Total hip replacement after failed femoral head and neck excision in two dogs and two cats.

Objective To document outcome in 2 dogs and 2 cats after conversion of femoral head and neck excision (FHNE) to total hip replacement (THR). Study Design Case series. Animals Dogs (n = 2) and 2 cats. Methods For 1 dog and 2 cats, THR was performed using cemented acetabular and femoral components. Noncemented acetabular and cemented femoral components were used in 1 dog. Results All animals presented with severe hip pain and chronic lameness after unsuccessful FHNE. Potential causes of suboptimal outcome after FHNE were incomplete resection of the femoral neck (n = 3) and fibrous adhesions involving the sciatic nerve (n = 2). Post-FHNE remodeling of the proximal femur and acetabulum necessitated unconventional modifications of surgical technique. In all 4 cases, final clinical outcome and radiographic reassessment were satisfactory. Aseptic loosening of the acetabular bone-cement interface necessitating surgical revision was the only complication noted in 1 cat. Conclusions Despite severe preoperative pain and chronic functional impairment in all cases, conversion of FHNE to THR produced marked clinical improvement including return to unrestricted exercise within 12 weeks of surgery.