An Acute Osteochondral Defect Secondary to Fabella Impaction: A Case Report

A healthy 37-year-old man sustained a knee injury after performing a deep flexion maneuver while skiing and noted immediate knee pain and swelling. Because of persistent inability to fully extend his knee and persistent posterolateral knee pain, he was evaluated and noted to have an acute osteochondral defect of the posterolateral femoral condyle directly adjacent to his fabella. After a trial of nonoperative interventions, he elected to undergo an arthroscopic-assisted open excision of the fabella and a chondroplasty of the posterolateral femoral condyle defect.

A traumatic osteochondral defect secondary to a lateral fabella impaction is a rare pathology but must be evaluated in patients performing deep flexion maneuvers who have persistent knee pain and mechanical symptoms. When there is a focal defect with increased edema of both the fabella and posterolateral femoral condyle, an arthroscopic chondroplasty and fabella excision is a valid treatment to return the patient back to desired activities.