Congenital dislocation of the patella and its operative treatment.

Twelve patients with 18 knees whose congenital permanent lateral dislocation of the patella was irreducible by nonoperative means are reported. All knees were operated on according to the same principles, including medial transfer of the patellar tendon. The age of the patients at operation varied between 3 and 19 years. The average follow-up time was greater than 13 years. All patients benefited greatly from the operation. Active knee extension ability was restored in all knees. Some extension deficit remained in two severely dysplastic patients. Congenital subluxation with habitual dislocation of the patella has been successfully treated by the method described.