Lateral release in chondromalacia patellae using clinical, radiologic, electromyographic, and muscle force testing evaluation.

Lateral release (division of the lateral retinaculum of the patella) is a common operative procedure to improve alignment of the patella in patients with chondromalacia patellae. We investigated the effects of lateral release using clinical follow-up and studied the changes in the radiologic measurements of the patellar alignment and electromyographic function of the stabilizing muscles of the knee, as well as using muscle-force tests of the thigh. The study included 75 patients. Diagnostic arthroscopy was done for all patients. In 42 patients with obvious incongruency of the patellofemoral joint observed at arthroscopy, open division of the lateral patellar retinaculum was performed in addition to arthroscopy. Four years after surgery, the results showed that although division of the lateral retinaculum of the patella reduced lateral patellar tilting and lateral patellar displacement, the postoperative physical capacity of the patients was not improved. Lateral release did not impair the electrical activity of thigh muscles. The Lysholm scores of the lateral release group and the control group were equal after four years.