Iliac (Lateral Window) Approach to the Pelvis

Positioning Options

• • Supine on radiolucent table with ipsilateral buttock bump (20-30 degree elevation) - most common for anterior column work
• • Lateral decubitus with affected side up - improves outer table access when abductor elevation planned
• • Arms tucked or abducted less than 90 degrees with padding
• • C-arm positioned for AP, obturator oblique, and iliac oblique views before draping

Surface Landmarks

• • Anterior superior iliac spine (ASIS) - start incision 2 cm posterior along crest to protect LFCN
• • Iliac crest from ASIS to posterior superior iliac spine (PSIS) - palpable throughout
• • Pubic tubercle - marks medial extent if extending to ilioinguinal
• • Greater trochanter - reference for lateral position

Pre-incision Checklist

• • Confirm LFCN sensory status pre-operatively
• • Mark ASIS and planned incision with indelible marker
• • Ensure C-arm can obtain all three Judet views without repositioning patient
• • Prepare for possible extension to full ilioinguinal or Stoppa approach

Superficial Interval

No true internervous plane exists superficially. The approach passes through subcutaneous fat and then the fascia over the iliac crest. The fascia is incised directly on the crest, preserving a cuff for later repair.

Deep Internervous Plane

• • Inner table: Between iliacus (femoral nerve) medially and the crest periosteum. Dissection is strictly subperiosteal.
• • Outer table (when required): Between tensor fascia lata (superior gluteal nerve) anteriorly and gluteus medius (superior gluteal nerve) posteriorly - truly internervous.
• • The plane on the outer table is developed only if full wing exposure or posterior column access is needed.

Clinical Pearl

The superior gluteal nerve enters the gluteus medius 5 cm proximal to the greater trochanter. Limit outer table dissection to the posterior 5 cm of the crest to avoid denervation.

Incision

• • Start 2 cm posterior to ASIS along the iliac crest
• • Extend posteriorly along the crest as far as the PSIS or as dictated by fracture
• • Length typically 10-15 cm for standard iliac window

Superficial Dissection

• • Divide skin and subcutaneous fat
• • Identify and protect the LFCN as it crosses or passes medial to the ASIS
• • Incise the fascia directly on the iliac crest, leaving a 3-5 mm cuff on the inner and outer lips for repair
• • Tag the fascia for later closure

Deep Dissection - Inner Table (Iliac Fossa)

• • Use a Cobb elevator to develop the subperiosteal plane on the inner table
• • Elevate iliacus muscle medially and inferiorly toward the pelvic brim
• • Continue dissection to expose the entire iliac fossa and the anterior aspect of the sacroiliac joint
• • Place pointed Hohmann retractors on the pelvic brim under direct vision, avoiding the iliac vessels
• • Irrigate frequently to visualize the psoas tendon and iliopectineal eminence

Deep Dissection - Outer Table (When Required)

• • Elevate gluteus medius and minimus subperiosteally from the outer table
• • Limit distal dissection to protect the superior gluteal neurovascular bundle
• • Expose the greater sciatic notch if posterior column or SI joint posterior access required

Reduction and Fixation

• • Reduce fracture using pointed reduction clamps, Schanz pins in the crest, or pelvic reduction forceps
• • Fix with 3.5 mm reconstruction plates contoured along the iliac crest or pelvic brim
• • Use lag screws from crest to brim for simple patterns
• • Confirm reduction with direct vision and fluoroscopy (AP, obturator, iliac obliques)

Superficial Layer

• • Lateral femoral cutaneous nerve (LFCN): 1-3 cm medial or directly over ASIS in 80 percent of patients. Protect with vessel loop. Injury rate 10-30 percent.
• • Superficial circumflex iliac artery: crosses the ASIS region. Coagulate or ligate if encountered.

Intermediate Layer

• • Iliacus muscle: devascularization occurs if not elevated subperiosteally. Leads to fatty atrophy and heterotopic ossification.
• • Tensor fascia lata origin: must be repaired to crest if detached.

Deep Layer

• • External iliac vessels: lie on the pelvic brim. Use only broad malleable retractors with minimal pressure. Never place pointed retractors blindly.
• • Iliohypogastric and ilioinguinal nerves: may be encountered if extending medially.
• • Superior gluteal artery and nerve: exit greater sciatic notch 2-3 cm posterior to the posterior crest. Protect during outer table work.

At-Risk During Reduction

• • Femoral nerve: lies on iliopsoas. Excessive medial retraction can cause neuropraxia.
• • Corona mortis (if extending medially): anastomotic vessel behind superior pubic ramus.

Proximal Extension

• • Extend posteriorly along the iliac crest toward the PSIS for more posterior iliac wing or SI joint access.
• • Can connect to the posterior approach (Kocher-Langenbeck) for combined anterior-posterior column fractures.

Distal/Medial Extension

• • Continue along the inguinal ligament to convert to full ilioinguinal approach (middle and medial windows).
• • Use the Stoppa (anterior intrapelvic) approach for quadrilateral surface and low anterior column access.

Procedures Performed Through This Window

• • ORIF of isolated iliac wing fractures
• • Fixation of high anterior column acetabular fractures (fracture line above iliopectineal eminence)
• • Anterior SI joint plating or screw fixation
• • Iliac crest bone graft harvest (tricortical strut or cancellous)
• • Limited exposure for anterior column screw placement in both-column fractures

Closure

• • Reattach iliacus and abdominal obliques to the inner lip of the crest using heavy non-absorbable suture through drill holes or over a bone bridge.
• • Repair tensor fascia lata and gluteal fascia to the outer lip.
• • Close subcutaneous tissue in layers.
• • Place a suction drain in the iliac fossa if extensive dissection performed.
• • Skin closure with staples or subcuticular suture.
• • Post-operative hip flexion precautions for 4-6 weeks to protect repair.