Recurrent subluxation and dislocation of the patella in association with athletic injuries.

Seventy-one patients with 81 operations for correction of patellar instability are reviewed. Follow-up was for at least five years. The various preoperative symptoms, signs, and radiographic findings are presented. Two types of patellar instability become clear. One type is usually bilateral and secondary to general ligamentous laxity. A second type, usually unilateral with distinct physical findings, is secondary to trauma. The operative technique and results of surgery and physical therapy are discussed. A new rational approach to the operative treatment of recurrent subluxation and dislocation of the patella is proposed. The operative procedure would depend on the Q angle. For a Q angle of less than 14 degrees, a proximal realignment is sufficient. For a Q angle greater than 14 degrees, a distal realignment would be necessary in addition.