import { OnePagerSummary, ExamWarning, InfoCardGrid, InfoCard, MnemonicCard, EvidenceCard, VivaScenarioSection, VivaScenario, ExamCheatSheet, ContentSection, ExamPearl, SafetyAlert, NumberHighlightRow, NumberHighlight, Tabs, Tab, ComparisonTable } from '@/components/mdx' **Infrapatellar branch of saphenous**. Location: Crosses anterior knee medially, can be injured with medial retraction. Injury = numb patch anterior knee (common, usually well-tolerated) **Arterial branches within tendon**. Location: 2-4cm proximal to patellar insertion, within tendon substance. Careful dissection, bipolar cautery. Bleeding obscures field **Articular surface deep to tendon**. Location: Visible when knee flexed. Risk with anchor placement too posterior or trans-osseous tunnel exit. Anchor 5mm from articular margin **Critical for patellar tracking**. Location: Medial patella border, oblique fibers. Must repair VMO insertion - failure causes lateral tracking and recurrent instability **Absolute Indications** - Complete quadriceps tendon rupture (inability to SLR or extend knee against gravity) - Partial rupture greater than 50% thickness with weak extension - Failed non-operative management of partial rupture - Bony avulsion of quadriceps tendon insertion **Relative Indications** - Partial rupture less than 50% with intact SLR (trial conservative first) - High-demand patient with partial tear wanting rapid return - Chronic rupture greater than 6 weeks (may need augmentation) **Timing** - Acute repair (less than 2-3 weeks) preferred - better tissue quality, easier repair - Acute repair (less than 6 weeks) still achievable with standard technique - Chronic repair (greater than 6 weeks) - expect retraction, scarring, may need augmentation or V-Y lengthening **Absolute Contraindications** - Active knee septic arthritis or soft tissue infection - Severe medical comorbidities precluding surgery - Patient unable to comply with postoperative immobilization **Relative Contraindications** - Uncontrolled diabetes (optimize HbA1c less than 8% if possible) - Active skin lesions over surgical site - Severe peripheral vascular disease - Morbid obesity (technical challenges, higher failure rate) - Dementia/non-compliance (bracing adherence critical) **Consider Augmentation in High-Risk Patients** - Diabetes mellitus (5x rupture risk, higher re-rupture) - Chronic kidney disease/dialysis (10x risk) - Chronic steroid use - Quinolone antibiotics (current or recent) - Gout - Previous local injection **Clinical Assessment** - Mechanism: eccentric quadriceps load (stumble, miss step) - often trivial in tendinopathy - Symptoms: sudden pop, immediate instability, unable to weight bear - Examination: suprapatellar gap (may be masked by hematoma), inability to SLR, inability to extend knee against gravity - Check contralateral side (5-10% bilateral) - Document neurovascular status **Imaging** - X-ray: lateral view shows PATELLA BAJA (Insall-Salvati less than 0.8), look for bony avulsion - Ultrasound: dynamic exam shows gap, loss of fibrillar pattern (operator dependent) - MRI: gold standard - confirms diagnosis, shows extent, assesses tissue quality (degenerative vs healthy) **Pre-operative Checklist** - Optimize diabetes (HbA1c target less than 8%) - Ensure adequate flexion for surgery (must achieve 90 degrees for tensioning) - Consent: 10-20% re-rupture risk, 15-30% mild extensor lag, 6-12 months recovery - Discuss rehabilitation compliance critical for success - Order hinged knee brace for postoperative use **Positioning** - Standard operating table - Bump under ipsilateral hip (neutral rotation) - Knee must flex freely to 90 degrees - test before draping - Sandbags available to maintain knee position during suturing - Thigh tourniquet **Implants** - Suture anchors: 3-4 anchors, 5.5mm or 6.5mm diameter - Each anchor loaded with 2 heavy sutures (#2 or #5 FiberWire/Ethibond) - Alternative: knotless anchors (SwiveLock, PushLock) - stronger fixation - Consider suture tape for augmentation in high-risk cases **Instruments** - Basic soft tissue set - Army-Navy or Langenbeck retractors - Allis clamps (for tendon traction) - Heavy needle drivers (for thick sutures) - Curved Mayo or Keith needles - Anchor insertion guide and drill - Bipolar cautery **Supplies** - Sterile tourniquet (thigh - 250-300mmHg) - Heavy braided suture (#2 Ethibond or #2 FiberWire) - 2-0 Vicryl for retinacular repair - Drain (10Fr Hemovac) - optional - Hinged knee brace or cylinder cast materials **Patient Position**: Supine with bump under ipsilateral hip for neutral leg rotation. Tourniquet on upper thigh (inflate to 250-300mmHg). Ensure knee can flex freely to at least 90 degrees - test before draping as this is essential for repair tensioning. **Anaesthesia**: General or spinal. Femoral nerve block provides good postoperative analgesia but delays quadriceps assessment. **Surgical Approach**: Anterior midline longitudinal approach over quadriceps tendon and superior patella **Surface Landmarks**: - Superior pole of patella - Quadriceps tendon (normally taut, will have palpable gap) - VMO bulge (medially) - Proximal extent of rupture (retracted tendon edge) ### Step 1: Incision and Exposure Midline longitudinal incision from 6-8cm proximal to superior pole of patella, extending to mid-patella (total 10-12cm). Incise through skin and subcutaneous tissue. Identify the rupture site - usually obvious with visible gap and hematoma. May need to extend proximally for chronic tears with retracted tendon. **Key Anatomy**: Most ruptures occur 1-2cm proximal to patellar insertion (watershed zone of hypovascularity). 30% are bony avulsions at insertion. Ruptures typically initiate medially at VMO insertion (weakest point) and propagate laterally. **EXAM KEY**: Midline incision gives best exposure and minimizes nerve injury. For chronic ruptures (greater than 6 weeks), extend proximally to mobilize retracted quadriceps. Identify torn retinacular edges which guide you to the injury. - Inadequate exposure hampers visualization of full tear extent - Incision too far medial risks saphenous nerve branches - Missing partial tears medially or laterally leads to incomplete repair ### Step 2: Hematoma Evacuation and Injury Assessment Evacuate hematoma with suction and copious irrigation. Systematically assess rupture pattern: - **Complete vs partial**: test each layer independently - **Location**: intrasubstance (1-2cm above patella) vs bony avulsion - **Chronicity**: acute (healthy tissue) vs chronic (degenerate, retracted) - **Layer involvement**: rectus (superficial), VMO/VL (intermediate), VI (deep) Gently retract patella distally with Langenbeck retractor to visualize proximal tendon edge. **EXAM KEY**: Complete rupture = discontinuity of ALL three quadriceps layers. Assess EACH LAYER independently. Partial tears often have intact intermediate layer (VMO/VL) maintaining some continuity and ability to SLR weakly. Chronic tears (greater than 6 weeks) have retraction, scarring, tissue degeneration - these need different approach. - Missing partial tear laterally (most tears begin medially and propagate) - Underestimating chronic changes (gap may be greater than expected) - Failure to assess tendon quality - degenerative tissue won't hold sutures ### Step 3: Proximal Tendon Preparation Identify proximal tendon stump - may be retracted significantly in chronic tears. Use Allis clamps to grasp tendon for traction. Debride frayed degenerative edges minimally (1-2mm) to create perpendicular edge, but preserve tendon length. Assess tendon excursion by pulling distally with knee at 30-40 degrees. **Tendon Quality Assessment**: Healthy tendon is white/pink, glistening, firm. Degenerative tendon is grey, friable, won't hold sutures (needs aggressive debridement or augmentation). Mark tendon layers with marking sutures to maintain orientation. **EXAM KEY**: Tendon QUALITY is critical predictor of success. Grey, friable tissue won't hold sutures - needs aggressive debridement or augmentation. For acute tears, minimal debridement. Test excursion by pulling tendon distally with knee at 30-40 degrees flexion - if excessive tension (can't approximate without force), may need proximal release or augmentation. - Excessive debridement reduces tendon length and increases repair tension - Inadequate debridement leaves degenerative tissue (repair failure) - Loss of layer orientation causes malrotation during repair ### Step 4: Patellar Bone Bed Preparation Use rongeur or curette to remove fibrous tissue and create bleeding bone surface on superior pole of patella (insertion site). Create flat 1-1.5cm width footprint from anterior to posterior cortex. Expose cortical bone but don't penetrate or weaken patella excessively. **Technical Goals**: Optimize biology for tendon-to-bone healing. Debride to 'bleeding bone' - punctate bleeding indicates healthy cortex. Mark proposed anchor positions before drilling. **EXAM KEY**: Goal is optimal tendon-to-bone healing environment. Remove ALL cartilage and fibrous tissue (impedes healing). Roughening with burr increases surface area. Avoid excessive bone removal (weakens patella, fracture risk). Create rectangular footprint matching tendon width. - Excessive bone removal weakens patella (fracture risk especially with osteoporosis) - Inadequate debridement (fibrous tissue) impairs healing - Violating articular surface posteriorly with aggressive preparation ### Step 5: Suture Anchor Placement Insert 3-4 suture anchors (5.5mm or 6.5mm) into superior pole of patella: - Position anchors in CORONAL plane, 5mm from articular surface - Space anchors 7-10mm apart transversely - Use anchor insertion guide, drill pilot hole - Insert anchor PERPENDICULAR to bone surface - Each anchor loaded with two heavy sutures (#2 or #5) - Confirm secure fixation - no articular penetration **Anchor Selection**: Knotless anchors (SwiveLock, PushLock) provide stronger fixation. Three anchors minimum for standard tear, four for large/chronic tears. **EXAM KEY**: Suture anchors are modern GOLD STANDARD - faster, biomechanically equivalent to trans-osseous tunnels, LESS patellar fracture risk (less than 2% vs 5-10% with tunnels). Position anchors 5mm from articular surface. Use knotless anchors if available - eliminates knot prominence and provides stronger fixation. - Anchor too posterior: articular penetration, chondral damage - Anchor too anterior: pullout from thin cortex - Anchor divergence: loss of fixation strength - Over-drilling/tapping pilot hole: anchor spins without purchase ### Step 6: Krackow Suture Placement in Tendon Pass anchor sutures through proximal tendon using locked KRACKOW technique: - Start at tendon edge - Pass from anterior to posterior - Lock by passing under previous throw - Repeat for 4-6 bites, extending 3-4cm from tendon edge - Each suture should engage ALL three layers (superficial, intermediate, deep) - Use curved Mayo or Keith needles **Alternative**: Mason-Allen horizontal mattress pattern with locking loop. **EXAM KEY**: Krackow (locked whipstitch) provides STRONGEST fixation - 4-6 points of fixation per suture with locking mechanism preventing pullout. Failure load approximately 300N. CRITICAL: engage ALL THREE layers, not just superficial rectus. Use heavy sutures (#2 minimum, #5 ideal). - Superficial sutures only (rectus layer): intermediate/deep layer failure - Too few bites (less than 4): inadequate fixation strength - Sutures too close to tendon edge: cheese-wiring and pullout - Unequal suture tension: eccentric force, tendon distortion ### Step 7: Repair Tensioning and Knot Tying **CRITICAL**: Position knee at 30-40 degrees flexion for tying. Pull sutures to advance tendon to patellar insertion site. Tie knots sequentially: 1. Central sutures first (establishes proper tension) 2. Medial sutures 3. Lateral sutures Use surgeon's knots (2-1-1 pattern) with 6-8 throws. Tension so tendon is snugly opposed to bone without excessive compression (allows 1-2mm tendon compression). **EXAM KEY**: Repair TENSION is the critical decision. Tie at 30-40 degrees flexion (position of maximum extensor force). If tied at 0 degrees, repair too loose at functional flexion. If tied at 90 degrees, too tight at extension. Goal: tendon snugly opposed throughout 0-90 degrees ROM. Test by passively flexing to 90 degrees after tying - should maintain approximation without gapping greater than 3mm. - Over-tightening: tendon necrosis, paradoxical gap formation - Under-tightening: gap at flexion, repair failure - Tying with knee extended: repair too loose at functional ROM - Unequal tension: eccentric forces cause lateral patellar tracking ### Step 8: Retinacular Repair Repair torn medial and lateral retinaculum with 2-0 braided absorbable suture (Vicryl) in interrupted figure-of-8 or simple pattern. Start at patellar insertion and work proximally. Ensure VMO insertion is secure. **Technique for Chronic Tears**: May need to mobilize adhesions and advance retinacular tissue. Consider imbrication (vest-over-pants overlap) for additional strength. **EXAM KEY**: Retinacular repair provides 30-40% additional strength to construct - ESSENTIAL, not optional. Most ruptures propagate through retinaculum. Repair BOTH medial and lateral sides. VMO insertion must be secure (critical for patellar tracking). For chronic tears with retraction, advance and imbricate tissue. - Inadequate retinacular repair: construct weakness, increased failure risk - Over-tight retinacular repair: limits ROM, causes patellar tilt - Missing lateral retinacular tear (tears propagate medial-to-lateral) ### Step 9: Augmentation (High-Risk Patients) For high-risk patients consider augmentation: - **Suture tape** (InternalBrace, FiberTape): load anchor with repair sutures AND tape, pass tape superficial to repair, anchor distally - increases failure load 40-60% - **Autograft** (semitendinosus): weave through repair - **Allograft** (Achilles or fascia lata): overlay **Indications for Augmentation**: Chronic rupture greater than 6 weeks, revision repair, poor tissue quality, high-risk patients (diabetes, CKD, steroids). **EXAM KEY**: Augmentation indicated for: (1) Chronic rupture greater than 6 weeks with tissue degeneration, (2) Revision after failed primary, (3) High-risk patients, (4) Poor tissue quality intraoperatively, (5) Repair under high tension. Suture tape technique increases failure load by 40-60% in biomechanical studies. - Over-reliance on augmentation to compensate for poor primary repair technique - Suture tape irritation if placed too superficially (may need removal) - Allograft: disease transmission risk (rare), delayed incorporation ### Step 10: Intraoperative Stability Assessment Release tourniquet. Test repair: 1. **Full extension**: ensure no extensor lag (passively extend knee fully without lifting thigh) 2. **Flexion test**: GENTLY flex knee passively to 90 degrees - Repair should remain intact without gapping - Feel for loss of resistance (indicates failure) - If gaps greater than 3mm at 90 degrees - repair too loose, re-tension Document maximum safe flexion angle achieved for postoperative physiotherapy. **EXAM KEY**: This is the PROOF of adequate repair. Under anaesthesia: passively extend knee fully (tests for lag). Then flex smoothly to 90 degrees - should feel firm resistance throughout arc. Sudden loss of resistance or visible gapping = repair failure requiring revision. Document safe flexion range for PT protocol. - Forced flexion beyond repair capacity causes intraoperative failure - Missing subtle gapping (becomes extensor lag postoperatively) - Testing beyond 90 degrees in borderline repairs: unnecessary risk ### Step 11: Closure and Hemostasis Achieve meticulous hemostasis with bipolar cautery. Close paratenon with 3-0 absorbable suture (provides smooth gliding surface). Consider 10Fr drain if concern for hematoma. Close subcutaneous layer with 2-0 absorbable suture. Skin closure with staples or 3-0 nylon. **EXAM KEY**: Paratenon closure often forgotten but improves gliding and cosmesis. Drain optional but helpful for 24 hours to prevent hematoma (increases infection risk and adhesions). Meticulous hemostasis essential - inflate/deflate tourniquet to identify bleeders before closure. - Hematoma: increased infection risk (2-5%), adhesions, stiffness - Tight closure: skin necrosis, wound breakdown - Drain placed anteriorly: erosion through thin skin ### Step 12: Immobilization Apply sterile dressing. Place knee in hinged brace or cylinder cast LOCKED in FULL EXTENSION (0 degrees). This is MANDATORY. **Postoperative Protocol**: - Brace locked at 0 degrees for 4 weeks - Non-weight bearing with crutches - Isometric quadriceps sets from day 1-2 - Weeks 4-6: unlock to 30 degrees for supervised PT, re-lock for ambulation - Weeks 6-8: progress to 60 degrees - Weeks 8-12: progress to 90 degrees, start partial weight bearing - Active flexion after 12 weeks - Full ROM by 16-20 weeks - Return to sport: 6-9 months minimum **EXAM KEY**: Extension immobilization is MANDATORY - prevents load on repair during early healing. Options: hinged brace (preferred - allows wound checks) or cylinder cast (more secure). Continue locked extension for 4-6 weeks, then progressive ROM. NWB minimum 6 weeks. Expect 6-12 months for full recovery. - No immobilization: repair failure (nearly certain) - Flexion immobilization: permanent flexion contracture - Over-tight dressing: compartment syndrome risk - Early unrestricted ROM: repair failure (10-20%) 1. Ciriello V, Gudipati S, Tosounidis T, et al. Clinical outcomes after repair of quadriceps tendon rupture: a systematic review. *Injury*. 2012;43(11):1931-1938. 2. Saragaglia D, Pison A, Rubens-Duval B. Acute and old ruptures of the extensor apparatus of the knee in adults (excluding knee replacement). *Orthop Traumatol Surg Res*. 2013;99(1 Suppl):S67-76. 3. Konrath GA, Chen D, Lock T, et al. Outcomes following repair of quadriceps tendon ruptures. *J Orthop Trauma*. 1998;12(4):273-279. 4. Ramseier LE, Werner CM, Heinzelmann M. Quadriceps and patellar tendon rupture. *Injury*. 2006;37(6):516-519. 5. Lighthart WA, Cohen DA, Levine RG, Parks BG, Boucher HR. Suture anchor versus suture through tunnel fixation for quadriceps tendon rupture: a biomechanical study. *Orthopedics*. 2008;31(5):441. 6. Hart ND, Wallace MK, Scovell JF, Krupp RJ, Cook C, Wyland DJ. Quadriceps tendon rupture: a biomechanical comparison of transosseous equivalent double-row suture anchor versus transosseous tunnel repair. *J Knee Surg*. 2012;25(4):335-339. 7. Boudissa M, Roudet A, Rubens-Duval B, Chaussard C, Saragaglia D. Acute quadriceps tendon ruptures: a series of 50 knees with an average follow-up of more than 6 years. *Orthop Traumatol Surg Res*. 2014;100(2):213-216. 8. Ilan DI, Tejwani N, Keschner M, Leibman M. Quadriceps tendon rupture. *J Am Acad Orthop Surg*. 2003;11(3):192-200. 9. Swamy GN, Nanjayan SK, Yallappa S, Bishnoi A, Pickering SA. Is ultrasound diagnosis reliable in acute extensor tendon injuries of the knee? *Acta Orthop Belg*. 2012;78(6):764-770. 10. Yepes H, Tang M, Morris SF, Stanish WD. Relationship between hypovascular zones and patterns of ruptures of the quadriceps tendon. *J Bone Joint Surg Am*. 2008;90(10):2135-2141.

Primary Quadriceps Tendon Repair with Suture Anchor Technique

Primary Quadriceps Tendon Repair with Suture Anchor Technique