Introduction Provides exposure to acetabulum proximal femur Indications include THR minimally invasive approach does not improve post-op gait kinematics when compared to traditional trans-gluteal approach patient at high risk for dislocation may benefit from antero-lateral approach since no posterior soft tissue disruption some concern that this approach can weaken the abductor and cause limping hemiarthroplasty ORIF of femoral neck fracture synovial biopsy of hip biopsy of femoral neck Intermuscular plane Between tensor fasciae latae (superior gluteal nerve) gluteus medius (superior gluteal nerve) Preparation Anesthesia general or spinal/epidural is appropriate Position generally performed in the lateral decubitus position patient's buttock close to the edge of the table to let fat fall away from incision Landmarks ASIS greater trochanter shaft of the femur Approach Incision make incision starting 2.5 cm posterior and distal to ASIS as it runs distal, it becomes centered over the tip of the greater trochanter crosses posterior 1/3 of trochanter before running down the shaft of the femur Superficial dissection incise fat in line with incision and clear fascia lata incise fascia incise in direction of fibers, this will be more anterior as your dissect proximal incise at the posterior border of the greater trochanter develop interval between tensor fasciae latae and gluteus medius there will be a small series of vessels in this interval externally rotate the hip to put the capsule on stretch identify origin of vastus lateralis Deep dissection detach abductor mechanism by one of two mechanisms trochanteric osteotomy (shown in this illustration) distal osteotomy site is just proximal to vastus lateralis ridge partial detachment of abductor mechanism place stay suture to prevent muscle split and damage to superior gluteal nerve nerve is 5cm proximal to the acetabular rim expose anterior joint capsule detach reflected head of rectus femoris from the joint capsule to expose the anterior rim of the acetabulum easier with leg flexed slightly elevate part of the psoas tendon from the capsule perform anterior capsulotomy dislocate hip with external rotation Extension proximal incise more fasciae latae proximally to allow increased adduction and external rotation of the leg distal incise down the deep fascia of the leg allows access to the vastus lateralis which can be elevated to allow direct access to the entire femur Dangers Femoral nerve most common problem is compression neuropraxia caused by medial retraction direct injury can occur from placing retractor into the psoas muscle Femoral artery and vein can be damaged by retractors that penetrate the psoas confirm that anterior retractor is directly on bone Abductor limp caused by trochanteric osteotomy and/or disruption of abductor mechanism caused by denervation of the tensor fasciae by aggressive muscle split Femoral shaft fractures usually occurs during dislocation (be sure to perform and adequate capsulotomy)