Fig. 8From: A modified surgical method for the treatment of ONFH: quadratus femoris muscle pedicle bone grafting with preservation of the posterior superior retinacular arteryChiseling of the quadratus femoris bone flap (right hip). a Drilling with a ring saw toward the femoral head. b The entry point of the bone groove at the outside of the hip capsule at the posterior base of the femoral neck c A bone column removed by a ring saw in the bone groove. d Measurement of the length of the bone columnBack to article page