Indications for patellofemoral arthroplasty were studied based on a 2-
to 10-year followup review. Of 183 patellofemoral prostheses implante
d between 1980 and 1990, 104 were associated with unicompartmental art
hroplasty, and 79 were implanted alone, Thirteen patients were lost to
followup, The results of 66 patellofemoral arthroplasties are reporte
d at an average followup of 66 months, The mean age of the patients at
surgery was 57 years, Underlying causes of the osteoarthritis include
d 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 grou
p, and 7 (29%) in the primary osteoarthritis group, In this latter gro
up, the indications of patellofemoral arthroplasty must be restricted
to lesions of the patellofemoral joint in a knee in neutral axis evalu
ated preoperatively on full standing and stress radiographs, The best
results of patellofemoral arthroplasty were obtained in osteoarthritis
after patellar dislocation or patellar fracture.