Posterior Approach to Acetabulum (Kocher-Langenbeck)
The posterior approach to acetabulum or as called (Kocher-Langenbeck approach) gives access to the posterior wall of the acetabulum and its posterior column.
- It also allows direct visualization of the dorsocranial part of the acetabulum, either through the fracture gap or via a capsulotomy.
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Posterior Approach to Acetabulum is used for:
- Total hip arthroplasty THA.
- Hip hemiarthroplasty.
- Removal of loose bodies.
- Dependent drainage of septic hip.
- Pedicle bone grafting.
- Posterior wall fractures.
- Posterior column fractures.
- Posterior wall and posterior column fractures.
- Simple transverse fractures (patient prone:
- Fractures must be less than 15 days old.
- Fractures line located at or below acetabular roof.
- No major anterior displacement.
- The Kocher-Langenbeck approach is the easiest of all acetabular approaches, and extensive blood loss is not usually encountered.
- Lateral position:
- Posterior wall and lip fractures (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 fractures (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.
- Landmarks:
- The greater trochanter.
- Incision:
- Longitudinal incision centered over greater trochanter:
- Start just below iliac crest, lateral to posterior superior iliac crest PSIS.
- Extend to 10 cm below tip of greater trochanter.
- Longitudinal incision centered over greater trochanter:
- There is no true internervous plane in the posterior approach to acetabulum.
- The gluteus maximus that is split in the line of its fibers is not significantly denervated because it receives its nerve supply well proximal to the split.
- 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 muscle.
- 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 contents of the greater sciatic notch include:
- The piriformis will provide a landmark leading to the greater sciatic notch:
- 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
- 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.
- Clear abductors and soft tissue to visualize posterior capsule and posterior wall region
- 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.
- Proximal Extension:
- The posterior approach to acetabulum (Kocher-Langenbeck approach) can be extended distally down to the level of the knee.
- Either split the vastus lateralis or elevate it from the lateral intermuscular septum to allow exposure of the lateral surface of the entire shaft of the femur.
- Distal Extension:
- The posterior approach to acetabulum (Kocher-Langenbeck approach) cannot be usefully extended proximally.
- The structures at risk during posterior approach to acetabulum (Kocher-Langenbeck approach) includes:
- Sciatic nerve:
- 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.
- Inferior gluteal artery.
- First perforating branch of profunda femoris.
- Femoral vessels.
- Superior gluteal artery and nerve.
- Sciatic nerve:
- Surgical Exposures in Orthopaedics book - 4th Edition
- Campbel's Operative Orthopaedics book 12th