import { OnePagerSummary, ExamWarning, InfoCardGrid, InfoCard, MnemonicCard, EvidenceCard, VivaScenarioSection, VivaScenario, ExamCheatSheet, ContentSection, ExamPearl, SafetyAlert, NumberHighlightRow, NumberHighlight, Tabs, Tab, ComparisonTable } from '@/components/mdx' **Location**: Branches cross dorsal-radial wrist 2-5mm from skin incision, superficial to extensor retinaculum **Protection**: Identify in subcutaneous tissue during approach, retract radially with vessel loops, protect throughout case **Location**: Emerges 5cm proximal to ulnar styloid, courses near 6th extensor compartment on ulnar wrist **Protection**: Identify during subcutaneous dissection ulnar side, retract and protect with moist sponge **Location**: Third extensor compartment, courses around Lister's tubercle - can be attenuated or frayed at this point **Protection**: Gentle retraction radially after opening retinaculum, avoid excessive traction on potentially weakened tendon **Location**: Supplies dorsal wrist capsule and ligaments, runs within capsular layers over scapholunate interval **Protection**: Preserve distal pedicle when creating capsular flap - distally-based design maintains vascular supply **Location**: Immediately deep to dorsal capsule, exposed after capsulotomy - scaphoid and lunate articular cartilage **Protection**: Avoid direct instrument contact with articular surfaces, careful K-wire insertion avoiding cartilage penetration ### Indications **Primary Indication**: Chronic scapholunate ligament tear with carpal instability **Specific Patient Selection Criteria**: - Scapholunate ligament injury confirmed on MRI or arthroscopy - Symptomatic instability with pain, weakness, clicking - REDUCIBLE scapholunate malalignment and DISI deformity - Timeline: 6 months to 2 years from injury (sub-acute to chronic) - Failed conservative management (splinting, activity modification, therapy) - NO radiographic evidence of SLAC arthritis (critical exclusion) - Adequate tissue quality for capsular flap reconstruction - Patient compliance for extended immobilization and rehabilitation **Radiographic Indications**: - Scapholunate interval greater than 3mm (Terry Thomas sign) - Scapholunate angle greater than 60-70 degrees on lateral (DISI pattern) - Cortical ring sign on PA view (flexed scaphoid viewed end-on) - Intact radioscaphoid, radiolunate, and capitolunate joints (no SLAC) ### Contraindications **Absolute Contraindications**: - SLAC wrist Stage II or higher (radioscaphoid arthritis present) - Irreducible scapholunate deformity (fixed malalignment) - Active infection in wrist or hand - Severe osteoporosis with fragile bone (K-wire fixation would fail) - Medical comorbidities precluding prolonged immobilization **Relative Contraindications**: - SLAC Stage I (radial styloid arthritis only) - consider with styloidectomy - Very chronic injuries (greater than 2-3 years) - poor tissue quality - Scaphoid malunion or lunate pathology complicating reduction - High-demand manual laborers (higher failure risk) - Poor patient compliance (will not maintain immobilization) - Revision surgery after failed previous SL reconstruction - Inflammatory arthropathy (rheumatoid arthritis) **Alternative Procedures When Contraindicated**: - SLAC Stage II-III: Four-corner fusion (scaphoid excision, capitate-lunate-hamate-triquetrum fusion) - SLAC Stage III-IV: Proximal row carpectomy or total wrist fusion - Acute SL tears (less than 6 weeks): Primary ligament repair - Chronic irreducible: Scaphoid-trapezium-trapezoid fusion with ligament reconstruction ### Scapholunate Ligament Complex Anatomy **Three Components of SL Ligament**: 1. **Dorsal Component** - STRONGEST portion, thick fibrocartilaginous structure (2-3mm thick, 10-12mm wide), primary restraint to scaphoid flexion and lunate extension 2. **Proximal (Membranous) Component** - Thin fibrocartilaginous layer, lines joint, weakest portion, tears first in acute injuries 3. **Palmar Component** - Intermediate strength, thinner than dorsal (1-2mm), weaker secondary restraint **Clinical Significance**: Dorsal component provides 80% of scapholunate stability - this is why dorsal capsulodesis works ### Normal Carpal Kinematics **Scaphoid Normal Position**: - Bridges proximal and distal carpal rows (acts as intercalated segment) - Natural tendency to FLEX (palmar tilt) due to distal row forces - Restrained by intact SL ligament dorsal component - Normal scaphoid-radius angle: 45-60 degrees **Lunate Normal Position**: - Central proximal row bone, keystone of wrist - Natural tendency to EXTEND (dorsal tilt) due to capitate forces - Restrained by intact SL ligament and lunotriquetral ligament - Normal capitate-lunate-radius angle: 0 degrees (± 10 degrees) ### Pathomechanics of SL Ligament Injury **Mechanism of Injury**: Hyperextension, ulnar deviation, and intercarpal supination (fall on outstretched hand most common) **Progressive Deformity Development**: 1. **Acute Phase** (0-6 weeks): Ligament tears (typically dorsal first), scaphoid begins flexing, lunate begins extending 2. **Subacute Phase** (6 weeks to 6 months): Progressive deformity, scapholunate gap widens, DISI pattern develops 3. **Chronic Phase** (greater than 6 months): Fixed deformity may develop, secondary restraints fail, arthritis risk increases 4. **SLAC Development** (years): Progressive arthritis - radial styloid, then radioscaphoid, then capitolunate **DISI Deformity** (Dorsal Intercalated Segment Instability): - Scaphoid FLEXES abnormally (palmar tilt) - unopposed by torn dorsal SL ligament - Lunate EXTENDS abnormally (dorsal tilt) - follows triquetrum - Scapholunate angle INCREASES to greater than 70 degrees (normal 30-60 degrees) - Scapholunate gap WIDENS to greater than 3mm (normal less than 2mm) ### Radiographic Findings **PA Radiograph Signs**: - **Terry Thomas Sign**: Scapholunate interval greater than 3mm (named after gap-toothed actor) - **Cortical Ring Sign**: Flexed scaphoid viewed end-on shows dense cortical ring of proximal pole - **Scaphoid Foreshortening**: Overall scaphoid length appears shorter due to flexion **Lateral Radiograph Signs**: - **Scapholunate Angle**: Greater than 70 degrees diagnostic of DISI (normal 30-60 degrees) - **Radiolunate Angle**: Lunate extended (dorsal tilt) relative to radius greater than 15 degrees - **Disrupted Gilula Lines**: Three smooth carpal arcs disrupted at scapholunate interval ### Dorsal Capsulodesis (This Procedure) **Concept**: Distally-based dorsal wrist capsular flap tethers scaphoid to lunate, recreating dorsal SL ligament function **Advantages**: - Uses local tissue (dorsal capsule and intercarpal ligament) - No tendon graft harvest required - Maintains distal blood supply to flap - Direct anatomic position over scapholunate interval - Can augment with suture anchors for stronger fixation **Disadvantages**: - Limited by capsular tissue quality in chronic cases - Moderate failure rate (10-30%) in severe chronic instability - Requires extended immobilization (8-12 weeks) - Some loss of wrist motion expected (30-40% ROM reduction) **Best For**: Subacute to early chronic SL instability, adequate tissue quality, moderate activity demands ### Modified Brunelli Procedure (BRB - Bone-Retinaculum-Bone) **Concept**: Strip of dorsal capsule passed through bone tunnel in scaphoid, creating dynamic tether **Technique**: - Create dorsal capsular strip (8-10mm wide) - Drill bone tunnel through scaphoid waist (dorsal to palmar) - Pass capsular strip through tunnel - Loop back and secure to dorsal capsule or scaphoid - Creates "tenodesis" effect preventing scaphoid flexion **Advantages**: Dynamic restraint, good biomechanical studies **Disadvantages**: Risk of scaphoid fracture through tunnel, capsule can pull through or tear ### SLAM Procedure (Scapholunate Axis Method) **Concept**: Tendon graft (palmaris longus or toe extensor) passed through bone tunnels in scaphoid and lunate in figure-8 configuration **Technique**: - Harvest palmaris longus or extensor digitorum longus (toe) - Drill bone tunnels in scaphoid (dorsal-palmar) and lunate (dorsal-palmar) - Pass graft in figure-8 pattern through both bones - Tension and secure graft **Advantages**: Strong fixation, addresses both bones, good for revision or severe cases **Disadvantages**: Tendon harvest morbidity, technically demanding, bone tunnel fracture risk ### Three-Ligament Tenodesis (Blatt Capsulodesis) **Concept**: Distally-based strip of dorsal capsule secured to distal scaphoid, preventing scaphoid flexion only **Technique**: Similar to dorsal capsulodesis but flap attached to scaphoid distal pole only (not lunate) **Advantages**: Simpler, addresses primary deforming force (scaphoid flexion) **Disadvantages**: Does not address lunate extension, less comprehensive reconstruction ### Instrument Requirements **Standard Hand Instrument Set**: - Hand surgery soft tissue set with fine dissecting instruments - Self-retaining retractors (small Gelpi or Weitlaner) - Freer elevators and periosteal elevators - Fine scissors (Metzenbaum, tenotomy) - Toothed and non-toothed forceps (0.5mm, 0.3mm) - Needle holders (fine, medium) **Specialized Wrist Instruments**: - Small rongeurs and curettes for bone preparation - High-speed burr (2mm, 3mm cutting and diamond burrs) - K-wire driver with 0.062 inch (1.6mm) K-wires - Bone clamp or pointed reduction forceps for scapholunate reduction - Wire cutter and bending tool **Fixation Options**: - K-wires: 0.062 inch diameter, adequate length - Suture anchors: 2.0mm or 2.4mm, absorbable or non-absorbable (2-4 anchors) - Bone tunnel drill bits: 1.5mm, 2.0mm if using transosseous technique - Suture: 2-0 or 3-0 braided non-absorbable (Ethibond, FiberWire) for flap fixation - Suture: 3-0 absorbable (Vicryl) for capsule closure - Suture: 4-0 absorbable for subcutaneous, 4-0 nylon for skin **Optional Augmentation Materials**: - Suture tape or high-strength suture for internal bracing - Tendon graft if performing augmented reconstruction (palmaris longus) ### Imaging Equipment **Essential**: - Mini C-arm fluoroscopy with radiolucent hand table - Lead protection for patient and surgical team - Sterile C-arm drape **Views Required**: - PA wrist view (assess scapholunate interval, cortical ring sign) - True lateral wrist view (assess scapholunate angle, DISI deformity) - Oblique views as needed for K-wire positioning ### Patient Positioning **Position**: Supine on operating table **Arm Position**: Extended on radiolucent hand table **Hand Position Options**: 1. **Flat on table** with towel roll under distal forearm for wrist extension 2. **Finger trap traction** (5-10 lbs) suspended - can aid visualization and reduction 3. **Lead hand** secured to table for stability during fluoroscopy **Tourniquet**: Upper arm pneumatic tourniquet at 250mmHg (adjust for patient size and blood pressure) ### Anesthesia Considerations **Preferred**: General anesthesia or brachial plexus block **Regional Block Options**: - Supraclavicular block (entire arm) - Infraclavicular block (good coverage) - Axillary block (adequate but can miss musculocutaneous) **Local Infiltration**: Consider local anesthetic infiltration along incision for post-operative pain (0.25% bupivacaine with epinephrine) ### Immobilization Protocol **Phase 1 (Weeks 0-4): Long Arm Cast** - Long arm cast or splint in neutral wrist position - Forearm in neutral rotation (prevents pronation-supination) - Elbow at 90 degrees flexion - **Rationale**: Long arm immobilization prevents forearm rotation which creates torsional stress on scapholunate reconstruction - K-wires remain in place - Fingers free for ROM exercises **Phase 2 (Weeks 4-8 to 10): Short Arm Cast** - Transition to short arm cast maintaining neutral wrist position - Continue full immobilization (no active wrist motion) - K-wires remain in place - **Total immobilization**: 8-12 weeks minimum **Phase 3 (Weeks 8-12): Wire Removal and Early Motion** - Obtain radiographs at 8 weeks - If alignment maintained (SL interval less than 3mm, SL angle 30-60 degrees), remove K-wires - Wire removal typically in clinic with local anesthetic - Transition to removable wrist splint - Begin hand therapy with GENTLE passive and active-assisted ROM only ### Rehabilitation Protocol **Weeks 8-12: Early Protected Motion** - Gentle wrist flexion-extension (AROM, AAROM) - Gentle radial-ulnar deviation - Forearm rotation (pronation-supination) - **NO strengthening or resistance** - Removable splint worn between therapy sessions - Goal: Prevent stiffness while protecting healing reconstruction **Weeks 12-16: Progressive Motion and Light Strengthening** - Progress ROM exercises - Begin gentle strengthening with therapy putty or foam ball - Light functional activities (writing, keyboard use, light ADLs) - Continue splint use for heavy activities or at night **Months 4-6: Strengthening and Functional Progression** - Progressive resistive exercises - Occupational therapy for work simulation - Sport-specific training if applicable - Gradual return to functional activities **Month 6+: Return to Activity** - Return to unrestricted activities if: - Pain-free or minimal pain with activities - ROM at least 70% of contralateral wrist - Grip strength at least 80% of contralateral - Maintained radiographic alignment - Lifelong counseling: Avoid high-impact loading when possible (may need activity modification) ### Follow-up Schedule **Week 2**: Wound check, cast assessment, pin site care education **Week 6**: Radiographs in cast (assess early alignment), cast assessment **Week 8-12**: Radiographs, K-wire removal if alignment maintained, begin therapy **Month 4**: Clinical and radiographic assessment, progress check **Month 6**: Clinical and radiographic assessment, clearance for activities **Year 1**: Final assessment with radiographs to assess for maintained reduction and any SLAC development **Annual thereafter**: Consider annual radiographs long-term to monitor for arthritis progression ### Radiographic Surveillance **Parameters Monitored**: - **Scapholunate interval**: Should remain less than 3mm - **Scapholunate angle**: Should remain 30-60 degrees (corrected DISI) - **Cortical ring sign**: Should be absent (scaphoid reduced) - **SLAC development**: Monitor for radial styloid, radioscaphoid, capitolunate arthritis **Red Flags for Failure**: - Widening SL interval greater than 3mm (loss of reduction) - Return of DISI deformity (SL angle greater than 70 degrees) - Development of SLAC arthritis changes - Persistent pain despite anatomic alignment (may indicate occult arthritis) ### Step 1: Positioning & Preoperative Imaging Assessment Position supine with arm extended on radiolucent hand table. Apply upper arm pneumatic tourniquet (not inflated yet). Position mini C-arm for PA and lateral wrist imaging. May use finger trap traction (5-10 lbs) or towel roll under distal forearm for wrist extension positioning. **Preoperative Fluoroscopic Assessment**: - PA view: Measure scapholunate interval (normal less than 3mm, pathologic greater than 3mm to 5mm or more) - Identify Terry Thomas sign (widened SL gap), cortical ring sign (flexed scaphoid) - Lateral view: Measure scapholunate angle (normal 30-60 degrees, DISI greater than 70 degrees) - Assess lunate position (extended in DISI pattern) - **Critical**: Confirm NO radioscaphoid or capitolunate arthritis (contraindication for reconstruction) - Document reducibility: Apply manual pressure and stress views to confirm deformity is reducible Inflate tourniquet to 250mmHg after exsanguination with Esmarch bandage. **Technical Tip**: EXAM KEY - 'Scapholunate ligament injury causes DISI deformity: lunate extends dorsally, scaphoid flexes palmarly. Diagnostic criteria: SL interval greater than 3mm on PA (Terry Thomas sign), SL angle greater than 70 degrees on lateral. Cortical ring sign shows flexed scaphoid viewed end-on. Must have NO arthritis for reconstruction - if SLAC wrist present (radioscaphoid or capitolunate arthritis), reconstruction will fail and patient needs salvage procedure like four-corner fusion.' - Proceeding with reconstruction when SLAC arthritis present leads to predictable failure - Missing irreducible deformity (fixed malalignment requires different procedure or bone grafting) - Inadequate preoperative imaging assessment of arthritis status ### Step 2: Incision & Superficial Dissection Make longitudinal dorsal wrist incision centered over scapholunate interval, extending from just proximal to Lister's tubercle distally to midcarpal level (approximately 6-8cm total length). Incise skin and subcutaneous tissue with sharp dissection. **Identify and protect superficial radial sensory nerve branches** on radial side of incision - typically 2-3 small branches cross the operative field 2-5mm from skin incision. Use vessel loops to retract branches radially. **Identify and protect dorsal sensory branch of ulnar nerve** on ulnar side near 6th extensor compartment - retract ulnarly. Identify extensor retinaculum. The longitudinal fibers of retinaculum are visible overlying extensor tendons. **Technical Tip**: EXAM KEY - 'I use longitudinal dorsal incision centered over scapholunate interval. This provides direct access to dorsal capsule. During subcutaneous dissection, I identify and protect superficial radial nerve branches on radial side and dorsal ulnar sensory branches on ulnar side - these are the most common nerves injured in dorsal wrist surgery. I use vessel loops for gentle retraction.' - Superficial radial sensory nerve branches: Typically 2-3 branches cross operative field, can cause painful neuroma if injured - Dorsal sensory branch ulnar nerve: Emerges 5cm proximal to ulnar styloid, courses near 6th compartment - Use loupe magnification for nerve identification in subcutaneous layer ### Step 3: Extensor Retinaculum Division & Tendon Management Incise extensor retinaculum longitudinally between 3rd compartment (EPL) and 4th compartment (EDC/EIP). This internervous interval provides direct access to dorsal capsule. Identify EPL tendon in 3rd compartment coursing around Lister's tubercle - retract radially with moist sponge or small retractor. **Note**: EPL can be attenuated or frayed at Lister's tubercle, especially in chronic cases - handle gently. Identify 4th compartment containing EDC and EIP tendons. Can retract these tendons ulnarly OR split the compartment longitudinally and pass between tendons for better exposure. The dorsal wrist capsule is now visible beneath the extensor tendons. **Technical Tip**: EXAM KEY - 'I open extensor retinaculum between 3rd and 4th compartments - this is internervous interval giving direct access to dorsal capsule over scapholunate. I retract EPL radially (protect carefully as it can be attenuated over Lister's tubercle) and retract EDC/EIP ulnarly. Can repair retinaculum at closure with Z-lengthening if needed to prevent extensor adhesions.' - EPL tendon injury: Can be attenuated over Lister's tubercle, avoid excessive traction - Extensor tendon adhesions: Minimize trauma to paratenon, gentle tissue handling - Retinaculum closure too tight: Can impair extensor tendon gliding ### Step 4: Capsulotomy & Creation of Distally-Based Capsular Flap Identify dorsal wrist capsule architecture. The dorsal radiocarpal ligament and dorsal intercarpal ligament form characteristic V or inverted-Y pattern converging on dorsal lunate. **Create Distally-Based Capsular Flap**: 1. Start proximally at distal radius dorsal rim 2. Incise longitudinally creating rectangular flap approximately 10-15mm wide 3. Extend distally 20-25mm to capitate/lunate level 4. **Leave distal attachment intact** - this is the vascular pedicle 5. Elevate flap from proximal to distal, preserving distal blood supply The flap incorporates dorsal radiocarpal ligament and portion of dorsal intercarpal ligament. Flap dimensions: 10-15mm wide, 20-25mm long, distally-based with hinge point over capitate-lunate region. After elevating flap, the scapholunate interval is fully exposed. May see frayed, attenuated, or completely absent dorsal SL ligament tissue. Scaphoid and lunate clearly visible. **Technical Tip**: EXAM KEY - 'I create DISTALLY-BASED dorsal capsular flap that will bridge the scapholunate interval and substitute for torn dorsal SL ligament. Flap dimensions approximately 10-15mm wide by 20-25mm long. Critical to preserve DISTAL pedicle - this maintains blood supply to flap. The dorsal SL ligament's dorsal component is the strongest portion providing 80% of stability - the capsulodesis recreates this anatomic restraint.' - Flap too thin or narrow: Will tear during tensioning or fixation - ensure adequate tissue thickness - Disrupting distal vascular pedicle: Leads to flap necrosis and reconstruction failure - Inadequate flap length: Won't reach both scaphoid and lunate with adequate tension - Damage to underlying articular cartilage: Avoid deep dissection into joint ### Step 5: Assess & Reduce Scapholunate Deformity With scapholunate interval exposed, assess pathology: - **Scapholunate gap**: Typically widened (greater than 3mm, often 5-8mm) - **Scaphoid position**: Flexed (palmar tilt) - see abnormal orientation - **Lunate position**: Extended (dorsal tilt) - DISI deformity **Reduction Maneuvers**: 1. **Scaphoid reduction**: Insert 0.062 inch K-wire into scaphoid waist as joystick handle. EXTEND scaphoid (dorsiflex, lift proximally) to correct flexion deformity 2. **Lunate reduction**: Manipulate lunate into FLEXION (palmar tilt) using instrument or direct pressure 3. **Close SL gap**: Apply manual pressure or use pointed reduction forceps/bone clamp to approximate scaphoid to lunate 4. **Fluoroscopic confirmation**: PA view shows SL interval less than 3mm, no cortical ring. Lateral view shows SL angle 30-60 degrees, corrected DISI **Temporary K-wire Fixation**: - Place two 0.062 inch K-wires across scapholunate joint in DIVERGENT pattern (prevents rotation) - Place one 0.062 inch K-wire from scaphoid into capitate (scaphocapitate wire for additional stability) - Leave K-wires proud of skin 1cm for later removal - Confirm position on fluoroscopy (wires cross joint but don't penetrate far cortex excessively) **Technical Tip**: EXAM KEY - 'Reduction is critical before reconstruction. I use K-wire joystick in scaphoid to EXTEND it (correct abnormal flexion). I flex the lunate. I close SL gap with reduction forceps. I confirm anatomic reduction on fluoroscopy: SL interval less than 3mm on PA, SL angle 30-60 degrees on lateral. I hold reduction with 3 temporary K-wires (2 scapholunate divergent, 1 scaphocapitate) while performing capsulodesis. This ensures healing in correct anatomic position.' - Inability to achieve reduction: May need bone graft in SL interval or consider different procedure - K-wire penetrating articular cartilage: Confirm extraarticular position on both views - Loss of reduction during reconstruction: Ensure K-wires adequately hold position - Scaphoid or lunate fracture: Avoid excessive force, especially in osteoporotic bone ### Step 6: Prepare Bone Surfaces for Capsular Flap Attachment With reduction maintained by K-wires, prepare scaphoid and lunate dorsal surfaces for capsular flap fixation. **Bone Surface Preparation**: - Use small rongeur or 2-3mm burr to gently roughen dorsal cortex of proximal scaphoid - Roughen dorsal surface of lunate similarly - Create slight trough or bed in bone to accept capsular flap (enhances contact and healing) - Depth: Superficial only (1-2mm) - do NOT penetrate joint or weaken bone structure - **Purpose**: Roughened bone surface promotes fibrous ingrowth and flap-to-bone healing **Alternative: Suture Anchor Preparation**: - If using suture anchors for stronger fixation (recommended for chronic or severe cases): - Place two 2.0mm or 2.4mm suture anchors in dorsal proximal scaphoid - Place two 2.0mm or 2.4mm suture anchors in dorsal lunate - Position anchors to allow capsular flap to bridge interval when sutured - Load anchors with 2-0 or 3-0 non-absorbable braided suture (FiberWire, Ethibond) **Technical Tip**: EXAM KEY - 'I prepare bone surfaces to enhance capsule-to-bone healing. I use small rongeur or burr to roughen dorsal cortex of scaphoid and lunate - creates bleeding bone surface promoting fibrous tissue ingrowth. Alternatively, I prefer suture anchors for more secure fixation, especially in chronic cases - 2 anchors in scaphoid, 2 in lunate, positioned dorsally to accept capsular flap. Anchors provide stronger fixation than sutures through bone tunnels.' - Scaphoid or lunate fracture: Especially with anchor insertion - predrill carefully - Penetrating radiocarpal or midcarpal joint with burr: Stay superficial on dorsal cortex - Anchor malposition: Should be dorsal surface, not articular - confirm on fluoroscopy - Weakening bone excessively: Keep preparation superficial (1-2mm depth maximum) ### Step 7: Dorsal Capsulodesis - Secure Capsular Flap The distally-based capsular flap is now secured to both scaphoid and lunate, bridging the scapholunate interval. The flap acts as a tether preventing scaphoid flexion and lunate extension. **Fixation Technique Option 1: Suture Anchors (Preferred)** - Pass sutures from scaphoid anchors through capsular flap at appropriate position - Tie sutures to secure flap to dorsal scaphoid with firm tension - Pass sutures from lunate anchors through capsular flap - Tie sutures to secure flap to dorsal lunate - Flap should bridge scapholunate interval under appropriate tension - Add additional interrupted sutures along flap edges for reinforcement **Fixation Technique Option 2: Transosseous Bone Tunnels** - Drill small (1.5-2.0mm) bone tunnels through scaphoid (dorsal to palmar) - Drill similar tunnels through lunate (dorsal to palmar) - Pass 2-0 or 3-0 braided non-absorbable suture through capsular flap - Pass suture through bone tunnels - Tie sutures on palmar side or over palmar cortex (may need small palmar incision) - Ensures strong fixation but technically more demanding **Flap Tension Assessment**: - **Too loose**: Won't prevent recurrent scapholunate gapping - inadequate restraint - **Too tight**: Will tear flap tissue or pull through bone - leads to failure - **Appropriate tension**: Flap under visible tension, approximates bones, no excessive blanching - Test: Gently stress scapholunate interval - should have minimal gapping with flap restraining **Technical Tip**: EXAM KEY - 'I secure dorsal capsular flap to both scaphoid and lunate using suture anchors - this provides strongest fixation. The flap bridges scapholunate interval creating TETHER that prevents pathologic motion. Appropriate tension is critical - too loose fails to prevent instability recurrence, too tight causes tissue failure. The flap substitutes for torn dorsal SL ligament which provided 80% of scapholunate stability. This is why dorsal capsulodesis works biomechanically.' - Capsular flap tearing: Ensure adequate tissue thickness, avoid excessive tension, use multiple sutures - Suture pulling through bone: Use anchors or ensure bone tunnels positioned to distribute force - Bone tunnel fracture: Keep tunnels small (1.5-2.0mm), avoid excessive number - Inadequate tension: Most common cause of reconstruction failure - flap must restrain motion ### Step 8: Augmentation Options (If Indicated) For severe chronic instability, high-demand patients, or revision cases, consider adding augmentation to simple capsulodesis. **Modified Brunelli (Bone-Retinaculum-Bone) Augmentation**: - Use additional strip of dorsal wrist capsule (separate from main flap) - Drill bone tunnel through scaphoid waist (dorsal to palmar, 3-4mm diameter) - Pass capsular strip through scaphoid tunnel - Loop strip back and secure to dorsal capsule or proximal scaphoid with suture anchors - Creates dynamic tether resisting scaphoid flexion **SLAM (Scapholunate Axis Method) Tendon Graft Augmentation**: - Harvest palmaris longus tendon (or toe extensor if palmaris absent) - Drill bone tunnels in scaphoid (dorsal to palmar) and lunate (dorsal to palmar) - Pass tendon graft in figure-8 pattern through both tunnels - Tension graft appropriately and secure with suture or interference screw - Provides strong internal brace augmenting capsulodesis **Decision Making**: Simple capsulodesis adequate for most subacute/early chronic cases. Consider augmentation if: revision surgery, severe chronic instability (greater than 2 years), poor tissue quality, high-demand manual laborer, competitive athlete. **Technical Tip**: EXAM KEY - 'For augmentation in severe cases, I use Bone-Retinaculum-Bone technique where capsular strip passes through scaphoid tunnel creating additional dynamic restraint, or SLAM procedure using tendon graft in figure-8 through scaphoid and lunate tunnels. These add strength for high-demand patients or revision surgery. However, simple dorsal capsulodesis is sufficient for most moderate instability cases caught relatively early (within 6 months to 2 years).' - Scaphoid fracture through bone tunnel: Higher risk with larger tunnels for tendon grafts - Tendon graft necrosis: Avoid excessive tension, maintain vascularity - Over-constraining joint: Can limit wrist motion excessively - Increased technical complexity and operative time ### Step 9: Final Reduction Assessment & K-Wire Position Confirmation After capsulodesis secured, perform final fluoroscopic assessment to confirm anatomic reduction and appropriate K-wire positioning. **PA Fluoroscopy View Assessment**: - Scapholunate interval: Should measure less than 3mm (normal 2-3mm) - Cortical ring sign: Should be ABSENT (indicates scaphoid reduced from flexion) - Gilula lines: Three smooth carpal arcs should be restored and parallel - No carpal step-off or malalignment - K-wire position: Wires cross scapholunate joint, adequate purchase in both bones **Lateral Fluoroscopy View Assessment**: - Scapholunate angle: Should measure 30-60 degrees (corrected from DISI) - Radiolunate angle: Should be 0 degrees ± 10 degrees (corrected lunate extension) - Capitate-lunate alignment: Should be colinear (no VISI or DISI pattern) - K-wire position: Adequate penetration but not excessively through far cortex **K-Wire Configuration**: - Two scapholunate K-wires in DIVERGENT pattern (prevents rotation) - One scaphocapitate K-wire for additional stability - Wires bent and cut outside skin with 1cm proud for later removal - Alternative: Bury wires under skin if preferred (requires mini-open for removal) - Protect wire ends with plastic guards and dressing **Technical Tip**: EXAM KEY - 'I confirm anatomic reduction on final fluoroscopy before closing. SL interval should be 2-3mm on PA view. SL angle 30-60 degrees on lateral - this corrects the DISI deformity. I use 3 K-wires total: 2 scapholunate divergent (prevent rotation), 1 scaphocapitate (additional stability). These wires protect the capsulodesis during healing for 8-12 weeks. I leave wires outside skin with bent ends and protective guards - easier for later removal than buried wires.' - Loss of reduction: If alignment inadequate, re-reduce before closing - don't accept suboptimal position - K-wire migration risk: Ensure adequate bending and secure dressing to prevent movement - Overcorrection: Excessive scaphoid extension can limit wrist extension - aim for normal alignment - Pin tract infection prevention: Educate patient on pin care, protective covering ### Step 10: Wound Closure Irrigate wound thoroughly with normal saline (3-6 liters) to remove bone debris and blood. **Layered Closure**: 1. **Capsule**: Attempt to close dorsal wrist capsule over reconstruction with 3-0 absorbable suture (Vicryl) if adequate tissue remains. Often capsule is thin after flap harvest - if inadequate tissue, leave capsule open (acceptable) 2. **Extensor Retinaculum**: Close retinaculum over extensor tendons with 3-0 absorbable suture - can perform Z-lengthening if tight to prevent extensor tendon adhesions and maintain smooth gliding 3. **Subcutaneous Layer**: Close with 4-0 absorbable suture (interrupted or running) 4. **Skin**: Close with 4-0 nylon interrupted vertical mattress or running subcuticular 4-0 absorbable suture 5. **K-wire Protection**: Apply sterile dressing around K-wire sites with protective plastic guards to prevent catching on clothing Apply soft sterile dressing (fluffs and gauze). **Technical Tip**: EXAM KEY - 'I close extensor retinaculum over tendons to provide smooth gliding surface - may Z-lengthen retinaculum if tight after reconstruction. Often don't have enough capsule to close after creating flap - this is acceptable, don't force tension closure. I protect K-wire sites with sterile dressing and plastic guards to prevent pin catching and reduce infection risk. Standard layered skin closure.' - Extensor tendon adhesions: Avoid tight retinaculum closure, gentle tissue handling, early mobilization after immobilization period - K-wire site infection: Proper pin care education, protective covering, remove wires at 8-12 weeks - Wound dehiscence: Avoid excessive tension on skin closure, ensure adequate hemostasis ### Step 11: Immobilization Apply LONG ARM CAST or well-molded LONG ARM SPLINT immediately after surgery. **Immobilization Position**: - Wrist: Neutral position (0 degrees flexion-extension) - Forearm: Neutral rotation (midposition between pronation-supination) - Elbow: 90 degrees flexion - Fingers: FREE for metacarpophalangeal and interphalangeal ROM exercises **Rationale for Long Arm Immobilization**: Prevents forearm rotation (pronation-supination) which creates torsional stress on scapholunate reconstruction. Short arm cast allows rotation and risks early failure. **Duration**: Long arm immobilization for 4 weeks, then transition to short arm cast for additional 4-8 weeks (total immobilization 8-12 weeks minimum). **Technical Tip**: EXAM KEY - 'I use LONG ARM immobilization for first 4 weeks because forearm rotation (pronation-supination) creates torsional stress on scapholunate reconstruction - short arm cast allows this rotation and risks failure. After 4 weeks, transition to short arm cast for 4-6 more weeks. Total casting 8-10 weeks minimum. K-wires remain during this entire period, protecting the healing capsulodesis. This extended immobilization is critical for success but will cause some stiffness requiring therapy later.' - Inadequate immobilization: Most common cause of reconstruction failure - ensure compliance - Short arm cast initially: Allows forearm rotation stressing repair - must use long arm - Prolonged immobilization: Necessary evil - causes stiffness but prevents failure - Cast complications: Monitor for pressure sores, compartment syndrome in early period ### Step 12: K-Wire Removal & Therapy Initiation At 8-12 weeks post-operatively, obtain radiographs to assess scapholunate alignment. **Radiographic Criteria for K-Wire Removal**: - Scapholunate interval maintained at less than 3mm on PA view - Scapholunate angle maintained at 30-60 degrees on lateral view - No loss of reduction or hardware failure - No signs of infection or complications **K-Wire Removal Technique**: - Typically performed in clinic or minor procedure room (not operating room) - Clean pin sites with chlorhexidine or betadine - Infiltrate local anesthetic (1% lidocaine) around each wire site - Use needle driver or wire removal pliers to grasp wire ends - Back out wires with gentle twisting and pulling motion - Remove scapholunate wires first, then scaphocapitate wire - Pin sites typically heal by secondary intention (small puncture wounds) - Apply sterile dressing, no sutures needed **Hand Therapy Initiation**: - Begin immediately after wire removal - Focus: Gentle ROM (active, active-assisted, gentle passive) - Wrist flexion-extension, radial-ulnar deviation, forearm rotation - NO strengthening initially - Removable wrist splint for protection between therapy sessions **Technical Tip**: EXAM KEY - 'K-wires removed at 8-12 weeks after confirming maintained reduction on radiographs. This is in-office procedure with local anesthetic - grasp wire ends with needle driver and back out with gentle rotation. Pin sites heal quickly without sutures. I start hand therapy immediately after wire removal for gentle ROM only - no strengthening until 12+ weeks. Extended immobilization causes stiffness, so early ROM important, but must wait for adequate healing time before removing wire protection.' - K-wire breakage during removal: If wire breaks, may need fluoroscopy to locate fragment, occasionally requires operative removal - Loss of reduction after wire removal: Indicates inadequate healing - may need revision surgery - Pin tract infection: Rare if good hygiene maintained - treat with oral antibiotics, earlier removal if needed ## References 1. Berger RA. The anatomy of the scapholunate ligament. *J Hand Surg Am*. 1996;21(1):70-76. doi:10.1016/S0363-5023(96)80158-7 2. Watson HK, Weinzweig J, Zeppieri J. The natural progression of scaphoid instability. *Hand Clin*. 1997;13(1):39-49. 3. Blatt G. Capsulodesis in reconstructive hand surgery. Dorsal capsulodesis for the unstable scaphoid and volar capsulodesis following excision of the distal ulna. *Hand Clin*. 1987;3(1):81-102. 4. Szabo RM, Slater RR Jr, Palumbo CF, Bassett RL. Dorsal intercarpal ligament capsulodesis for chronic, static scapholunate dissociation: clinical results. *J Hand Surg Am*. 2002;27(6):978-984. doi:10.1053/jhsu.2002.36525 5. Brunelli GA, Brunelli GR. A new surgical technique for carpal instability with scapho-lunar diastasis. *Ann Chir Main Memb Super*. 1995;14(4-5):207-213. doi:10.1016/s0753-9053(05)80285-1 6. Harvey EJ, Hanel DP, Knight JB, Tencer AF. Autograft replacements for the scapholunate ligament: a biomechanical comparison of hand-based autografts. *J Hand Surg Am*. 1999;24(5):963-967. doi:10.1053/jhsu.1999.0963 7. Weiss AP. Scapholunate ligament reconstruction using a bone-retinaculum-bone autograft. *J Hand Surg Am*. 1998;23(2):205-215. doi:10.1016/S0363-5023(98)80116-0 8. Garcia-Elias M, Lluch AL, Stanley JK. Three-ligament tenodesis for the treatment of scapholunate dissociation: indications and surgical technique. *J Hand Surg Am*. 2006;31(1):125-134. doi:10.1016/j.jhsa.2005.10.011 9. Chabas JF, Gay A, Valenti D, Guinard D, Legre R. Results of the modified Brunelli tenodesis for treatment of scapholunate instability: a retrospective study of 19 patients. *J Hand Surg Am*. 2008;33(9):1469-1477. doi:10.1016/j.jhsa.2008.05.028 10. Rosenwasser MP, Miyasajsa KC, Strauch RJ. The RASL procedure: reduction and association of the scaphoid and lunate using the Herbert screw. *Tech Hand Up Extrem Surg*. 1997;1(4):263-272. doi:10.1097/00130911-199712000-00007

Scapholunate Ligament Reconstruction - Dorsal Capsulodesis

Scapholunate Ligament Reconstruction - Dorsal Capsulodesis