Steroid-associated osteonecrosis: Epidemiology, pathophysiology, animal model, prevention, and potential treatments (an overview)

Xie, Xin-Hui; Wang, Xin-Luan; Yang, Hui-Lin; Zhao, De-Wei; Qin, Ling

Core decompression through creation of a surgical drilled bone tunnel is one of the least invasive surgical procedures in early ON stages when the ON lesion is still small (Fig. 3) . Core decompression is usually performed in Ficat Stage II or earlier stages to prevent the subchondral collapse in SAON. Biologically, it helps to reduce intraosseous pressure and provide a conduit for angiogenesis to revascularise subchondral bone. However, concerns still do exist, including those related to incomplete reconstructive repair and its potential to weaken the trabecular bone within and next to the necrotic region when the necrotic lesion was relatively large [1, 67, 68] . However, once the femoral head develops a subchondral fracture, the efficacy of the core decompression will drop significantly.