Gibson Approach to the Hip (Abductor-Sparing Posterior)

What it exposes. The Gibson approach is a posterolateral approach to the hip performed in the lateral decubitus position. It develops the true internervous plane between gluteus maximus (inferior gluteal nerve) and gluteus medius (superior gluteal nerve) to reach the hip joint from behind — without splitting gluteus maximus and without detaching the abductors. It gives wide posterior access to the femoral head and neck, the posterior capsule, and (with extension) the posterior acetabular column. Why this approach is chosen. The Gibson is selected when posterior access to the hip is required and the abductor mechanism should be preserved. Because it works a genuine internervous plane, it keeps the inferior gluteal nerve territory to gluteus maximus intact and leaves gluteus medius and minimus attached to the trochanter. The payoff is preserved abductor strength, a lower risk of a Trendelenburg gait, and an intact posterior soft-tissue envelope that can be repaired to reduce post-arthroplasty dislocation. It is also the anatomical foundation of the surgical dislocation of the hip (Ganz), which extends it proximally with a trochanteric flip. Indications. - Primary posterior or posterolateral total hip arthroplasty where preservation of the abductor mechanism is desired

• Hip hemiarthroplasty for displaced femoral neck fractures (especially in the active elderly patient)
• Open reduction of posterior fracture-dislocations of the hip (e.g. Pipkin fractures with an incarcerated fragment)
• Surgical dislocation of the hip (Ganz) for femoral head pathology — the Gibson interval is the foundation on which the trochanteric-flip extension is built
• Synovectomy, loose-body removal and drainage of the hip joint
• Resection of selected posterior femoral head and neck tumours with limb-salvage intent Contraindications. - Previous posterior surgery with dense scarring that distorts the internervous plane (relative — consider anterolateral)
• Active infection in the skin or deep soft tissues over the approach
• When anterior access to the hip is the principal requirement (use an anterior or anterolateral approach)
• A markedly elevated dislocation risk in whom a posterior route is to be avoided (consider anterolateral, dual mobility, or a constrained construct) Where it sits in the posterior hip family.

The defining internervous plane. The anterior leaf is gluteus medius (superior gluteal nerve) and the posterior leaf is gluteus maximus (inferior gluteal nerve). Because the two muscles share no nerve, the plane between them can be developed without denervating either — this is the defining anatomical advantage of the Gibson. The Moore and Kocher-Langenbeck approaches instead split gluteus maximus in the line of its fibres; the Gibson reflects maximus posteriorly as a single intact muscle, preserving the inferior gluteal nerve territory and keeping the muscle available as a strong, fully innervated layer for closure.

Position and landmarks. Place the patient in a rigid lateral decubitus position with the affected limb uppermost. Pad the bony prominences (greater trochanter, fibular head and lateral malleolus of the dependent leg), place an axillary roll two finger-breadths distal to the apex of the dependent axilla to protect the brachial plexus, and secure the pelvis with anterior and posterior support posts (or a bean-bag) so it cannot roll. Flex and pad the dependent knee to protect the common peroneal nerve, support the upper limb on an arm-board, and drape the limb free so the hip can be flexed, adducted and internally rotated to dislocate. Mark the greater trochanter (the centre of the incision), the femoral shaft axis (guides the distal limb), and the posterior superior iliac spine and iliac crest (the limits of any proximal extension).

Work from skin to joint in a defined sequence: deepen to the fascia, split the fascia lata, develop the maximus–medius internervous plane (the defining step), expose the short external rotators, divide and reflect them over the sciatic nerve, and open the posterior capsule. Internally rotating the hip at the right moment puts each layer under tension in turn.

Anatomy to know before you cut. The femoral head is supplied principally by the deep branch of the medial femoral circumflex artery (MFCA), which runs along the superior border of quadratus femoris, crosses the posterior capsule and enters the head through the subsynovial retinacular vessels on the postero-superior neck. This is why dividing the short external rotators too close to the capsule — or dividing quadratus femoris — risks avascular necrosis of the head. The short external rotators, from superior to inferior, are piriformis, gemellus superior, obturator internus, gemellus inferior and quadratus femoris: the first four are divided close to the trochanter and reflected, while quadratus femoris is preserved to guard the MFCA.

Structures at risk. The four neurovascular structures that define the safe corridor of the approach are summarised below, with the manoeuvre that protects each.

Extensile options. - Proximal/posterior (to the acetabulum): curve the incision toward the posterior superior iliac spine and split the proximal part of gluteus maximus in the line of its fibres to reach the posterior column and posterior wall — this converts the Gibson into the Kocher-Langenbeck exposure. The superior gluteal nerve and artery limit how far proximally you can dissect between the abductors.

• Proximal by trochanteric flip (Ganz surgical dislocation): a greater-trochanter osteotomy leaving the vastus lateralis and abductors attached reflects the whole abductor–vastus complex anteriorly, giving 360-degree access to the femoral head while preserving the deep branch of the MFCA. This is the extensile form of choice for femoral head pathology.
• Distal (along the femur): extend the distal limb down the femoral shaft in line with the intermuscular septum for diaphyseal work, peri-prosthetic fractures, or distal extension of arthroplasty exposure. Closure — as important as the exposure. Close in layers: repair the posterior capsule with non-absorbable sutures over the tags; re-attach the short external rotators to their trochanteric cuff or through bone tunnels (this is the dislocation-reducing step); close the fascia lata and gluteal aponeurosis over a drain; then close subcutaneous tissue and skin. The historical dislocation rate of the posterior approach falls substantially when the posterior capsule and short external rotators are repaired — treat the closure with the same care as the exposure. Document the final sciatic nerve examination before the patient leaves the operating room.

• Primary posterior or posterolateral total hip arthroplasty — the most common application; the abductors are preserved.
• Hip hemiarthroplasty for a displaced femoral neck fracture in the active elderly.
• Open reduction of posterior fracture-dislocation of the hip — Pipkin fragments and incarcerated loose bodies.
• Posterior acetabular wall and column ORIF through the proximal/posterior (Kocher-Langenbeck) extension — see acetabular fracture ORIF: Kocher-Langenbeck approach.
• Surgical dislocation of the hip (Ganz) via the trochanteric-flip extension for femoral head fracture, slipped capital femoral epiphysis remodelling, femoroacetabular impingement and head-preserving tumour work.
• Synovectomy and loose-body removal, including posterior impingement lesions.
• Resection of selected posterior femoral head and neck tumours with limb-salvage intent.

Guidelines, registries and global practice. Posterior and posterolateral approaches to the hip are taught and used worldwide across every examination system. The anatomical principles — the maximus–medius internervous plane, protection of the sciatic nerve by the reflected short external rotators, and preservation of the medial femoral circumflex artery — are convergent across all modern arthroplasty and trauma teaching. | Body | Position on posterior hip approaches | |------|--------------------------------------| | AO Foundation | Posterior approaches for posterior wall and column acetabular fractures; meticulous soft-tissue handling and protection of the sciatic nerve and femoral head blood supply are standard | | AAOS / national arthroplasty registries | Posterior approach remains a common, safe exposure for primary THA when capsular and soft-tissue repair is performed; dislocation risk is mitigated by repair and by component positioning | | EFORT / European consensus | Enhanced posterior soft-tissue repair and appropriate component version are recommended to minimise post-operative instability | - Posterior approaches account for a substantial share of primary total hip arthroplasty in major registries (NJR, AOANJRR, SHAR, AJRR), with dislocation rates that have fallen as routine posterior soft-tissue repair has been adopted.

• Femoral head blood supply anatomy and the risk of avascular necrosis after posterior trauma are consistent across published anatomical and clinical series. Global practice variation: in high-resource settings, specialised retractors, leg-positioning supports, and computer-assisted or robotic guidance for component orientation are common. In resource-limited settings, the same anatomical principles are applied with standard instrumentation, and the posterior approach remains a versatile, low-equipment exposure for arthroplasty and trauma. Consent (globally applicable): discuss sciatic nerve injury (the principal nerve at risk, usually a traction neuropraxia), post-operative dislocation and the role of posterior soft-tissue repair, infection, leg-length inequality, heterotopic ossification, and the small risk of avascular necrosis when the femoral head blood supply is threatened.