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Surgical Dislocation Technique

Dr. Gourineni's operative notes on the safe surgical dislocation approach

The following are Dr. Gourineni's operative notes and technical pearls for the surgical dislocation of the hip (SSD). This technique, developed by Professor Reinhold Ganz, provides 360° access to the femoral head and acetabulum while preserving the blood supply to the femoral head.

These are personal operative notes intended for surgeons familiar with the SSD approach. They supplement — not replace — formal training with an experienced mentor.

Positioning & Draping

Lateral position with an anterior leg bag to hold the leg when the hip is flexed, adducted, and externally rotated for the dislocation. Do not touch the outside of the bag and do not lift the bag up to prevent contamination from the lower parts of the bag that go below the assistant's waist level. A plastic C-arm drape works well.

Incision & Approach

The length of the straight lateral midline incision can be minimized by starting only an inch or two below the greater trochanter (GT) and extending proximally. 8–10 cm is adequate. The IT band incision is extended well down along the thigh with large scissors — it often bleeds, and packing a large sponge into the fasciotomy under the intact skin and subcutaneous tissue controls this.

The fascia lata proximal to the ITB is very thin and splits into two layers that sandwich gluteus maximus. The superficial layer is divided and the anterior border of G. Max is released and retracted posteriorly. Occasionally G. Max does not extend to the lateral midline and the muscle under the fascia lata is G. medius. Dividing the trochanteric bursa down to the vastus lateralis origin and developing that level proximally shows G. Max to be superficial and G. med to be deep to the bursa.

Greater Trochanter Osteotomy

The hip is placed in extension and full internal rotation. Expose the posterior aspect of the GT, posterior border of G. medius, and the short external rotators by lifting the trochanteric bursa off these structures. The sciatic nerve can be palpated but does not need further dissection unless scarred from previous surgery.

The GT osteotomy is done to remove a 10–15 mm thick piece with most of G. medius and all of vastus lateralis attached to it. When the piece is moved anteriorly after elevating the muscles along with it, the entire hip capsule from the piriformis posteriorly to the iliopsoas bursa anteriorly is exposed.

GT Osteotomy Pearls

  • A step-cut osteotomy allows more secure GT reattachment — especially important in SCFE cases where GT advancement is required
  • In SCFE, the step-cut is contraindicated because the GT needs advancement at the end
  • A broad and curved osteotome allows a shallower cut anteriorly to avoid getting into the anterior neck

Capsulotomy & Dislocation

A Z-shaped capsulotomy provides wide access. The anterior limb of the capsulotomy is extended close to the acetabular rim to avoid damaging the labrum. The posterior limb follows the posterior neck to the piriformis insertion.

Dislocation is achieved by flexion, adduction, and external rotation of the hip. The ligamentum teres is divided to complete the dislocation and place the head in the leg bag. Traction sutures on the capsular flaps maintain retraction throughout the procedure.

Retinacular Flap Development

The lateral retinacular vessels (LRV) are the critical blood supply to the femoral head. They run in the posterior retinaculum along the posterosuperior neck. Elevation of the retinacular flap must preserve these vessels.

Anterior Flap

Can be elevated with any periosteal elevator or cut sharply at the capsular insertion into the intertrochanteric area. It needs to be elevated to the lesser trochanter. If not already torn from the head, it must be cut at the epiphyseal attachment to allow posterior displacement of the epiphysis. There are no blood vessels going to the head in this flap until the medial synovial fold is reached at the 6 o'clock position.

Posterior Flap

The piriformis fossa, GT overhang, and firm attachment of posterior capsule and muscles make simple subperiosteal elevation difficult and dangerous to the all-important lateral retinaculum. Various techniques can be used: straight osteotome, curette to scoop out GT bone, or sharp elevation of the retinaculum with excision of exposed bone. The posterior flap is elevated to the lesser trochanter. Excision of all GT bone extending above the lateral neck increases neck length (relative neck lengthening) and creates valgus neck shaft angle. Removal of bone posterior to the neck level increases excursion of the posterior flap.

Relocation & GT Reattachment

After completing the intra-articular work, confirm that pulsatile bleeding from a drill hole in the femoral head confirms intact blood supply. Irrigate the wound thoroughly and remove all bone debris from the acetabulum.

Reduce the head into the acetabulum. Close the capsular flaps loosely with fine absorbable suture. Advance the GT distally, laterally, and posteriorly to stabilize the hip joint. The hip is held in abduction and internal rotation to facilitate GT advancement and fixation. Two 3.5 mm cortical screws provide adequate fixation passing posterior to the neck screws with good purchase into the medial cortex around the lesser trochanter.

Post-op Protocol

  • Antibiotics and PCA for 24 hours
  • Hip abduction and anterior precautions for 2–4 weeks
  • Toe-touch weight bearing with crutches
  • X-ray and bone scan on post-op day 2
  • Stationary bicycle after 2 weeks
  • Increased weight bearing after 4 weeks; off crutches when GT and neck healing confirmed on X-ray
  • Release to sports at 3 months
  • X-rays at 0, 2, 6, 12, 25, and 50 weeks, then yearly for 2 years

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