The calcar replacement femoral component for total hip arthroplasty: design, uses and surgical technique.
A new femoral component for total hip arthroplasty (THA) has been designed for use in patients in whom the calcar region is missing, hence called the calcar replacement device. Experience with its use in 18 hips has indicated that common causes for calcar deficiency requiring this implant are resorption of the calcar region secondary to failure of a prior THA, settling of an endoprosthesis or destruction by tumor. The use of a conventional femoral component in these situations is not recommended because of the lack of adequate bony support. The device is also valuable in restoring leg length in cases of substantial bone loss in the proximal part of the femur. In an entirely different indication, this device may be used to restore hip motion in patients with severely restricted movement secondary to extensive heterotopic ossification. In three of four hips with this condition, excision of the heterotopic bone and use of the calcar replacement device achieved restoration of an arc of 75 degrees or more in the flexion-extension plane.