The use of extracorporeal shock waves in the treatment of osteonecrosis of the femoral head: a systematic review

Osteonecrosis is a progressive clinical condition with significant morbidity, which primarily affects weight-bearing joints and is characterized by the death of the bone, or part of it, because of insufficient circulation. The hip is the most common compromised joint. In osteonecrosis of the femoral head (ONFH), the collapse of the femoral head is a result of mechanically weak bone submitted to a load of weight, and can be associated with incapacitating pain and immobility. Both nonsurgical and surgical treatment options have been used with differing levels of success, and nonoperative treatment modalities such as bisphosphonates, statins, anticoagulants, and extracorporeal shock wave therapy (ESWT) for early-stage disease have been described, but exact indications have not been established yet. The aim of this study was to make a systematic review of the use of ESWT in the treatment of ONFH. MEDLINE, LILACS, and Scielo databases were searched using the keywords "shock wave", "osteonecrosis", "avascular necrosis", "aseptic necrosis" and "femoral head". The search period was between 1966 and 2009. Only five articles that fulfilled the previously established criteria were obtained. Of these five articles, two were randomized clinical trials, one open label study, one comparative prospective study, and one was a case report. The present review demonstrated that there are no controlled and double-blind studies about the efficacy of ESWT in the treatment of ONFH. On the other hand, the published noncontrolled studies appear to demonstrate some favorable result, which justifies new research in this area.