Notas / Notes - Active Congress.......

MIÉRCOLES / WEDNESDAY
80
DIAGNOSIS OF THE PAINFUL
CEMENTLESS HIP
Rudolph Geesink MD PhD
Professor of Orthopaedic Surgery, Maastricht University,
Netherlands
If the goals of arthroplasty to restore longevity of pain-free
function are not met, the patient may visit the surgeon for
further diagnosis and selection of treatment. Many factors
may be responsible for problems in arthroplasty and radiology
is an important diagnostic instrument. However with cementless
arthroplasty radiological failure criteria are much more
difficult to define compared to cemented arthroplasty. This
is mainly caused by the great variety in fixation principles
and design factors of cementless hip implants.
- material (stiffness, titanium or CoChr alloys)
- design (cylindrical 2-D 3-D wedge)
- surface texture (macro-texture, porous-or fiber-mesh
coating)
- biological coating (HA-coating of variable length)
In addition there are multiple failure mechanisms for implants:
- fracture, device or bone
- disturbed biomechanics
- loosening
- infection
- wear & lysis
- stress-shielding
- pain without any of previous problems
Radiological diagnostic tools may include:
- standard X-rays, protocol & lateral for position and gross
fixation
- interface study using contrast or nuclear arthrography
- technetium, gallium or indium scintigraphy to rule out
in-fection
- CT-scan to detect hidden osteolysis (modern metal removal
software)
- fluoroscopy rarely necessary
Through systematic use of radiological tools, proper interpretation
of clinical signs plus knowledge of potential failure mechanisms
it is usually possible to arrive at a diagnosis and
prove or disprove one of the previous failure mechanisms.
Points to remember:
- interpret clinical signs
- know the implant characteristics
- be aware of potential problems
- choose correct diagnostic tools
- interpret radiographic signs
- check for infection
- diagnosis usually possible preoperatively
THE INCIDENCE OF THIGH PAIN AND
CLINICAL OUTCOME OF A TAPERED
FEMORAL STEM
Victor M. Goldberg, M.D; Sam Akhavan, M.D.
Case Medical Center, Department of Orthopaedics
Cleveland, Ohio (USA)
Tapered femoral components were designed to provide a
cementless alternative in patients with narrow femoral canals.
Major concerns with this stem include perioperative fracture
and thigh pain. To ascertain the frequency of these concerns,
we retrospectively reviewed 100 consecutive hips in 97 patients
with osteoarthritis who underwent total hip arthroplasty with
a tapered fibermetal femoral component. Patients were evaluated
postoperatively using Harris Hip Scores and sequential
radiographs. The average age of the patients was 56.5 years
(range 33.7-73.5 yrs). Minimum followup was 6 years (average
6-10 yrs). One patient died at 1.3 years and was excluded
from the study. Four patients had incomplete perioperative
fractures of the calcar without extension below the lesser trochanter.
All fractures were recognized perioperatively and
fixed with cerclage wires without further problems. Four patient
underwent revision surgery, two for recurrent dislocation secondary
to malpositioning of the acetabular cup, one for a
greater trochanteric fracture after a fall, and one for a fractured
zirconium femoral head. At last followup, the mean Harris Hip
Score was 98 (Range 86-100); two patients had mild anterior
thigh pain. All femoral stems appeared to have bony integration
radiographically. Tapered femoral stems provide a cementless
alternative in patients with a narrow femoral canal without
undue risk of perioperative fracture of thigh pain.
LEG LENGTH INEQUALITY:
PREVENTION AND MANAGEMENT
Douglas A. Dennis, MD
Adjunct Professor, Department of Biomedical Engineering
University of Tennessee, Assistant Clinical Professor,
University of Colorado Health Sciences Center, Clinical
Director, Rocky Mountain Musculoskeletal Research
Laboratory
Denver, Colorado (USA)
Leg length discrepancy (LLD) is an undesired complication
of total hip arthroplasty (THA). It creates numerous potential
adverse effects including low back pain, sciatica, limp, hip
instability, increased hip forces, hip pain (in non-implanted