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 */} {/* SECTION 2: EXAM WARNING */} The **sciatic nerve is at highest risk** in this approach (15-20% palsy rate). Identify nerve proximal to piriformis, protect throughout, avoid retraction for more than 15 minutes continuously, monitor somatosensory evoked potentials if available. **Piriformis, superior gemellus, obturator internus, inferior gemellus** must be released from greater trochanter and tagged for repair. This exposes posterior capsule and protects sciatic nerve. Always repair at end of case. **Posterior wall fractures often associated with hip dislocation.** Assess femoral head for impaction injury (indentation fracture), chondral injury, and loose bodies. Femoral head impaction greater than 4mm may need bone grafting. Split gluteus maximus **in line with its fibers** (oblique, superior-lateral to inferior-medial). This is internervous between superior gluteal nerve (superior fibers) and inferior gluteal nerve (inferior fibers). Stay in safe zone to avoid denervation. {/* SECTION 2.6: MANAGEMENT ALGORITHM */} **Fixation options for posterior wall:** **Fluoroscopic assessment:** - **Obturator oblique** - best view for posterior wall reduction - **AP pelvis** - overall joint congruence - **Iliac oblique** - posterior column if involved **Stability testing:** - After fixation, test hip through range of motion - Assess for posterior subluxation - If unstable, may need additional fixation or consider trochanteric advancement Anatomic reduction and stable fixation are the goals for optimal long-term outcomes. ### Critical Final Step - External Rotator Repair **Why repair external rotators:** - Creates soft tissue cushion between sciatic nerve and hardware - Reduces sciatic nerve palsy risk - Improves hip external rotation strength - May reduce heterotopic ossification **Repair technique:** Refresh bone at greater trochanter insertion sites Drill holes for suture passage if using bone tunnels Or place suture anchors in greater trochanter Bring superior gemellus + obturator internus + inferior gemellus back to trochanter Use heavy non-absorbable suture (No. 2 Ethibond) Secure through bone tunnels or to anchors Repair piriformis tendon to greater trochanter Most important for nerve protection Check tension - should be snug but not overly tight **Capsule repair:** - Repair posterior capsule if sufficient tissue remains - Use absorbable suture (No. 1 Vicryl) - T-capsulorrhaphy if possible **Superficial closure:** - Approximate gluteus maximus fascia (2-0 Vicryl) - Scarpa's fascia (3-0 Vicryl) - Skin (staples or subcuticular suture) **Drain:** - Deep subfascial drain (15-19Fr round drain) - Remove at 24-48 hours Meticulous external rotator repair is as important as fracture fixation for protecting the sciatic nerve. {/* SECTION 9: COMPLICATIONS */} **Sciatic nerve palsy:** - **Most feared complication** of Kocher-Langenbeck approach - Incidence 15-20% (higher than any other orthopaedic approach) - Risk factors: prolonged retraction, stretching, hardware impingement, hematoma - **Common peroneal division more vulnerable** than tibial division - Presentation: foot drop, numbness in foot - **Management**: Most resolve spontaneously over 6-18 months; EMG at 3-6 weeks; consider exploration if complete palsy or no recovery at 6 months **Sciatic palsy prevention strategy:** 1. Identify nerve proximally before rotator release 2. Hip and knee flexion to relax nerve 3. Intermittent retraction (release every 15 minutes) 4. SSEP monitoring if available 5. Repair external rotators to cushion nerve from hardware 6. Gentle surgical technique The Kocher-Langenbeck approach has the **highest heterotopic ossification (HO) risk** of all acetabular approaches (20-40% vs 10-20% for ilioinguinal). Extensive muscle dissection and bone injury predispose to HO formation. **Prophylaxis is mandatory**: indomethacin 75mg daily for 6 weeks starting post-op day 1, OR single-dose radiation therapy 7 Gy within 72 hours of surgery. Prophylaxis reduces HO incidence to 5-10%. {/* SECTION 10: POSTOPERATIVE CARE */} Monitor for sciatic nerve function (foot dorsiflexion, sensation) DVT prophylaxis (LMWH or rivaroxaban) Pain control (epidural or PCA) Begin indomethacin for HO prophylaxis (75mg daily) Toe-touch weight bearing (10-20kg) - posterior wall needs protection Hip ROM exercises (avoid extremes of flexion/adduction/internal rotation) Continue indomethacin for 6 weeks total Monitor wound, drain removal at 24-48h X-rays at 6 weeks to assess healing Progress to partial weight bearing (50%) if callus visible Increase ROM exercises Gait training with physiotherapy Full weight bearing when fracture healed (usually 12 weeks) Progressive strengthening Return to activities as tolerated Monitor for late sciatic nerve recovery **Hip precautions (if posterior wall fracture):** - Avoid flexion greater than 90 degrees for 6 weeks - Avoid adduction past midline for 6 weeks - Avoid internal rotation for 6 weeks - These positions stress posterior wall repair **Sciatic nerve monitoring:** - Daily foot drop assessment in hospital - If deficit present, serial EMG/NCS at 3 weeks, 6 weeks, 3 months - Ankle-foot orthosis (AFO) if foot drop persists - Most palsies recover over 6-18 months **Long-term outcomes:** - Good-to-excellent results in 70-90% with anatomic reduction - Post-traumatic arthritis 20-30% at 10 years - Heterotopic ossification common but usually asymptomatic - Sciatic nerve palsies recover in 60-80% of cases {/* SECTION 11: EVIDENCE BASE */} {/* SECTION 12: VIVA SCENARIOS */} {/* SECTION 13: MCQ PRACTICE POINTS */} **Q: What is the internervous plane for the Kocher-Langenbeck approach?** A: The approach splits the **gluteus maximus muscle in line with its fibers**, working between the **superior gluteal nerve** (supplies superior fibers) and **inferior gluteal nerve** (supplies inferior fibers). Both nerves are branches of the sciatic nerve. **Q: Where does the sciatic nerve exit the pelvis and what is its relationship to piriformis?** A: The sciatic nerve exits the pelvis through the **greater sciatic notch below the piriformis muscle** in 90% of patients (anatomical variations exist). This is why identifying the nerve proximal to piriformis before releasing the muscle is critical. **Q: What is the significance of a posterior wall fracture involving greater than 40% of the wall?** A: Posterior wall fragments **greater than 40% of the wall** (measured on CT axial cuts) are at high risk of hip instability and **require surgical fixation**. Fragments less than 40% may be stable if concentric reduction is achieved and the hip is stable through range of motion. **Q: Why is it important to repair the short external rotators at the end of a Kocher-Langenbeck approach?** A: Repairing the external rotators (piriformis and conjoint tendon) **creates a soft tissue cushion between the sciatic nerve and hardware**, significantly reducing the risk of nerve palsy. Studies show repair reduces palsy incidence from 22% to 13%. **Q: What is the incidence of heterotopic ossification after Kocher-Langenbeck approach and how is it prevented?** A: The K-L approach has **20-40% heterotopic ossification risk** - the highest of all acetabular approaches. Prevention is with **indomethacin 75mg daily for 6 weeks** starting post-op day 1, OR **single-dose radiation 7 Gy** within 72 hours of surgery. Prophylaxis reduces incidence to 5-10%. {/* SECTION 14: EXAM CHEAT SHEET */} **Trauma Centre Referral:** Complex acetabular fractures requiring the Kocher-Langenbeck approach are managed at Level 1 trauma centres in Australia. Specialist pelvic and acetabular surgeons are available at major metropolitan centres. **Timing Considerations:** Australian practice follows international guidelines for surgery within 5-10 days of injury to allow patient optimization while avoiding excessive scar formation and heterotopic ossification. **DVT Prophylaxis:** Mechanical and pharmacological prophylaxis per Australian guidelines. Low molecular weight heparin is PBS-subsidised for VTE prevention in major trauma patients. **Intraoperative Monitoring:** Somatosensory evoked potentials (SSEPs) and continuous EMG monitoring for sciatic nerve are available at major centres for high-risk cases. **Rehabilitation Pathway:** Protected weight bearing for 6-12 weeks with physiotherapy. Medicare-funded rehabilitation services available through public hospitals and Enhanced Primary Care programs.

Kocher-Langenbeck Approach to the Acetabulum

Kocher-Langenbeck Approach to the Acetabulum