Weight-bearing osteochondral lesions of the lateral femoral condyle following patellar dislocation in adolescent athletes.

In patients with patellar dislocation, osteochondral injury is often an indication for early surgical intervention. However, no studies have identified a relationship between injury to the weight-bearing surface of the lateral femoral condyle following a patellar dislocation and the eventual need for surgical treatment. The authors hypothesized that a significant number of patients sustain injury to the weight-bearing surface of the lateral femoral condyle following an acute patellar dislocation.Radiographs and magnetic resonance images were retrospectively reviewed and the patterns of injury were evaluated for 80 patients with a diagnosis of acute patellar dislocation, including the presence of osteochondral damage, the location of the medial patellofemoral ligament injury, and concomitant meniscal pathology. Magnetic resonance imaging identified a 27.5% incidence of osteochondral injury involving the articular, weight-bearing region of the lateral femoral condyle following an acute lateral patellar dislocation. Surgical intervention was performed in more than 60% of these injuries, and most were not identified with plain radiographs. Injury to the weight-bearing surface of the lateral femoral condyle following patellar dislocation was 3.6 times more common in boys in the current study population.Osteochondral injury to the weight-bearing surface of the lateral femoral condyle may occur in a high percentage of patients following a lateral patellar dislocation and in a higher percentage of boys than girls. Patients with tenderness over the lateral femoral condyle following an acute lateral patellar dislocation should undergo magnetic resonance imaging.