The diagnosis and treatment of medial subluxation of the patella after lateral retinacular release.

Five patients with medial subluxation of the patella occurring after isolated lateral retinacular release were treated between July 1985 and July 1989. The diagnosis was made by clinical examination. The patients complained of pain, swelling, and giving way after the lateral release. All five patients had increased medial passive patellar mobility, a positive gravity subluxation test, and a positive medial apprehension test. All patients failed conservative treatment. The patients were treated by reconstruction of the lateral retinaculum using sensory epidural anesthesia. At an average followup of 3.3 years, four of the five patients had no symptoms of instability and the medial patellar mobility and gravity subluxation tests were negative. There were three excellent and two good results using the grading system of Merchant and Mercer.