Unicortical transverse osteochondral fracture of the patella: a case report.

Chondral lesions are relatively common and they usually occur as a result of high energy trauma. Chondral fractures of the patella ordinarily occur during an acute dislocation of the patella. Patellar chondral fractures without either a dislocation or a patella fracture are extremely rare. We have treated a 25-year-old male who had a unicortical transverse osteochondral fracture of the patella without a dislocation which was produced by high energy trauma. Chondral fractures of the patella are often overlooked because they are difficult to detect on plain radiographs. A persistent cartilaginous irregularity from either a chondral or osteochondral fracture may lead to the development of secondary osteoarthrosis. In this case, restoration of the articular surface was achieved by elevation of the compressed osteochondral fragment. This case demonstrates that understanding the mechanism of injury can be helpful in the treatment of osteochondral lesions.