[Biphosphonate in the treatment of avascular necrosis of the femoral head].

Avascular necrosis (AVN) is a multifactorial, heterogeneous group of disorders that lead to a final common pathway of mechanical failure of the bone joint dysfunction. Pain in avascular necrosis is the result of resorption of necrotic bone during revascularization, before new bone has formed or consolidated enough for load-bearing. Biphosphonate can reduce bone resorption, thus prolonging the bone formation phase available, so that structural failure may be avoided. The aim of this study was to make a systematic review of the use of bisphosphonate in the treatment of AVN.