SMW Supplementum 193 - Swiss Medical Weekly

19 S SWiSS Med Wkly 2012;142(Suppl 193) · www.smw.ch Free communications
Conclusion: Joint pain is strongly associated with SF leptin
concentrations. Increased pain observed in women and in obese
patients may be related to high leptin levels. However, due to the
cross-sectional study design a causal relation between leptin and joint
pain cannot be ascertained.
FM70
Statins may reduce femoral osteolysis in patients
with total hip arthroplasty
Anne Lübbeke-Wolff1 , Guido Garavaglia2 , Christophe Barea1 ,
Alexis Bonvin1 , Constantinos Roussos1 , Pierre Hoffmeyer1 1Hôpitaux Universitaires de Genève; 2Ospedale Regionale
di Bellinzona
Background: Periprosthetic osteolysis threatening the survival of
implants is the main long-term complication after total hip arthroplasty
(THA). Statins are frequently taken by elderly patients. In experimental
studies their use has been associated with reduction of osteoclastic
activity and subsequent periprosthetic osteolysis as well as with
promotion of bone formation around implants. Our objective was to
evaluate the influence of statin use on the development of femoral
osteolysis within five years after THA.
Methods: We conducted a nested case-control (case-cohort) study
with 100% sampling including all THAs presenting with femoral
osteolysis at the five year visit (cases) and compared them with those
without osteolysis at five years (controls). Cases and controls were
identified from a cohort of primary THAs operated between January
2001 and December 2005 with the same uncemented cup and the
same 28 mm head size. Periprosthetic osteolysis was assessed on
standardised radiographs by a surgeon blinded to the patient’s
exposure status.
Results: 735 primary THAs were included, mean age 68 years, 54%
in women. Five years after surgery osteolysis had developed around
the femoral component of 40 THAs (5.4%). Ever-use of statins was
much less frequent among cases (5 of 40, 12.5%) than among
controls (199 of 695, 28.6%). The crude risk ratio of femoral osteolysis
among statin users was 0.36 (95% CI 0.14; 0.92). After adjusting for
age, sex, patient activity level, body mass index, diagnosis, type of
bearing surface, and type of stem in a multiple logistic regression
analysis, the adjusted risk ratio was 0.38 (95% CI 0.15; 0.99).
Conclusion: Statin use was associated with a substantially reduced
risk of developing femoral osteolysis five years after primary
THA. Statins may be useful for reducing the risk of implant failure
following THA.
FM71
Use of the Hohmann brace does not prevent recurrent
dislocation after primary THA
Jean-Christophe Richard, Hermes H. Miozzari,
Anne Lübbeke, Pierre Hoffmeyer, Robin Peter
HCUGE
Introduction: Two thirds of first dislocations after primary total hip
arthroplasty (THA) can be treated conservatively after successful
closed reduction, in the absence of component malposition1. Use of an
abduction brace such as the Hohmann brace is precognized by many
orthopaedics surgeons but evidence about its usefulness is sparse.
DeWal et al.2 in 2004 reported no efficacy of such a brace in
preventing re-dislocation after THA using mostly a posterior approach
(38/42 patients). Our objective was to investigate whether the use of
an abduction brace was associated with reduction of (1) recurrent
dislocation and (2) revision surgery in patients with a first episode of
dislocation after primary THA operated upon with different approaches.
Methods: We conducted a retrospective cohort study. Between 3/1996
and 6/2011, we identified 92 patients with hip dislocation after THA,
close reduction under general anaesthesia followed by a conservative
treatment with a minimum f/u of 6 months. 68 patients had a Hohmann
brace for a mean of 10.7 weeks and 24 patients had no contention at
all. There were 52 men and 40 women. Mean age at dislocation was
71 years. A transgluteal approach was used in 78 patients, a posterior
in 9, an anterior in 4 and a trochanter flip in 1 patient. Primary outcome
was recurrent dislocation; secondary outcome was revision for
recurrent dislocation. The results were adjusted with the propensity
score method for diagnosis (primary or secondary osteoarthritis,
fracture), gender, age, previous surgery, ASA score, BMI, year of
intervention, cup size, cup inclination, neck length, surgical approach
and participation in preoperative patient education.
Results: Within the Hohmann group the incidence of re-dislocation
was 39.7% (27/68 patients) compared to 33.3% (8/24) in the other
group. Incidence of revision was 22.1% (15/68) compared to 16.7%
(4/24). Logistic regression for recurrent dislocation showed an
unadjusted odds ratio of 1.3 (95% CI 0.5–3.5), p = 0.581. When
adjusted the odds ratio was 0.7 (95% CI 0.2–2.0), p = 0.478. The
unadjusted odds ratio for revision THA was 1.4 (95% CI 0.4–4.8),
p = 0.576 and the adjusted 1.0 (95% CI 0.3–3.7), p = 0.991.
Conclusion: Use of the Hohmann brace did not substantially reduce
the risk of recurrent dislocation or revision surgery for instability after
primary THA.
1. Daly PJ, Morrey BF. J Bone Joint Surg. 74A: 1334, 1992. 2. Dewal H,
et al. J Arthroplasty. 2004 Sep;19(6):733–8.
FM72
Risk factors for dislocation following primary total hip
arthroplasty
Domizio L. Suvà, Anne Lübbeke, Doris Zimmermann,
Robin Peter, Pierre Hoffmeyer
Service d’orthopédie, Hôpitaux Universitaires de Genève
Introduction: Dislocation occurs in 1–5% of patients after primary
THA and is the second cause of revision after aseptic loosening. The
risk is highest during the first postoperative 6 months. While implantand
surgery-related risk factors have been extensively reported, there
is less data concerning patient-related risk factors.
Objective: To determine which patients’ characteristics are associated
with an increased incidence of dislocation during the first 6 months
after primary THA while simultaneously taking into account implantand
surgery-related factors.
Methods: We included all primary THA patients operated between
1998 and 2010, using a lateral approach and 28 mm head. The data
were prospectively collected using the Geneva Hip Arthroplasty
Registry, and we analyzed the impact of gender, age, BMI,
co-morbidities, ASA score, neurologic disorders, primary versus
secondary OA, prior surgery, SF-12 physical and mental health status,
activity level, and participation in a preoperative education program.
Risk factors were evaluated using uni- and multi-variate logistic
regression. Implant- and surgery-related factors as cup inclination,
surgical approach, head size, cup size and surgeon experience were
controlled for by either restriction or adjustment if necessary.
Results: Overall, 3,264 primary THAs were included (mean age
70 years (±11), 58% women). Among them 60 dislocations (1.8%)
occurred during the first 6 months post-operative. The risk ratio
was higher for men than women, for patients with BMI ≥30, >2
co-morbidities, an ASA score 3–4, and prior hip surgery as well as
for patients who had not participated in the preoperative education
program. In the multivariate analysis all but the ASA score remained
significant predictors of dislocation.
Conclusion: Our study reports the largest number of patient-related
risk factors for dislocation to date. These results may help surgeons in
identifying high risk patients, thus selecting the best strategy which
should include preoperative patient education.
FM73
Outcomes of cable vs. wire fixation five years after
total hip arthroplasty
Panayiotis-L. Christofilopoulos1 , Berton Charles2 ,
Anne Lubbeke Wolff3 , Gabor Janos Puskas4 , Pierre Hoffmeyer3 1 2 3 4 HCUGE; CHU Lille; HUG; Uniklinik Balgrist
Introduction: Cables and wires are currently used for fixation of
greater trochanter or femoral fractures and osteotomies in complex
primary and revision hip arthroplasty. Better results have been
reported with cables regarding greater trochanter consolidation and
breakage resistance. However, cables have been associated with
increased osteolysis and subsequent aseptic loosening. No recent
study has compared the results of cable versus wire fixation. Our
objective was to evaluate 5-year clinical and radiographic outcomes
and complication rates of a cable system, and compare them to results
of wire fixation.
Methods: Prospective cohort study including all primary and revision
THAs performed between 3/1996 and 12/2005 with cable or wire
fixation of fractures or osteotomies. Clinical and radiographic
evaluation performed 5 years postoperative.
Results: Cables were used in 51 THAs and wires in 126 THAs. Three
patients with cables developed a foreign-body reaction. After five years
radiographs of 33 THAs with cables and 91 with wires showed an
implant breakage of 36% and 46%, respectively. With cable fixation a
significantly higher risk was found of non-union (36 vs. 21%; RR 1.7
(95% CI 1.0; 3.2)), osteolysis around the fixation (52 vs. 11%; RR 4.7
(95% CI 2.4; 9.2)) and femoral and acetabular osteolysis. Cable
breakage increased the risk of osteolysis to 86%. Clinical results did
not substantially differ between the two groups.
Conclusion: 5 years after THA we found a significantly higher risk
of non-union and osteolysis with the cable system. In the presence
of cable breakage almost 90% had developed osteolysis.