What is avascular necrosis ?

Avascular necrosis: Bone is a living tissue that is constantly turning over; this involves tightly regulated systems of bone addition and subtraction. In order to deliver the cells that are responsible there needs to be adequate blood flow. If the blood flow is disrupted significantly, the affected areas can undergo avascular necrosis (avn). Avn can lead to collapse of the area and arthritis if it occurs near joints.

AVN: More information needed. In some bones (humeral + femoral head) if diagnosed before collapse and arthritis begins, there may be some value to core decompression. Some centers have shown decreased progression of collapse with free vascular fibula grafting (hip). No consensus regarding treatment before collapse. Once collapse occurs, some sort of resurfacing/replacement required to manage pain.