Avascular Necrosis of the Intermedioradial Carpal Bone in a 6-Month-Old Dog

Abstract A 6-month-old neutered male dog presented for investigation of right thoracic limb lameness of 6-week duration following an acute injury. Radiography and computed tomography revealed focal osteolysis of the intermedioradial carpal bone. Histopathology of the bone revealed osteonecrosis, bone resorption, fibrous proliferation and new bone formation suggestive of avascular necrosis. Pancarpal arthrodesis was performed to stabilize the carpus and resulted in resolution of lameness and return to normal exercise. Avascular necrosis of carpal bones is rare and unreported in skeletally immature dogs. The imaging and histopathological changes in this dog's intermedioradial carpal bone bear strong similarity to Legg-Calvé-Perthes disease and the two presentations may have a similar traumatic vascular pathology.