import { OnePagerSummary, ExamWarning, InfoCardGrid, InfoCard, MnemonicCard, EvidenceCard, VivaScenarioSection, VivaScenario, ExamCheatSheet, ContentSection, ExamPearl, SafetyAlert, NumberHighlightRow, NumberHighlight, Tabs, Tab, ComparisonTable } from '@/components/mdx' **LOCATION**: Variable anatomy, multiple branches, 2-5mm dorsal to typical medial incision line **PROTECTION**: Sharp dissection with early identification, vessel loops for retraction, gentle handling only, avoid cautery near nerve **LOCATION**: 8-10mm plantar to MTP joint line at medial eminence, travels with plantar vessels **PROTECTION**: Limit eminence resection to 3-4mm, stay in line with shaft, avoid extending plantarly with saw **LOCATION**: 5mm lateral to lateral MTP capsule, runs between flexor and extensor tendons to hallux **PROTECTION**: Incremental lateral release under direct vision, palpate dorsalis pedis pulse, release only if sesamoids unreduced **LOCATION**: 15-20mm lateral to TMT joint between EHL and EHB tendons, gives deep plantar branch **PROTECTION**: Stay medial with TMT incision, identify EHL as landmark, subperiosteal dissection only, palpate pulse before/after **LOCATION**: Dorsal metaphyseal vessels enter dorsally, nutrient artery midshaft, plantar periosteal supply critical **PROTECTION**: Minimal soft tissue stripping (Scarf higher risk), keep osteotomy apex at dome (Chevron), limit translation to 50-70% width ## Procedure Selection Framework ### Primary Decision: Measure Deformity Severity **Weight-bearing AP radiographs MANDATORY:** Hallux Valgus Angle (normal less than 15°) Intermetatarsal Angle (normal less than 9°) Distal Metatarsal Articular Angle (normal less than 10°) ### Decision Tree **MILD DEFORMITY (IMA less than 13°, HVA less than 30°):** - **CHEVRON** first choice - Congruent joint required - Good bone quality - Older, lower demand patients - Sesamoid grade 1-2 **MODERATE-SEVERE DEFORMITY (IMA 13-18°, HVA 30-40°):** - **SCARF** first choice - Most versatile - translation, rotation, shortening, plantarflexion - Allows up to 70% translation (vs 50% Chevron) - Any age, activity level - Sesamoid grade 2-3 **SEVERE DEFORMITY (IMA greater than 18-20°):** - **LAPIDUS** required - Corrects at apex of deformity (TMT) - Eliminates TMT mobility - Definitive correction - Lowest recurrence rate (less than 5%) ### TMT Hypermobility Assessment - CRITICAL **Clinical Test:** 1. Stabilize hindfoot and midfoot with one hand 2. Grasp 1st metatarsal head with other hand 3. Dorsally and plantarly translate 1st MT 4. Measure excursion **Interpretation:** - Normal: less than 5mm translation - Borderline: 5-9mm - **ABNORMAL: greater than 9mm = LAPIDUS INDICATION** regardless of IMA **Rationale:** Hypermobility allows 1st MT to drift into varus postoperatively - distal osteotomies (Chevron/Scarf) will fail from recurrent instability. Lapidus fuses TMT eliminating mobility. ### Additional Lapidus Indications - **Metatarsus primus varus** (structural deformity at TMT level) - **Revision surgery** after failed Chevron/Scarf - **Young active patients** wanting definitive correction - **MTP joint varus** (lateral joint space widening) - **TMT arthritis** (relative indication - already degenerative) ### Sesamoid Position Grading **Grade 1:** Normal position under metatarsal head **Grade 2:** Less than 50% lateral subluxation **Grade 3:** Greater than 50% lateral subluxation - **lateral release likely needed** **Grade 4:** Complete lateral subluxation - **lateral release required** **Examiner Expects:** "My decision algorithm: First measure IMA on weight-bearing AP - this drives procedure selection. IMA less than 13° = Chevron if congruent joint and good bone. IMA 13-18° = Scarf for versatility. IMA greater than 18° = Lapidus. Then I assess TMT hypermobility clinically - greater than 9mm translation is absolute Lapidus indication regardless of IMA. Finally consider patient factors - revision, young active, or metatarsus primus varus favor Lapidus. Sesamoid position determines if lateral release needed." ## Chevron Osteotomy - Technical Details ### Indications - Mild deformity: HVA less than 30°, IMA less than 13° - **Congruent MTP joint** (DMAA less than 10°) - Good bone quality (osteoporosis relative contraindication) - Sesamoid grade 1-2 - Older or lower demand patients ### Contraindications - Moderate-severe deformity (undercorrection risk) - Incongruent joint (DMAA greater than 10°) - Poor bone quality - Revision surgery - TMT hypermobility ### Surgical Steps **1. Medial longitudinal incision** 3-4cm from mid-proximal phalanx to metatarsal neck, 2-3mm dorsal to joint line **2. Inverted-L capsulotomy** exposing metatarsal head and neck **3. Medial eminence resection** 3-4mm in line with shaft (NO more - destabilizes sesamoids) **4. V-shaped osteotomy:** - **60° angle** (30° each arm) - **Apex at DOME** of metatarsal head - KEY for inherent stability - Arms 8-10mm length each - Microsagittal saw with irrigation **5. Capital fragment translation:** - Lateral translation 3-4mm (max 50% metatarsal width) - Slight plantarflexion if needed - **Impaction** for stability **6. Single screw fixation:** - 2.0-2.5mm headless compression screw - **Perpendicular to osteotomy** for compression - Lag technique - Bury screw head **7. Capsular imbrication** - pants-over-vest technique **8. Akin osteotomy** if residual HVA greater than 15° or high DASA ### Key Technical Points **Critical Apex Position:** "The apex MUST be at the DOME of the metatarsal head - this provides inherent stability allowing single screw fixation. If apex too dorsal or plantar, loses stability and risks AVN from devascularization. The V-shape locks together with impaction." **Translation Limit:** "Maximum 50% translation (3-4mm typically) to preserve blood supply. Greater than 50% risks AVN from disrupting plantar periosteal vessels. Chevron has lower correction power than Scarf/Lapidus - if need more correction, wrong procedure." **Single Screw Adequate:** "V-shape provides rotational stability - single screw adequate unlike Scarf which needs two. Screw must be perpendicular to osteotomy for compression. Headless avoids prominence and hardware removal." ### Outcomes - **Success rate:** 85-95% for mild deformity - **Recurrence:** 5-10% (higher if too severe initially) - **AVN:** Less than 1% (lowest of all procedures) - **Patient satisfaction:** 85-90% ### Advantages vs Scarf/Lapidus - **Simplest technique** - single screw, inherent stability - **Shortest surgery time** - 45-60 min - **Fastest recovery** - heel WB immediately, normal shoes 8-12 weeks - **Lowest AVN risk** - less soft tissue stripping - **Lowest cost** - single screw vs two or plate ### Disadvantages - **Limited correction power** - max 50% translation - **Only mild deformity** - undercorrects if too severe - **Cannot address TMT hypermobility** - **Recurrence if wrong indication** ## Scarf Osteotomy - Technical Details ### Indications - Moderate-severe deformity: HVA 30-40°, IMA 13-18° - **Most versatile procedure** - multiplanar correction - Any age, activity level - Congruent or mildly incongruent joint - Sesamoid grade 2-3 (lateral release if needed) ### Contraindications - Severe deformity IMA greater than 18° (undercorrection) - TMT hypermobility greater than 9mm (will fail) - Poor bone quality (osteoporosis) - Revision after Scarf (consider Lapidus) ### Surgical Steps **1. Extended medial longitudinal incision** 6-8cm exposing entire metatarsal shaft **2. Extended capsulotomy** preserving soft tissue attachments **3. Medial eminence resection** 3-4mm **4. Identify plantar cortex** - CRITICAL landmark for osteotomy orientation **5. Z-shaped osteotomy - THREE CUTS:** **Horizontal cut (most critical):** - **PARALLEL to plantar cortex** - absolutely critical - **2:1 dorsal:plantar ratio** (dorsal 2/3 of bone) - 25-30mm length - Creates longitudinal plane **Proximal vertical cut:** - 60° angle - Exits dorsally - 10-12mm length **Distal vertical cut:** - 60° angle - Exits plantarly - 10-12mm length **6. Capital fragment manipulation:** - Lateral translation 5-8mm (up to 70% width) - Rotation to correct DMAA if needed - Shortening 2-3mm if needed - Plantarflexion if transfer metatarsalgia risk - **Impaction for bone contact** **7. TWO screw fixation:** - 2.5-3.0mm headless compression screws - **Proximal screw first** (controls position) - **Distal screw second** - Both **perpendicular to osteotomy** for compression - Prevents rotation **8. Capsular imbrication** **9. Lateral release if sesamoids unreduced** ### TROUGHING - Most Common Complication **Definition:** Dorsiflexion malunion where capital fragment sinks dorsally into shaft **Incidence:** 5-10% of Scarf procedures **Cause:** Horizontal cut NOT parallel to plantar cortex - Non-parallel cuts create geometry allowing dorsal angulation - Excessive dorsal translation during reduction - Inadequate impaction - poor bone contact **Consequences:** - Transfer metatarsalgia (2nd/3rd MT overload) - Patient dissatisfaction - May require revision **Prevention:** 1. **Horizontal cut PARALLEL to plantar cortex** - identify cortex as landmark 2. **2:1 ratio** keeps cut in dorsal 2/3 3. **Impaction** for bone contact 4. **Two perpendicular screws** for compression 5. **Fluoroscopy** confirms no dorsiflexion "The horizontal cut MUST be PARALLEL to the plantar cortex - this is the single most important technical point of Scarf. I identify the plantar cortex before starting the osteotomy and use it as my guide. Non-parallel cuts change the geometry allowing dorsal sinking. The 2:1 dorsal:plantar ratio and impaction with two perpendicular screws prevent migration." ### Outcomes - **Success rate:** 85-95% for moderate-severe - **Recurrence:** 5-10% (if inadequate soft tissue balance or too severe) - **Troughing:** 5-10% - **AVN:** 1-2% (higher than Chevron - more stripping) - **Patient satisfaction:** 85-90% ### Advantages vs Chevron/Lapidus - **Most versatile** - translation, rotation, shortening, plantarflexion - **Greater correction power** - up to 70% translation vs 50% Chevron - **Preserves TMT motion** vs Lapidus fusion - **Faster recovery than Lapidus** - 6 weeks vs 12 weeks - **Corrects DMAA** through rotation ### Disadvantages - **Cannot address TMT hypermobility** - will fail - **Higher AVN than Chevron** - 1-2% vs less than 1% - **Troughing risk** - 5-10% - **Technical difficulty** - three precise cuts - **Longer surgery** than Chevron - 60-75 min ## Lapidus Arthrodesis (1st TMT Fusion) - Technical Details ### Indications - **Severe deformity:** IMA greater than 18-20° - **TMT hypermobility:** Greater than 9mm dorsoplantar translation (absolute) - **Metatarsus primus varus** - structural deformity at TMT - **Revision surgery** after failed Chevron/Scarf - **Young active patients** wanting definitive correction - **MTP joint varus** (lateral space widening) ### Contraindications - Poor bone quality requiring fusion - Active infection - Severe peripheral vascular disease - Non-compliance (NWB protocol) - Heavy smokers (relative - 3x nonunion risk) ### Surgical Steps **1. Dorsomedial incision** 4-5cm over 1st TMT joint, medial to EHL tendon **2. Identify dorsalis pedis artery** between EHL and EHB - typically 15-20mm lateral, palpate pulse **3. T-shaped capsulotomy** exposing TMT joint dorsally and medially **4. Confirm joint level** with fluoroscopy if uncertain (vs intercuneiform) **5. Joint preparation:** - Remove articular cartilage with flat cuts - Sagittal saw or osteotomes - 2-3mm each surface (minimize bone removal) - **Keep surfaces PARALLEL** - critical for alignment - Curette to bleeding cancellous bone - Fenestration with 2.0mm drill if sclerotic - Fish-scale subchondral plate for vascularity **6. Reduction:** - Bring 1st MT lateral to correct IMA to less than 10° - **AVOID DORSIFLEXION** - most common error - Maintain **neutral or slight plantarflexion** (5-10°) - Align 1st MT with lesser rays on lateral view - Check with lateral fluoroscopy - Provisional K-wires **7. Definitive fixation - DORSOMEDIAL LOCKING PLATE:** - Gold standard technique - Low-profile anatomic plate - 3 proximal screws into cuneiform - 3 distal screws into metatarsal - All **locking screws** for angular stability - **Supplemental lag screw** dorsal-to-plantar for compression - Lag screw placed first, then plate **8. Fluoroscopy confirmation:** - **AP:** IMA less than 10°, sesamoid reduction, hardware position - **LATERAL:** Rule out dorsiflexion, 1st MT aligns with lesser rays - **Oblique:** Overall alignment **9. Bone grafting** (optional): - Local autograft from eminence - If gap greater than 2mm - Enhances union **10. Capsular repair** over fusion if tissue adequate ### DORSIFLEXION MALUNION - Devastating Complication **Most common technical error** in Lapidus **Cause:** - Cuneiform is wider dorsally than plantarly (trapezoid shape) - Naturally pushes into dorsiflexion if not carefully controlled - Inadequate attention to lateral fluoroscopy - Plantar gapping during reduction **Consequences:** - **Transfer metatarsalgia** - 2nd/3rd MT overload - Patient dissatisfaction - Prolonged recovery - May require revision osteotomy **Prevention:** 1. **Lateral fluoroscopy MANDATORY** intraoperatively 2. Aim **neutral or slight plantarflexion** (5-10°) 3. Align 1st MT with lesser rays 4. Check **no plantar gapping** during reduction 5. Lag screw provides plantarflexion compression "Dorsiflexion malunion is the #1 error in Lapidus and causes devastating transfer metatarsalgia. The cuneiform shape naturally pushes into dorsiflexion. I ALWAYS use lateral fluoroscopy intraoperatively and aim for neutral or slight plantarflexion. The 1st MT must align with the lesser rays. A dorsal-to-plantar lag screw provides compression that counteracts dorsiflexion tendency." ### Fixation Options **Dorsomedial Locking Plate (Current Gold Standard):** - Nonunion rate: 5% - Angular stability - Low profile - No need for cast - Most expensive **Two Crossed Screws (Traditional):** - Nonunion rate: 10-15% - Less angular stability - Higher malunion risk - Requires cast immobilization - Lower cost **Plate PLUS Lag Screw (Recommended):** - Combines stability and compression - Lowest nonunion rate - Best malunion prevention ### Outcomes - **Success rate:** 90-95% - **Nonunion:** 5% (plate) to 10-15% (screws only) - **Recurrence:** Less than 5% (lowest of all procedures) - **Transfer metatarsalgia:** 10-20% (often from dorsiflexion) - **Patient satisfaction:** 85-90% ### Advantages vs Chevron/Scarf - **Corrects at apex of deformity** (TMT) not distal compensation - **Addresses TMT hypermobility** - fuses joint - **Greatest correction power** - severe IMA - **Lowest recurrence** - less than 5% - **Definitive correction** for young active patients - **Revision solution** after failed distal procedures ### Disadvantages - **Longest recovery** - 12 weeks protected WB vs 6 weeks - **NWB 6 weeks** - patient compliance critical - **Nonunion risk** - 5-15% depending on fixation - **Shortening** if excessive bone removal - **Eliminates TMT motion** (though minimal functional impact) - **Most expensive** - plate hardware - **Smoking** increases nonunion 3x ### Additional Complications (Lower Frequency) **Stiffness/Reduced ROM:** 15-25% especially Chevron/Scarf at MTP joint - Aggressive capsular tightening, adhesions, articular damage - Prevention: balanced capsular repair, early ROM (2-3 weeks) - Management: physical therapy, manipulation under anesthesia if severe (rare) **Wound Complications:** 5-10% (higher in smokers, diabetics, revision) - Dehiscence, skin necrosis, delayed healing - Prevention: gentle tissue handling, minimize tension, smoking cessation - Management: local wound care, delayed primary closure, skin graft if severe **Hardware Prominence/Irritation:** 10-15% non-headless screws, 5% headless, Lapidus plate 5-10% - Palpable hardware, bursitis, pain with shoes - Prevention: headless screws, low-profile plate, bury hardware - Management: hardware removal after union (Chevron/Scarf 6 months, Lapidus 12 months) **Infection:** 1-2% primary, higher revision - Superficial or deep (osteomyelitis if bone involved) - Prevention: antibiotic prophylaxis, sterile technique, minimize OR time - Management: superficial - antibiotics. Deep - I&D, hardware retention if stable, 6 weeks IV antibiotics **Complex Regional Pain Syndrome:** 1-2% - Disproportionate pain, vasomotor changes, allodynia - Prevention: minimize trauma, early mobilization, adequate analgesia - Management: multidisciplinary - PT, stellate ganglion blocks, medications **Patient Position**: Supine with foot at end of table, small bump under ipsilateral hip for external rotation, ankle block or general anesthesia, ankle or thigh tourniquet (250mmHg) **Surgical Approach**: Varies by procedure: Medial longitudinal for Chevron/Scarf, dorsomedial over TMT for Lapidus, all protect dorsomedial cutaneous nerve **Incision**: Medial longitudinal for Chevron (3-4cm) and Scarf (6-8cm), dorsomedial for Lapidus (4-5cm) ### Step 1: Decision-Making Framework - CRITICAL FIRST STEP Decision-Making Framework - CRITICAL FIRST STEP: PROCEDURE SELECTION based on: (1) SEVERITY: Measure HVA (hallux valgus angle) and IMA (intermetatarsal angle) on weight-bearing AP X-ray. (2) TMT MOBILITY: Assess 1st TMT hypermobility clinically (greater than 9mm dorsoplantar translation abnormal) and consider on lateral stress X-ray. (3) DEFORMITY LOCATION: Metatarsus primus varus vs MTP joint pathology. (4) PATIENT FACTORS: Age, activity, bone quality, expectations. CHEVRON: Mild (HVA 15-30°, IMA 10-13°), congruent joint, good bone. SCARF: Moderate-severe (HVA 30-40°, IMA 13-18°), need multi-planar correction. LAPIDUS: Severe IMA greater than 18-20°, TMT hypermobility greater than 9mm, metatarsus primus varus, revision, young active patient. **Technical Tip**: EXAM KEY: 'Decision tree: MILD deformity (IMA less than 13°) = Chevron. MODERATE-SEVERE (IMA 13-18°) = Scarf. SEVERE (IMA greater than 18°) OR hypermobile TMT = Lapidus. TMT hypermobility test: stabilize midfoot, dorsoplantarly translate 1st MT - greater than 9mm abnormal. Lapidus corrects at APEX of deformity (TMT), Chevron/Scarf correct distally.' - Wrong procedure for severity (Chevron for severe = undercorrection/recurrence) - Missing TMT hypermobility (distal procedure fails, recurrence) - Not assessing bone quality (osteoporosis affects fixation choice) ### Step 2: Preoperative Planning & Marking Preoperative Planning & Marking: Weight-bearing radiographs MANDATORY: AP, lateral, oblique. Measure: HVA (normal less than 15°), IMA (normal less than 9°), DMAA (distal metatarsal articular angle, normal less than 10°), DASA (distal articular set angle of phalanx). Assess: sesamoid position (grade 1-4 lateral subluxation), joint congruency, TMT arthritis, lesser metatarsal lengths. Clinical: ROM, severity of bunion, lesser toe deformities, neurovascular status. Mark anatomy: first MTP joint line, metatarsal shaft (Scarf), TMT joint (Lapidus), dorsomedial nerve course. **Technical Tip**: EXAM KEY: 'Weight-bearing X-rays essential - non-weight bearing underestimates deformity. Key measurements: HVA, IMA, DMAA. Sesamoid grading: 1 (normal under MT head), 2 (less than 50% subluxed), 3 (greater than 50% subluxed), 4 (completely lateral to ridge). Grade 3-4 need lateral release. Assess lesser MTs - if short, risk transfer metatarsalgia.' - Non-weight bearing films = underestimate deformity - Missing high DMAA (may need rotational correction) - Not assessing TMT joint (may have arthritis) ### Step 3: Surgical Approach & Nerve Protection Surgical Approach & Nerve Protection: CHEVRON/SCARF: Medial longitudinal incision 3-4cm (Chevron) or 6-8cm (Scarf) from mid-proximal phalanx to mid-metatarsal, 2-3mm dorsal to joint line. LAPIDUS: Dorsomedial 4-5cm over TMT joint, staying medial to EHL. ALL approaches: Sharp dissection, identify dorsomedial cutaneous nerve early (variable anatomy, often multiple branches), protect with vessel loops, gentle retraction only. Avoid cautery near nerve. Develop plane to capsule. **Technical Tip**: EXAM KEY: 'DORSOMEDIAL CUTANEOUS NERVE most at risk across all procedures - 5-10% injury rate. I identify EARLY with sharp dissection, protect with vessel loops, NO excessive traction or cautery. LONGITUDINAL incisions protect nerves better than transverse. Medial approach (Chevron/Scarf) keeps lateral neurovascular bundle safe.' - Nerve injury - painful neuroma requiring revision - Aggressive cautery - nerve injury - Inadequate exposure - technical difficulty ### Step 4: Capsulotomy & Joint Exposure Capsulotomy & Joint Exposure: CHEVRON: Inverted-L capsulotomy 3-4cm exposing metatarsal head/neck. SCARF: Extended inverted-L or linear capsulotomy entire metatarsal shaft length 6-8cm. LAPIDUS: T-shaped capsulotomy at TMT joint exposing dorsally and medially. ALL: Preserve capsular tissue for closure (soft tissue balance). Expose medial eminence. SCARF: Identify plantar cortex as guide for osteotomy orientation. LAPIDUS: Confirm TMT joint level with fluoroscopy if uncertain. **Technical Tip**: EXAM KEY: 'Capsulotomy extent matches procedure: Chevron needs 3-4cm (head/neck only), Scarf needs 6-8cm (entire shaft for Z-osteotomy), Lapidus 4-5cm at TMT. I preserve capsule for later imbrication - addresses soft tissue laxity, maintains correction. For Scarf: plantar cortex identification CRITICAL for parallel horizontal cut.' - Excessive stripping - AVN risk (especially Scarf 1-2%) - Inadequate exposure for Scarf - cannot perform full Z - Wrong joint level for Lapidus (intercuneiform instead of TMT) ### Step 5: Medial Eminence Resection Medial Eminence Resection: ALL procedures: Remove medial eminence with sagittal saw in line with medial metatarsal shaft border. Typical resection 3-4mm. CRITICAL: Avoid over-resection which destabilizes sesamoids and increases hallux varus risk. Smooth edges with rongeur. Palpate plantarly to ensure no plantar prominence. Save bone as local graft if needed (especially Lapidus). **Technical Tip**: EXAM KEY: 'Eminence resection 3-4mm in line with shaft - NOT more. Over-resection destabilizes sesamoid complex, increases varus risk significantly. I smooth edges and check no plantar step-off. For Lapidus, I save this bone as local graft option for TMT fusion.' - Over-resection - sesamoid instability, hallux varus - Plantar extension - medial plantar nerve injury - Thermal injury from saw - avascular necrosis ### Step 6: Osteotomy Performance - PROCEDURE-SPECIFIC Osteotomy Performance - PROCEDURE-SPECIFIC: CHEVRON: 60° V-shaped osteotomy through metatarsal head, apex at DOME (critical for stability), arms 8-10mm each, microsagittal saw. Translate capital fragment laterally 3-4mm (max 50% width), slight plantarflexion if needed. SCARF: Z-shaped three cuts - (1) Horizontal 2:1 dorsal:plantar ratio PARALLEL to plantar cortex 25-30mm length, (2) Proximal vertical exits dorsally 60°, (3) Distal vertical exits plantarly 60°. Translate laterally 5-8mm (up to 70% width), can rotate/shorten/plantarflex. LAPIDUS: Remove cartilage from TMT joint with flat cuts 2-3mm each surface maintaining parallel surfaces, curette to bleeding bone, minimize resection to preserve length. **Technical Tip**: EXAM KEY: 'CHEVRON: V-apex at DOME = inherent stability. SCARF: 2:1 dorsal:plantar ratio CRITICAL - prevents troughing (most common error). Horizontal cut MUST be PARALLEL to plantar cortex. LAPIDUS: Flat parallel cuts with minimal bone removal less than 5mm total - excessive shortening = transfer metatarsalgia. SCARF allows most versatility (translate, rotate, shorten, plantarflex).' - CHEVRON: Apex too dorsal/plantar = instability, translation greater than 50% = AVN risk - SCARF: Non-parallel horizontal cut = TROUGHING/dorsiflexion malunion (5-10%), excessive translation greater than 70% = instability - LAPIDUS: Excessive resection greater than 5mm = shortening/transfer metatarsalgia, non-parallel surfaces = malunion ### Step 7: Reduction & Provisional Fixation Reduction & Provisional Fixation: CHEVRON/SCARF: Translate capital fragment laterally per plan. Impaction for stability. Check: sesamoid reduction, appropriate IMA correction, no rotational deformity, metatarsal length appropriate. Hold with K-wires or clamps. LAPIDUS: Reduce TMT joint bringing 1st MT lateral to correct IMA to less than 10°. CRITICAL: Avoid DORSIFLEXION (most common Lapidus error) - maintain neutral or slight plantarflexion. Check lateral fluoroscopy. Provisional K-wires maintain position. **Technical Tip**: EXAM KEY: 'SESAMOID REDUCTION is critical endpoint for all - if sesamoids not reduced under MT head, need lateral release OR more correction. For LAPIDUS: DORSIFLEXION malunion is #1 error - MUST check lateral fluoroscopy, aim neutral or slight plantarflexion. Cuneiform is wider dorsally = naturally pushes into dorsiflexion if not careful.' - Unreduced sesamoids = high recurrence risk ALL procedures - LAPIDUS dorsiflexion = transfer metatarsalgia (most common error) - Overcorrection = hallux varus risk - Loss of reduction during definitive fixation ### Step 8: Definitive Fixation - PROCEDURE-SPECIFIC Definitive Fixation - PROCEDURE-SPECIFIC: CHEVRON: Single 2.0-2.5mm headless compression screw perpendicular to osteotomy. Lag technique for compression. Headless preferred (no removal needed). SCARF: TWO 2.5-3.0mm headless screws perpendicular to osteotomy - proximal first (control), then distal. Must be perpendicular for compression. LAPIDUS: Dorsomedial locking plate (gold standard, 5% nonunion) with 3+3 locking screws PLUS supplemental lag screw dorsal-to-plantar for compression. Plate provides angular stability, screw provides compression. **Technical Tip**: EXAM KEY: 'CHEVRON: Single screw adequate - V-shape inherently stable. SCARF: TWO screws needed - longer osteotomy, prevent rotation. Both perpendicular to osteotomy for compression. LAPIDUS: Dorsomedial locking PLATE current gold standard (5% nonunion vs 10-15% screws alone). Supplemental lag screw adds compression. Headless screws avoid prominence/removal for all.' - Screws not perpendicular = loss of compression/correction - SCARF: Single screw = rotation/instability - LAPIDUS: Screws only without plate = higher nonunion (10-15%) - Screw prominence if not headless - Joint penetration - Fracture during insertion ### Step 9: Fluoroscopic Confirmation & Assessment Fluoroscopic Confirmation & Assessment: Mandatory intraoperative imaging: AP view - confirm IMA correction (less than 10° goal), sesamoid reduction, hardware position, osteotomy alignment. Lateral view - CRITICAL for Lapidus to rule out dorsiflexion, confirm 1st MT aligns with lesser rays, hardware position. Oblique view - overall alignment, no joint penetration. If ANY malposition: correct NOW before proceeding. **Technical Tip**: EXAM KEY: 'Fluoroscopy MANDATORY for all procedures. Three views: AP (IMA correction, sesamoids), LATERAL (CRITICAL for Lapidus dorsiflexion check), oblique (overall). Cannot correct after closure - MUST confirm position before proceeding. For Lapidus: lateral view non-negotiable - dorsiflexion malunion devastating.' - Missing malposition before closure - revision needed - Lapidus: Missing dorsiflexion on lateral = transfer metatarsalgia - Accepting suboptimal correction - recurrence risk ### Step 10: Lateral Soft Tissue Release (if indicated) Lateral Soft Tissue Release (if indicated): Perform if sesamoids NOT reduced after bony correction. Through same medial incision if possible, or separate dorsal incision in 1st-2nd interspace. Release: lateral capsule sharply, adductor hallucis tendon from lateral base of proximal phalanx/lateral sesamoid. CRITICAL: PROTECT lateral digital neurovascular bundle 5mm lateral to capsule. Palpate for dorsalis pedis pulse. Gradual release, check sesamoid position incrementally. **Technical Tip**: EXAM KEY: 'Lateral release if sesamoids unreduced - especially Grade 3-4 subluxation. I release lateral capsule and adductor hallucis. DANGER: Lateral digital neurovascular bundle is 5mm lateral to capsule - injury causes numbness, pain. I release incrementally, check sesamoid position after each cut. Aggressive release = varus risk.' - Lateral digital nerve injury (5mm from capsule) - permanent numbness - Vascular injury - hallux ischemia - Excessive release - hallux varus/instability - Incomplete release - persistent sesamoid subluxation ### Step 11: Akin Osteotomy (adjunct if needed) Akin Osteotomy (adjunct if needed): Add Akin if: (1) Residual HVA greater than 15° after metatarsal correction, (2) DASA greater than 10° (interphalangeal valgus), (3) To fine-tune final alignment. Medial-based closing wedge 2-3mm at proximal phalanx base. Remove small dorsomedial wedge with sagittal saw. Close wedge, fix with single 2.0mm screw or staple. Avoid overcorrection causing interphalangeal varus. **Technical Tip**: EXAM KEY: 'Akin is common adjunct to Chevron/Scarf - adds 5-10° correction if needed. Medial closing wedge at phalanx base. Indications: residual HVA greater than 15°, high DASA/interphalangeal valgus. Careful not to overcorrect - interphalangeal varus cosmetically poor. Fix with screw or staple. Rarely needed with Lapidus as TMT correction usually sufficient.' - Overcorrection - interphalangeal varus deformity - IP joint stiffness from fixation - Inadequate fixation - loss of correction - Phalanx fracture ### Step 12: Capsular Repair & Soft Tissue Balance Capsular Repair & Soft Tissue Balance: Medial capsule REEFING (imbrication) critical for soft tissue balance. Overlap medial capsule - 'pants-over-vest' or 'vest-over-pants' technique. Balance tension: adequate to maintain correction but not causing stiffness. Absorbable sutures (2-0 Vicryl). This addresses medial laxity and helps maintain alignment. For Lapidus: repair capsule over TMT fusion if tissue sufficient. **Technical Tip**: EXAM KEY: 'Medial capsule imbrication as important as bony correction - addresses soft tissue laxity. I overlap capsule with balanced tension. Too loose = recurrence from medial instability. Too tight = stiffness, overcorrection. This soft tissue component maintains long-term correction.' - Overtightening - stiffness (especially Chevron/Scarf), overcorrection - Inadequate reefing - recurrence from medial laxity - Loss of correction if capsule not balanced ### Step 13: Wound Closure Wound Closure: Subcutaneous layer with absorbable sutures (3-0 or 4-0 Vicryl). Skin: subcuticular with absorbable (4-0 Monocryl) or interrupted non-absorbable (4-0 nylon). Handle skin edges gently - compromised vascularity common in chronic bunions. Steri-strips for wound support. **Technical Tip**: EXAM KEY: 'Gentle tissue handling during closure - bunion skin often has compromised vascularity. I use subcuticular absorbable for better cosmesis or interrupted nylon if tension concerns. Steri-strips support wound. Wound complications 5-10% across all procedures, higher in smokers/diabetics.' - Wound dehiscence (5-10% risk, higher in revision) - Skin necrosis from tension or poor vascularity - Hematoma from inadequate hemostasis - Infection (1-2% primary, higher revision) ### Step 14: Dressing & Immobilization Dressing & Immobilization: BUNION DRESSING: Gauze fluffed between 1st-2nd toes (prevents drift back to valgus), hallux maintained in corrected position with gauze padding around foot, compression wrap (not too tight - vascular compromise). CHEVRON/SCARF: Stiff-soled postoperative shoe for 6 weeks - heel and midfoot weight-bearing, NO forefoot loading. LAPIDUS: Below-knee cast or CAM boot NON-weight bearing 6 weeks, then protected weight-bearing boot 6 more weeks. **Technical Tip**: EXAM KEY: 'Bunion dressing maintains correction: gauze between toes prevents valgus drift, compression controls swelling. CHEVRON/SCARF: heel WB in postop shoe 6 weeks protects osteotomy. LAPIDUS: NWB 6 weeks MANDATORY (fusion), then protected WB 6 weeks. Lapidus has LONGEST recovery - counsel patients preoperatively.' - Dressing too tight - vascular compromise, compartment syndrome (rare) - Inadequate immobilization - loss of correction, hardware failure - Early full weight-bearing - nonunion (Lapidus), fracture (Chevron/Scarf) ### Step 15: Postoperative Protocol - PROCEDURE-SPECIFIC Postoperative Protocol - PROCEDURE-SPECIFIC: CHEVRON/SCARF: Bunion dressing 2 weeks. Sutures 10-14 days. Heel WB in stiff shoe 6 weeks, NO forefoot loading. ROM exercises start 2-3 weeks. Transition supportive shoes 6-8 weeks. Normal shoes 8-12 weeks. X-ray 6 weeks confirms union. Full activity 3-4 months. LAPIDUS: NWB cast/boot 6 weeks. X-ray at 6 weeks - if healing, transition to WB boot 6 more weeks. Supportive shoes 12 weeks. Full activity 4-6 months. Union takes 3-4 months. Serial X-rays 6wks, 12wks, 6mo. **Technical Tip**: EXAM KEY: 'Recovery timeline critical for patient counseling: CHEVRON/SCARF: 6 weeks protected WB, 8-12 weeks normal shoes, 3-4 months full activity. LAPIDUS: 6 weeks NWB, 12 weeks protected WB, 4-6 months full activity. Lapidus TWICE as long recovery - discuss preoperatively. All need X-ray at 6 weeks minimum to confirm healing.' - Early weight-bearing - hardware failure, loss of correction, nonunion (Lapidus) - Inadequate follow-up - missing complications - Patient non-compliance - poor outcomes CHEVRON/SCARF: Bunion dressing 2 weeks, heel WB stiff shoe 6 weeks (NO forefoot), ROM start 2-3 weeks, regular shoes 8-12 weeks, full activity 3-4 months. LAPIDUS: NWB cast/boot 6 weeks, X-ray at 6 weeks, transition WB boot additional 6 weeks if healing, regular shoes 12 weeks, full activity 4-6 months. All: sutures 10-14 days, X-ray 6 weeks minimum, avoid high heels 6 months. Smoking cessation MANDATORY especially Lapidus. ## References 1. Coughlin MJ, Jones CP. Hallux valgus: demographics, etiology, and radiographic assessment. Foot Ankle Int. 2007;28(7):759-777. doi:10.3113/FAI.2007.0759 2. Robinson AH, Limbers JP. Modern concepts in the treatment of hallux valgus. J Bone Joint Surg Br. 2005;87(8):1038-1045. doi:10.1302/0301-620X.87B8.16467 3. Barg A, Harmer JR, Presson AP, et al. Unfavorable outcomes following surgical treatment of hallux valgus deformity: a systematic literature review. J Bone Joint Surg Am. 2018;100(18):1563-1573. doi:10.2106/JBJS.17.00975 4. Coetzee JC. Scarf osteotomy for hallux valgus repair: the dark side. Foot Ankle Int. 2003;24(1):29-33. doi:10.1177/107110070302400105 5. Lapidus PW. The author's bunion operation from 1931 to 1959. Clin Orthop Relat Res. 1960;16:119-135. 6. Cottom JM, Vora AM. Fixation of Lapidus arthrodesis with a plantar interfragmentary screw and medial locking plate: a report on 109 patients. J Foot Ankle Surg. 2013;52(4):465-469. doi:10.1053/j.jfas.2013.02.016 7. Austin DW, Leventen EO. A new osteotomy for hallux valgus: a horizontally directed "V" displacement osteotomy of the metatarsal head for hallux valgus and primus varus. Clin Orthop Relat Res. 1981;(157):25-30. 8. Weil LS. Scarf osteotomy for correction of hallux valgus. Historical perspective, surgical technique, and results. Foot Ankle Clin. 2000;5(3):559-580. 9. Ray RG, Ching RP, Christensen JC, Hansen ST Jr. Biomechanical analysis of the first metatarsocuneiform arthrodesis. J Foot Ankle Surg. 1998;37(5):376-385. doi:10.1016/s1067-2516(98)80043-0 10. Hyer CF, Scott RT, Swiatek M. A retrospective comparison of four plate constructs for first metatarsal-cuneiform arthrodesis: static plate, static plate with lag screw, locked plate, and locked plate with lag screw. J Foot Ankle Surg. 2012;51(3):285-287. doi:10.1053/j.jfas.2012.02.008

Hallux Valgus Correction - Comprehensive Decision-Making Guide (Chevron, Scarf, Lapidus)

Hallux Valgus Correction - Comprehensive Decision-Making Guide (Chevron, Scarf, Lapidus)