Patellofemoral disorders treated by operations.

Thirty-six patients with patellofemoral disorders treated with various operative procedures were evaluated after an average follow-up period of 29 (6 to 72) months. Instability of the patella, either recurrent dislocation or subluxation, was present preoperatively in 27 knees (Group A). Twelve patients (Group B) were operated on for chondromalacia, which was not combined with a history of instability. Good results were obtained in 15 cases in Group A and in only three cases in Group B. Simple procedures, lateral release alone and medial duplication alone appeared to be ineffective methods.