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 */} **Retropubic space** between bladder anteriorly and pubic symphysis posteriorly. This avascular plane is the key to the approach - develop it bluntly to access the medial pelvic wall without entering peritoneum or damaging bladder. The modified Stoppa provides **superior access to quadrilateral surface** compared to ilioinguinal medial window. Direct visualization allows placement of buttress plates to prevent medial subluxation of femoral head. **Mobilize bladder posterolaterally** off the quadrilateral surface. This is the key maneuver - gentle blunt dissection in correct plane. Foley catheter essential to decompress bladder and reduce injury risk. Just as in ilioinguinal approach, **corona mortis** is encountered crossing superior pubic ramus. Must identify and ligate before proceeding laterally. Same 10-30% incidence and hemorrhage risk. {/* SECTION 2.5: QUICK DECISION GUIDE */} {/* SECTION 3: MNEMONICS */} {/* SECTION 4: OVERVIEW */} The **modified Stoppa approach** was adapted from the Stoppa hernia repair technique and popularized for acetabular fractures by Cole and Bolhofner in the 1990s. It provides intrapelvic access to the quadrilateral surface and medial acetabular structures. **Historical evolution:** - **Original Stoppa**: Developed for inguinal hernia repair using retropubic space - **Cole and Bolhofner (1994)**: Applied to acetabular fracture surgery - **Sagi et al (2000s)**: Refined technique and indications - **Current**: Increasingly preferred for quadrilateral surface access **Why it gained popularity:** - Superior quadrilateral surface visualization vs ilioinguinal medial window - Lower nerve injury risk (no lateral femoral cutaneous nerve at risk) - Better cosmetic result (Pfannenstiel incision) - Combines well with other approaches The **modified Stoppa approach provides superior access to the quadrilateral surface** compared to the medial window of the ilioinguinal approach. Working intrapelvically allows direct visualization and plate application to prevent medial subluxation. However, Stoppa cannot access the iliac wing or high anterior column - these still require ilioinguinal lateral/middle windows. **Current indications:** - Isolated quadrilateral surface fractures - Associated both-column fractures (with medial displacement) - T-type fractures (anterior component) - Low anterior column with quadrilateral involvement - Often combined with lateral window ilioinguinal or separate lateral incision {/* SECTION 5: ANATOMY */} **The space of Retzius is the key anatomical space** - a potential extraperitoneal space between the bladder and the posterior surface of the pubic symphysis. **Boundaries of space of Retzius:** - **Anterior**: Posterior surface of pubic symphysis and superior rami - **Posterior**: Anterior wall of bladder and peritoneum - **Superior**: Peritoneal reflection - **Inferior**: Pelvic floor (levator ani, obturator internus) - **Lateral**: Pelvic sidewall and external iliac vessels **Quadrilateral surface anatomy:** - **Location**: Medial wall of acetabulum, inner table of pelvis - **Shape**: Quadrilateral (four sides) - superior border is pelvic brim, inferior is obturator foramen, anterior is superior ramus, posterior is ischium - **Function**: Resists medial subluxation of femoral head - **Fracture significance**: Fractures allow medial displacement of head into pelvis The **bladder must be mobilized in the correct plane** to prevent injury. Always place a Foley catheter to decompress the bladder before dissection. The correct plane is between bladder wall and pelvic bone - this is relatively avascular. If you see muscle fibers (detrusor), you're in the bladder wall. If you see peritoneum, you're too superficial. Use gentle blunt dissection with a sponge stick. **Window anatomy:** | Window | Boundaries | Exposes | Fixation | |--------|------------|---------|----------| | **First Window (Medial)** | Bladder (medial) and external iliac vessels (lateral) | Quadrilateral surface, superior ramus | Quadrilateral buttress plate | | **Second Window (Lateral)** | External iliac vessels (medial) and psoas (lateral) | Low anterior column, pelvic brim | Infrapectineal plate if needed | {/* SECTION 5.5: INTERNERVOUS PLANE */} **No true internervous plane exists for this approach.** The modified Stoppa approach works through the **Space of Retzius** (retropubic space), which is an extraperitoneal potential space. The dissection essentially separates the rectus abdominis muscles (inter-muscular) but then proceeds in a plane that is defined by fascial boundaries rather than nerve supplies. Unlike the ilioinguinal approach which works between nerve territories (femoral/gluteal/lateral femoral cutaneous), the Stoppa approach is an **intrapelvic, extraperitoneal approach**. It avoids major traversing nerves of the anterior thigh. The **obturator nerve** is the only major nerve at risk, located on the pelvic sidewall on the obturator internus muscle. {/* SECTION 6: INDICATIONS */} **Isolated quadrilateral surface fractures:** - Medial wall displaced - Risk of femoral head subluxation into pelvis - Best access for buttress plate application **Associated both-column fractures:** - Medial displacement of articular surface - Spur sign present - Often combined with Kocher-Langenbeck for posterior component **T-type fractures:** - Anterior component (stem of T) involves quadrilateral - Combined with posterior approach for transverse component **Low anterior column with quadrilateral involvement:** - Inferior extent of anterior column - May combine with lateral window ilioinguinal for superior column The Stoppa approach is specifically designed for medial structures and excels where ilioinguinal medial window is limited. **Stoppa + Lateral Window Ilioinguinal:** - Low anterior column + quadrilateral - Stoppa for medial, lateral window for iliac wing - Single patient position (supine) **Stoppa + Kocher-Langenbeck:** - Both-column with medial displacement - Associated both-column patterns - T-type fractures - Requires repositioning or two-team approach **Stoppa + Percutaneous Screw:** - Quadrilateral + posterior column without wall - Stoppa for anterior, screw for posterior - Minimizes surgical trauma The modified Stoppa is rarely used in isolation - it typically combines with other techniques for complete fracture management. **Absolute contraindications:** - Previous lower midline laparotomy with extensive adhesions - Active pelvic infection - Bladder injury requiring repair (relative - may still be possible) **Relative contraindications:** - Previous pelvic surgery (increases difficulty) - Extensive scarring in retropubic space - Pregnancy (relative - can be done but carefully) **When NOT to use Stoppa:** - High anterior column fractures (no access to iliac wing) - Anterior wall without quadrilateral involvement (ilioinguinal better) - SI joint pathology (need ilioinguinal lateral window) Understanding the limitations of the Stoppa approach is as important as knowing its strengths. {/* SECTION 7: PREOPERATIVE PLANNING */} **Imaging assessment:** - **CT scan with 3D reconstruction**: Essential for understanding fracture pattern - Assess quadrilateral displacement and rotation - Measure gap (if greater than 10mm, strongly consider fixation) - Identify associated fracture components **Fracture characteristics to document:** - Quadrilateral fragment size and displacement - Posterior column involvement - Femoral head position (centrally located vs subluxed medially) - Marginal impaction - Intra-articular loose bodies **Implant planning:** - Quadrilateral buttress plates (pre-contoured or standard reconstruction plates) - 3.5mm cortical screws (various lengths 40-80mm) - Infrapectineal plating if anterior column involved - May need spring plates for specific patterns **Patient preparation:** - Foley catheter (essential - placed before prep) - Bowel preparation if peritoneal entry anticipated - DVT prophylaxis (SCDs, chemical prophylaxis post-op) - Antibiotics (cefazolin 2g or equivalent) The quadrilateral buttress plate acts as an **internal buttress preventing medial subluxation** of the femoral head. It spans from the superior pubic ramus anteriorly to the ischium posteriorly, creating a shelf that resists medial displacement. Screw fixation into intact bone (ramus and ischium) provides stability. This is biomechanically superior to trying to reduce and fix the quadrilateral fragment itself. {/* SECTION 8: PATIENT POSITIONING */} **Standard Position:** - **Supine** on a radiolucent table (essential for fluoroscopy) - **Arms** can be tucked or on boards (tucked preferred to allow surgeon movement) - **Bump** under the ipsilateral hip is usually **NOT** recommended as it makes the quadrilateral surface more vertical and harder to visualize. A flat pelvis is preferred. - **Draping**: Wide preparation from nipples to knees. Foley catheter access is essential. **Setup Checklist:** 1. **Foley Catheter**: MANDATORY. Must be placed before draping to decompress bladder. 2. **Fluoroscopy**: Ensure C-arm can swing for Inlet, Outlet, and Judet views without table obstruction. 3. **Surgeon Position**: Surgeon stands on the CONTRA-lateral side to look across the pelvis at the fracture. 4. **Assistant Position**: Assistant stands on the IPSI-lateral side to retract the bladder. {/* SECTION 9: SURGICAL TECHNIQUE */} ### Intrapelvic Approach Classification ### Surgical Window Classification | Window | Boundaries | Access | Fixation Options | |--------|------------|--------|------------------| | **First Window** | Bladder (medial), external iliac vessels (lateral) | Quadrilateral surface, superior ramus | Quadrilateral buttress plate | | **Second Window** | External iliac vessels (medial), psoas (lateral) | Pelvic brim, low anterior column | Infrapectineal plating | ### Judet-Letournel Fractures Suited to Stoppa The modified Stoppa is NOT a replacement for ilioinguinal - it is an alternative for specific fracture patterns involving the quadrilateral surface. High anterior column and iliac wing fractures still require ilioinguinal lateral and middle windows. ### Preoperative Patient Assessment **General Assessment:** - **Hemodynamic status**: Ensure stable before definitive fixation - **Associated injuries**: Polytrauma common with acetabular fractures - **Urological status**: Rule out bladder or urethral injury (blood at meatus, high-riding prostate) - **Neurological exam**: Document sciatic nerve function pre-operatively **Acetabular-Specific Assessment:** - **Soft tissue envelope**: Morel-Lavallée lesion over greater trochanter (posterior injury) - **Hip stability**: Assess for femoral head dislocation (requires urgent reduction) - **Timing**: Most acetabular fractures repaired at 3-7 days (allows resuscitation, decreases bleeding) ### Physical Examination for Approach Selection | Finding | Significance | Approach Implication | |---------|--------------|----------------------| | Anterior abdominal scars | Previous surgery | May preclude Stoppa if extensive adhesions | | Midline laparotomy scar | Prior peritoneal entry | Increased difficulty in Stoppa | | Pfannenstiel scar | Previous C-section/hernia | Usually still allows Stoppa | | Groin mass/hernia | May need concurrent repair | Stoppa allows hernia inspection | ### Contraindication Assessment If blood at urethral meatus or gross hematuria, obtain **retrograde urethrogram** (if urethral injury suspected) and **CT cystogram** before surgery. Known bladder injury is not an absolute contraindication but requires urology consultation and careful surgical planning. ### Imaging Protocol for Approach Planning **Standard Radiographs:** - **AP Pelvis**: Assess overall alignment, femoral head position - **Judet Views** (obturator and iliac obliques): Define column involvement - **Inlet/Outlet views**: Assess pelvic ring if associated injury **CT Scan (Essential):** - **Axial images**: Quadrilateral surface displacement, articular step-off - **Coronal reformats**: Column involvement height assessment - **Sagittal reformats**: Dome involvement, impaction - **3D reconstructions**: Fracture pattern visualization, surgical planning ### Key Imaging Findings Favoring Stoppa | CT Finding | Measurement | Stoppa Indication | |------------|-------------|-------------------| | Quadrilateral displacement | Greater than 10mm medial | Strong indication | | Femoral head subluxation | Medial migration visible | Requires buttress plate | | Low anterior column | Fracture below iliopectineal eminence | Accessible via Stoppa | | High anterior column | Fracture extends to iliac crest | Stoppa insufficient - need ilioinguinal | ### Advanced CT Analysis **Marginal Impaction Assessment:** - Look for fragments pushed into metaphysis - May require bone grafting after reduction - Plan approach to directly visualize impacted area **Intra-articular Fragment Assessment:** - Loose bodies require extraction - May influence approach selection (need direct articular visualization) On axial CT, trace the **iliopectineal line** (anterior column) and **ilioischial line** (posterior column). If the iliopectineal line fracture is below the pelvic brim level, Stoppa can access it. If the fracture extends above the brim toward the iliac crest, ilioinguinal lateral window is required. ### Approach Selection Algorithm ### Timing of Surgery - **Emergent (less than 24h)**: Only if femoral head irreducible dislocation - **Early (3-5 days)**: Preferred timing - allows resuscitation, reduces bleeding - **Delayed (5-14 days)**: Still acceptable outcomes - **Late (greater than 21 days)**: Increased difficulty, may need extensile approaches ### Combined Approach Strategy **Stoppa + Kocher-Langenbeck (Most Common Combination):** - **Positioning options**: - Sequential: Supine for Stoppa, then lateral for K-L - Two-team: Lateral position with anterior surgeon reaching across - Floating: Modified lateral allows both approaches **Stoppa + Lateral Ilioinguinal Window:** - Single supine position - Can use combined incision or separate incisions - Indicated for low anterior column extending beyond quadrilateral When combining Stoppa with Kocher-Langenbeck, consider operative time carefully. Prolonged prone or lateral positioning increases DVT risk. Many surgeons prefer staged procedures 5-7 days apart for complex fractures to reduce physiological stress. ### Implant Selection | Plate Type | Application | Screw Direction | |------------|-------------|-----------------| | Quadrilateral buttress | Medial wall support | Ramus (anterior), ischium (posterior) | | Infrapectineal plate | Low anterior column | Along pelvic brim | | Spring plate | Marginal impaction support | Variable based on fragment | | Reconstruction plate | Contouring for complex patterns | Multiple directions | ### Skin Incision Options **Pfannenstiel incision (preferred):** - Transverse suprapubic incision 2-3cm above pubic symphysis - Length 10-15cm - Better cosmetic result - Familiar to general surgeons and gynecologists **Low midline incision (alternative):** - Vertical midline from umbilicus toward symphysis - Better extensibility if needed - Higher wound complication rate Most surgeons prefer the **Pfannenstiel incision** for modified Stoppa - it provides adequate exposure with better cosmetic results and lower wound complication rates. The low midline incision is reserved for cases requiring extensile exposure or when Pfannenstiel is contraindicated (previous incision, extensive scarring). The incision choice depends on fracture pattern, patient factors, and surgeon preference. ### Developing the Space of Retzius Incise anterior rectus sheath transversely (Pfannenstiel) or vertically (midline) Identify rectus abdominis muscles Separate muscles in midline (linea alba for midline; retract laterally for Pfannenstiel) Identify transversalis fascia Gently dissect down to pubic symphysis Feel bladder dome (soft, mobile with Foley catheter balloon palpable) Begin blunt dissection between bladder and symphysis Use sponge stick or finger dissection Sweep bladder posteriorly and laterally off pubis Develop space laterally to pelvic sidewall Identify superior pubic ramus bilaterally Palpate pubic symphysis (anterior) Identify superior rami bilaterally Confirm you are extraperitoneal (no bowel visible) Place retractors to hold space open The **correct plane is between bladder wall and bone** - this is relatively avascular. If you encounter significant bleeding, you may be in bladder wall or have entered vessels. If you see glistening peritoneum, you're too superficial. If you see detrusor muscle, you're in bladder wall. The correct plane is loose areolar tissue that sweeps easily with blunt dissection. Development of space of Retzius is the foundational step - all subsequent exposure depends on this. ### First Window - Quadrilateral Surface Exposure **Boundaries:** - Medial: Mobilized bladder - Lateral: External iliac vessels Continue blunt dissection posterolaterally Mobilize bladder off quadrilateral surface Work toward obturator foramen Retract bladder medially with broad retractor Identify external iliac artery and vein on pelvic sidewall These are lateral boundary of first window Do not need to mobilize for first window access Approach superior pubic ramus carefully Identify any vessels crossing ramus (corona mortis) Clip or ligate with ties (2-0 silk) Confirm hemostasis before proceeding Complete subperiosteal dissection along quadrilateral surface Identify fracture lines Expose superior ramus anteriorly Expose ischium posteriorly for plate application The first window provides complete quadrilateral surface exposure for fracture reduction and buttress plate application. ### Fracture Reduction and Plate Application **Reduction maneuvers:** - **Pelvic clamp**: Compress fracture if displaced laterally - **Ball-spike pusher**: Push displaced quadrilateral fragment laterally - **Pointed reduction forceps**: Hold reduction temporarily - **Assess with fluoroscopy**: Inlet view shows quadrilateral reduction **Quadrilateral buttress plate application:** Pre-contoured quadrilateral plate (if available) OR 3.5mm reconstruction plate contoured to shape Plate spans from superior ramus (anteriorly) to ischium (posteriorly) Place plate on quadrilateral surface (inner pelvic wall) Anterior screws into superior pubic ramus Posterior screws into ischium or retroacetabular surface Central screws may be left empty (act as buttress) Drill and measure carefully 3.5mm cortical screws, typically 40-60mm length Avoid intra-articular penetration (check fluoroscopy) Obturator oblique view shows retroacetabular safe zone Fluoroscopy: AP, obturator oblique, inlet views Confirm plate position and screw lengths Assess reduction of quadrilateral surface Check for intra-articular hardware **Posterior screws from quadrilateral plate** can be directed into the ischium or into the **retroacetabular safe zone** (between sciatic notches). The obturator oblique view shows this zone well. Screws must avoid the hip joint - aim posteriorly and inferiorly, not laterally into acetabulum. Adequate fixation resists medial subluxation of the femoral head and provides stability for healing. ### Wound Closure **Hemostasis:** - Meticulous - large dead space in retropubic region - Check for bladder injury (fill with methylene blue if suspicious) - Ensure corona mortis ligated **Layers:** - Posterior rectus sheath (if entered) - 0 or 1 absorbable continuous - Anterior rectus sheath - 0 or 1 absorbable continuous - Scarpa's fascia - 2-0 absorbable interrupted - Skin - staples or subcuticular suture **Drain:** - Retropubic drain (10mm flat or 15Fr round) - Exit through separate stab incision - Remove at 24-48h when output less than 30mL/day **Post-closure:** - Check Foley catheter still draining (ensure not kinked or clamped) - Final fluoroscopy (AP, obturator, inlet) - Document neurovascular status Closure completes the procedure with attention to hemostasis and bladder integrity. {/* SECTION 9: COMPLICATIONS */} **Bladder injury management:** - Recognize intraoperatively (if possible) - methylene blue test - Primary two-layer repair (3-0 absorbable suture) - Foley catheter for 7-10 days - Cystogram before catheter removal - Urology consultation if complex **Vascular injury management:** - Direct pressure for control - Vascular surgery consultation - Primary repair for small injuries - Graft if extensive injury The modified Stoppa approach has **significantly lower nerve injury risk** compared to ilioinguinal approach. No lateral femoral cutaneous nerve at risk (this is sacrificed in 10-15% of ilioinguinal cases). Femoral nerve is not dissected. Only obturator nerve at potential risk, and this is rarely injured with proper technique. This is a significant advantage of Stoppa for isolated quadrilateral fractures. {/* SECTION 10: POSTOPERATIVE CARE */} Foley catheter remains for 24-48 hours Monitor drain output (remove when less than 30mL/24h) DVT prophylaxis (LMWH or rivaroxaban) Early mobilization to chair with assistance Toe-touch weight bearing (10-20kg) Hip and knee ROM exercises Avoid hip flexion greater than 90 degrees initially Continue DVT prophylaxis for 4-6 weeks Partial weight bearing (50%) Increase ROM and strengthening X-rays at 6 weeks to assess healing Progress weight bearing based on healing Full weight bearing when callus visible Progressive strengthening Return to activities as tolerated Monitor for post-traumatic arthritis **Bladder-specific care:** - Foley catheter for 24-48 hours (longer if bladder injury) - Monitor for hematuria (common, usually resolves) - Encourage fluids once catheter removed - If bladder repaired: catheter 7-10 days, cystogram before removal **Long-term outcomes:** - Good-to-excellent results in 75-85% with anatomic reduction - Similar outcomes to ilioinguinal for quadrilateral fractures - Lower nerve injury complications - Better cosmetic satisfaction {/* SECTION 11: EVIDENCE BASE */} ### Clinical Outcomes Summary **Functional Results:** - **Good to excellent**: 75-85% with anatomic reduction (less than 2mm step-off) - **Fair**: 10-15% with imperfect reduction or complications - **Poor**: 5-10% with significant malreduction or post-traumatic arthritis ### Comparison to Ilioinguinal Approach ### Predictors of Outcome **Positive Prognostic Factors:** - Anatomic reduction (less than 2mm step-off) - Younger patient age (under 55 years) - Simple fracture pattern - Surgery within 14 days of injury - Intact femoral head cartilage **Negative Prognostic Factors:** - Residual displacement greater than 2mm - Marginal impaction greater than 10mm - Age greater than 60 years - Associated femoral head injury - Initial posterior dislocation Acetabular fracture outcomes are assessed using **Matta radiographic criteria**: Excellent = anatomic reduction (0mm displacement), Good = less than 2mm, Fair = 2-3mm, Poor = greater than 3mm. Clinical outcomes correlate strongly with quality of reduction - anatomic reduction gives 80%+ good/excellent results. ### Long-Term Considerations - **Post-traumatic arthritis**: 20-30% at 10-20 years even with good reduction - **Heterotopic ossification**: 15-25% (reduced with prophylaxis) - **Conversion to THA**: 10-20% at 10 years - **AVN femoral head**: 5-10% (higher with initial dislocation) {/* SECTION 12: VIVA SCENARIOS */} {/* SECTION 13: MCQ PRACTICE POINTS */} **Q: What is the space of Retzius and what are its boundaries?** A: The **space of Retzius is the retropubic extraperitoneal space** between the bladder anteriorly and the posterior surface of the pubic symphysis. Boundaries: anterior = pubis, posterior = bladder and peritoneum, lateral = pelvic sidewall and external iliac vessels, inferior = pelvic floor. **Q: What is the primary advantage of modified Stoppa over ilioinguinal medial window for quadrilateral surface fractures?** A: **Superior direct visualization and access to the quadrilateral surface** working intrapelvically. The Stoppa approach allows buttress plate application under direct vision, whereas ilioinguinal medial window has limited inferior and posterior access to the quadrilateral surface. **Q: What is the biomechanical function of a quadrilateral buttress plate?** A: The plate acts as an **internal shelf preventing medial subluxation of the femoral head** into the pelvis. It spans from superior pubic ramus anteriorly to ischium posteriorly, creating a mechanical buttress that resists medial displacement forces. **Q: Why does the modified Stoppa approach have lower nerve injury risk than ilioinguinal approach?** A: The Stoppa approach does **not dissect the lateral femoral cutaneous nerve** (injured or sacrificed in 10-15% of ilioinguinal cases) and does **not mobilize the femoral nerve**. The only nerve at potential risk is the obturator nerve, which is rarely injured with proper technique. **Q: What are the anatomical limitations of the modified Stoppa approach?** A: Stoppa **cannot access the iliac wing, sacroiliac joint, or high anterior column** - it is limited to medial structures (quadrilateral surface, superior pubic ramus, low anterior column). These superior structures require ilioinguinal lateral window or separate lateral approach if fixation needed. {/* SECTION 14: EXAM CHEAT SHEET */} **Major Trauma Services:** - Acetabular fractures are tertiary referrals - Major trauma centres in each state (Level 1) - Inter-hospital retrieval for complex pelvic/acetabular injuries - Fellowship-trained pelvic surgeons at major centres **Training Pathway:** - AOA Orthopaedic Training Program - Pelvic and acetabular fellowship post-FRACS - AO Pelvic Course attendance - 47936: ORIF acetabular fracture, first column - 47939: ORIF acetabular fracture, second column (additional) - 47942: ORIF acetabular fracture, complex (both columns) **DVT Prophylaxis Guidelines:** - NHMRC recommendations for major pelvic surgery - Extended prophylaxis 28-35 days post-operatively - Chemical prophylaxis commenced 12-24h post-op For the Australian orthopaedic exam, you must understand indications for Stoppa vs ilioinguinal, know the key anatomical structures (space of Retzius, corona mortis), and be able to describe the surgical technique step-by-step. Acetabular fracture management is a common viva topic testing decision-making and surgical planning skills.

Modified Stoppa Approach to the Acetabulum

Modified Stoppa Approach to the Acetabulum