import { OnePagerSummary, ExamWarning, InfoCardGrid, InfoCard, MnemonicCard, EvidenceCard, VivaScenarioSection, VivaScenario, ExamCheatSheet, ContentSection, ExamPearl, SafetyAlert, NumberHighlightRow, NumberHighlight, Tabs, Tab, ComparisonTable } from '@/components/mdx' **Location**: Dorsal ridge of scaphoid (junction between waist and proximal pole) - dorsal carpal branch of radial artery enters through foramina at dorsal ridge **Protection**: Minimal periosteal stripping. Create radially-based capsular flap. Use elevator gently only where necessary. Preserve soft tissue attachments at dorsal ridge. No aggressive curettage or debridement near dorsal surface. **Location**: Terminal branches cross dorsal wrist in subcutaneous tissue radial to 3rd compartment, over radial border of anatomical snuffbox **Protection**: Identify branches during skin incision. Protect with vessel loops and gentle retraction. Avoid cautery near nerve. Keep incision centered over Lister's (more ulnar than SRN branches). **Location**: Dorsal SL ligament runs from dorsal scaphoid to dorsal lunate just ulnar to scaphoid - strongest portion of SL complex **Protection**: Capsulotomy OVER scaphoid, not extending ulnarly into SL interval. Gentle capsular elevation. Avoid instruments in SL interval. Careful reduction maneuvers - no excessive rotation. **Location**: EPL tendon in 3rd compartment courses around Lister's tubercle with sharp turn, vulnerable to ischemia and rupture **Protection**: Gentle retraction only. No prolonged tension. Preserve blood supply during retraction. Confirm smooth gliding after retinaculum repair. Warn patient of delayed rupture risk. **Location**: Proximal scaphoid articular surface articulates with scaphoid fossa of distal radius - vulnerable to guidewire, screw, and instrument penetration **Protection**: Fluoroscopic confirmation of wire position before drilling. Check screw length measurement twice. Avoid excessive force during reduction. Countersink screw head below articular surface with retrograde technique. ## Absolute Indications - **Displaced proximal pole fracture (Herbert B3)** - displacement greater than 1mm - **Proximal pole non-union** - failed conservative management or delayed presentation - **AVN of proximal pole** - requires vascularized bone graft (1-2 ICSRA) + fixation ## Relative Indications - **Non-displaced proximal pole fracture in high-demand patient** - athletes, manual laborers - **Failed volar approach to proximal pole** - inadequate visualization, unable to achieve fixation - **Proximal pole fracture with scapholunate ligament injury** - allows direct SL repair ## Contraindications ### Absolute - **Severe comminution** - fragment too small for any fixation (may need salvage procedures) - **Active infection** - relative emergency, debridement first ### Relative - **Severe osteoporosis** - screw purchase inadequate, consider K-wire augmentation - **Waist or distal pole fractures** - volar approach preferred for better access ## Pre-operative Planning **Imaging Requirements** - Plain radiographs: PA, lateral, scaphoid views (PA with ulnar deviation), oblique - CT scan: Assess fragment size (can it accept screw?), displacement, comminution, arthritic changes - MRI: Essential to assess AVN (T1 dark signal indicates need for vascularized graft) **Decision Algorithm** 1. Fragment size assessment: greater than 25% of scaphoid length required for retrograde screw 2. AVN assessment: If present on MRI, plan 1-2 ICSRA vascularized graft 3. Screw trajectory: Retrograde (proximal-to-distal) preferred; antegrade (distal-to-proximal) if fragment too small 4. Graft planning: Non-vascularized cancellous for non-union without AVN; vascularized ICSRA for AVN **Equipment Checklist** - Mini C-arm positioned for perfect scaphoid views BEFORE draping - Headless compression screw set (variety of lengths 16-30mm) - 0.045-inch guidewire, cannulated drill bits - K-wires for provisional fixation and joystick control - Microsurgical instruments if planning ICSRA vascularized graft - Wrist positioning bump for 10-20° flexion ## Osseous Anatomy **Scaphoid Blood Supply - CRITICAL CONCEPT** - **Dorsal vessels (70-80%)**: Dorsal carpal branch of radial artery enters at DORSAL RIDGE (junction of middle and proximal thirds) - **Volar vessels (20-30%)**: Volar carpal branches enter at tubercle and waist on volar surface - **Proximal pole**: NO direct blood supply - 100% retrograde intraosseous flow from dorsal ridge vessels - **Clinical significance**: Proximal pole fracture interrupts retrograde flow causing 30-50% AVN risk **Scaphoid Geometry** - Proximal pole: Intra-articular, articulates with scaphoid fossa of radius - Waist: Junction between proximal and distal poles, narrowest point - Tubercle: Distal pole volar prominence, attachment of TCL and thenar muscles - Dorsal ridge: Watershed area between dorsal vessels (most critical blood supply entry) ## Soft Tissue Anatomy **Extensor Compartments (Dorsal Wrist)** - **3rd compartment**: EPL tendon (single tendon), courses around Lister's tubercle - **4th compartment**: EDC tendons (4 tendons), EIP tendon - **Lister's tubercle**: Bony prominence on dorsal distal radius, separates 3rd and 4th compartments - **Internervous plane**: Between EPL and EDC - both posterior interosseous nerve but different terminal branches **Dorsal Wrist Capsule and Ligaments** - **Dorsal radiocarpal ligament (DRC)**: From radius to carpal bones, reinforces dorsal capsule - **Dorsal intercarpal ligament (DIC)**: Between carpal bones - **Scapholunate ligament**: Dorsal portion is primary stabilizer - must preserve during exposure **Neurovascular Structures** - **Superficial radial nerve**: Terminal branches cross dorsal wrist radially, innervate dorsal thumb/first web - **Radial artery**: Dorsal carpal branch provides blood supply to scaphoid via dorsal ridge - **1-2 ICSRA**: Intercompartmental supraretinacular arteries between 1st-2nd or 2nd-3rd compartments - used for vascularized grafts ## Surface Landmarks - **Lister's tubercle**: Palpable prominence on dorsal distal radius - **Anatomical snuffbox**: Bordered by APL/EPB radially, EPL ulnarly - scaphoid tubercle palpable in base - **3rd compartment**: EPL tendon palpable ulnar to anatomical snuffbox - **4th compartment**: EDC tendons palpable with finger extension ## Positioning Nuances **Wrist Flexion vs Extension** - Dorsal approach uses wrist FLEXION 10-20° (opposite of volar approach) - Flexion opens dorsal scaphoid space and brings proximal pole into operative field - Extension closes dorsal space and hides proximal pole **C-arm Setup** - Test BEFORE draping: PA, lateral, oblique scaphoid views - PA view: Arm in neutral rotation, scaphoid elongated with ulnar deviation - Lateral view: True lateral of wrist, scaphoid long axis visible - Oblique: 45° pronation, assesses screw position relative to joint ## Screw Trajectory Options **Retrograde Technique (Proximal-to-Distal)** - **Indications**: Proximal fragment greater than 25% scaphoid length - **Advantages**: Best compression, excellent purchase, direct visualization of proximal pole - **Technique**: Wire at CENTER of proximal pole articular surface, aim parallel to scaphoid axis - **Key point**: Screw head buries into articular cartilage - cartilage heals over (confirmed by literature) - **Pitfall**: Screw head proud above cartilage causes radiocarpal impingement **Antegrade Technique (Distal-to-Proximal)** - **Indications**: Proximal fragment too small for retrograde entry (less than 25% scaphoid) - **Advantages**: Larger entry point at waist, salvages fixation for small fragments - **Technique**: Wire from waist directed proximally into proximal pole - **Key point**: Screw head at waist must be countersunk below dorsal cortex - **Pitfall**: Inadequate proximal pole engagement (need 10-15mm minimum screw purchase) ## Bone Grafting Decision Tree **Non-union WITHOUT AVN** - Non-vascularized cancellous graft from distal radius adequate - Harvest from same incision: window in radius 2cm proximal to joint - Pack graft around non-union site after debridement to bleeding bone - Union rate: 85-90% **Non-union WITH AVN (T1 dark on MRI)** - Vascularized bone graft ESSENTIAL - non-vascularized grafts fail - 1-2 ICSRA pedicled graft from dorsal distal radius - Provides structural support AND revascularization - Union rate: 85-90% with ICSRA vs 50% with non-vascularized in AVN ## ICSRA Vascularized Graft Technique **Identification** - Identify 1st-2nd intercompartmental supraretinacular artery (between APL/EPB and ECRL/ECRB) - OR 2nd-3rd ICSRA (between ECRL/ECRB and EPL) - Small vessel 0.5-1mm diameter coursing on dorsal radius between compartments **Harvest** - Rectangular bone block 8-10mm x 15-20mm from dorsal radius - Preserve arterial pedicle attached to bone - Rotate graft 90° into scaphoid non-union defect - Screw fixation through graft into distal scaphoid **Healing** - MRI at 3 months: Look for revascularization (T1 signal improvement) - Union typically 12-24 weeks - Superior to free vascularized grafts (medial femoral condyle) for proximal pole ## Intraoperative Complications **Proximal Fragment Too Small** - Recognition: Cannot accept guidewire or screw without fragmentation - Management: Convert to antegrade technique OR K-wire fixation OR accept non-operative in elderly - Prevention: Pre-operative CT assessment of fragment size **Loss of Reduction During Screw Insertion** - Recognition: Fragment displacement on fluoroscopy during screw tightening - Management: Remove screw, re-reduce, provisional K-wire before screw re-insertion - Prevention: Provisional K-wire fixation, perfect wire placement, gentle screw insertion **Screw Penetration of Radiocarpal Joint** - Recognition: Screw visualized in joint space on fluoroscopy, "pop" feeling during insertion - Management: Remove screw, shorter screw, re-measure length carefully - Prevention: Measure twice, check length on fluoroscopy before screw insertion **SL Ligament Injury** - Recognition: Widened SL interval on fluoroscopy, instability on probing - Management: Repair SL ligament with suture anchor, consider K-wire temporary SL fixation - Prevention: Capsulotomy over scaphoid only, gentle reduction maneuvers ## Early Complications (0-6 weeks) **Superficial Radial Nerve Injury** - Recognition: Numbness dorsal thumb/first web, painful neuroma with Tinel's - Management: Observation for neuropraxia (6-12 weeks), neuroma excision if persistent pain - Prevention: Identify and protect SRN branches during exposure **EPL Rupture** - Recognition: Loss of thumb IP extension, EPL tendon discontinuity on exam - Management: EPL tendon transfer (EIP to EPL) or graft reconstruction - Prevention: Gentle EPL retraction, confirm smooth gliding, retinaculum repair prevents bowstringing **Wound Complications** - Recognition: Dehiscence, infection (rare), hematoma - Management: Wound care, antibiotics if infected, drainage if hematoma significant - Prevention: Meticulous hemostasis, layered closure, avoid tension ## Late Complications (6 weeks - 6 months) **AVN Development** - Recognition: T1 dark signal on MRI at 3-6 months, sclerotic appearance on X-ray - Management: Revision with 1-2 ICSRA vascularized graft if significant symptoms - Prevention: Preserve dorsal blood supply, minimal periosteal stripping, early diagnosis with MRI - Prognosis: 30-50% risk even with optimal technique - WARN patient pre-operatively **Non-union** - Recognition: Persistent fracture line at 12-16 weeks, no bridging callus on CT - Management: Revision with bone graft (vascularized if AVN) and refixation - Prevention: Adequate immobilization (8-10 weeks), avoid smoking, optimal screw placement - Rate: 15-20% for proximal pole vs 5-10% for waist **Hardware Complications** - Recognition: Screw prominence causing pain, screw cutout from small fragment, screw breakage (rare) - Management: Screw removal after union (4-6 months), revision fixation if cutout before union - Prevention: Adequate screw countersinking, appropriate screw selection for fragment size ## Long-term Complications (greater than 6 months) **SNAC Arthritis** - Recognition: Progressive wrist pain, decreased motion, radiographic arthritis (radial styloid stage 1, radioscaphoid stage 2, capitolunate stage 3) - Management: Early: activity modification, NSAIDs; Late: salvage procedures (4-corner fusion, PRC, wrist fusion) - Prevention: Anatomic reduction, early union, prevent non-union/malunion **Stiffness** - Recognition: Decreased wrist extension (most common with dorsal approach), flexion - Management: Hand therapy, dynamic splinting, arthroscopic capsular release if severe - Prevention: Early protected ROM after union, avoid excessive immobilization beyond 10 weeks **Malunion** - Recognition: DISI pattern on lateral X-ray, scapholunate angle greater than 60°, abnormal carpal kinematics - Management: Corrective osteotomy if symptomatic, salvage if arthritic - Prevention: Anatomic reduction confirmed on all fluoroscopy views ## Union Rates **Proximal Pole Acute Fractures** - Overall union rate: 80-85% with ORIF (vs 60-70% non-operative) - Time to union: 12-20 weeks (longer than waist fractures 8-12 weeks) - Factors affecting union: AVN presence, fragment size, smoking, compliance with immobilization **Proximal Pole Non-union** - With non-vascularized graft (no AVN): 85-90% union - With vascularized graft (AVN present): 85-90% union - Without bone graft (AVN present): 50-60% union (inadequate) ## Functional Outcomes **Return to Activity** - Light activity: 8-10 weeks after surgery - Full unrestricted activity: 4-6 months after solid union - Contact sports: 6 months minimum (later than waist fractures) **Range of Motion Recovery** - Expect 80-90% of contralateral wrist motion - Extension most affected with dorsal approach (vs flexion with volar approach) - Final ROM achieved by 6-12 months **Grip Strength** - 85-95% of contralateral grip at 1 year - Correlates with union achievement and absence of complications ## Comparative Evidence **Dorsal vs Volar Approach for Proximal Pole** - Dorsal approach: Better visualization of proximal pole, access to ICSRA grafts, higher stiffness rate - Volar approach: Traditional for waist fractures, limited proximal pole access, lower stiffness - Recommendation: Dorsal approach specifically for proximal pole fractures **Retrograde vs Antegrade Screw** - Retrograde (dorsal): Better compression for proximal pole if fragment adequate - Antegrade (volar or dorsal): Better for small proximal fragments - Biomechanical studies: No significant difference in compression if perfect central placement ## Long-term Studies **5-Year Follow-up Data** - Union maintenance: 95% remain united - SNAC arthritis development: 15-20% (higher if malunion or AVN) - Patient satisfaction: 80-85% good to excellent results - Hardware removal rate: 5-10% ### Step 1: Positioning & Dorsal Approach Planning Positioning & Dorsal Approach Planning: Position forearm PRONATED with wrist flexed 10-20° over bump. This flexion opens up dorsal scaphoid space and brings proximal pole into operative field. Test C-arm for perfect PA, lateral, and oblique scaphoid views BEFORE draping. Mark Lister's tubercle - palpable dorsal prominence on distal radius. Plan incision centered on Lister's between 3rd and 4th compartments. Review imaging: proximal pole fracture location, displacement, size of proximal fragment. **Technical Tip**: EXAM KEY: 'Dorsal approach is SPECIFICALLY for proximal pole fractures - provides direct visualization of proximal pole and access to dorsal blood supply. Wrist FLEXION (not extension like volar) opens dorsal scaphoid space. I palpate Lister's tubercle as key landmark. Forearm pronated. C-arm setup critical - proximal pole can be difficult to visualize on fluoroscopy. Dorsal approach allows screw insertion from proximal to distal (retrograde) or distal to proximal (antegrade) depending on fragment size.' - Wrong approach for waist fracture - volar preferred - Excessive wrist extension - closes dorsal scaphoid space - Poor C-arm setup - inadequate intraoperative imaging - Failure to assess fragment size pre-operatively ### Step 2: Incision & Retinaculum Division Incision & Retinaculum Division: 4cm longitudinal incision over Lister's tubercle extending from distal radius to carpus. Incise through skin and subcutaneous tissue. Identify and protect superficial radial nerve (SRN) branches with vessel loops. Identify extensor retinaculum. Incise retinaculum longitudinally between 3rd (EPL) and 4th (EDC) compartments. Elevate retinacular flaps for later repair. Identify EPL tendon in 3rd compartment (single tendon), EDC tendons in 4th compartment (multiple tendons). **Technical Tip**: EXAM KEY: 'I make longitudinal incision over Lister's tubercle - this is the landmark separating 3rd and 4th extensor compartments. I identify SRN branches in subcutaneous tissue and protect them with vessel loops or gentle retraction. I incise retinaculum between EPL (3rd) and EDC (4th) - this is an INTERNERVOUS plane. EPL is posterior interosseous nerve, EDC is also PIN but different branches. I elevate retinacular flaps for later repair to prevent bowstringing. EPL is single tendon, EDC has 4 tendons to digits 2-5.' - SRN branch injury - painful neuroma and Wartenberg syndrome - EPL injury during retinaculum division - Incising wrong compartment - Inadequate retinacular flap elevation - difficult repair ### Step 3: Retract EPL & Expose Capsule Retract EPL & Expose Capsule: Retract EPL tendon RADIALLY (away from field). Retract EDC tendons ULNARLY. This exposes radiocarpal joint capsule over scaphoid. The capsule overlies proximal scaphoid and scapholunate interval. Identify Lister's tubercle on radius - this is reference point. Dorsal radiocarpal ligament (DRC) and dorsal intercarpal ligament (DIC) visible on capsule. **Technical Tip**: EXAM KEY: 'I retract EPL radially and EDC ulnarly - this opens up the interval and exposes dorsal wrist capsule. The dorsal capsule contains important ligaments: DRC (radiocarpal) and DIC (intercarpal). The scaphoid proximal pole lies deep to this capsule, just radial to the scapholunate interval. I must preserve EPL blood supply during retraction - gentle traction only, no prolonged tension. Use self-retaining retractors carefully.' - Excessive EPL retraction - ischemia and delayed rupture - Inadequate exposure - poor visualization of proximal pole - Disorientation of anatomy - injury to SL structures - Damage to dorsal wrist ligaments ### Step 4: Capsulotomy & Scaphoid Exposure - PRESERVE BLOOD SUPPLY Capsulotomy & Scaphoid Exposure - PRESERVE BLOOD SUPPLY: Make CAREFUL longitudinal capsulotomy over proximal scaphoid. Create radially-based capsular flap to preserve DRC and DIC ligaments. Exposure reveals proximal pole of scaphoid. CRITICAL: Minimize periosteal stripping - the dorsal blood supply enters at dorsal ridge (area between waist and proximal pole). Use elevator gently. Remove minimal soft tissue. Identify fracture site. If non-union, fibrous tissue visible. **Technical Tip**: EXAM KEY: 'This is the CRITICAL step - I must expose proximal pole while preserving dorsal blood supply. The dorsal vessels enter at the DORSAL RIDGE between waist and proximal pole - this is 70-80% of scaphoid blood supply. I create capsular flap with minimal periosteal stripping. Only remove soft tissue necessary for visualization. Aggressive stripping causes AVN. For acute fractures, hematoma present. For non-union, fibrous tissue or sclerotic bone. I preserve all soft tissue attachments at dorsal ridge where vessels enter.' - Excessive periosteal stripping - disrupts blood supply causing AVN - Injury to scapholunate ligament - causes SL dissociation and DISI - Inadequate exposure of proximal fragment - poor reduction - Joint cartilage damage during exposure ### Step 5: Assess Fragment & Plan Fixation Assess Fragment & Plan Fixation: Assess proximal pole fragment size. Small fragment (less than 25% scaphoid) may not accept screw. Assess displacement, rotation, and angulation. Clean fracture site gently - remove hematoma or fibrous tissue. For acute fracture with good fragment size, plan screw fixation. SCREW DIRECTION OPTIONS: (1) RETROGRADE (proximal to distal) - screw inserted from proximal pole into distal fragment. Preferred if proximal fragment large enough. (2) ANTEGRADE (distal to proximal) - screw from waist into proximal pole. Used if proximal fragment too small for retrograde. **Technical Tip**: EXAM KEY: 'I assess proximal fragment size - this determines fixation strategy. Proximal pole fractures (Herbert B3) have high AVN risk due to tenuous blood supply. RETROGRADE screw (proximal to distal) preferred if fragment accepts screw - provides compression and good purchase. ANTEGRADE screw (distal to proximal, like volar approach) if fragment too small. For very small fragments (less than 25%), may need alternative fixation (K-wires, headless pins) or accept non-operative in elderly. For non-union with AVN, I plan vascularized bone graft (1-2 ICSRA) at this stage.' - Forcing screw into small fragment - causes fragmentation - Inadequate fracture site preparation - impedes union - Missed AVN on pre-op imaging - graft not planned - Failure to plan screw trajectory appropriately ### Step 6: Fracture Reduction Fracture Reduction: Reduce fracture anatomically. Techniques: (1) Joystick with 0.9mm K-wire in proximal fragment to control rotation and angulation. (2) Wrist positioning - slight flexion/extension to align fragments. (3) Direct manipulation with elevator or dental pick. Check reduction: cortical alignment on volar, dorsal, radial, ulnar sides. No articular step-off. Provisionally stabilize with K-wire if needed. Confirm reduction on fluoroscopy PA, lateral, and oblique. **Technical Tip**: EXAM KEY: 'Dorsal approach allows direct visualization of proximal pole reduction - major advantage over percutaneous techniques. I use K-wire joystick in proximal fragment for precise control of rotation and angulation. Perfect reduction is CRITICAL - any malunion of proximal pole causes abnormal kinematics and arthritis. I check all cortical surfaces align on direct visualization and fluoroscopy. If reduction unstable or fragment too small, I use K-wire provisional fixation before screw. I confirm reduction on PA (no displacement), lateral (scapholunate angle 30-60°), and oblique (cortical alignment) views.' - Incomplete reduction - malunion causes arthritis and abnormal kinematics - Fragment comminution during manipulation - Loss of reduction during screw insertion - Iatrogenic SL injury with excessive manipulation ### Step 7: Guidewire Placement - Retrograde Technique Guidewire & Screw Insertion - Retrograde Technique: RETROGRADE (proximal to distal): With fracture reduced, place guidewire at CENTER of proximal pole articular surface. Aim wire parallel to scaphoid long axis toward distal pole. Check wire position on fluoroscopy - PA (central), lateral (parallel to dorsal cortex), oblique (no joint violation). Advance wire across fracture into distal fragment. Wire should be in center of distal scaphoid on all views. Confirm wire position before proceeding. **Technical Tip**: EXAM KEY: 'For retrograde dorsal screw, I place guidewire at CENTER of proximal pole articular surface - this seems counterintuitive but headless screw buries completely below cartilage and heals over. Wire must be parallel to scaphoid long axis. CRITICAL: wire must be central on ALL fluoroscopy views - PA, lateral, and oblique. Eccentric wire causes malreduction or screw cutout. I advance wire carefully across fracture site maintaining reduction. Wire should reach distal pole cortex for measurement. Check wire position multiple times before drilling.' - Eccentric wire placement - fracture displacement or screw cutout - Wire trajectory not parallel to scaphoid axis - malreduction - Loss of reduction during wire insertion - Radiocarpal joint violation with wire - SL ligament injury during guidewire placement ### Step 8: Screw Insertion - Retrograde Technique Screw Insertion - Retrograde Technique: Measure screw length from proximal pole to distal scaphoid cortex. Drill with cannulated drill over guidewire. Insert headless compression screw. Screw head BURIES into proximal pole articular surface - must be countersunk BELOW cartilage level. Advance screw until leading threads engage distal fragment and compression achieved. Final fluoroscopy confirms screw position, fracture compression, no joint penetration. **Technical Tip**: EXAM KEY: 'I measure screw length carefully - from proximal pole surface to distal cortex, usually 20-28mm for average scaphoid. I drill with cannulated drill - gentle pressure to avoid fragment comminution. Headless compression screw provides interfragmentary compression as trailing threads wider than leading threads. Screw head MUST countersink below articular cartilage surface - I confirm this on lateral fluoroscopy. Screw head proud above cartilage causes radiocarpal impingement. Cartilage heals over buried screw head - confirmed in literature. Final fluoroscopy shows screw centered in scaphoid, fracture compressed, no joint violation.' - Screw head proud above proximal pole - radiocarpal impingement and arthritis - Over-drilling - loss of screw purchase in small fragment - Screw too long - penetrates distal pole cortex or STT joint - Screw too short - inadequate compression - Fragment comminution during screw insertion ### Step 9: Alternative - Antegrade Screw Technique Alternative - Antegrade Screw Technique: ANTEGRADE (if proximal fragment too small for retrograde): Create small dorsal window at waist level. Place guidewire from waist directed PROXIMALLY into proximal pole fragment. Check wire central on all views. Wire should engage proximal pole fragment adequately (at least 10-15mm). Measure, drill, and insert headless screw from waist to proximal pole. Screw provides compression of proximal fragment onto distal. Countersink screw head at waist level below dorsal cortex. **Technical Tip**: EXAM KEY: 'Antegrade technique is alternative if proximal fragment too small for retrograde screw entry (less than 25% scaphoid). I place guidewire from WAIST directed proximally into proximal pole - similar trajectory to volar approach but from dorsal. Advantage: larger entry point at waist allows easier screw insertion. Disadvantage: screw doesn't bury completely, head at waist level must be countersunk below dorsal cortex to avoid extensor irritation. I ensure adequate proximal pole engagement - minimum 10-15mm screw purchase in proximal fragment. This technique salvages fixation when proximal pole very small.' - Inadequate proximal pole engagement - screw pulls out, non-union - Screw head prominent dorsally - extensor tendon irritation - Fracture displacement during screw insertion from waist - Screw penetrates proximal pole articular surface into radiocarpal joint ### Step 10: Bone Grafting if Non-Union or AVN Bone Grafting if Non-Union or AVN: For proximal pole non-union or AVN, bone grafting essential. OPTIONS: (1) Non-vascularized cancellous from distal radius - harvest from same incision, window in radius 2cm proximal to joint, pack around fracture site. (2) Vascularized bone graft (1-2 ICSRA) - pedicled bone graft based on 1st or 2nd dorsal intercompartmental supraretinacular artery, for AVN with dark MRI signal. ICSRA graft: identify artery between 1st-2nd or 2nd-3rd compartments, harvest bone from radius with arterial pedicle, rotate into scaphoid non-union site, screw fixation through graft. **Technical Tip**: EXAM KEY: 'Proximal pole non-union has high failure rate without bone graft due to tenuous blood supply. For NON-UNION without AVN: non-vascularized cancellous graft from distal radius adequate - I harvest through small window 2cm proximal to joint, pack graft around non-union site after debridement to bleeding bone. For AVN (MRI T1 dark signal): vascularized bone graft ESSENTIAL - non-vascularized fails. 1-2 ICSRA graft is pedicled vascularized graft from dorsal distal radius based on supraretinacular vessels between compartments. I identify vessel between 1st-2nd compartments (or 2nd-3rd), harvest rectangular bone block 8x15mm with pedicle attached, rotate 90° into scaphoid defect, provides both blood supply and structural support. Union rate 85-90% with ICSRA vs 50% without in AVN cases.' - Inadequate debridement of non-union site - persistent non-union - ICSRA pedicle injury - graft becomes non-vascularized and fails - Graft too large - disturbs scaphoid anatomy and kinematics - Not addressing AVN with vascularized graft - high failure rate - Donor site morbidity from radius graft harvest ### Step 11: Confirm Fixation and Final Fluoroscopy Confirm Fixation and Final Fluoroscopy: Perform final fluoroscopy views - PA, lateral, oblique. Confirm: (1) Screw position central in scaphoid on all views, (2) Screw head buried below proximal pole cartilage (retrograde) or waist cortex (antegrade), (3) Fracture anatomically reduced with no gap, (4) No joint penetration, (5) Adequate screw length and engagement. Test fracture stability under direct vision. Document intraoperative findings and images. **Technical Tip**: EXAM KEY: 'Final fluoroscopy is critical quality control step. I obtain perfect PA, lateral, and oblique views. On PA: screw should be centered in scaphoid, no displacement. On lateral: screw parallel to scaphoid axis, scapholunate angle 30-60° (no DISI), screw head buried. On oblique: no joint violation, screw centered. I test fracture stability by gentle manipulation - should be rigid with screw fixation. If any concern about reduction or screw position, I revise NOW rather than accept suboptimal fixation. Document all findings for operative note and patient discussion.' - Accepting suboptimal reduction - leads to malunion - Missing joint penetration - causes arthritis - Inadequate documentation - medicolegal issues - Excessive radiation exposure to hands ### Step 12: Capsular and Retinacular Repair Capsular and Retinacular Repair: Irrigate wound thoroughly. Repair dorsal capsule with 3-0 absorbable suture using interrupted or figure-of-8 technique to restore ligamentous stability. Ensure SL ligament intact and stable. Repair extensor retinaculum between 3rd and 4th compartments with 3-0 absorbable suture. Check EPL glides smoothly through 3rd compartment over Lister's tubercle without bowstringing. **Technical Tip**: EXAM KEY: 'Capsular repair is important to restore proprioception and dorsal wrist stability. I use 3-0 absorbable suture with interrupted or figure-of-8 technique. Retinaculum repair is CRITICAL - prevents EPL bowstringing which causes loss of thumb extension power and potential delayed rupture. I reconstruct the retinaculum between 3rd and 4th compartments, ensuring EPL courses through Lister's tunnel properly. I test EPL gliding by passive thumb IP flexion/extension - should glide smoothly without catching. Extensor tendon adhesions are risk with dorsal approach - meticulous repair minimizes this.' - Inadequate retinaculum repair - EPL bowstringing and rupture risk - Capsule not repaired - proprioceptive deficits and instability - Over-tight retinaculum repair - EPL stenosis and triggering - Injury to EPL during repair ### Step 13: Skin Closure and Dressing Skin Closure and Dressing: Close subcutaneous tissue with 4-0 absorbable suture. Close skin with 4-0 or 5-0 nylon interrupted sutures or running subcuticular absorbable suture. Apply sterile dressing. Apply well-padded thumb spica splint with wrist neutral, thumb in column position (IP joint free for motion). Confirm adequate padding over bony prominences and no constriction. **Technical Tip**: EXAM KEY: 'I close in layers - subcutaneous 4-0 absorbable, skin with interrupted nylon or running subcuticular. For hand surgery, I prefer interrupted nylon for easier removal and wound inspection. Post-op splinting is CRITICAL: thumb spica with wrist neutral (not extended), thumb column position, IP joint FREE for motion to prevent stiffness. Immobilization protocol same as volar approach: thumb spica 6-8 weeks until union. However, proximal pole fractures take LONGER to unite - typically 12-20 weeks. I warn patients about prolonged healing time and AVN risk (30-50%).' - Wound tension - dehiscence or necrosis - Thumb IP joint immobilized - stiffness - Inadequate padding - pressure sores - Splint too tight - compartment syndrome or vascular compromise ## Immediate Post-operative (0-2 weeks) **Immobilization** - Thumb spica splint with wrist neutral, thumb column position - IP joint FREE for active motion (prevents stiffness) - Elevate hand above heart for 48-72 hours - Ice therapy for pain and swelling **Wound Care** - Keep surgical dressing clean and dry - Suture removal at 10-14 days - Monitor for infection (rare, less than 1%) **Pain Management** - Multimodal analgesia: acetaminophen + NSAIDs (if no contraindication) - Short course of opioids (3-5 days) for severe pain - Cryotherapy ## Early Post-operative (2-8 weeks) **Immobilization** - Convert to thumb spica cast at 2 weeks - Continue casting for 6 weeks total (8 weeks from surgery) - LONGER than waist fractures due to proximal pole tenuous blood supply **Radiographic Follow-up** - X-rays at 2, 6 weeks: assess fracture position, no hardware loosening - Expect minimal callus (scaphoid is intra-articular, limited periosteal reaction) **Activity Restrictions** - No lifting, pushing, pulling with affected hand - Light ADLs with splint on (eating, typing) - No sports or heavy labor ## Mid Post-operative (8-12 weeks) **Mobilization** - Removable thumb spica splint at 8 weeks IF early union signs - Begin hand therapy: AROM wrist and thumb - Gentle strengthening at 10 weeks - Continue splint protection between exercises **Radiographic Follow-up** - X-rays at 8, 12 weeks - CT scan often needed to confirm union (proximal pole union difficult to see on plain films) - Union typically 12-20 weeks (LONGER than waist fractures) **Activity Progression** - Light resistive activities at 10 weeks - Gradual return to work (office work 8-10 weeks, manual labor 12-16 weeks) ## Late Post-operative (3-6 months) **Advanced Rehabilitation** - Progressive strengthening program - Proprioceptive training - Return to sports protocol **Radiographic Follow-up** - X-rays at 16, 20 weeks if union uncertain - CT scan gold standard for confirming union - MRI at 3-6 months if concern for AVN (T1 signal assessment) **Return to Full Activity** - Unrestricted activity at 4-6 months after solid union - Contact sports at 6 months minimum (LATER than waist fractures) - Counsel patient: AVN can develop in 30-50% even with optimal surgery ## Long-term Follow-up (greater than 6 months) **Monitoring** - Annual X-rays first 2 years to detect AVN or SNAC arthritis - Hardware removal rarely needed (5-10% for symptomatic prominence) - Patient education on signs of non-union, AVN, arthritis **Expected Outcomes** - Union rate: 80-85% for acute fractures with ORIF - ROM: 80-90% of contralateral wrist - Grip strength: 85-95% of contralateral - Return to pre-injury activity: 85% of patients at 1 year ## References 1. Gelberman RH, Menon J. The vascularity of the scaphoid bone. J Hand Surg Am. 1980;5(5):508-513. - Seminal anatomic study defining scaphoid blood supply patterns showing dorsal vessels provide 70-80% supply entering at dorsal ridge, establishing foundation for understanding AVN risk in proximal pole fractures. 2. Kawamura K, Chung KC. Treatment of scaphoid fractures and nonunions. J Hand Surg Am. 2008;33(6):988-997. - Comprehensive review of scaphoid fracture treatment demonstrating proximal pole fractures have highest AVN rate (30-50%) and non-union rate (15-20%) requiring specialized surgical approaches. 3. Merrell GA, Wolfe SW, Slade JF 3rd. Treatment of scaphoid nonunions: quantitative meta-analysis of the literature. J Hand Surg Am. 2002;27(4):685-691. - Meta-analysis showing 85-90% union rates with vascularized bone grafts for AVN proximal pole non-unions vs 50-60% with non-vascularized grafts, establishing ICSRA grafts as gold standard. 4. Megerle K, Bertel D, Germann G, Lehnhardt M, Kall S, Sauerbier M. The significance of the 1-2 intercompartmental supraretinacular artery (1-2 ICSRA) as a distally pedicled dorsal wrist bone flap. J Hand Surg Eur Vol. 2011;36(7):563-568. - Detailed anatomic study of ICSRA vascularized graft technique for proximal pole non-union with AVN. 5. Slade JF 3rd, Dodds SD. Minimally invasive management of scaphoid nonunions. Clin Orthop Relat Res. 2006;445:108-119. - Describes percutaneous and limited open techniques for scaphoid ORIF including dorsal approach for proximal pole fractures with retrograde screw fixation. 6. Herbert TJ, Fisher WE. Management of the fractured scaphoid using a new bone screw. J Bone Joint Surg Br. 1984;66(1):114-123. - Original description of headless compression screw for scaphoid fixation and Herbert classification of scaphoid fractures (B3 = proximal pole). 7. Trumble TE, Clarke T, Kreder HJ. Non-union of the scaphoid. Treatment with cannulated screws compared with treatment with Herbert screws. J Bone Joint Surg Am. 1996;78(12):1829-1837. - Randomized trial showing headless compression screws achieve 85-90% union for scaphoid non-unions with appropriate bone grafting. 8. Shin AY, Bishop AT. Vascularized bone grafts for scaphoid nonunions and Kienbock's disease. Orthop Clin North Am. 2001;32(2):263-277. - Review of vascularized bone graft options including pedicled ICSRA grafts and free medial femoral condyle grafts for scaphoid AVN. 9. Sotereanos DG, Darlis NA, Dailiana ZH, Sarris IK, Malizos KN. A capsular-based vascularized distal radius graft for proximal pole scaphoid pseudarthrosis. J Hand Surg Am. 2006;31(4):580-587. - Clinical series demonstrating 88% union rate with capsular-based vascularized grafts from dorsal radius for proximal pole non-union with AVN. 10. Kerluke L, McCabe SJ. Nonunion of the scaphoid: a critical analysis of recent natural history studies. J Hand Surg Am. 1993;18(1):1-3. - Natural history study showing untreated scaphoid non-unions progress to SNAC arthritis in 95% of cases within 10 years, emphasizing importance of achieving union.

Scaphoid ORIF - Dorsal Approach (Proximal Pole)

Scaphoid ORIF - Dorsal Approach (Proximal Pole)