Vascular Anatomy of the Proximal Femur and the Risk of Avascular Osteonecrosis

The high complication rate associated with femoral neck (FN) fracture, particularly the development of avascular necrosis (AVN) of the femoral head (FH), may be explained by the vascular anatomy of the proximal femur. The FH AVN is a devastating disease and greatly affects the quality of life. Therefore, clarifying the arterial blood supply to the FH is the aim of this short review. Despite the rich blood supply to the FH, it is one of the most susceptible bone structures to AVN. It is supplied from two main blood sources: the femoral artery through the medial and lateral circumflex femoral arteries, and the internal iliac artery through the superior and inferior gluteal arteries, as well as the obturator artery. The main blood supply vessels pass through the retinacular capsule of the hip joint along the relatively long FN. Displaced fragments after a FN fracture can tear these blood vessels, affecting the blood supply to the FH. Early management of such cases may reduce the risk of developing AVN. Future studies are highly recommended to further explore the main source of blood supply to the FH especially at different ages. Clarification of such arrangement can help explain the risk of development of FH AVN and allow safe surgical exposure of such region.