Aseptic osteonecrosis of the hip in the adult: current evidence on conservative treatment.

Treatment of Avascular Osteonecrosis (AVN) of the femoral head to prevent progression to an arthritic hip is a challenging subject. Many conservative treatment options have been proposed in the literature. Weight bearing restriction as a stand-alone therapy is insufficient in preventing disease progression but it may be useful when combined with pharmacological agents or surgery. Bisphosphonate treatment in AVN might be efficient in early stages of disease, however there are no clear recommendations on length of treatment and therapeutic dosage and, considered the limited evidence and potential side effects of treatment, it could be considered in a pre-collapse stage in selected cases. Current literature suggests that low molecular weight heparin could lower disease progression in idiopathic AVN with quality of evidence being very low. Also the evidence to support the use of statins or vasodilators in the treatment of osteonecrosis is very low and their use cannot be recommended. Extracorporeal shock wave therapy may improve pain and function in early stages of disease with a low evidence, but there doesn't seem to be a significant change in time to the occurrence of femoral head collapse. Only one study has been conducted with pulsed electromagnetic fields therefore no recommendation can be given on clinical use of PEF in AVN. Evidence on hyperbaric oxygen therapy in the treatment of AVN is very limited and the high cost of treatment and the limited availability of structures that can provide the service poses other concerns about its feasibility. Based on current evidence, conservative treatment may be considered in early stages of asymptomatic AVN instead of observation only.