Articular cartilage sleeve fracture of the lateral humeral condyle capitellum: a previously undescribed entity.

Salter-Harris type IV fractures of the lateral humeral condyle are well-recognized injuries that have been previously described and classified. The case of an 11-year-old boy who sustained an unusual fracture of the distal humerus with the free fragment composed of 75% of the articular cartilage of the capitellum is presented. The cartilage was attached to only a thin shell of subchondral capitellar bone in continuity with the lateral aspect of the distal humeral physis and metaphysis. Radiographs did not show the magnitude of the articular cartilage component of the fracture, although physical examination was significant for elbow crepitus through a limited range of motion. Open reduction and internal fixation were necessary to achieve a congruous joint and restore anatomic alignment.