Osteochondral lesions of the capitellum usually are seen in young baseball pitchers, racket sports athletes, and gymnasts . The same valgus stress that in the adult throwing athlete produces MCL tears can give an impaction osteochondral lesion in the child or adolescent. When the lesion is seen in children less than 12 years old with open physes, it is called Panner osteochondrosis. When it occurs in adolescents, it is called OCD. Although there is some controversy, many authors believe that the two conditions share the same cause . Typical Panner osteochondrosis lesions in which there is only minimal flattening of the capitellar subchondral bone plate typically resolve without sequelae . Older adolescents with an OCD lesion, especially if the physes are fusing and there is a discrete osteochondral fragment, may develop chronic sequelae, such as long-term pain, premature osteoarthritis, loss of terminal extension, and chronic instability of the radial head [7,8].
Osteochondral lesions of the capitellum can have several appearances on MRI images. Early or small lesions appear as a crescentic subchondral area of signal abnormality in the anterolateral capitellum . They are usually low to intermediate signal on T1-weighted images and high signal on T2-weighted images and may have some flattening of the subchondral bone plate (Fig. 4). The adjacent articular cartilage may be irregular. More severe or advanced lesions have a bone fragment with a linear area of high or low signal at its interface with the adjacent bone marrow.
MRI is helpful for several reasons in the patient with suspected osteochon-dritis dissecans. First, lesions can be diagnosed on MRI before they are seen radiographically . In small osteochondral lesions early treatment may prevent chronic symptoms . Second, MRI can help with preoperative planning by showing accurately the size of the lesion, the integrity of the cartilage, and if there are associated loose bodies, particularly chondral bodies. Third, MRI can show accurately the size and viability of an osteochondral fragment and
Fig. 4. OCD lesion in a 16-year-old male. Coronal T2-weighted image shows a focal area of high signal (arrow) in the capitellum. (From Kijowski R, De Smet A. Radiography of the elbow for evaluation of patients with osteochondritis dissecans of the capitellum. Skeletal Radiol 2005;34:266-71; with permission.)
whether it is unstable . The most common finding of an unstable OCD fragment on MRI is linear high signal on T2-weighted images along most of the interface between the fragment and the capitellum . This high signal represents either fluid or granulation tissue, both of which occur in unstable OCD lesions. OCD fragments that are stable do not have this high signal along the interface.
Some authors advocate performing an MRI arthrogram for patients with a suspected OCD of the capitellum. If contrast extends into a linear defect at the margins of the fragment, the fragment usually is mobile and unstable (Fig. 5) .
Fig. 5. Unstable OCD lesion in a 17-year-old male. Sagittal fat-suppressed Tl-weighted image shows linear high signal (arrow) gadolinium contrast surrounding the OCD fragment.
Was this article helpful?
It's time for a change. Finally A Way to Get Pain Relief for Your Arthritis Without Possibly Risking Your Health in the Process. You may not be aware of this, but taking prescription drugs to get relief for your Arthritis Pain is not the only solution. There are alternative pain relief treatments available.