Introduction Southern/Moore approach and the Kocher-Langenbeck approach both use the same interval Kocher-Langenbeck is used to refer to an approach used to address the acetabulum which is more extensile Southern/Moore approach more commonly refers to a more limited hip arthroplasty approach incision is identical to Kocher-Langenbeck, except localized posterior to greater trochanter Provides exposure to posterior wall of acetabulum lateral aspect of the posterior column of acetabulum indirect access to true pelvis and anterior aspect of posterior column through palpation proximal femur Indications THA hip hemiarthroplasty removal of loose bodies dependant drainage of septic hip pedicle bone grafting posterior wall fx posterior column fx posterior wall and posterior column fx simple transverse fx (patient prone) fx must be less than 15 days old fx line located at or below acetabular roof no major anterior displacement Intermuscular plane No internervous plane gluteus maximus innervated by inferior gluteal nerve nerve branches of upper 1/3 of muscle cross intended interval of dissection halfway between level of greater trochanter and PSIS muscle split is stopped when first nerve branch to upper part of muscle is encountered Vascular plane upper 1/3 of muscle supplied by superior gluteal artery lower 2/3 of muscles supplied by inferior gluteal artery line of fat on surface marks interval Preparation Anesthesia patient must be relaxed Position lateral position posterior wall and lip fxs (can use skeletal traction when using lateral position) allows for femoral head dislocation position of choice for joint arthroplasty allows buttock tissue to "fall away" from the field prone position for transverse fx (flex the knee to prevent stretching of sciatic nerve) femoral head is maintained in reduced position throughout procedure improves quadrilateral surface access improved access to cranial and anterior aspect of posterior wall fractures Imaging ensure appropriate imaging can be obtained prior to formal prepping and draping Approach Incision longitudinal incision centered over greater trochanter start just below iliac crest, lateral to PSIS mini-incision approach shows no longterm benefits to hip function extend to 10 cm below tip of greater trochanter Superficial dissection through subcutaneous fat incise fascia lata in lower half of incision extend proximally along anterior border of gluteus maximus split gluteus maximus muscle along avascular plane release portion of gluteal sling to aide in anterior retraction of muscle belly detach short external rotators after tagging the piriformis should be tagged and released approximately 1.5cm from the tip of the greater trochanter to avoid damaging the blood supply to the femoral head the piriformis will provide a landmark leading to the greater sciatic notch the contents of the greater sciatic notch include: piriformis superior and inferior gluteal vessels and nerves sciatic and posterior femoral cutaneous nerves internal pudendal vessels nerves to the obturator internus and quadratus femoris the obturator internus should be tagged 1.5 cm from the greater trochanter and blunt dissection should be used to follow its origin to the lesser sciatic notch posterior retraction will protect the sciatic nerve clear abductors and soft tissue to visualize posterior capsule and posterior wall region Deep dissection no further dissection is needed in setting of isolated posterior wall fracture palpable exposure of quadrilateral plate to assess reduction of posterior column accomplished by elevation of obturator internus elevation access can be enlarged by release of sacrospinous ligament hip joint exposure perform marginal capsulotomy capsular attachments to posterior wall fragments need to be kept intact to prevent devascularization femoral traction can allow visualization of intra-articular surface of hip joint osteotomy of greater trochanter extends access along external surface of anterior column Dangers Sciatic nerve initially located along posterior surface of quadratus femoris muscle quadratus femorus anatomy is constant; rarely damaged in setting of fracture extend hip and flex knee to prevent injury minimize chance of injury by using proper gentle retraction and releasing your short external rotators (obturator internus) posteriorly to protect the sciatic nerve from traction treat injury with observation and use of ankle-foot orthosis prognosis for recovery of tibial division is good despite severe initial damage prognosis for recovery of peroneal division is dependant on severity of initial injury Inferior gluteal artery leaves pelvis beneath piriformis if it is cut and retracts into the pelvis, then treat by flipping patient, open abdomen, and tie off internal iliac artery First perforating branch of profunda femoris at risk of injury with release of gluteus maximus insertion Femoral vessels at risk with failure to protect anterior aspect of the acetabulum, or with placement of retractors anterior to the iliopsoas muscle Superior gluteal artery and nerve leaves the pelvis above the piriformis and enters the deep surface of the gluteus medius. this tethering limits upward retraction of gluteus medius and blocks you from reaching the iliac crest injury can cause excessive bleeding injury to artery can occur with aberrant instrument placment during posterior iliac bone graft harvest Quadratus femoris excessive retraction and injury must be avoided to prevent damage to medial circumflex artery Heterotopic Ossification debride necrotic gluteus minimus muscle to decrease incidence of HO