Successful revision of a femoral head ostectomy (complicated by postoperative sciatic neurapraxia) to a total hip replacement in a cat.

A three-year-old neutered male Domestic Medium Hair cat was referred for evaluation of a right hindlimb monoparesis of one month duration following a femoral head ostectomy (FHO) performed elsewhere. Examination of the limb revealed muscle atrophy and decreased sensory perception over the sciatic nerve distribution with conscious proprioception and postural reaction deficits. The tentative diagnosis was sciatic neurapraxia. Radiographs taken prior to the FHO revealed a chronic nonunion right femoral neck fracture. The FHO was performed to remove the remnant of the femoral head and neck remaining in the acetabulum. Surgery was performed to explore the sciatic nerve and to revise the FHO into a total hip replacement. Sciatic nerve entrapment was present. Tethering sutures and extensive perineural adhesions were released to restore nerve gliding. Postoperatively, activity was limited for six weeks; normal activity resumed at eight weeks. Rehabilitation treatments were provided to maximise the patient's excellent recovery.