Blood supply of Head of Femur

Blood supply to the head of the femur

4 groups of arteries :

1. Extra-capsular arterial ring
   1. Trochanteric anastomosis
   2. Major contributions posteriorly from the horizontal branch of the medial femoral circumflex artery and anteriorly from ascending branch of the lateral femoral circumflex artery
2. Ascending cervical branches
   1. Retinacular branches
   2. Arise from extra-capsular arterial ring
   3. Pass up beneath the synovial and capsular reflections
   4. In their passage they give branches to the metaphysis of the femoral neck
   5. There is a free intramedullary anastomosis between branches of the superior nutrient artery system, branches of the extra-capsular ring, branches of the ascending cervical branches and the subsynovial ring
   6. Form 4 groups; superior, inferior, medial and lateral
   7. The lateral group supplies most of the blood to femoral head
   8. At the margin of the articular cartilage, these vessels form a second ring the subsynovial intracapsular ring
3. Subsynovial intracapsular ring (Chung)
   1. Circulus articuli vasculosis
   2. This ring may be complete or incomplete (complete more often in males)
   3. From this ring, epiphyseal branches arise that enter the femoral head
4. Artery of the ligamentum teres
   1. From the lateral branch of the obturator artery
   2. Supplies small area about the fovea