Management of avascular necrosis of the femoral head--an overview.

The most common cause of AVN of the femoral head is a displaced subcapital or transcervical fracture. Circumstances here differ significantly from those encountered in the patient with nontraumatic AVN, especially because the traumatic variety is seen most often in the elderly population. Attempts to preserve the femoral head are generally not indicated and the treatment of choice for the hip with sufficient pain and disability is either endoprosthetic replacement or total hip replacement. In contradistinction, nontraumatic AVN occurs primarily in younger adults and is often bilateral. In these patients the goal is to preserve, not to replace, the femoral head. "Conservative" or nonsurgical management has generally been unsuccessful. Results with established surgical procedures have been inconsistent and frequently disappointing, often because they have been instituted too late. Although no approach is completely effective, in general the earlier treatment begins, the better the results will be. Early diagnosis, therefore, is essential. This depends on a heightened clinical awareness of this condition. The importance of various imaging techniques, including high-quality plain radiographs, technetium scans, and magnetic resonance imaging must be stressed. Newer procedures for the treatment of early AVN are being developed and evaluated. These currently include the use of vascularized grafts, osteochondral allografts, transtrochanteric rotational osteotomy, and electrical stimulation. I hope that one or more of these approaches will prove useful in preserving the femoral head. Until such time, I shall continue to use bone grafting with decompression to treat hips with limited involvement. When definite collapse of the femoral head has occurred and when pain and disability are sufficient to require surgical intervention, the treatment of choice is arthroplasty. Although many still favor the use of a bipolar femoral endoprosthesis, I believe that total hip replacement provides more consistent, more durable, and better results. Whichever arthroplasty is chosen, I anticipate continually improving results with advances in technique and component design.