Hegemann disease is osteochondrosis of the humeral trochlea, similar to Panner disease, but much less common. Patients are typically between the ages of 7–13 years, and present with swelling and restricted range of motion
Radiographs reveal rarefaction of the ossification center of the trochlea with condensation and collapse. Because the trochlea has a multicentric, irregular, and granular ossification center compared to the capitulum, comparison views and radiographic follow-up should be used to distinguish normal variants of ossification from Hegemann disease.
The main differential consideration is osteochondritis dissecans, which tends to affect older patients (12-15 years, around the time of epiphyseal plate ossification), does not affect the entire ossification center (only the subchondral bone), and is not a self-limited process. Chondroblastoma is also a consideration, as it tends to affect the epiphysis.