Etiological factors in osteochondritis dissecans. An experimental study into the etiological factors in osteochondritis dissecans in the canine humeral head using overloading with and without somatotropin and thyrotropin hormone treatment and mechanical trauma.

The overloaded humeral heads of the six growing Labrador retrievers treated with somatotropin and thyrotropin hormone showed the most pronounced changes of the articular cartilage and subchondral home, resembling changes in the early stage of spontaneous osteochondritis dissecans. The overloading alone used in 16 dogs without hormone treatment produced no changes, except that two Labrador retrievers showed increased radiodensity subchondrally during the first 4-6 weeks of the observation period. The mechanical traumas of the articular cartilage and the epiphyseal bone regenerated and did not result in changes resembling those of spontaneous osteochondritis dissecans.