Arthroscopic lateral release for patellar pain or instability.

Forty-five arthroscopic lateral releases were reviewed with a follow-up from 2 to 6 years (average 4 years). Satisfactory results were obtained in 60% of the patellar pain group (20 knees) and 68.5% of the instability group (19 knees). The results in osteoarthrosis (6 knees) were unsatisfactory. Postoperative hemarthrosis was infrequent (2.2%). Unfavorable prognostic factors are an incomplete release with an insufficient postoperative passive patellar tilt in the pain group and more than five preoperative dislocations in the instability group. After failure of conservative treatment, a lateral release can be reasonably used in pain syndromes with a tight lateral retinaculum and lateral patellar tracking and in milder cases of instability.