import { ComparisonTable, ContentSection, EvidenceCard, ExamCheatSheet, ExamPearl, ExamWarning, InfoCard, InfoCardGrid, MedicalImage, MnemonicCard, OnePagerSummary, SafetyAlert, Tab, Tabs, Timeline, TimelineItem, VivaScenario, VivaScenarioSection } from '@/components/mdx' {/* SECTION 1: ONE-PAGER SUMMARY */} {/* MISSING IMAGE: /images/topics/ilioinguinal-approach-acetabulum/web-sourced/3-fracture-of-the-rt-acetabulum.png {/* MISSING IMAGE: /images/topics/ilioinguinal-approach-acetabulum/web-sourced/3-fracture-of-the-rt-acetabulum.png */} */} {/* SECTION 2: EXAM WARNING */} **Lateral, middle, medial windows** provide sequential exposure of the anterior acetabulum. The external iliac vessels are the central landmark - lateral to vessels is lateral window, medial to vessels is medial window. Understanding window anatomy is essential. **Aberrant obturator artery or vein** connecting external iliac to obturator system occurs in 10-30%. Found crossing superior pubic ramus. Must identify and ligate before medial dissection to prevent catastrophic bleeding. The **lateral femoral cutaneous nerve** crosses the iliac crest lateral to ASIS. Often sacrificed for adequate exposure, causing anterolateral thigh numbness. Counsel patients pre-operatively about this complication. True internervous approach: **femoral nerve** (on iliopsoas, retract laterally) and **obturator nerve** (deep to vessels, retract medially). This anatomical safety allows extensive exposure without motor nerve injury. {/* SECTION 2.5: QUICK DECISION GUIDE */} {/* SECTION 3: MNEMONICS */} {/* SECTION 4: OVERVIEW */} The **ilioinguinal approach** was described by Emile Letournel in the 1960s for surgical treatment of anterior acetabular fractures. It remains a fundamental approach for pelvic and acetabular trauma surgery. **Historical significance:** - First systematic approach to anterior acetabulum - Allowed fixation of previously inoperable fractures - True internervous plane approach - Template for modern pelvic surgery **Modern evolution:** - Modified Stoppa approach supplements or replaces medial window access - Anterior intrapelvic approach combines ilioinguinal and Stoppa concepts - Percutaneous techniques for select simple patterns - Navigation and robotics emerging Emile Letournel revolutionized acetabular fracture surgery in the 1960s-1970s. His classification and surgical approaches (ilioinguinal and Kocher-Langenbeck) remain the foundation of modern acetabular fracture treatment. The ilioinguinal approach demonstrates true internervous plane dissection. **Current role:** - Gold standard for anterior column fractures - Required for both-column fractures (combined with K-L) - Increasingly supplemented by modified Stoppa for quadrilateral surface - Steep learning curve - typically 20-30 cases to achieve proficiency {/* SECTION 5: ANATOMY */} **The pelvis has a unique three-dimensional anatomy** requiring understanding of bony landmarks, neurovascular structures, and muscle relationships. **Bony anatomy:** - **Iliac wing** - lateral window access - **Pelvic brim** - middle window access, anterior column superior - **Quadrilateral surface** - medial window access, inner wall of acetabulum - **Superior pubic ramus** - medial window, anterior column inferior component **Neurovascular relationships:** **Muscle anatomy:** - **Iliopsoas** - femoral nerve lies on muscle; retract laterally as unit - **Iliacus** - fills iliac fossa; lateral window between psoas and iliacus - **Pectineus** - origin on superior ramus; may need release for exposure - **Rectus abdominis** - medial attachment to pubis; preserve if possible The ilioinguinal approach is a **true internervous approach** - it works between the femoral nerve (lateral, on iliopsoas) and obturator nerve (medial, deep to vessels). This anatomical fact allows extensive exposure without denervating any muscles. Retract the iliopsoas laterally to protect femoral nerve, retract vessels and obturator medially. **The three windows:** | Window | Boundaries | Exposes | Fractures Accessed | |--------|------------|---------|-------------------| | **Lateral** | Iliopsoas (medial) and iliacus (lateral) | Iliac wing, SI joint | Anterior column high, iliac wing | | **Middle** | Iliopsoas (lateral) and vessels (medial) | Pelvic brim, anterior column | Anterior column, anterior wall | | **Medial** | Vessels (lateral) and cord/round ligament (medial) | Quadrilateral, superior ramus | Anterior column low, both column | {/* SECTION 5.5: INTERNERVOUS PLANE */} The ilioinguinal approach is a **true internervous approach**. The dissection exploits the interval between the **Femoral Nerve** (lateral - supplying Iliopsoas, Quads, Sartorius, Pectineus) and the **Obturator Nerve** (medial - supplying Adductors, Gracilis, Obturator Externus). The **External Iliac Vessels** separate these two nervous territories. **Plane Details:** - **Lateral Window:** Plane is *within* the Femoral Nerve territory (between Iliacus and Psoas). Femoral nerve lies on Psoas, so dissecting between Psoas and Iliacus is safe IF nerve is identified. - **Middle Window:** Plane between Femoral Nerve (lateral/Psoas) and External Iliac Vessels (medial). - **Medial Window:** Plane medial to the External Iliac Vessels (Obturator nerve is deep/medial). {/* SECTION 6: INDICATIONS */} **Absolute indications:** - Displaced anterior column fractures - Displaced anterior wall fractures - Both-column fractures (combined with Kocher-Langenbeck) - Anterior column + posterior hemitransverse patterns **Relative indications:** - T-type fractures (anterior component) - Associated anterior column and posterior hemitransverse - Selected transverse fractures (with anterior extension) **Fracture displacement criteria:** - Greater than 2-3mm step-off in weight-bearing dome - Roof arc less than 45 degrees on any view - Posterior wall involvement greater than 40% - Marginal impaction greater than 5mm - Incongruent reduction on CT The ilioinguinal approach provides comprehensive anterior acetabulum exposure for complex fracture patterns. **Absolute contraindications:** - Medical unfitness for prolonged surgery - Active pelvic infection - Irreconstructable acetabulum (salvage arthroplasty indicated) **Relative contraindications:** - Timing greater than 3 weeks (consider staged or salvage) - Severe osteoporosis (fixation may not hold) - Extensive comminution (may need additional approaches) - Previous surgery with scarring **Timing considerations:** - Ideal: 3-5 days (swelling subsided, mobilization still possible) - Acceptable: up to 3 weeks - Beyond 3 weeks: difficulty increases exponentially due to callus and heterotopic bone Delayed presentation requires careful consideration of surgical vs non-operative management. **Modified Stoppa approach:** - Better access to quadrilateral surface - Less dissection than medial window of ilioinguinal - Cannot access iliac wing or high anterior column - Increasingly popular alternative or supplement **Anterior intrapelvic (Keel) approach:** - Combines ilioinguinal and Stoppa concepts - Single incision, multiple windows - Requires significant experience **Kocher-Langenbeck:** - Posterior approach for posterior wall/column - Combined with ilioinguinal for both-column fractures - Two-stage or simultaneous surgery The choice between approaches depends on fracture pattern and surgeon experience with each technique. {/* SECTION 7: PREOPERATIVE PLANNING */} **Clinical assessment:** - Mechanism of injury (high vs low energy) - Associated injuries (chest, abdomen, extremities) - Neurovascular examination (sciatic, femoral, obturator) - Skin condition (Morel-Lavallée lesion) **Imaging:** **AP pelvis** (standard view) **Judet views** - obturator oblique (45° toward injured side) shows anterior column and posterior wall; iliac oblique (45° away) shows posterior column and anterior wall **Fine-cut CT** (1-2mm slices) with 3D reconstruction Assess: fracture lines, comminution, impaction, marginal impaction, femoral head injury, intra-articular fragments Assess fracture reducibility Identify blocks to reduction Useful for delayed presentations **Letournel classification review:** - Identify fracture pattern (elementary vs associated) - Determine which columns are involved - Assess posterior wall involvement (if any) **Surgical planning:** - Approach selection (ilioinguinal vs modified Stoppa vs combined) - Implant planning (reconstruction plates, screws, spring plates) - Anticipated reduction maneuvers - Plan for windows needed (all three vs selected) **Obturator oblique** (rotate toward injury 45°): Shows **anterior column** (iliopectineal line) and **posterior wall** (rim). **Iliac oblique** (rotate away 45°): Shows **posterior column** (ilioischial line) and **anterior wall**. Systematic review of six key lines on AP and Judet views allows fracture pattern classification. {/* SECTION 8: POSITIONING */} **Patient Position:** - **Supine** on a radiolucent table (Must be radiolucent for Judet views). - **Arms** folded across chest (avoids interference with lateral view) or on arm boards (if far lateral). - **Bump** under the ipsilateral hip is generally **NOT** recommended for Ilioinguinal as it closes the anterior approach, but some surgeons use a small bump to help with lateral window access. - **Foley Catheter**: Mandatory. - **Draping**: Wide prep from nipple line to knees. Leg must be free to drape for manipulation (hip flexion relaxes Psoas). **Setup Checklist:** 1. **C-arm**: Complicated positioning. Opposite side of table must be clear for C-arm to swing for Inlet/Outlet/Judet views. 2. **Surgeon**: Stands on IPSI-lateral side (unlike Stoppa). 3. **Assistant**: Stands on CONTRA-lateral side or cephalad/caudad. {/* SECTION 9: SURGICAL TECHNIQUE */} ### Skin Incision and Superficial Dissection **Incision:** - Begins 2cm medial and proximal to ASIS - Curves along iliac crest for 6-8cm - Turns distally following inguinal ligament - Extends to pubic tubercle (total 15-20cm) **Superficial dissection:** Divide subcutaneous tissue along incision Identify and preserve or sacrifice lateral femoral cutaneous nerve (crosses 2cm medial to ASIS) If sacrificed, warn patient of anterolateral thigh numbness Identify external oblique aponeurosis Incise aponeurosis along inguinal ligament Identify internal oblique and transversus abdominis Detach muscle origins from iliac crest (subperiosteal) Expose inguinal ligament inferior border Identify femoral vessels emerging beneath ligament Mobilize spermatic cord (male) or round ligament (female) for retraction The superficial dissection exposes the three windows by creating access to the iliac wing laterally and the pelvic brim medially. ### Lateral Window - Iliac Wing and SI Joint **Boundaries:** - Medial: Iliopsoas muscle - Lateral: Iliacus muscle on iliac fossa **Technique:** Develop interval between iliopsoas (medial) and iliacus (lateral) This is an internervous plane (femoral nerve on both muscles) Blunt dissection usually adequate Subperiosteal dissection along inner iliac fossa Expose iliac wing from crest to SI joint Retract iliopsoas medially (femoral nerve retracts with it) Identify fracture lines on iliac wing Clear soft tissue and hematoma Prepare for reduction and fixation **Uses:** - High anterior column fractures - Iliac wing fractures - SI joint if needed - Plate application along pelvic brim The lateral window provides access for the superior extent of anterior column fractures. ### Middle Window - Pelvic Brim and Anterior Column **Boundaries:** - Lateral: Iliopsoas muscle (and femoral nerve on it) - Medial: External iliac artery and vein **Technique:** Identify external iliac artery and vein **Critical step**: Mobilize vessels medially off pelvic brim Divide lymphatics as needed (ligate to prevent lymphocele) Preserve genitofemoral nerve on psoas if possible Develop plane between iliopsoas (lateral) and vessels (medial) Subperiosteal dissection along pelvic brim Expose entire anterior column from SI joint to pubis Identify fracture line at pelvic brim Reduce fracture with pointed reduction forceps Temporary fixation with K-wires Apply plate along pelvic brim (reconstruction plate) Mobilizing external iliac vessels is the **key maneuver** of the ilioinguinal approach. Use gentle blunt dissection. The vessels are robust but must be protected. Division of lymphatics is acceptable but ligate them to prevent lymphocele. This mobilization creates the middle window and allows access to the entire pelvic brim. The middle window is the workhorse for anterior column fracture fixation. ### Medial Window - Quadrilateral Surface and Superior Ramus **Boundaries:** - Lateral: External iliac vessels (mobilized medially) - Medial: Spermatic cord (male) or round ligament (female) **Critical first step - Corona Mortis:** Before developing medial window, **identify corona mortis** - aberrant vessel connecting obturator to external iliac system, crosses superior pubic ramus. Present in 10-30% of patients. Can be arterial, venous, or both. **Must ligate before dissection** to prevent catastrophic bleeding. Approach superior ramus cautiously, identify any aberrant vessels, ligate with clips or suture ligature. **Technique:** Approach superior pubic ramus carefully Identify any vessels crossing ramus (corona mortis) Ligate with clips or 2-0 silk ties Confirm hemostasis before proceeding Retract spermatic cord/round ligament medially Retract external iliac vessels laterally Expose superior pubic ramus and quadrilateral surface Identify fracture of superior ramus or quadrilateral surface Reduce with pointed clamps Apply plate to superior ramus or quadrilateral buttress plate **Modern alternative:** The modified Stoppa approach provides superior access to quadrilateral surface and is increasingly preferred for medial-sided pathology. Many surgeons now use ilioinguinal for lateral and middle windows only, adding Stoppa approach for medial access. The medial window completes the three-window exposure, allowing access to the entire anterior acetabulum. ### Fracture Reduction and Internal Fixation **Reduction sequence:** 1. Reduce iliac wing (lateral window) if fractured 2. Reduce superior anterior column at pelvic brim (middle window) 3. Reduce inferior component at superior ramus (medial window) 4. Confirm reduction with fluoroscopy (AP, obturator, iliac views) **Reduction techniques:** - **Pointed reduction forceps** (essential tool for pelvic fractures) - **Ball-spike pusher** for manipulation of fragments - **Schanz pins** in ilium or femoral head (joystick control) - **Femoral distractor** if needed for length/rotation **Fixation principles:** **Fluoroscopic views to check:** - **AP pelvis**: Overall alignment, joint congruence - **Obturator oblique**: Anterior column (iliopectineal line), posterior wall - **Iliac oblique**: Posterior column, anterior wall - **Inlet/outlet**: If combined with posterior injury Adequate reduction is defined as less than 2mm step-off in weight-bearing dome with congruent joint surfaces. ### Wound Closure **Deep layers:** - Repair abdominal muscles to iliac crest (2-0 absorbable suture) - Repair inguinal ligament if detached - Ensure hemostasis (meticulous - large dead space) **Drain:** - Deep subfascial drain recommended (remove at 24-48h) - Monitor output (potential for lymphocele or seroma) **Superficial layers:** - Reapproximate subcutaneous fat (3-0 absorbable) - Skin (staples or subcuticular suture) - Sterile dressing **Post-closure check:** - Neurovascular examination (femoral, obturator, sciatic) - Final fluoroscopy (AP, obturator, iliac) - Document hardware position and reduction Closure completes a long, complex procedure requiring meticulous technique throughout. {/* SECTION 9: COMPLICATIONS */} **Intraoperative complications:** Sudden bleeding from depth of wound during vessel mobilization Identify source (external iliac artery vs vein vs corona mortis) Direct pressure with pack Do not blindly clamp (may worsen injury) Improve exposure with retraction Small injuries: direct repair with 5-0 or 6-0 prolene Larger injuries: call vascular surgery Temporary shunt if needed for limb perfusion {/* SECTION 10: POSTOPERATIVE CARE */} ICU or high-dependency monitoring if prolonged surgery or blood loss DVT prophylaxis (LMWH or rivaroxaban) Analgesia (epidural or PCA, transition to oral) Neurovascular checks Toe-touch weight bearing (10-20kg) with crutches or walker Hip and knee range of motion exercises Avoid hip flexion greater than 90 degrees (protects anterior repair) Continue DVT prophylaxis for 4-6 weeks Progress to partial weight bearing (50%) Increase ROM exercises X-rays at 6 weeks to assess healing Continue mobilization Full weight bearing as tolerated (once callus visible on X-ray) Strengthening exercises Return to light activities X-rays at 12 weeks, 6 months, 1 year **Long-term outcomes:** - Good-to-excellent results in 70-85% with anatomic reduction - Post-traumatic arthritis risk 20-30% at 10 years - Heterotopic ossification common but usually asymptomatic - Function recovery continues up to 2 years post-injury {/* SECTION 11: EVIDENCE BASE */} {/* SECTION 12: VIVA SCENARIOS */} {/* SECTION 13: MCQ PRACTICE POINTS */} **Q: What are the boundaries of the middle window in the ilioinguinal approach?** A: The middle window is bounded **laterally by the iliopsoas muscle** (with femoral nerve on it) and **medially by the external iliac artery and vein**. This window provides access to the pelvic brim and is the primary window for anterior column fixation. **Q: What makes the ilioinguinal approach a true internervous approach?** A: The approach works between the **femoral nerve** (lateral, on iliopsoas muscle) and the **obturator nerve** (medial, deep to external iliac vessels). No muscles are denervated because the dissection stays between nerve territories. **Q: What is corona mortis and what is its significance in the ilioinguinal approach?** A: Corona mortis is an **aberrant vessel connecting the obturator to external iliac system**, crossing the superior pubic ramus. It occurs in **10-30% of patients** and can cause massive bleeding if injured. It must be identified and ligated before medial window dissection. **Q: Which nerve is most commonly injured in the ilioinguinal approach and what is the consequence?** A: The **lateral femoral cutaneous nerve** is most commonly injured (10-15% incidence), often intentionally sacrificed for adequate exposure. This results in numbness over the anterolateral thigh (meralgia paresthetica). Patients should be counseled pre-operatively about this complication. **Q: What are the primary indications for the ilioinguinal approach?** A: **Anterior column fractures, anterior wall fractures, and both-column fractures** (combined with Kocher-Langenbeck for posterior component). The approach provides comprehensive access to the entire anterior acetabulum through three anatomical windows. {/* SECTION 14: EXAM CHEAT SHEET */} **Trauma Centre Referral**: Complex acetabular fractures requiring the ilioinguinal approach are managed at Level 1 trauma centres with subspecialty pelvic trauma expertise. The Australian Trauma Quality Improvement Program (AusTQIP) supports centralisation of complex pelvic surgery. **Timing Considerations**: Australian practice follows international guidelines for surgery within 5-10 days to allow swelling resolution. Extended delays may occur for transfer from regional centres. **DVT Prophylaxis**: Mechanical and pharmacological prophylaxis per Australian guidelines. Low molecular weight heparin is PBS-subsidised. Extended prophylaxis for 28-35 days post-surgery is standard practice. **Transfusion Services**: Australian Red Cross Lifeblood provides blood products. Cell salvage is routinely available at major trauma centres. Massive transfusion protocols are established for significant pelvic haemorrhage. **Rehabilitation Pathway**: Protected weight bearing for 6-12 weeks depending on fracture pattern and fixation. Physiotherapy coordinated through hospital outpatient services with transition to community providers.

Ilioinguinal Approach to the Acetabulum

Ilioinguinal Approach to the Acetabulum