The use of bisphosphonate in the treatment of avascular necrosis: a systematic review.

Up to now, there is no uniformly accepted treatment for avascular necrosis (AN) that alleviates pain and retards its progression. The aim of clinical and surgical treatments is usually only to improve blood support in the avascular area. The objective of the present study was to make a systematic review of the use of bisphosphonates in the treatment of AN. Studies in which bisphosphonate was used for the treatment of AN were researched through the MEDLINE databases (from 1966 to 2007) and the Cochrane Central Register of Controlled Trials and using the following terms: "avascular necrosis," "aseptic necrosis," "bisphosphonates," "alendronate," "pamidronate," "zoledronate," and "risedronate". Only seven articles that met the previously established criteria were obtained from MEDLINE, and none were obtained from the Cochrane Central Register of Controlled Trials. Of these seven articles, two were randomized clinical trials and five were prospective comparative studies; one of them corresponded to an extension of a previous study. The present review demonstrates that there are no controlled and double-blind studies about the efficacy of bisphosphonates in the treatment of AN. Therefore, the data are still insufficient for justifying its use for this indication. On the other hand, noncontrolled studies appear to demonstrate favorable results, particularly in diminishing pain, improving mobility, and lowering the incidence of articular collapse, which justifies new studies being developed in this area.