Is there a place for patellofemoral arthroplasty?

Indications for patellofemoral arthroplasty were studied based on a 2- to 10-year followup review. Of 183 patellofemoral prostheses implanted between 1980 and 1990, 104 were associated with unicompartmental arthroplasty, and 79 were implanted alone. Thirteen patients were lost to followup. The results of 66 patellofemoral arthroplasties are reported at an average followup of 66 months. The mean age of the patients at surgery was 57 years. Underlying causes of the osteoarthritis included patellar dislocation or dysplasia (22), patellar fracture (20), and primary osteoarthritis (24). A metallic femoral groove was associated with a polyethylene patella with no metal backing. Two (9%) prostheses were revised in the dysplasia group, 1 (5%) in the posttraumatic group, and 7 (29%) in the primary osteoarthritis group. In this latter group, the indications of patellofemoral arthroplasty must be restricted to lesions of the patellofemoral joint in a knee in neutral axis evaluated preoperatively on full standing and stress radiographs. The best results of patellofemoral arthroplasty were obtained in osteoarthritis after patellar dislocation or patellar fracture.