Clinical and radiographic evaluation of subsidence in two femoral stem models for a total hip replacement in dogs.

Canine cementless total hip arthroplasty (THA) is a successful technique for the management of hip arthrosis; however, serious potential complications, such as femoral fractures and subsidence of the femoral stem, can occur. To evaluate the effect of two femoral stem designs in reducing subsidence in dogs, twenty-four hips from twenty-one dogs undergoing THA were assessed. The twenty-four arthroplasties were divided into two experimental groups: G1 with a first generation, and G2, which is the second generation, system were used. All the dogs were clinically and radiographically evaluated immediately post-operatively and at 30 (M1) and 120 days post-operatively (M2). Three of ten arthroplasties in the G1 system had subsidence and six of fourteen had subsidence in the G2 system. Both systems are effective for management of hip arthrosis. The varus positions with the sub-optimal filling were not related to the subsidence. The two stem designs both showed some resistance to subsidence, but clinical problems were not identified in any case.