Patellar complications after total knee arthroplasty.

One hundred total knee arthroplasties implanted between 1989 and 1993 in 70 women and 30 men (average age 67.4 years) have been retrospectively reviewed. Six late patellar complications occurred: two fractures, two subluxations, one dislocation and one loosening. Four had a further operation. The patient's age, type of implant, lateral patellar release, thickness of the implant and the final range of movement were studied. Complications have been more common in men (8.7%) than women (5.2%) with a statistically significant difference (p < 0.05). This may be because men make a greater functional demand on their arthroplasties. No other factors were relevant.