Beaumont Hospital; Oakland University William Beaumont School of Medicine
Osteochondral lesions are an uncommon cause of elbow pain seen in young athletes involved in sports such as baseball or gymnastics with throwing or tumbling actions. It is a focal injury of the cartilage and underlying bone. Injuries typically occur on the anterolateral aspect of the capitellum, which is relatively poorly vascularized. Though rare, osteochondral injuries of trochlea, radial head, or olecranon may occur. The injury is believed to result from activities involving repetitive valgus stress and patients present with pain and swelling along lateral aspect of elbow. Progression of injury may result in intra-articular bodies, clicking, locking, flexion contracture, and instability. Osteochondrosis of the capitellum, also known as Panner disease, is in the spectrum of osteochondral injuries of the elbow and is seen in athletes under the age of 10–12 years and in most cases is self-limiting. Knowledge of imaging characteristics of osteochondral injuries is essential for early and accurate diagnosis and appropriate treatment to prevent long-term debilitating conditions. The lesions may often be seen on radiographs. MRI is considered the most useful imaging modality for assessment of this entity and aids in early detection, staging, surgical planning, and post-surgical evaluation. CT may also be helpful, especially in detection of displaced intra-articular bodies.
Educational Goals / Teaching Points
This exhibit provides a pictorial review of normal anatomy of the elbow with emphasis on contours of the articular surfaces to avoid pitfalls and misdiagnosis; describes (with examples) the characteristic findings of osteochondral injuries as seen on radiographs, MRI, and CT, and the distinguishing imaging features of osteochondrosis, osteochondral lesions, mimics and pitfalls; and discusses staging of osteochondral lesions and postoperative evaluation.
Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Panner disease and osteochondral lesions have distinguishable features on radiographs and MRI. With Panner disease, cartilage of the capitellum is usually preserved as seen on MRI. In contrast, with an osteochondral lesion, the cartilage and underlying bone are involved and sclerosis, fragmentation, and flattening of the articular surface is seen with progression of disease. MRI arthrography may help in detection of a completely detached fragment if contrast extends deep to the lesion through a defect in the subchondral bone plate. CT is useful in detection of intra-articular fragments.
Familiarity with imaging characteristics of osteochondral injuries is essential for early detection and accurate staging. Treatment planning and prognosis is based on imaging findings that can distinguish between stable and unstable lesions.