[Therapy of osteonecrosis. Basic principles and decision aids].

The treatment of osteonecrosis of the femoral head involves a continuum based on a radiographic spectrum of disease. Core decompression or pharmacological agents can be utilized for the earliest small or medium-sized pre-collapsed lesions. For these types of lesions, osteotomy has been tried by various authors with moderate success. For small or medium lesions that are post-collapse, various bone grafting procedures have been used. This approach should be tempered with a look at the articular cartilage if this is damaged or the lesion is large. Limited femoral resurfacing can be used for hips that do not have acetabular involvement. If there is acetabular involvement, total hip replacement remains the treatment of choice. There are present innovations in total hip arthroplasty that hopefully will lead to increased longevity of these prostheses with newer polyethylenes as well as the use of ceramic and other types of interfaces. Another possible advance for this disease would be the use of metal on metal standard prostheses, as well as metal on metal resurfacing arthroplasties. In terms of a salvage of the femoral head, all of the different procedures--core decompression, osteotomy, bone grafting--can be enhanced by new advances in the development of the utilization of bioactive factors. These range from osteoinductive agents such as cytokines, angiogenic stimulating factors, and bone morphogenetic proteins. In addition, osteoconductive substances may be helpful and can be combined with osteoinductive substances. These bioactive factors are described in detail in another chapter of this issue. With the ushering in of the millennium, there is hope for better results with this disease.