controversy, to define the current standard of care
and help generate research questions.
Method: Using the standard techniques for survey development
we presented six clinical scenarios of acute knee
dislocations (at least three ligaments) to all orthopaedic
surgeons affiliated with Canadian medical schools. The
scenarios were designed to cover the common combinations
of knee dislocations in both a 25 year old active
individual and a 50 year old sedentary individual. The
responses were divided into three groups. Group A
consisted of those with fellowship training, or practices
focused on, sports knee. Group B was comprised of surgeons
with trauma fellowship or a sub-specialty trauma
practice. Group C were the remaining surgeons without
these subspecialty foci. We report on the responses of
groups A and B.
Results: An average of ten different treatment algorithms
were reported for each scenario but there was
agreement on the need for early surgical management
in the young active individual with a knee dislocation
and all dislocations involving a lateral sided injury.
Conversely, there was a lack of consensus regarding the
need for surgical treatment of the 50 year old individual
with bi-cruciate injury and medial collateral ligament.
The most common combinations of reconstruction and
repair are reported for each clinical scenario. Surgeons
strongly favor early surgical intervention, within three
weeks of injury, except for the 50 year old sedentary
individual with a bi-cruciate plus medial sided injury.
Allograft was the most popular choice to reconstruct the
PCL and lateral ligament. For the ACL graft there was
a near equal distribution between hamstrings, patellar
tendon and the use allograft tissue.
Conclusion: In the absence of higher level evidence, the
information from this survey helps define the standard
of care in Canada and identifies areas of controversy
which would be a priority for a multi-centre prospective
trial.
174. POSTEROMEDIAL CORNER INJURY
PATTERNS IN TRAUMATIC KNEE
DISLOCATIONS
Jaskarndip Chahal, Dawn Pearce*, Tom
McCarthy, Jeff Dawson, Anthea Liebenberg*,
Daniel B. Whelan*
University of Toronto; *St. Michael’s Hospital,
University of Toronto
Purpose: Traumatic knee dislocations are complex injuries.
A thorough knowledge of the pattern of ligament
damage is essential to plan for definitive treatment. Injuries
to the structures of the posteromedial corner (posterior
oblique ligament, the semi-membranosus tendon
and its expansions, the meniscofemoral and meniscotibial
ligaments, posterior horn of the medial meniscus and
posterior reflections of the deep and superficial medial
collateral ligament) can contribute to rotational laxity
and have not been previously described in the setting of
knee dislocations. We set out to evaluate the injury patterns
of the posteromedial corner in a series of traumatic
knee dislocations.
Method: A radiographic (MRI) study was conducted on
22 multi-ligament knee injuries in 22 patients, managed
at a level one trauma centre by a single surgeon between
July 2006 and May 2008.
Results: There were 14 male and 6 female patients with
an average age of 29. The mechanism of injury was high
velocity in 10 cases, and low velocity in 12 cases. One
case (ACL/PCL/posterolateral corner injury) was associated
with a vascular injury. While the incidence of MCL
injury was 59%, injury specific to the PMC was evident
on MRI in 81.8% (18/22) of cases. The deep and superficial
MCL were involved in 13/18 and 12/18 PMC injuries,
respectively. The posterior oblique ligament was
injured in 11/18 cases and the semi-membranosus and
its expansions were injured in 10/18 cases (all distal).
Injuries to the posterior horn of the medial meniscus
(9/18 cases) were associated with a tear of the meniscofemoral/meniscotibial
ligaments in all cases.
Conclusion: Injury to the PMC was common with highgrade
multi-ligament knee injuries in this series. PMC
injuries were more common than MCL injuries alone.
Injury to the posterior horn of the medial meniscus was
predictive of more extensive PMC injury in all cases.
The posteromedial corner of the knee is an under recognized
area where important injuries can occur in the setting
of a dislocatable knee. Future research will involve
the correlation of the injury patterns described in this
series to clinical measures of knee instability and laxity.
COA PAPER SESSION 19: TRAUMA UPPER
EXTREMITY AND TRAUMA GENERAL
175. EVALUATION OF PRIMARY CARE
MANAGEMENT FOR ISOLATED LIMB
INJURY: STUDY ON 166 CONSECUTIVE
PATIENTS REFERRED TO ORTHOPAEDIC
SURGERY IN A LEVEL 1 TRAUMA CENTER
Dominique Rouleau, Stefan Parent, Debbie
Feldman*, Valérie Deslauriers*
Hôpital Sacré-Coeur de Montreal; *Université de
Montreal
Purpose: Musculoskeletal injuries affect up to 13% of
adults annually. Despite this high incidence, quality of
primary care, including analgesia, may be sub-optimal.
The goal of this study is to describe the quality of primary
care for ambulatory patients with isolated limb
injury and to identify related factors.
Method: A cross sectional study was undertaken on 166
consecutive ambulatory adult patients with isolated limb
injury who presented to orthopedics service in a Level
one Trauma Centre. Quality of care was assessed by
evaluating analgesia, walking aids, immobilization, and
quality of referral diagnosis according to actual expert
recommendations. Patient satisfaction was assessed by
Visit Satisfaction Questionnaire.
Results: This study revealed low quality of primary care
for more than 50% of injured patients. More than half
the patients had pain level over 5/10 and more than a
quarter had insufficient/absent analgesia prescriptions.
A third had unacceptable immobilization and 36% of
patients with a lower limb injury did not receive a walking
aid prescription. A total of 37% had an absent or
inadequate referral diagnosis. Factors associated with
lower quality depended on the specific quality indicator
and included: living further away from the hospital,
younger age, initially consulting at another health care
center, having a fracture, and being a smoker.
Conclusion: The high frequency of low quality of care
underlines the necessity for orthopedic surgeons to be
involved in primary care education. Identifying factors
associated with lower quality of care will orient efforts
to improve medical care of patients with isolated traumatic
injury.
176. PATIENT SATISFACTION FOLLOWING
CLAVICLE FRACTURE FIXATION:
HORIZONTAL VERSUS VERTICAL INCISION
John Choi, Elton Edwards
The Alfred Hospital
Purpose: To document outcomes and patient satisfaction
in relation to the incision used following clavicle
fracture fixation. In literature, the incidence of incisional
numbness following operative fixation of clavicle
fractures is reported to be between 7-29%. Such wound
related problems contribute significantly to the dissatisfaction
of patients with operatively treated clavicle fractures.
Wound related problems can be bothersome and
disabling and this is poorly documented.
Method: All primary clavicle fractures treated with
plating at the Alfred Hospital between 01/06/2003 and
01/06/2006 were included in the study. Patients were
asked to complete paper-based questionnaires assessing
satisfaction, pain, scar satisfaction, presence of numbness
and the degree of disability following clavicle fixation.
Their clinical notes and X-rays were reviewed for
evaluation. The study sample was then divided into two
groups; horizontal incision versus vertical incision then
the data was analysed.
Results: The response rate was 65% (35/54). 74% of
patients reported as having “good” or better outcome
following their clavicle fracture fixation. There was no
statistically significant difference in pain scores. However,
there were statistically significant differences observed in
the presence of numbness (vertical 21% versus horizontal
62%) and the disability from the numbness between the
two incision types. Overall satisfaction between the two
groups was also significantly different.
Conclusion: This study confirms that scar-related problems
significantly affect the satisfaction following plating
of clavicle fractures and numbness appears to be one
of the most significant factors. Vertical incisions appear
to reduce the incidence of numbness and lead to better
patient satisfaction. Our results suggest that vertical
incision is an attractive alternative approach in clavicle
fracture fixation.
177. LOCKED PLATE FIXATION VERSUS
NON-OPERATIVE TREATMENT FOR
DISPLACED, EXTRA-ARTICULAR PROXIMAL
HUMERUS FRACTURES: ARE FUNCTIONAL
AND QUALITY OF LIFE OUTCOMES
BETTER?
Gerard Slobogean, Mohit Bhandari*, Peter J.
O’Brien
UBC; *McMaster University
Purpose: To compare the functional outcome and quality-of-life
following a displaced extra-articular proximal
humerus fracture treated with open reduction and locking
plate fixation versus non-operative management. To
provide preliminary data for a subsequent prospective
clinical trial.
Method: Eligible subjects were identified through
retrospective searches of a large emergency department
admission database and the orthopaedic trauma
database. All subjects ages ³ 55 treated for a proximal
humerus fracture between 2002 to 2005 were invited to
participate. The Disabilities of Arm, Shoulder, and Hand
(DASH), Health Utilities Index Mark 3 (HUI), Euroqol-
5D (EQ-5D), and the SF-36 questionnaires were mailed
to all eligible subjects. Initial radiographs were reviewed
using the AO/OTA classification system. Only patients
with A3, B1, B2, or B3 fractures were included.
Results: Thiry-four subjects were included: 15 were
treated with sling immobilization and 19 with locked
plate ORIF. The non-operative group was approximately
seven years older (mean age 74 versus 67, p = 0.046).
DASH scores were similar between the groups: ORIF
26.6 ± 24 and Sling 26.5 ± 20. The 95% CI surrounding
the 0.01 point difference (-16.0 to 15.9) slightly exceeds
the 13 point cutoff for the instrument’s measurement
error (minimal detectable change). Using univariable
analysis, no statistically significant differences in health
state values were detected. The mean HUI value for the
ORIF group was 0.68 versus 0.75 for the sling (p=0.48).
Mean EQ-5D values were 0.77 for the ORIF group
and 0.80 for the sling group (p=0.73). The SF-36 PCS
scores were also similar between the two groups: ORIF
41.1 versus Sling 39.8 (p=0.77). When controlling for
age and pre-injury function, a 0.09 point difference in
HUI values was detected favouring the sling treatment
(p=0.036). No differences in DASH, EQ-5D, or SF-36
PCS scores were detected using regression models.
Conclusion: The results of this small cohort suggest, for
extra-articular fractures, the functional and quality of
life outcomes may be similar between the two interven-
J BONE JOINT SURG [BR] 2011; 93-B:SUPP III

280 COA/CORS/CORA
tions. No trial comparing locked plate fixation and nonoperative
management has been reported. A total of 96
subjects will be needed for a prospective clinical trial
comparing the two treatments (DASH difference 15,
80% power, 0.05 two-sided alpha).
178. TYPE 2D MONTEGGIA ELBOW
FRACTURE-DISLOCATIONS: PATTERN
OF INJURY, SURGICAL TECHNIQUE OF
FIXATION AND OUTCOME
Darius Viskontas*, Daphne M. Beingessner, Sean
Nork, Julie Agel
* UBC; University of Washington
Purpose: To describe the pattern of injury, surgical technique
and outcomes of Monteggia type IID fracture
dislocations.
Method: Design: Retrospective review of prospectively
collected clinical and radiographic patient data in
orthopaedic trauma database with prospectively collected
outcome scores. Setting: Level 1 university based
trauma center. Patients / Participants: All patients with
Monteggia type IID fracture dislocations admitted from
January 2000 to July 2005. Intervention: Review of
patient demographics, fracture pattern, method of fixation,
complications, additional surgical procedures, and
clinical and radiographic outcome measures. Main Outcome
Measurements: Clinical outcomes: elbow range
of motion, QuickDASH (Quick Disabilities of the Arm,
Shoulder and Hand), PREE (Patient Rated Elbow Evaluation),
complications. Radiographic outcomes: quality
of fracture reduction, healing time, degenerative change
and heterotopic ossification.
Results: Sixteen patients were included in the study.
All fractures united. There were seven complications
in 6 patients including 3 contractures with associated
heterotopic ossification, 1 pronator syndrome and late
radial nerve palsy, 1 radial head collapse and a DVT in
the same patient and 1 with prominent hardware. Outcome
scores were obtained on 11 patients at an average
of 49 months (range 25 – 82 months) post-operatively.
The average Quickdash score was 11 (range 0-43) and
the average PREE score was 13 (range 0-34).
Conclusion: Monteggia IID fracture dislocations are
complex injuries with a recurring pattern. Rigid anatomic
fixation, early range of motion and avoidance of
complications leads to a good outcome.
179. ELBOW HEMIARTHROPLASTY FOR
DISTAL HUMERAL FRACTURES
Alex Malone*, Peter Zarkadas † , Stuart Jansen,
Jeff Hughes
*University of Otago, Christchurch; † Lions Gate
Hospital; Royal North Shore, Sydney
Purpose: This study reviews the early results of elbow
hemiarthroplasty for distal humeral fractures.
Method: Elbow hemiarthroplasty was performed on
30 patients (mean 65 years; 29-91) for unreconstructable
fractures of the distal humerus or salvage of failed
internal fixation. A ‘triceps on’ approach was used in
six and an olecranon osteotomy in 24. A Sorbie Questor
prosthesis (Wright Medical Technology) was used in 14
patients and a Lattitude (Tornier) in 16. Clinical review
at a mean of 25 months (3-88) included the American
Shoulder and Elbow Surgeons elbow outcomes instrument
(ASES), Mayo Elbow Performance Index (MEPI)
and radiological assessment.
Results: At follow up of 28 patients mean flexion deformity
was 25 degrees, flexion 128 degrees, range of pronosupination
165 degrees, mean ASES 83, MEPI 77 and
satisfaction 8/10. Acute cases scored better than salvage
cases. Re-operation was required in 16 patients (53%);
two revisions to a linked prosthesis for periprosthetic
fracture and aseptic loosening at 53 and 16 months, 12
metalwork removals and four ulnar nerve procedures.
Posterolateral rotatory instability was present in one
elbow, four had laxity and pain on loading (two with
prosthesis or pin loosening), four had laxity associated
with column fractures (two symptomatic) and ten had
asymptomatic laxity only. The triceps on approach had
worse laxity and clinical scores. Uncomplicated union
occurred in all olecranon osteotomies and 86% of
column fractures. One elbow had an incomplete cement
mantle and seven had lucencies >1 mm; one was loose
but acceptable. Five prostheses were in slight varus and
two were flexed. Two elbows had early degenerative
changes and 15 developed an osteophytic lip on the
medial trochlea.
Conclusion: Early results of elbow hemiarthroplasty
show good outcomes after complex distal humeral fractures,
despite a technically demanding procedure, metalware
removal in 40%, symptomatic laxity in 12% and
column non-union in 8%. Better results are obtained for
treatment in the acute setting and with use of an olecranon
osteotomy.
180. COMPARTMENT SYNDROME CAUSES A
SYSTEMIC INFLAMMATORY RESPONSE AND
REMOTE ORGAN INJURY
Abdel-Rahman Lawendy, Gregory McGarr, Joel
Phillips, David W. Sanders, Aurelia Bihari, Amit
Badhwar
University of Western Ontario
Purpose: Severe compartment syndrome is associated
with renal failure, end organ damage, and systemic
inflammatory response syndrome (SIRS). Intravital
videomicroscopy (IVVM) is a useful tool to study capillary
perfusion and inflammation in end organs such
as the liver and lungs. In this study, the systemic effect
of hindlimb compartment syndrome was studied using
hepatic IVVM. The purpose was to measure the effect
of increased hindlimb intracompartmental pressure on
hepatocyte viability, inflammation, and blood flow in a
rodent model.
Method: Ten Wistar rats were randomised into control
(C) and Compartment Syndrome (CS) groups. Animals
were anaesthetized with 5 % isoflurane. Mean
arterial pressure was monitored using a carotid artery
catheter. Elevated intracompartmental pressure (EICP)
was induced by saline infusion into the anterior compartment
of the hind limb and maintained for 2 hours
between 30–40mmHg in the CS group. Two hours following
fasciotomy, the liver was analyzed using IVVM
to quantify capillary perfusion as a measure of microvascular
dysfunction. The numbers of adherent and
rolling leukocytes in venules and sinusoids were quantified
to measure the inflammatory response. Irreversible
hepatocyte injury was measured using a fluorescent vital
dye which labels the nuclei of severely injured cells.
Results: Hepatocellular injury was significantly higher
in the CS group (325±103 PI labeled cells/10-1 mm2)
compared to controls (30±12 PI labeled cells/10-1
mm2)(p=0.0087). The number of adherent venular
white blood cells (WBC) was significantly higher for the
CS group (5±2/hpf) than controls (0.2±0.2)(p=0.0099).
Volumetric blood flow was not significantly different
between CS and controls.
Conclusion: After only 2 hours of compartment syndrome
in this animal model, the number of activated white
blood cells increased 25-fold and liver cellular injury
increased 10-fold compared to controls. Marked systemic
inflammation and hepatocellular damage was detected in
response to isolated limb compartment syndrome. Compartment
syndrome is a low-flow ischemia/reperfusion
injury with a profound inflammatory response. Further
research into the severe end-organ damage associated
with compartment syndrome is required.
181. HYPOTHERMIA IN COMPARTMENT
SYNDROME
David W. Sanders, Gladys Chan, Amit Badhwar
University of Western Ontario
Purpose: Compartment syndrome is a limb-threatening
condition. Treatment is urgent decompression by fasciotomy.
However, orthopedic surgeons are often confronted
by a limb at risk for compartment syndrome,
in which treatments to preserve tissue might be considered.
Hypothermia has shown promise as a technique
of maintaining tissue viability in transplant surgery,
replant surgery and soft tissue injury. Cooling reduces
microvascular dysfunction, inflammation and edema.
This study was designed to determine whether tissue
cooling might reduce muscle damage in the setting of
elevated intracompartmental pressure. Purpose This
study investigated the effect of hypothermia on tissue
perfusion, viability and the inflammatory response in an
animal model of elevated intracompartmental pressure.
We hypothesize that hypothermia will preserve muscle
tissue viability in an animal model of elevated intracompartmental
pressure.
Method: Twenty Wistar rats were randomized. Five
animals had elevated intracompartmental pressure for
2 hours (CS). Five had elevated pressure and hindlimb
cooling to 25oC (CS-HY). Five had hindlimb cooling
to 25oC (HY) and 5 were control animals (C). All animals
were anaesthesized for study. Core temperature was
maintained over 30oC. Elevated ICP was maintained
(30mmHg) using a saline infusion technique (groups CS
and CS-HY). After 2 hours, fasciotomies were completed
and intravital microscopy was used to measure tissue
viability, microvascular perfusion and inflammation.
Results: The use of hypothermia reduced tissue damage
by approximately 50% in the CS-HY group (8.2%
injured cells) compared with the CS group (16.5%
injured cells). There was no difference in capillary perfusion
comparing the CS and CS-HY groups (p>0.05).
The number of adherent inflammatory cells was fewer
comparing the CS-HY with the CS groups, but this did
not reach statistical significance with the numbers available
for study.
Conclusion: Hypothermia preserved tissue viability in an
animal model of elevated intracompartmental pressure.
Fasciotomy remains the gold standard treatment for
established compartment syndrome. However cooling
may be useful to preserve tissue viability in extremities
that are at risk of developing compartment syndrome.
The clinical utility of hypothermia for compartment
syndrome requires further study.
182. A COMPARISON OF COMPLICATION
RATES AND OUTCOMES FOLLOWING LIMB-
LENGTHENING FOR POST-TRAUMATIC
VERSUS CONGENITAL/DEVELOPMENTAL
DEFORMITY
Jeffrey M. Potter*, Peter O’Brien † , Piotr Blachut † ,
Emil H. Schemitsch, Michael McKee
* Queen’s University, Department of Medicine;
†
UBC; St. Michael’s Hospital, University of
Toronto
Purpose: To conduct a study to identify differences in
complication rates and outcomes between previously
recognized sub-groups commonly treated for limb
length discrepancies (LLD).
Method: Forty-two males and 13 females were treated
for LLD at two level-one trauma centres. Mean LLD
was 4.4 cm (range 1.8 to 18cm). There were 44 femoral
segments (in 41 patients) and 14 tibia segments lengthened.
Forty were post-traumatic, and 18 congenital/
developmental. Objective data regarding complications,
length achieved, and lengthening duration was collected
from patient records. Two groups were compared for
differences: Developmental (congenital and developmental
etiology combined; LLD occurred prior to
skeletal maturity and treatment involved creating new
length) versus post-traumatic (restoration of previously
existing length), and tibia versus femoral lengthening.
Results: A mean of 4.4 cm of length was achieved over a
mean duration of 83 days, for a mean lengthening index
of 18.9 days/cm. Superficial pin tract infections were the
most common complication, occurring in 33 segments
(56%). Deep infection occurred in six segments (10%).
Three of these six had a history of open fracture, and
a fourth had a history of infection during initial fracture
management. All were successfully treated with
irrigation and debridement, and exchange nailing. The
developmental group had significantly greater incidence
of flexion contracture (13% versus 78%, p

COA/CORS/CORA 281
(45% versus 16%, p=0.04). Tibia segments had a significantly
greater lengthening index (29 d/cm versus 18
d/cm, p=0.03).
Conclusion: Limb lengthening is an involved process
with potential for serious complications. Patients who
had limb-lengthening for congenital/ developmental discrepancies
had a higher rate of adjacent joint contracture
and subsequent requirement for surgical release.
Patients with post-traumatic lengthening had a higher
rate of hardware removal, and the lengthening index
was greater for tibiae than femora. Deep infection
remains a significant concern. This study provides information
for physicians and patients on the rate and type
of complications that can be expected both overall, and
within specific LLD treatment groups.
183. LOCKED PLATING OF OPEN DISTAL
FEMUR FRACTURES
David Barei, Craig Greene*, Daphne M.
Beingessner
Harborview Medical Center; *Baton Rouge
Orthopaedic Clinic
Purpose: Non-union and secondary reduction loss complicate
open distal femur fractures with bone loss. We
hypothesize that locking plates decrease subsequent
bone grafting in these injuries, yet maintain alignment;
immediate post-fixation radiographic features predict
primary union.
Method: From 2001 to 2004 inclusive, 34 adults with
36 open AO/OTA C-type distal femur fractures were
reviewed. All were treated with locking plates and
3-month minimum follow-up. Union required radiographic
bridging callus on 2/4 cortices combined with
lack of symptoms. Alignment was assessed on initial and
united radiographs. Antibiotic beads within a metaphyseal
defect defined clinically important bone loss.
Results: Eleven of 20 fractures with bone loss (55%)
underwent staged bone grafting to achieve union, versus
two of 16 fractures without bone loss (13%). The presence
of antibiotic beads was significantly associated
with staged bone grafting (p

282 COA/CORS/CORA
operatively and the mean percentage of correction, as
well as loss of correction determined. We also analyzed
the length of surgery (hours), length of hospitalization
and complications.
Results: The mean preoperative major curve was 52.5
degrees in Group 1, 52. degrees in Group 2, and 48.8
degrees in Group 3. The mean percent postoperative
correction (POC%) at 1 month was 67.2, 65.2, and 63.4
% in the 3 groups, respectively (p=0.531). The mean
percent post-operative correction (POC%) at 24 month
was 55.6% for Group 1, 56.6% for Group 2 and 51.5%
for Group 3 (p=0.478). The mean percent loss of correction
(LOC%) at 24 months was 3.1%, 2.25%, and
2.9% respectively(p=0.648). One-way ANOVA demonstrated
no significant differences in patient age, number
of levels fused, length of surgery, or length of hospital
stay. There were no implant related complications.
Conclusion: Hybrid constructs with one or more pairs
of pedicle screws and all-hook constructs for distal foundations
in SSI provided similar major curve correction,
percentage postoperative correction, and are associated
with a minimal loss of correction postoperatively. There
was no significant difference between length of surgery,
hospital stay or complications.
188. THORACOSCOPIC ANTERIOR
INSTRUMENTATION AND FUSION
AS TREATMENT FOR ADOLESCENT
IDIOPATHIC SCOLIOSIS: A SYSTEMATIC
REVIEW OF THE LITERATURE
Ron El-Hawary, David Russell, Alex M.
Soroceanu, Colleen O’Connell
Dalhousie University
Purpose: Traditionally, the accepted treatments for
adolescent idiopathic scoliosis (AIS) have included
open anterior thoracotomy with instrumentation and
posterior spinal fusion and instrumentation. Thoracoscopic
instrumentation is a newer technique, whose role
remains controversial. This systematic review of the literature
aims to better understand thoracoscopic instrumentation
as a treatment for AIS and to discuss it in the
context of the alternative techniques currently used.
Method: The most commonly used medical databases
(PUBMED, Medline, EMBASE, Cinahl, and the
Cochrane library) were searched up to April 2008 using
the search terms “VATS”, “thoracoscopic scoliosis”
and “thoracoscopic scoliosis instrumentation”. Two
reviewers independently performed the literature evaluation.
There were no language restrictions. Because the
number of randomized controlled trials was anticipared
to be small, we included relevant non-randomized trials,
observational studies, and uncontrolled studies.
Results: Eleven studies met the strict inclusion criteria
for the systematic review, of which the majority were
level III and IV evidence. Four hundred and forty-five
cases have been reported, 80% of them female, with
the vast majority having a diagnosis of AIS. Similar
surgical techniques were used and had a mean operative
time of 355 minutes, mean blood loss of 444 ml,
and mean hospital stay of 5.1 days. Mean pre-operative
curve magnitude was 47.9o; post-operative curve magnitude
was 16.3o, with a correction of 62%. Number of
levels instrumented was 6.3, pulmonary function testes
returned to pre-operative values by 2-years post-operative,
and complication rate was 21.6%, including a pulmonary
complication rate of 9.2%. SRS questionnaires
revealed that patients were satisfied.
Conclusion: The major drawbacks of the thoracoscopic
approach are the operative time and incidence
of early pulmonary complications. Advantages include:
minimally invasive, less blood loss, short hospital stay,
excellent curve correction, few levels fused, good patient
satisfaction, and no long term effect on pulmonary function.
With appropriate surgeon training, careful patient
selection, and precise surgical technique, this technique
can offer an acceptable alternative to the more traditional
procedures.
189. PROSPECTIVE COHORT ANALYSIS OF
PRIMARY PYOGENIC INFECTION OF THE
SPINE IN INTRAVENOUS DRUG USERS
John Street, Brian Lenehan, Michael Boyd, Marcel
Dvorak, Brian K. Kwon, Scott Paquette, Charles
G. Fisher
UBC
Purpose: To evaluate the demographics, presentation,
treatment and outcomes of spinal infection in a population
of Intravenous Drug Users.
Method: Data on all patients with pyogenic spinal
infection presenting to a quaternary referral center was
obtained from a prospectively maintain database.
Results: Over the five-year study period, there were
102 patients treated for Primary Pyogenic Infection of
the Spine of which 51 were Intravenous Drug Users
(IVDU). Of this IVDU group there were 34 males.
Mean age was 43 years (range 25 – 57). Twenty-three
had HIV, 43 Hepatitis C and 13 Hepatitis B. All were
using cocaine, 26 were also using Heroin and 44 more
than three recreational drugs. Thirty patients presented
with axial pain with a mean duration of 51 days (range
3-120). Thirty-one were ASIA D or worse with eight
ASIA A. Mean Motor Score of patients with deficit was
58.6. Most common ASIA Motor Levels were C4 and
C5. Mean duration of neurological symptoms was seven
days (range 1-60). Blood parameters on admission were
in keeping with sepsis in immunocompromised patients.
None had previous surgery for spinal infection. Twentysex
were receiving IV antibiotics for known spinal
infection. 44 patients were treated surgically. 32 had
infection of the cervical spine, 9 Thoracic and 3 Lumbar.
22 had a posterior approach alone, 13 had anterior only
while 9 required combined. Mean operative time was
263 mins (range 62 – 742). 13 required tracheostomy.
7 required early revision for hardware failure and 2 for
surgical wound infection. Mean duration of antibiotic
treatment was 49 days (range 28-116). 26 patients had
single agent therapy. 17 had MSSA and 17 MRSA. At
discharge 28 patients had neurological improvement
(mean 20 ASIA points, range 1-55), 11 had deterioration
(mean 13, range 1-50) and 5 were unchanged.
There were no in-hospital deaths. At 2 years after index
admission 13 patients were dead and none were attending
the unit for follow-up.
Conclusion: Primary pyogenic spinal infection in
IVDU’s typically presents with sepsis and acute cervical
quadriplegia. Surgical management must be prompt and
aggressive with significant neurological improvement
expected in the majority of patients.
190. COMPARATIVE STABILITY OF TWO C1-
C2 TRANSARTICULAR SCREW SALVAGING
FIXATION TECHNIQUES
Hossein K. Elgafy, Tejaswy Potluri, Ahmad
Faizan, Scot Foster, Nikhil Kulkarni, Amanesh
Goyal, Vijay Goel
University of Toledo
Purpose: The current gold-standard for atlanto-axial
fixation is C1-C2 Transarticular Screw (TS) fixation. In
certain cases, the complicated nature of vertebral artery
injury could make the application of bilateral transarticular
screws impossible. This study biomechanically
compares three atlantoaxial transarticular salvaging
fixation techniques.
Method: Nine Fresh ligamentous human cervical spine
specimens (C0-C4) were thawed and the tissue surrounding
the spine, except the ligaments and discs,
was carefully removed. Pure moments were applied to
skull in increments of 0.5 Nm from 0 Nm to 2.0 Nm
with the help of loading arms, nylon strings and pulleys.
The specimens were tested in extension (EXT),
flexion (FLEX), left lateral bending (LB), right lateral
bending (RB), left axial rotation (LR) and right axial
rotation (RR) for all the cases. The positions of the
LEDs were recorded using an Optotrak Motion Measurement
System (Northern Digital, Waterloo, Ontario,
Canada) and was converted into three rotations (flexion/extension,
lateral bending and axial rotation) using
rigid body kinematic principles in relation to the fixed
base. The specimens were tested intact and after type II
odontoid fracture, were instrumented and tested with
three fixation constructs: 1) C1-C2 TS on right side and
C1LMS-C2PS on contralateral side 2) C1-C2 TS on
right side and C1LMS-C2IL on the contralateral side
and 3) C1-C2 TS on right side with sublaminar wire.
Results: All of the three instrumented cases significantly
reduced motion across C1-C2 segment in all the modes
when compared to intact (P

COA/CORS/CORA 283
192. THE PREVALENCE OF SPINAL
MAGNETIC RESONANCE IMAGING
CHANGES IN SURGICAL VERSUS NON-
SURGICAL PATIENTS? A RETROSPECTIVE
STUDY
Frederick Cheng*, Oma Persaud, Raja Y.
Rampersaud
*University of Toronto, Toronto; University of
Toronto, University Health Network, Krembil
Neuroscience Program, Toronto
Purpose: Magnetic resonance imaging (MRI) is the diagnostic
imaging modality of choice for spinal disorders.
The high prevalence of “abnormal” MRI findings within
asymptomatic individuals is well established, however,
referrals to spine surgeons are often based on symptomatically
discordant or non-surgical MRI ‘abnormalities’.
The purpose of this study was to determine the
prevalence of typical spine MRI abnormalities among
symptomatic surgical candidates (SC) and non-surgical
(NS)patients.
Method: A retrospective cohort study was conducted on
1,585 patients (with a lumbar MRI) seen by a spine surgeon.
The cohorts were compared in terms of the total
amount, type, severity and number of levels of abnormalities
on MRI. All patients were prospectively stratified
regarding surgical candidacy.
Results: There was no difference between the cohorts
(n=722-SC / 863-NS) in terms of the total amount of
structural abnormalities present (p=0.26). There was no
difference in the prevalence of DDD, disc-herniation or
previous surgery (p> 0.2). However, there was a higher
prevalence of spinal stenosis (0.513 vs. 0.394) and spondylolisthesis
(0.263 vs. 0.112) within the SC (p≤0.01).
Logistic-regression showed that patients with disc-herniation,
stenosis or spondylolisthesis were 1.49, 1.61 and
2.84 times more likely to be SC respectively (p≤0.001).
Subjects with a report of severe/large herniation or stenosis
were 3.30 and 2.25 times (p

284 COA/CORS/CORA
Decreased ankle power and persistant internal rotation
are more frequently seen in feet that have undergone surgery
despite initial nonoperative treatment, compared to
those treated only by either the Ponseti protocol or the
French physical therapy program.
197. LONG TERM RESULTS OF ILIZAROV
TREATMENT IN RELAPSED CLUB FEET- A
COMPARISON OF SCORING SYSTEMS WITH
A PATIENT’S PERSPECTIVE OF OUTCOME
Amit Datta, Shakir Syed, Curtis Robb, Chris
Bradish
Royal Orthopaedic Hospital Birmingham, UK
Purpose: The Ponseti method of clubfoot treatment has
revolutionised the management of this condition. Prior
to the introduction of the Ponseti regime to the UK in
the late 1990’s children were frequently treated by open
surgical releases. The aim of our study is to compare
the patient’s perspective of outcome following Ilizarov
treatment against the long-term outcome generated by
the formal scoring systems.
Method: We identified nine patients and 14 feet from
the theatre logbooks, treated by the senior author (CB),
with recurrent deformity of idiopathic clubfeet, using an
ilizarov external fixator between 1994 and 1996. A variety
of objective and subjective scoring systems were used
to compare the results following Ilizarov treatment.
Results: International Clubfoot Study Group (ICFSG)
scores on six patients gave two excellent feet, one good
foot, four fair feet and one poor foot. Giving an excellent/
good rate of only 37.5% with a mean follow up of 13.5
years. The Reinker & Carpenter scoring system resulted
in five feet graded as excellent, one as good and two
were rated poor. Giving an excellent/good rate of 75%.
Functional questioning was also undertaken, six of seven
(85%) patients deemed their treatment a success and
were glad to have undergone treatment with an ilizarov
frame. All but one patient is in higher education pursuing
a vocational career or are in full time employment.
Conclusion: Our results show that 85% of our patients
who were treated with an Ilizarov frame for correction
of a relapsed clubfoot were happy with their long term
outcome. Thus the patient’s perspective of the long term
results of Ilizarov treatment for relapsed club foot are very
encouraging. These results do not appear to correlate well
with the International Clubfoot Study Group scores.
198. SUPRACONDYLAR HUMERUS
FRACTURES IN OLDER CHILDREN:
TREATMENT MODALITIES AND
OUTCOMES
Brent G. Mollon, W. S. McGuffin † , Jamie A.
Seabrook ‡ , K. Kellie Leitch †
The University of Western Ontario, London, ON;
†
Schulich School of Medicine & Dentistry, The
University of Western Ontario, London, ON;
‡
Department of Paediatrics, Children’s Health
Research Institute, Department of Sociology,
London Health Sciences Centre, London, ON
Purpose: The treatment algorithm for supracondylar
humerus fractures in children under age seven is wellestablished.
However, the best treatment option for these
fractures in older children (8-14 year olds) is debated.
The purpose of this study was to assess the efficacy of
closed versus open fixation methods of this fracture type
in older children. We hypothesize that closed reduction
and percutaneous pinning (CRPP) is as effective as open
reduction and internal fixation (ORIF).
Method: A retrospective chart review was completed of all
patients 8-14 years old treated for supracondylar humerus
fractures at one centre from 2000-2007. IRB approval was
obtained for this study. Demographics, treatment methods,
pre- and post-operative complications, functional and
radiographic outcomes were reviewed. Values are reported
as mean ± standard deviation.
Results: Seventy-eight eligible patients were identified:
60 (76.9%) were treated with CRPP, and 18 (23.1%)
were treated with ORIF. Demographics and fracture
characteristics were similar between the CRPP and
ORIF groups, although patients treated with ORIF were
older (p

COA/CORS/CORA 285
202. INTRATHECAL MORPHINE ANALGESIA
IN IDIOPATHIC SCOLIOSIS SURGERY: DOES
GENDER OR RACIAL GROUP AFFECT
OPTIMAL DOSING?
Jochen P. Son-Hing, Connie Poe-Kochert, Paul A.
Tripi, Jennifer Potzman, George H. Thompson
Rainbow Babies and Children’s Hospital
Purpose: Do children from different gender or racial
groups receive different analgesic doses for the same
acute pain condition? We previously reported on intrathecal
morphine for preemptive analgesia in children
undergoing posterior spinal fusion (PSF) and segmental
spinal instrumentation (SSI) for idiopathic scoliosis
(IS). We determined the optimal dose range to maximize
analgesia while minimizing adverse effects. The purpose
is to ensure this adopted protocol is equally effective
across gender and racial groups.
Method: We studied 407 intrathecal morphine patients.
Those given a moderate dose of 9-19 mcg/kg (n=293)
had the most effective and safe postoperative pain relief.
This group consisted of 246 female and 47 male patients.
There were 224 Caucasian (CA) and 63 African-American
(AA) patients. Other ethnicities were excluded. Factors
analyzed included postoperative Wong-Baker visual
analog pain scores (VAS), time to first opioid rescue
dose, total morphine dose over the first 48 hours, and
postoperative complications.
Results: For female and male gender, mean VAS pain
scores in post-anesthesia care unit (PACU) were 0.48
and 0.56, mean times to first opioid rescue dose were
999.1 and 1003.3 minutes, and total morphine over the
first 48 hours were 1.5mg/kg in both groups, respectively.
Respiratory depression and PICU admission
occurred in 2 (4.2.%) and 4 (1.6%) patients, respectively.
For CA and AA patients, mean VAS pain scores
in PACU were 0.48 and 0.46, mean times to first opioid
rescue dose were 991.7 and 1031.9 minutes, and total
morphine over the first 48 hours were 1.5mg/kg and
1.3mg/kg, respectively. Respiratory depression occurred
in 5 (2.2.%) and 2 (3.2%) patients and PICU admission
occurred in 4 (1.8.%) and 4 (6.3%) patients, respectively.
StudentÂ’s t-test and Fisher exact test demonstrated
no significant differences between genders for all
variables, and no significant differences between races
except less total morphine for AA patients over the first
48 hours (p=0.0024).
Conclusion: An optimal intrathecal morphine dose range of
9-19 mcg/kg provides effective and safe postoperative pain
relief in children undergoing PSF and SSI for IS, regardless
of gender or race. Intrathecal morphine can be given with
the assurance that it does not discriminate against gender
or provide less optimal analgesia to AA patients.
203. APICAL VERTEBRA PEDICLE
MORPHOLOGY IN SCOLIOSIS
Denise Mackey, Firoz Miyanji, Renjit Varghese,
Davor Saravanja, Christopher W. Reilly
UBC
Purpose: There is scant literature with respect to reproducibility
in radiological measurements of vertebral
morphology. The purpose was to determine the reliability
of measurement of various parameters of vertebral
morphology in idiopathic scoliosis.
Method: Ten patients with AIS were investigated with
standardised low dose multi-slice helical CT. Axial
reconstructions in the plane of the T8 (apical) vertebra
were performed prone, as per Jamieson et al (2008).
Antero-posterior (AP) canal diameter, left and right
pedicle width, canal width, left and right mid-point to
medial pedicle length, left and right pedicle length, and
cord length, left and right transverse angles, and left and
right canal area were measured by our spine surgeons
and spine surgery fellow. Statistical analysis for intraclass
coefficients (ICC) for intra and inter observer reliability
was then performed.
Results: Intra-observer reliability was excellent, with a
mean ICC score of 0.930 (range 0.608-0.996), across all
fourteen variables. Inter-observer reliability was very good
with a mean ICC score of 0.890 (range 0.360-0.987),
across all variables. There was poor inter-observer reliability
for measurement of the transverse pedicle angles
(0.360 – 0.446). The intra-observer reliability for transverse
pedicle angles, whilst good (0.608- 0.861), was
worse than any of the other intra-observer reliabilities.
Conclusion: We demonstrate excellent intra, and inter
observer reliability for measurement of apical vertebrae
morphology in AIS. This tool can be utilized in
the further study of pedicle dysplasia. Measurement of
transverse pedicle angle was less reliable than any of the
other measurement variables. A standardised measurement
of the morphology of vertebral canal, pedicles
and vertebral body morphology is reliable both within
individual observers, and across a group of observers. A
standardised measure for further investigation has been
validated which will enable study of the evolution of pedicle
dysplasia over time. This will lead to a better understanding
of the etiology of pedicle dysplasia in scoliosis.
204. CONTINUOUS INTRAVENOUS
MORPHINE INFUSION FOR POSTOPERATIVE
ANALGESIA FOLLOWING POSTERIOR
SPINAL FUSION FOR IDIOPATHIC SCOLIOSIS
Connie Poe-Kochert, Paul A. Tripi, Jennifer
Potzman, Jochen P. Son-Hing, George H.
Thompson
Rainbow Babies and Children’s Hospital
Purpose: Postoperative pain is common following posterior
spinal fusion (PSF) and segmental spinal instrumentation
(SSI) for idiopathic scoliosis (IS). It is often
treated with intravenous morphine patient controlled
analgesia (PCA), but no studies have examined continuous
morphine infusion. The purpose of this study was to
identify the safety and efficacy of continuous morphine
infusion without PCA for post-operative pain management
in these patients.
Method: We retrospectively reviewed 338 consecutive
patients from 1992 to 2006 who received continuous
morphine infusion. Following induction of general anesthesia
and prior to surgical incision, patients received
intrathecal morphine for preemptive analgesia. Anesthesia
was maintained with 50% nitrous oxide and up to
0.6% isoflurane, with minimal or no intravenous opioids.
Following surgery, pre-ordered morphine infusion
(0.01 mg/kg/hr) began when patients first reported pain.
The infusion rate was titrated using a strict protocol
based on frequent assessment of vital signs, Wong-Baker
visual analog pain scores (VAS), and clinical status. The
infusion continued until patients were able to take oral
analgesics at postoperative day 2-3. Factors analyzed
included patient demographics, intrathecal morphine
dosage, intraoperative intravenous opioid dosage, pain
scores through the third postoperative day, interval to
start of morphine infusion, total morphine requirement
in the first 48 postoperative hours, and postoperative
complications.
Results: Mean intrathecal morphine dose was 15.45
mcg/kg and mean interval to start of morphine infusion
was 15:45 hours. Mean VAS pain scores were
3.05, 4.48, 4.48, and 4.60 at 12 hours, 1, 2, and 3 days
postoperatively. The total mean dosage of morphine in
the first 48 hours postoperatively was 0.03 mg/kg/hr.
Nausea/vomiting, pruritis, respiratory depression, and
PICU admissions related to the morphine drip occurred
in 13.3%, 4.1%, 0%, and 0% of the patients during the
same time period.
Conclusion: A low frequency of adverse events and a
mean postoperative pain score of 5 or less demonstrates
that continuous postoperative morphine infusion is a
safe and effective method of pain management in children
following PSF and SSI for IS. Continuous morphine
infusion without PCA is a safe, alternative method of
pain control for postoperative patients with IS.
J BONE JOINT SURG [BR] 2011; 93-B:SUPP III