Injuries at the articulating surfaces of bone (chondral, osteochondral, subchondral fractures and osteochondrosis dissecans)
Fractures involving the articulating surfaces of bone are a common cause of joint disability. Management options are as numerous as the terms used to describe these lesions. These terms include osteochondral, transchondral, flake or chip fractures as well as osteochondrosis (osteochondritis) dissecans. The understanding of these traumatic lesions and their sequelae has been increased by modern imaging technology, especially magnetic resonance imaging (MRI). This paper reviews the mechanism of these injuries, their incidence, clinical presentation, radiological appearance and the principles of their treatment. Hyaline cartilage, subchondral bone plate and subchondral cancellous bone have to be seen as an anatomic unity. Subchondrally located cancellous microfractures, osteochondral fractures and solely chondral fractures are different manifestations of impaction injuries at the articulating surfaces. We believe that osteochondrosis dissecans in most cases is also the result of undiagnosed injury at the articulating surface of bone.