Surgical treatment of congenital dislocation of the patella

Eleven patients with 17 involved knees were surgically treated for congenital dislocation of the patella between 1978 and 1993. Ten patients with 13 involved knees followed up for a minimum of 2 years postoperatively composed the study group. Six patients had both involved knees operatively treated. In four patients, congenital dislocation of the patella was associated with a recognizable syndrome. All patients had fixed, painful lateral dislocation of the patella that could not be reduced. The average age at presentation was 7 years and 9 months (range, 2 months to 15 years). All patients underwent an extensive procedure including lateral release and advancement of the vastus medialis obliquus. Skeletally immature children underwent medial transfer of the entire patellar tendon. Skeletally mature patients underwent medial transfer of the tibial tubercle. Ten patients with 13 involved knees were followed up for > or = 2 years. Mean follow-up was 5.1 years (range, 1-17.5). At last follow-up, all patients reported a marked increase in activity tolerance and relief of pain. Average extension lag improved from 15 degrees before to 2 degrees after surgery. One superficial wound infection occurred; no patient developed a deep infection. One peroneal neurapraxia occurred but resolved with observation. Redislocation of the patella occurred in the immediate postoperative period in one patient. Operative treatment of congenital dislocation of the patella can predictably improve knee function when all aspects of the complex pathologic anatomy are addressed.