Background: An osteochondral fracture in the posterolateral margin of the capitellum is recognized as being a cause of posterolateral rotatory instability (PLRI).
Methods: Five patients who presented with chronic PLRI of the elbow were associated with an osteochondral fracture in the posterolateral margin of the capitellum (Osborne-Cotterill lesion). All presented instability and deficient radiocapitellar articulation at extension. Ligament reconstruction was performed in the first three cases, and combined ligament and osseous reconstruction was performed in the other two cases.
Results: Simple excision and ligament reconstruction resulted in one failure out of three, and combined ligament and osseous reconstruction resulted in no failure out of two.
Conclusions: Osteochondral defect in the posterolateral aspect of the capitellum is an important indicator of PLRI; however, the result of this study suggests ligament reconstruction for those with a large bone defect may not be always successful.