Ganz Trochanteric Flip Approach to the Hip

What it exposes. The Ganz trochanteric flip approach gives circumferential, 360-degree access to the femoral head, the head-neck junction and the acetabular rim — safely, without the avascular necrosis risk of a traditional dislocation. It is the gold-standard exposure for femoroacetabular impingement needing open osteochondroplasty, femoral head fractures (Pipkin types), osteochondral lesions, and acetabular rim pathology with labral repair. Why this approach (and not a standard one). Traditional posterior or anterior approaches cannot deliver the whole femoral head without jeopardising its blood supply. Ganz designed the digastric trochanteric osteotomy specifically so the trochanter — with gluteus medius and vastus lateralis still continuous — can be flipped anteriorly, leaving the deep branch of the MFCA undisturbed along the quadratus femoris. A Z-capsulotomy then permits anterior dislocation while the posterior capsule and labrum are preserved for stability. Position & landmarks. Most often lateral decubitus on a radiolucent table (beanbag or lateral supports, axillary and chest rolls, all pressure points padded, the entire leg prepped and draped free to allow full flexion, adduction and external rotation). Supine is an alternative when combined anterior work is planned. Position the C-arm for AP and cross-table lateral views without re-patient repositioning. Palpate and mark the anterior superior iliac spine, the greater trochanter, the vastus ridge (the inferior border of the trochanter and the start of the osteotomy), the iliac crest and the posterior superior iliac spine. Incision. The skin incision follows the Gibson interval — it begins about 6 to 8 cm proximal to the greater trochanter along a line toward the ASIS, curves posteriorly over the trochanter, then runs distally along the lateral femur for 8 to 10 cm (total 15 to 20 cm). The proximal limb reaches the iliac crest if needed; the distal limb allows extension onto the femoral shaft. Primary indications. - Symptomatic femoroacetabular impingement (cam, pincer or mixed) requiring osteochondroplasty and labral repair when arthroscopic access is insufficient

• Displaced femoral head fractures (Pipkin types I to IV) needing anatomic reduction and fixation
• Osteochondral lesions of the femoral head requiring grafting, microfracture or fixation
• Acetabular rim fractures and associated labral pathology
• Synovial chondromatosis or pigmented villonodular synovitis requiring complete synovectomy
• Selected benign tumours of the femoral head and neck (chondroblastoma, osteochondroma)
• Residual deformity after Perthes disease or slipped capital femoral epiphysis requiring correction Contraindications. Active infection around the hip; severe osteoporosis precluding secure trochanteric fixation; previous surgery with scarring that would compromise the MFCA; medical comorbidities precluding major surgery; and isolated posterior wall acetabular fractures, which are better treated through a Kocher-Langenbeck approach. Alternatives. Hip arthroscopy for contained cam lesions and simple labral tears; the Smith-Petersen anterior approach for limited anterior pathology; Kocher-Langenbeck for posterior wall and column acetabular fractures; and combined approaches for complex pelvic deformities.

Work down through the Gibson interval to the greater trochanter, perform the digastric osteotomy that defines the approach, protect the MFCA, then deliver the femoral head through a Z-capsulotomy.

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Structures at risk, by layer

Extensile options. Extend proximally along the iliac crest to reach the ilium and acetabular roof (useful for combined periacetabular osteotomy or rim reconstruction), limited by the superior gluteal neurovascular bundle to roughly 5 cm proximal to the ASIS. Extend distally by splitting vastus lateralis in its midline to reach the femoral shaft (protect the nerve to vastus lateralis in the anterior third of the muscle). The approach can be combined with a Smith-Petersen for global acetabular access or with a posterior column approach for complex acetabular fractures, with staged positioning where needed. In revision cases with prior surgery the MFCA may be scarred — consider pre-operative angiography or proceed with extreme caution. Closure. Irrigate thoroughly, reduce the femoral head, and repair the capsule with heavy absorbable suture if possible (many surgeons leave the Z-capsulotomy open). Reattach the greater trochanter with two or three 3.5 mm or 4.5 mm cortical screws with washers, or a trochanteric cable system, aiming for anatomic reduction and compression. Close the fascia lata, subcutaneous tissue and skin in layers; drains are optional. Complications

Recovery. Touch or partial weight bearing (20 to 30 kg) for 6 to 8 weeks, advancing to full weight bearing at 8 to 12 weeks once trochanteric union is radiographic. Aim for 0 to 90 degrees flexion by 6 weeks; start abduction exercises at 6 weeks and avoid resisted abduction until 8 to 12 weeks. Follow-up radiographs at 2, 6 and 12 weeks, then 6 months and 1 year to watch for AVN.

• Femoroacetabular impingement osteochondroplasty (cam and pincer resection) with labral preservation.
• Femoral head fracture fixation (Pipkin types I to IV) under direct vision, using headless compression screws or bioabsorbable pins.
• Osteochondral lesion grafting, microfracture or fixation.
• Acetabular rim fracture fixation and labral repair.
• Selected femoral head osteonecrosis core decompression with grafting.
• Excision of benign tumours of the head and neck (chondroblastoma, osteochondroma).
• Synovial chondromatosis or pigmented villonodular synovitis debridement and complete synovectomy.