Transverse Fracture of the Proximal Humeral Articular Cartilage in Dogs (So-called Osteochondritis Dissecans)

Abstract

A disease in young, predominantly male dogs of heavier breeds, commonly called osteochondritis dissecans of the shoulder, was found to be a transverse fracture of humeral articular cartilage along the ‘tidemark’ (the junction of uncalcified and calcified cartilage) rather than through necrotic subchondral bone. The lesion was characterized by a profile of plaques of remnant calcified cartilage in the floor of the defect, with variable proliferation of fibrous tissue, fibrocartilage, primitive cartilage, and bone derived from the underlying tissue. The sequestral fragment was composed of viable hyaline cartilage with small areas of calcified cartilage in the deep surface.