[Osteochondral fractures of the knee joint, its classification and its relationship to osteochondrosis dissecans.]

The author deals with the classification of osteochondral fractures of the knee joint. The existing classification schemes of lesion of the articular surface are rather general and do not distinguish between different causes of their onset. The only exception is the classification of G. Muhr who divides traumatic lesion of the articular cartilage into contusions, impressions and fractures. Contusions include subchondral hematoma and fissures of the articular surface. Among impressions are impression fractures, spring impressions of the articular edge. Fractures are divided into isolated chondral fractures and osteochondral fractures. Osteochondrosis dissecans is not an unequivocally defined nosological unit. The frequently used term osteochondritis dissecans is incorrect as the inflammation is the sequela of the disease rather than its cause. Classified in this category are different, in most cases chronic lesions of the articular surface, and quite often also sequelae of acute osteochondral fractures. In the authors' view the term osteochondrosis dissecans should be reserved only for lesions affecting the medial condyle of femur where primary changes involve subchondral bone and the involvement of articular surface is secondary. In any case the problem of the role of an acute or chronic trauma in the aetiology of osteochondrosis dissecans of the knee and other joints has not been so far reliably solved. Key words: knee joints, osteochondral fractures, classification, osteochondrosis dissecans.