Morphology of osteochondrosis and sequelae in pigs.

The morphologic features of osteochondrosis were studied in skeletons of 176 pigs of different ages. Macroscopic and histologic as well as radiologic and microradiographic methods were used. Osteochondrosis was found to be a generalized disease, characterized by a disturbance of endochondral ossification. It was concluded that early changes occur at about 4 months of age in the growth cartilage. Both the metaphyseal growth cartilage (growth plates) and epiphyseal growth cartilage (joint cartilage) were affected. Abnormal hypertrophy and hyperplasia of cartilage as well as focal degeneration were seen in the early cases. Osteochondrosis was found to lead to abnormal skeletal growth and change in shape of various bones and joints. Serious manifestations of osteochondrosis were epiphyseolysis and osteochondritis dissecans. A quantitative difference was found between different individuals in development of osteochondrosis. The onset of clinical signs was thought to depend on degree and localization of osteochondrosis.