FRAGMENTATION OF THE MEDIAL MALLEOLUS OF DOGS WITH AND WITHOUT TARSALOSTEOCHONDROSIS

Fragmentation of the medial malleolus of the tibia was found radiograp hically in 5 canine tarsi which did not have evidence of osteochondros is of the medial trochlear ridge, An additional 5 tarsi were found whe re both medial malleolar fragmentation and osteochondrosis of the medi al trochlear ridge were present. Radiographic evidence of degenerative joint disease was present in 3 of 5 dogs with medial malleolar fragme ntation alone, and 5 of 5 dogs with medial malleolar fragmentation and medial trochlear ridge osteochondrosis. Eight of the 9 dogs were Rott weilers. Considering the sites of occurrence of osteochondrosis in oth er species, the authors propose that medial malleolar fragmentation co uld be secondary to osteochondrosis of the medial malleolus. Osteochon drosis of the medial malleolus has not been previously reported in dog s. Histological examination of the medial malleolar fragmentation was unavailable because surgery was not performed, therefore the hypothesi s that the medial malleolar fragmentation is due to osteochondrosis wa s not proven.