Acetabulum – Ilioinguinal Approach

Modern Study Review (AI-Generated)

High-Yield Summary

The Ilioinguinal approach is a cornerstone anterior surgical exposure for displaced acetabular fractures involving the anterior column, pelvic brim, and quadrilateral surface. It provides direct visualization and access for open reduction and internal fixation (ORIF) of anterior column and both-column fractures. While still considered a gold standard for these fracture patterns, it has been partially supplanted by extensile and minimally invasive techniques, including arthroscopic-assisted approaches, in select cases.

Applied Anatomy & Intervals

Internervous Interval

• No true internervous plane.
• Dissection proceeds via muscle-splitting and careful mobilization of neurovascular structures.

Anatomic Landmarks

• Anterior Superior Iliac Spine (ASIS)
• Pubic tubercle
• Inguinal ligament
• Iliac crest (lateral border)
• Symphysis pubis

Patient Positioning & Setup

Table Type:

• Radiolucent flat or fracture table

Patient Position:

• Supine with the greater trochanter positioned at the table edge to facilitate fluoroscopic imaging

Specialized Equipment:

• Urinary catheter for bladder decompression (mandatory)
• C-arm fluoroscopy positioned contralateral or ipsilateral as needed
• Limb positioners for traction or manipulation as required

Surgical Technique (The “Vital Steps”)

Incision & Superficial Dissection

• Curved incision beginning approximately 5 cm above the ASIS, extending medially to 1 cm above the pubic tubercle, then continuing to the midline.
• Incise subcutaneous fat to expose the external oblique aponeurosis.
• Identify and protect the lateral femoral cutaneous nerve at the lateral edge of the dissection.
• Divide the external oblique aponeurosis from the superficial inguinal ring to the ASIS.

Deep Dissection & Exposure

• Identify the round ligament (females) or spermatic cord (males) medially as a key landmark.
• Divide the anterior rectus sheath to expose the rectus abdominis muscle.
• Strip the iliacus muscle from the inner iliac wing to expose the sacroiliac joint.
• Transversely divide the rectus muscle approximately 1 cm proximal to its insertion.
• Develop the retropubic space (space of Retzius) between the bladder and pubic symphysis.
• Peel internal oblique and transversus abdominis fibers off the inguinal ligament to avoid injury to the inferior epigastric vessels and deep inguinal ring.
• Mobilize the peritoneum superiorly to expose the external iliac vessels.
• Isolate the external iliac vessels (middle neurovascular bundle).
• Identify and protect the iliopsoas muscle and femoral nerve laterally.
• Expose the medial surface of the acetabulum and superior pubic ramus for fracture visualization and fixation.

The “Danger Zone”

Post-Operative Pearl

Early mobilization is encouraged; however, limit hip flexion beyond 90° initially to protect the repair and avoid tension on the femoral nerve and iliopsoas muscle. Weight-bearing status is dictated by fracture pattern and fixation stability.

Classic Clinical Notes

Acetabulum – ilioinguinal approach

• Position: Supine with greater trochanter at edge of table
• Need: Urinary catheter

• Incision: Curved anterior incision starting 5 cm above ASIS, extending 1 cm above pubic tubercle to midline

• No internervous plane

• Dissection:
• Incise subcutaneous fat
• Expose aponeuroses of external oblique
• Lateral femoral cutaneous nerve at lateral edge of dissection
• Divide external oblique from superficial inguinal ring to ASIS
• Identify round ligament or spermatic cord (medial bundle)
• Divide anterior part of rectus sheath to expose underlying rectus
• Strip iliacus from inside of wing of ilium — can expose SI joint
• Divide rectus transversely 1 cm proximal to insertion
• Develop plane between back of symphysis and bladder (space of Retzius)
• Peel fibers of internal oblique and transversus from inguinal ligament — avoids inferior epigastric artery and deep inguinal ring
• Push peritoneum upwards to expose external iliac vessels
• Isolate external iliac vessels (middle bundle)
• Isolate iliopsoas and femoral nerve (lateral bundle)
• Expose medial surface of acetabulum and superior pubic ramus

• Dangers:
• Femoral nerve: runs beneath inguinal ligament lying on iliopsoas; avoid excessive retraction
• Inferior epigastric artery: passes medial to deep inguinal ligament
• Spermatic cord: contains vas deferens and testicular artery
• Bladder: easily mobilized off back of symphysis
• Corona mortis:
• Anastomosis of branch of obturator artery and external iliac artery
• Occurs in 25-30% of patients
• On undersurface of external iliac artery

Last Updated on January 25, 2026 by Christian Veillette