Diagnosis and treatment of osteochondritis dissecans of the humeral capitellum.

Osteochondritis dissecans (OCD) of the humeral capitellum is a critical elbow injury in adolescent overhead throwing athletes. However, its etiology remains unknown. Medical examinations using ultrasonography found that the prevalence of capitellar OCD among adolescent baseball players was approximately from 1% to 3%. A plain anteroposterior radiograph with the elbow in 45° of flexion is essential for the diagnosis of an OCD lesion. The stability of OCD lesions is evaluated on plain radiographs, computed tomography, and magnetic resonance imaging (MRI). Imaging features of the unstable lesions are an epiphyseal closure of the capitellum or a lateral epicondyle, a displaced fragment, or irregular contours of the articular surface and a high signal interface on T2-weighted MRI. A stable lesion has the potential to be healed with conservative treatment. By contrast, surgical treatment should be considered if there is no radiographic improvement within 3 months. In addition, surgery should be performed for the lesions that cause pain during daily activities, have a locking phenomenon, or which are assessed by imaging as obviously unstable. Arthroscopic debridement/loose body removal can be performed for small lesions (≤12 mm in diameter). For large lesions (>12 mm), preservation and/or reconstruction of the articular surface should be selected, such as bone-peg fixation of the lateral part of the fragment and osteochondral autograft transplantation (OAT) from the knee. In the future directions, there is no comparative study of OAT from the knee and rib. In addition, little is known about its long-term outcome, or resulting osteoarthritis. A recent meta-analysis showed that grafts harvested from the knee may lead to donor site morbidity (7.8%). Thus, a novel cartilage tissue engineering approach is anticipated.