Hip – Extended Posterior & Surgical Hip Dislocation (Kocher-Langenbeck/Gibson/Ganz)

Indications

Posterior Approach to Hip, arteries of the gluteal and posterior femoral regions, gray’s anatomy plate 544
Arteries of the gluteal and posterior femoral regions, Gray’s Anatomy plate 544. Image by Henry Vandyke Carter, Wikimedia Commons, Public domain.
  • Posterior wall and posterior column acetabular fractures
  • Transverse and T-type fractures with mainly posterior displacement
  • Irreducible or incarcerated posterior hip dislocation
  • Pipkin femoral head fractures, via surgical dislocation
  • FAI, labral and chondral surgery, and modified Dunn realignment for SCFE

Position

  • Kocher-Langenbeck prone or lateral, hip extended and knee flexed throughout to slacken the sciatic nerve
  • Ganz dislocation lateral decubitus with a sterile bag anterior to the table

Landmarks and Incision

  • Landmarks are the PSIS, greater trochanter and femoral shaft
  • Kocher-Langenbeck runs from near the PSIS to the trochanter tip, then down the shaft
  • Gibson and Ganz use a straight lateral incision centred on the trochanter, slightly anterior

Internervous Plane

  • Kocher-Langenbeck has none, splitting gluteus maximus (inferior gluteal nerve) in line with its fibres
  • Gibson uses the interval between anterior gluteus maximus and TFL and gluteus medius (superior gluteal nerve)
  • Gibson reflects all of gluteus maximus posteriorly, avoiding denervation of its anterior part

Superficial Dissection

  • Fascia lata incised in line with the femur
  • Gluteus maximus split proximally only to the first nerve branches to its anterior part

Deep Dissection

Kocher-Langenbeck

  • Sciatic nerve identified on quadratus femoris
  • Piriformis and conjoint tendon divided 1.5 cm from insertion to protect the deep MFCA branch
  • Exposes the posterior column from greater sciatic notch to ischial tuberosity

Ganz surgical dislocation

  • Trochanteric flip osteotomy keeps gluteus medius and vastus lateralis on the fragment
  • Cut exits anterior to piriformis, which stays on the stable trochanter
  • Z-shaped anterolateral capsulotomy stays anterior to the retinacular vessels and lesser trochanter
  • Anterior dislocation in flexion and external rotation after dividing the ligamentum teres

Structures at Risk

  • Sciatic nerve, especially with hip flexion or forceful retraction
  • Deep MFCA branch, posterior to obturator externus and anterior to the conjoint tendon
  • Superior gluteal neurovascular bundle at the greater sciatic notch

Extension

  • Proximal extension limited by the superior gluteal bundle
  • Trochanteric osteotomy improves exposure of the superior acetabulum and dome

Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 10 October 2026.