Traumatic Osteonecrosis of the Femoral Head

Osteonecrosis (ON) of the femoral head is a rare but devastating complication following fractures of the proximal femur or hip dislocation. Traumatic ON derives from the interruption of the blood flow to the femoral head, which is mainly supplied by the medial circumflex femoral artery (MCFA) in the adult hip [1, 2]. The incidence of ON depends on the fracture pattern and the integrity of the deep branch of the MCFA. While fractures with close proximity to the nutrient vessels (femoral head and neck fractures) have a considerable risk for ON, it rarely occurs in fractures which do not interfere with the MCFA (intertrochanteric or femoral shaft fractures). In addition to traumatic interruption of the femoral head blood supply, the MCFA can be injured iatrogenically. Symptoms and radiographic changes in hips with ON of the femoral head usually occur late and often months after the trauma. There is no curative treatment and therefore prevention is most important.