INTRODUCTION: The direct superior approach (DSA) is a minimally invasive approach to total hip arthroplasty. It has a single incision, excellent visualization, minimal muscle trauma, and favorable clinical results [1]. This approach preserves the iliotibial band and the more inferior short external rotators of the hip, which may result in increased hip stability, faster postoperative recovery, and less postoperative pain.PROCEDURE: The patient is placed in the lateral decubitus position as anterior as possible on the operating table. The incision is made from the posterior superior corner of the greater trochanter and extends proximally and posteriorly for a distance of 9-12 cm. The superficial fascia of the gluteus maximus is incised, avoiding surgical dissection into the iliotibial band. The fibers of the gluteus maximus muscle are separated longitudinally down to the pericapsular fat, which is resected with electrocautery. A thin right angle retractor is placed into the plane between the gluteus medius and the gluteus minimus, retracting the medius anteriorly and exposing the piriformis along the posterior border of the minimus. The conjoined tendon is detached from its insertion on the greater trochanter, and is then elevated off the posterior hip capsule, and sutured to the apex of the skin incision. This provides continuous anatomic retraction of the sciatic nerve away from the surgical field, as well as exposure of the posterior acetabulum during the reaming process. A "J" shaped capsular incision is made, and the visible superior and posterior labral tissue is removed. Intracapsular retractors are then placed and the hip is dislocated. The neck length is measured and the femoral neck cut is made. After the head fragment is removed, a long curved retractor is placed over the anterior rim of the acetabulum. A thin right angle retractor is placed through the inferior capsule and outside the transverse acetabular ligament at the inferior margin of the acetabulum. The superior capsular flap is elevated for a distance of 1.5 cm above the superior rim of the acetabulum at the "12 o'clock" position. A bladed right angle retractor is tapped into the superior acetabular bone in this position. The first retractor is then replaced with a second curved retractor, which is placed more superiorly on the anterior acetabular wall, at the level of the anterior inferior iliac spine. This prevents the anterior retractor from interfering with the reamer. A short neck, 55 degree angled reamer is used to ream the acetabulum. This instrument allows acetabular reaming without detaching any part of the quadratus femoris or the external obturator. When the reaming is complete, the cup is implanted using an angled cup impactor. The femur is then exposed by placing the hip into 40 degrees of flexion, 40 degrees of adduction, and 40 degrees of internal rotation, The proximal femur is elevated with a thin shafted calcar retractor. A thin right angle retractor is then placed intracapsular at the junction of the anterior femoral neck and the base of the anterior greater trochanter. This retracts the hip abductor muscles, and delivers the proximal femur into the central part of the wound. A bladed right angle retractor is used on the medial calcar to retract the external obturator muscle. The proximal femur is then sequentially broached and the femoral component is implanted. After the head is applied and the hip is reduced, the superior and inferior capsular flaps are closed side to side, without using bone tunnels. The conjoined tendon is repaired to the posterior gluteus medius tendon. The fascia and skin are closed in layers. No hip precautions are used post-operatively.[1] Roger, D., and Hill, D.: Minimally Invasive Total Hip Arthroplasty Using a Transpiriformis Approach. Clinical Orthopedics and Related Research, Vol 470, No. 1: Online, 2011.