Geometric analysis of the proximal femur in a diverse sample of dogs

Dogs are often used as experimental models for studies of human hip replacement. A precise knowledge of femoral morphology is required to improve osteointegration of cementless prostheses by bone ingrowth or determination of the best design for total hip prostheses. To better understand the differences between breeds, we measured or calculated 24 external and internal features of the femur on standard radiographs of dogs that differed greatly in size and body type. We considered the appropriateness of the canine model for human total hip replacement studies and show that human and canine femurs differ in characteristics like anteversion, cortico-medullary index or endosteal shape. Knowledge of these differences and similarities makes it possible to design well-adapted stems for dogs.