Chondral fractures of the knee. Arthrographic, arthroscopic, and clinical manifestations.

Chondral fractures are a distinct clinical entity and should be distinguished from the more frequently recognized osteochondral fracture. They occur most often in the medial femoral condyle of young adults following a rotational injury or direct blow to the knee. Clinically, the chondral fracture mimics a torn meniscus and may or may not be associated with a meniscal tear. Unlike osteochondral fractures, chondral fractures exhibit no specific abnormalities on routine radiography, necessitating arthroscopy or arthrography for diagnosis. The abnormality is seen as as a scooped-out defect or linear fracture in the articular cartilage on arthrography; on arthroscopy the findings are similar, though the fracture may appear stellate in cases of a direct blow to the knee.