Chronic pain along the lateral condyle of humerus

Discussion

Osteochondral defect (OCD) is one of the entities in the wide spectrum of osteochondral lesions of bone. There is no consensus on the etiology of OCD. The cause appears to result from direct repetitive micro trauma, overuse (in athletes), or secondarily from loss of blood supply to the subchondral bone. The most common location for an OCD is the knee joint followed by the ankle and elbow joints. The role of imaging in osteochondral injury is first to diagnose the abnormality, and then characterize it according to the extent of involvement, stability of the lesion, and any associated complications. Magnetic resonance imaging is the most sensitive and reliable imaging technique for the assessment of osteochondral lesions, but plain radiography is usually the first imaging that was carried out.1 The diagnosis of OCD is made on 2 standard views; plain radiograph of the involved joint with oblique views taken if necessary. Osteochondral defect is seen as a focal radioopaque lesion with perilesional radiolucency disrupting the subchondral cortical line. Fragmentation of the articular surface and presence of articular bodies suggest an unstable lesion on plain radiography.

The diagnosis is suggested on MRI by identifying signal changes, or morphologic changes at the articular surface. The presence of a focal articular surface defect with high signal intensity between the lesion and normal bone on fluid sensitive sequence indicates an unstable lesion on MRI. These findings can be noted in our case on T2W and PD sequence images (Figure 2). The unstable lesion identified on MRI can remain attached, or can detach and appear as a separate displaced articular body, usually adjacent to the defect. In such cases, MR arthrography can improve the staging accuracy for osteochondral lesions.2

Treatment for an osteochondral defect depends on the status of the articular surface and underlying bone. The aim of treatment should be to achieve painless range of motion and to preserve chondral integrity. Conservative treatment in the form of an extended period of rest with non-steroidal anti-inflammatory drugs; active physiotherpy is reserved for patients with a stable and viable lesion. The success rate of nonoperative treatment for stable lesions is 50%.3 A spectrum of surgical treatments are available for patients with failed conservative treatment, and unstable or nonviable lesions. Surgical options ranges from arthoscopic debridement to osteochondral autograft transfer. Other surgical options include internal fixation of the fragment using bioabsorbable screws if the size of the fragment is enough for screw purchase, debridement of the nonviable fragment with microfracture of the underlying subchondral bone, or the use of an osteochondral graft.4 Very little literature is available, which suggests that the preferred treatment is arthroscopic debridement with, or without drilling.