import { OnePagerSummary, ExamWarning, InfoCardGrid, InfoCard, MnemonicCard, EvidenceCard, VivaScenarioSection, VivaScenario, ExamCheatSheet, ContentSection, ExamPearl, SafetyAlert, NumberHighlightRow, NumberHighlight, Tabs, Tab, ComparisonTable } from '@/components/mdx' **Most commonly injured nerve**. Location: Terminal branch of musculocutaneous, crosses antecubital fossa superficially - identify and protect in subcutaneous tissue **Protected by SUPINATION**. Location: Crosses radial neck in pronation - full supination rotates tuberosity anteriorly and moves PIN posterolaterally away from surgical field **Medial in antecubital fossa**. Location: Lies medial to biceps tendon in antecubital fossa - retract medially during exposure **Travels with radial artery**. Location: Runs with radial artery, then branches laterally - can be injured with aggressive lateral retraction **Absolute Indications for Surgery:** - Complete distal biceps tendon rupture - Active patient requiring full supination/flexion strength - Acute rupture (<4 weeks optimal timing) - Failed non-operative treatment (partial tears) **Relative Indications:** - Partial tears (>50%) failing conservative treatment - High-demand athletes or manual workers - Chronic rupture in active patient (may need graft) **Non-Operative Consideration:** - Elderly, sedentary patients accepting strength loss - Significant comorbidities increasing surgical risk - Low-demand patients who accept 30-40% supination weakness **Absolute:** - Active infection - Unable to comply with rehabilitation **Relative:** - Chronic rupture (>6-8 weeks) with significant retraction (may need graft) - Very elderly, sedentary patient - Significant comorbidities (uncontrolled diabetes, vascular disease) - Smoker (relative - higher complication rate) **Two-Incision Contraindications:** - Prior ulnar fracture or hardware - Heterotopic ossification history - Synostosis risk factors **Clinical Examination:** - Hook test (Ruland): Most specific - cannot hook finger under intact tendon - Biceps squeeze test: No passive supination when muscle squeezed - Supination strength testing (compare to contralateral) - Palpable defect in antecubital fossa - Proximal muscle belly retraction **Imaging:** - X-ray: Rule out avulsion fracture (rare) - MRI: Confirm complete vs partial, measure retraction, assess tendon quality - Ultrasound: Dynamic assessment, can see retraction with flexion **Timing Considerations:** - Acute (<4 weeks): Primary repair usually possible - Subacute (4-8 weeks): May need more dissection, tendon shortening - Chronic (>8 weeks): Often need graft reconstruction (Achilles allograft) **Counseling:** - Discuss approach options (single vs two incision) - Complications: nerve injury, HO, synostosis, re-rupture - Expected outcomes: 95%+ good/excellent for acute repairs **Essential:** - Forearm tourniquet or arm tourniquet - Marking pen - Small self-retaining retractor (Weitlaner) - Army-Navy retractors - Rongeur or burr for tuberosity preparation **Fixation Options:** - Cortical button system (EndoButton, BicepsButton) - Cannulated drill system for button - Suture anchors (alternative) - Interference screw (alternative) **Suture:** - High-strength suture (FiberWire, FiberLoop) - Whipstitch needle - Passing sutures **Recommended:** - Fluoroscopy (optional - button position) - Nerve stimulator (if revision or complex) ### Biceps Tendon Anatomy **Insertion:** - Radial tuberosity (ulnar aspect) - Footprint approximately 22mm × 11mm - Short head inserts more distally - Long head inserts more proximally on tuberosity **Function:** - Primary supinator of forearm (most powerful) - Secondary elbow flexor - Loss of biceps = 30-40% supination strength loss, 10-20% flexion loss ### Key Neurovascular Relationships **Lateral Antebrachial Cutaneous Nerve (LABCN):** - Terminal branch of musculocutaneous nerve - Emerges lateral to biceps in distal arm - Crosses antecubital fossa superficially - Most commonly injured nerve in distal biceps repair **Posterior Interosseous Nerve (PIN):** - Branch of radial nerve - Crosses radial neck in pronation - **SUPINATION protects PIN** - moves tuberosity anteriorly, PIN posterolaterally - Danger zone with two-incision technique **Radial Recurrent Artery:** - Leash of vessels near radial tuberosity - Must be cauterized for exposure ### Step 1: Patient Positioning **Position:** - Supine on operating table - Arm on arm board, supinated - Arm tourniquet (upper arm) or forearm tourniquet - Elbow extended or slightly flexed **Technical Tip**: Forearm tourniquet allows assessment of tendon excursion if needed. Arm tourniquet provides bloodless field throughout. ### Step 2: Skin Incision **Single anterior (Boyd-Anderson modified):** - Transverse or oblique incision in antecubital fossa - Approximately 3-4cm, centered over biceps tendon - Can extend proximally if tendon retracted - Transverse incision follows Langer's lines (better cosmesis) - Stay lateral to brachial artery pulse - Avoid crossing flexion crease (risk of contracture) - May need second proximal incision if tendon very retracted ### Step 3: Superficial Dissection **Identify and protect LABCN:** - LABCN crosses antecubital fossa superficially - Emerges lateral to biceps, runs medially - MOST COMMON nerve injury - identify early - Retract and protect throughout **Develop interval:** - Between brachioradialis (lateral) and pronator teres (medial) - Identify radial artery - retract medially - Biceps tendon stump visible in this interval **Technical Tip**: If you don't see LABCN, you haven't looked hard enough. It crosses the field in almost all patients - identify and protect it before deep dissection. ### Step 4: Tendon Retrieval **Locate and retrieve biceps tendon:** - Usually retracted to antecubital crease or above - May need proximal incision if significantly retracted - Use finger dissection to free tendon from adhesions - Deliver tendon through distal wound **Tendon preparation:** - Debride frayed end minimally (preserve length) - Whipstitch with high-strength suture (FiberWire) - Krackow or locking whipstitch pattern - Leave suture tails for button passage - If tendon won't reach tuberosity without tension, consider: - More extensive release of lacertus fibrosus - Graft reconstruction (Achilles allograft) - Do NOT repair under excessive tension ### Step 5: Expose Radial Tuberosity **Position forearm:** - **FULL SUPINATION** - critical for PIN protection - Supination rotates tuberosity anteriorly - Moves PIN to posterolateral, away from surgical field **Clear tuberosity:** - Identify radial tuberosity on anteromedial radius - Clear soft tissue from tuberosity footprint - Cauterize radial recurrent vessels (leash of Henry) - Visualize entire footprint **Technical Tip**: SUPINATION is the key safety maneuver. The PIN wraps around the radial neck in pronation - full supination moves it away from your instruments by rotating the tuberosity anteriorly. ### Step 6: Prepare Tuberosity **For cortical button fixation:** - Place guide pin at center of tuberosity footprint - Confirm position with image if desired - Drill unicortical with appropriately sized cannulated drill - Complete drilling through far cortex - Ensure button will pass and flip **Socket preparation (optional):** - Create unicortical socket at tuberosity to seat tendon - Improves bone-tendon contact - Do not make socket too deep (weakens bone) - Keep forearm SUPINATED during drilling - Drill perpendicular to radius - Protect soft tissues with retractors - Do not plunge through far cortex aggressively ### Step 7: Button Passage and Fixation **Thread button:** - Pass tendon sutures through button eyelet - Insert button into drill hole - Push through to far cortex - Flip button by pulling on sutures (feel "pop") **Confirm button engagement:** - Tug on sutures - should feel solid - Fluoroscopy if any doubt - Button should be flush on far cortex **Technical Tip**: The "pop" when the button flips is reassuring. If you don't feel it, image to confirm the button is through and flipped. An unflipped button will pull out. ### Step 8: Tendon Docking and Tensioning **Dock tendon into socket:** - Pull tendon into tuberosity socket - Tension with elbow at 30-40° flexion, forearm supinated - Tendon should reach tuberosity without excessive tension **Assess tension:** - Should allow full elbow extension without gap - Should not create flexion contracture - Check pronation/supination ROM - Over-tensioning = flexion contracture, limited extension - Under-tensioning = weakness, incomplete healing - Target: full extension possible with tendon engaged ### Step 9: ROM Check and Hemostasis **Intraoperative testing:** - Full elbow extension - tendon should remain docked - Full flexion - no impingement - Full pronation and supination - smooth, no catching **Hemostasis:** - Release tourniquet - Bipolar cautery for bleeding points - Ensure no hematoma formation ### Step 10: Closure **Layered closure:** - Close deep fascia if possible (not tight) - Subcutaneous absorbable sutures - Skin closure (nylon or absorbable) - Sterile dressing **Immobilization:** - Posterior splint at 90° elbow flexion - Forearm in neutral to slight supination - Early motion protocol starts 1-2 weeks ### Indications for Two-Incision Approach **Consider when:** - Anatomic footprint restoration desired - Chronic rupture requiring extensive exposure - Revision surgery - Surgeon preference/training ### Technique Differences **Anterior incision:** - Same as single incision for tendon retrieval - Smaller incision may be used **Posterior incision (muscle-splitting):** - Made over posterior radius, lateral to ulna - Split common extensor muscles - Expose radial tuberosity from posterior - Creates bone tunnels or uses suture anchors ### Heterotopic Ossification Risk **Higher with two-incision technique:** - Reported in 15-50% of cases - Usually asymptomatic - Can cause significant stiffness or synostosis - Modified technique (muscle splitting vs subperiosteal) reduces risk **Exam Key**: Cortical button provides the strongest fixation (~250N ultimate strength), allowing earlier and more aggressive rehabilitation. It is now the preferred fixation method for most surgeons. ### Nerve Injury Details **LABCN (most common):** - Incidence: 10-25% transient, 1-5% permanent - Causes lateral forearm numbness - Usually resolves with observation - Prevention: identify early, protect carefully **PIN:** - Incidence: 1-3% - Causes finger extension weakness - SUPINATION is protective - Most recover with observation ### Immediate Post-operative **Immobilization:** - Posterior splint at 90° elbow flexion - Forearm in neutral to slight supination - Duration: 1-2 weeks ### Early Rehabilitation (Weeks 1-6) **Week 1-2:** - Splint immobilization - Finger and wrist ROM - Gentle elbow ROM out of splint (passive extension, active flexion) **Week 2-4:** - Remove splint - Progressive active ROM - Avoid terminal extension (limit to -30°) - NO resisted supination **Week 4-6:** - Progress to full ROM - Gentle active supination - Light ADLs ### Intermediate Rehabilitation (Weeks 6-12) **Week 6-8:** - Begin isometric strengthening - Light resisted supination - Progress ROM **Week 8-12:** - Progressive resistance training - Concentric then eccentric loading - Sport-specific activities begin ### Return to Activity - Light desk work: 2-4 weeks - Light manual work: 6-8 weeks - Heavy manual work: 12-16 weeks - Full sports: 4-6 months - Expected outcomes: 95%+ satisfaction, near-normal strength flexion", "Ecchymosis and palpable defect antecubital fossa" ] }, { heading: "Critical Technical Points", points: [ "SUPINATION protects PIN - maintain throughout tuberosity work", "Identify LABCN early - most commonly injured nerve", "Cortical button = strongest fixation (~250N)", "Tension at 30-40° flexion - should allow full extension" ] }, { heading: "Danger Structures", points: [ "LABCN - superficial, crosses field, most common injury", "PIN - protected by supination, at risk in pronation", "Radial artery - retract medially", "Radial recurrent vessels (leash of Henry) - cauterize" ] }, { heading: "Timing Considerations", points: [ "Acute (<4 weeks): Primary repair - best outcomes", "Subacute (4-8 weeks): More dissection needed, possible shortening", "Chronic (>8 weeks): Often requires graft reconstruction" ] }, { heading: "Single vs Two Incision", points: [ "Single: Lower HO/synostosis risk, preferred by most", "Two-incision: More anatomic footprint, higher HO risk", "Both have similar functional outcomes", "Modified muscle-splitting reduces HO in two-incision" ] }, { heading: "Exam Tips", points: [ "Hook test is most specific clinical sign", "Untreated = 30-40% supination loss, 10-20% flexion loss", "SUPINATION is the key safety maneuver - know why", "Button > anchor > screw > tunnel for fixation strength" ] } ]} /> 1. Grewal R, et al. Single versus double-incision technique for the repair of acute distal biceps tendon ruptures: A randomized clinical trial. J Bone Joint Surg Am. 2012;94(13):1166-1174. 2. Recordon JA, et al. Repair of acute distal biceps tendon ruptures using cortical button vs interference screw fixation: A randomized controlled trial. J Shoulder Elbow Surg. 2015;24(3):e57-e62. 3. Chavan PR, et al. Repair of the ruptured distal biceps tendon: A systematic review. Am J Sports Med. 2008;36(8):1618-1624. 4. Kodde IF, et al. Distal biceps repair: A systematic review of reoperation and re-rupture rates. J Shoulder Elbow Surg. 2018;27(8):1455-1463. 5. Bain GI, et al. Repair of distal biceps tendon rupture: A new technique using the Endobutton. J Shoulder Elbow Surg. 2000;9(2):120-126. 6. Kelly EW, et al. Complications of repair of the distal biceps tendon with the modified two-incision technique. J Bone Joint Surg Am. 2000;82(11):1575-1581. 7. Dunphy TR, et al. Surgical treatment of distal biceps tendon ruptures: An anatomic and clinical review. J Shoulder Elbow Surg. 2017;26(12):2172-2180. 8. Schmidt CC, et al. The role of supination in distal biceps tendon repair. J Shoulder Elbow Surg. 2015;24(7):1093-1098. 9. O'Driscoll SW, et al. The clinical anatomy of the biceps tendon insertion. J Shoulder Elbow Surg. 2007;16(5):e6-e11. 10. Nesterenko S, et al. Distal biceps tendon repair: Clinical outcomes of surgical treatment. J Shoulder Elbow Surg. 2010;19(2 Suppl):2-8.

Distal Biceps Tendon Repair

Distal Biceps Tendon Repair