Total ankle arthroplasty - three-component total ankle arthroplasty in western France: a radiographic study.

INTRODUCTION: Although the literature has confirmed the short and intermediate term efficacy of three-component mobile-bearing total ankle arthroplasty (TAA), the development of progressive periprosthetic bone abnormalities threatens the intermediate and long term survival of these implants. The aim of this study was to evaluate whether TAA quality requirements were met and analyze radiological changes in arthroplasties performed by members of the French Western Orthopedics Society. MATERIALS AND METHODS: This retrospective multicenter study included 173 patients who underwent three-component mobile-bearing arthroplasty between 1997 and 2010 in eight centers in western France. The etiology was osteoarthritis (OA) in 78% of cases and rheumatoid arthropathy in 13% of cases. The radiographic assessment included preoperative and final postoperative standing anteroposterior (AP) and lateral view radiographs. Radiographs were reviewed for ankle alignment, improper implant positions, and periprosthetic bone anomalies. Intraprosthetic range of motion was evaluated in 111 cases on dynamic radiographs. RESULTS: Mean follow-up was 34 months (± 5). Fifteen percent of the cases presented implant malposition. Alignment was normal in 76% of cases. Intraprosthetic range of motion was 20.5° (± 3) in the cases that were evaluated. Bone cysts were observed in 33% of cases, radioluncencies in 72%, ossifications in 39%, migration of the tibial component in 5% and migration of the talar component in 27%. The latter were correlated to a range of motion of less than 15°. Additional surgery was necessary in 8% of cases to revise implants and/or for conversion to arthrodesis. DISCUSSION: The high rate of radiolucencies and bone cysts at a mean follow-up of 2.8 years is of concern and these arthroplasties should be closely monitored. Stiff ankles seemed to be at a higher risk for subsidence. LEVEL OF EVIDENCE: IV - Retrospective study.

[Dimensions of the lateral condyle in non-arthritic valgus knees. A cadaver study]. / Dimensions du condyle fémoral latéral dans les genu valgum non-arthrosiques. Etude cadavérique.

PURPOSE OF THE STUDY: Although the valgus slope of the femoral condyles seen in valgus knee is thought to be due to hypoplasia of the lateral femoral condyle, this fact has not been proved. The aim of this study was therefore to evaluate the difference between the size of the lateral femoral condyle of neutral and valgus knees. MATERIAL AND METHODS: There were 41 non-arthritics lower limbs taken from 27 caucasians donors. Angular measurements were taken with respect to the mechanical axis of the bones. Femurs were then isolated from the tibia, all soft tissue was removed with respect to the articular cartilage. An osteometric system developed for this study allowed each femur to be precisely photographed in perpendicular planes. Each femur was mounted on the osteometric system. The dimensions (depth and height) of each lateral femoral condyle were obtained using direct measurements from standardized photographs. Knees were considered neutral when the tibiofemoral mechanical angle (TFMA) was between 181 degrees and 176.6 degrees and considered valgus when over 181 degrees. To be compared, measurements were related to the transepicondylar width of each femur. The related dimensions were then compared for both categories of knees (valgus and neutral). There were 18 valgus knees (mean TFMA 182.7 degrees +/- 0.8) and 23 neutral knees (mean TFMA 179.1 degrees +/- 1.6). A validation for the technique was performed by measuring six points on a same femur by the same person seven times. This revealed standard deviations of 0.7 millimeters which was small enough for our purpose. The relationships between the related measurements were analyzed using the Mann & Whitney U test. Significance was accepted at a P value of less than 0.05. RESULTS: The related depth of the lateral femoral condyle was bigger for valgus knees 32.0 (+/- 2.5) than for the neutral knees 30.5 (+/- 2.0). The related heights of the lateral femoral condyle were about equal 28.7 (+/- 1.8). DISCUSSION: Using a population of non arthritic knees, our data demonstrated that the lateral femoral condyle is thicker in valgus knees compared to neutral knees, thus in contradiction with the most common view. We suggest that in fixed valgus knees, beside arthritic wear, there is no deficiency of the posterior lateral condyle of the femur.

[Shoulder instability]. / Epaule instable.

Shoulder instability is a sign described by the patient. The etiology of this instability is varied: sometimes it is the result of a traumatic luxation with tear of the gleno-humeral inferior ligament, sometimes it is the result of an abnormal hyperlaxity. The examiner must be able to do a difference between these two causes because treatment and consequence are very different. Nevertheless, these two factors can be associated at variable degrees. A careful history and examination, a precise x-rays and scanning can help the examiner to solve this difficult problem.