import { OnePagerSummary, ExamWarning, InfoCardGrid, InfoCard, MnemonicCard, EvidenceCard, VivaScenarioSection, VivaScenario, ExamCheatSheet, ContentSection, ExamPearl, SafetyAlert, NumberHighlightRow, NumberHighlight, Tabs, Tab, ComparisonTable } from '@/components/mdx' **Location**: Crosses medial aspect of patellar tendon obliquely 1-2cm below inferior pole of patella, runs superficially in subcutaneous tissue **Protection**: Use vertical midline incision (not medial parapatellar which transects nerve). Accept universal numbness of anterolateral knee as unavoidable with any approach **Location**: Vascular ring formed by superior and inferior geniculate arteries surrounds patella in periosteum and attached capsular tissue **Protection**: Minimize periosteal stripping during bone plug harvest - use saw for precise cuts. Maintain paratenon coverage. Excessive stripping risks patellar AVN (rare but reported) **Location**: Remaining medial and lateral portions of patellar tendon after central third harvest - must be minimum 5mm width each side (ideally 7-8mm) **Protection**: Precisely measure and mark central third (10mm width maximum). Use ruler to ensure adequate remnants. Inadequate remnants increase rupture risk 5-10 fold (baseline 0.5-1%) **Location**: Secondary ossification center at tibial tuberosity - fuses to proximal tibia at age 15-17 years in males, 13-15 years in females **Protection**: In adolescents, palpate and visualize apophyseal line on fluoroscopy/radiographs. Harvest tibial bone plug proximal to apophysis avoiding cartilaginous junction to prevent avulsion injury **Location**: Runs from medial femoral condyle to posterior tibial plateau - positioned immediately posterior to ACL footprint and intercondylar notch **Protection**: During notch debridement, stay anterior and preserve posterior ACL remnant fibers as barrier. During tibial tunnel drilling, avoid posterior malposition >7mm behind anterior tibial spine which risks PCL perforation **Patient Position**: Supine with commercial leg holder (or lateral thigh post) allowing full ROM. Tourniquet on thigh (optional - I prefer not to use routinely). Ensure full passive extension to 0° and flexion >120°. Hip flexed 30-45°. Contralateral leg in stirrup or abducted on leg rest. **Surgical Approach**: Arthroscopic via anterolateral viewing and anteromedial working portals. Central midline incision over patellar tendon for BTB harvest (can use small medial parapatellar incision alternatively). **Incision**: Portal incisions: 5mm stab incisions at joint line - anterolateral 1cm lateral to patellar tendon, anteromedial adjacent to medial patellar tendon border. BTB harvest: 6-8cm vertical midline incision from inferior pole of patella to tibial tubercle, centered over patellar tendon. ## BTB Graft Classification Systems ### Graft Harvest Techniques **Patellar Tendon Width Classification** - **Central Third (Standard)**: 10mm width from central patellar tendon - **Narrowed Graft**: 8mm width for smaller patients or wider remnant preservation - **Medial Third**: Alternative harvest from medial portion (preserves lateral for future surgery) **Bone Plug Harvest Methods** - **Oscillating Saw Technique**: Precise cuts, minimal fracture risk, preferred method - **Osteotome Technique**: Risk of fracture propagation, outdated - **Trephine Technique**: Cylindrical plugs, risk of plug divergence ### Tunnel Drilling Approaches **Femoral Tunnel Techniques** - **Transtibial**: Through tibial tunnel at 90° flexion - results in non-anatomic high anterior tunnel position - **Trans-Anteromedial Portal (Preferred)**: Independent drilling at 110-120° flexion - achieves anatomic footprint position - **Outside-In**: Through lateral femoral cortex - technically demanding, risk of divergence - **All-Inside**: Suspensory fixation, no cortical breach - allows bone plug retention but loses bone-to-bone healing **Tibial Tunnel Techniques** - **Standard Transtibial**: 55° angle via anteromedial approach - standard technique - **Two-Incision**: Separate anterior incision for guide placement - outdated - **All-Inside**: Retrograde drilling - preserves tibial cortex for future revision ### Fixation Method Classification **Femoral Fixation Options** - **Interference Screw (Preferred for BTB)**: Metal or bioabsorbable, 7-9mm diameter, highest pullout strength >1000N - **Cross-Pin Fixation**: TransFix or RigidFix devices - more complex, no clear advantage - **Cortical Button with Post**: RetroButton or Endobutton - for suspensory backup fixation - **Hybrid Fixation**: Interference screw plus cortical backup - belt-and-suspenders approach **Tibial Fixation Options** - **Interference Screw (Preferred)**: 7-9mm diameter, 20-25mm length, placed parallel to bone plug - **Post and Washer**: Screw with spiked washer over cortical surface - backup fixation - **Staple Fixation**: Historical method, outdated due to loosening ## Evidence-Based Graft Selection ### BTB vs Hamstring Autograft - Meta-Analysis Data **Failure Rates (Equivalent)** - BTB: 5-10% failure rate at 5-10 years - Hamstring: 5-10% failure rate at 5-10 years - No significant difference in multiple meta-analyses (>20 studies, >5000 patients) **Stability Outcomes (Equivalent)** - Lachman test positive: BTB 5-10%, Hamstring 5-10% - Pivot shift positive: BTB 5-8%, Hamstring 5-10% - Side-to-side difference >3mm: BTB 8-12%, Hamstring 10-15% - Both restore stability equally well **Return to Sport (Slight BTB Advantage)** - BTB: 80-85% return to pre-injury level at 9-12 months - Hamstring: 75-80% return to pre-injury level at 9-12 months - BTB may allow 4-6 weeks earlier RTS due to faster bone healing (controversial) **Donor Site Morbidity (BTB Disadvantage)** - Anterior knee pain: BTB 20-30%, Hamstring 10-15% (significant difference) - Kneeling pain: BTB 30-40%, Hamstring 10-15% (significant difference) - Subjective knee scores: Slightly favor hamstring in some studies ### Patient-Specific Selection Criteria **Prefer BTB Autograft** - High-demand collision athletes (rugby, AFL, NFL, hockey) - Military, law enforcement, firefighters - Revision ACL reconstruction (bone-to-bone healing advantage) - Multi-ligamentous knee injury requiring strong fixation - Patient preference for "gold standard" with longest data - Concurrent bony procedures (high tibial osteotomy, meniscal transplant) **Prefer Hamstring Autograft** - Occupations requiring kneeling (carpet layers, plumbers, tilers) - Patients prioritizing cosmesis (smaller incision, less scarring) - Smaller patients or adolescents (relative patellar tendon size) - Patients with anterior knee pain or patellofemoral symptoms - Patellar tendinopathy or patellar tendon concerns **Prefer Quadriceps Autograft (Emerging)** - Compromise option combining advantages of both - Larger graft diameter (typically 9-11mm) - Lower donor site morbidity than BTB - Faster bone healing than hamstring if bone block used - Revision surgery or salvage cases ## Patellar Tendon Anatomy ### Macroscopic Structure **Dimensions** - Length: 40-50mm from inferior pole of patella to tibial tubercle - Width: 25-35mm at midsubstance (central third = 8-12mm) - Thickness: 4-6mm at midsubstance - Cross-sectional area: 100-150mm² **Attachments** - Proximal: Inferior pole of patella (entire width) - Distal: Tibial tubercle (entire width) - Lateral: Medial and lateral retinacula and patellar fascia **Vascular Supply** - Inferior pole of patella: Extraosseous anastomotic ring from superior and inferior geniculate arteries - Patellar tendon midsubstance: Paratenon vessels from infrapatellar fat pad - Tibial tubercle: Periosteal vessels from recurrent anterior tibial artery **Nerve Supply** - Infrapatellar branch of saphenous nerve: Crosses medially 1-2cm below inferior pole - universal injury with harvest causing anterolateral knee numbness - Proprioceptive fibers from joint capsule ### Microscopic Structure **Collagen Architecture** - Type I collagen: 70-80% dry weight, organized in longitudinal parallel bundles - Type III collagen: 5-10%, increases with degeneration - Crimp pattern: Wavy configuration at rest, straightens with tension - Cross-linking: Pyridinoline and deoxypyridinoline provide tensile strength **Cellular Components** - Tenocytes: Specialized fibroblasts aligned between collagen bundles - Sparse cellularity compared to other tissues (1-5% by volume) **Biomechanical Properties** - Ultimate tensile strength: 2900-3500N for entire tendon - Central third (10mm): 2200-2600N tensile strength - Elastic modulus: 600-800 MPa - Failure mode: Typically bone plug avulsion rather than midsubstance rupture ## ACL Footprint Anatomy ### Femoral Footprint **Location** - Lateral wall of medial femoral condyle - Posterior to Blumensaat's line - Clock position: 10:30 (right knee) or 1:30 (left knee) for AM bundle center **Dimensions** - Total footprint: 18-22mm anteroposterior, 8-12mm superoinferior - Anteromedial (AM) bundle: Superior and anterior, 8-10mm diameter - Posterolateral (PL) bundle: Inferior and posterior, 6-8mm diameter **Landmarks** - Resident's ridge: Lateral intercondylar ridge marking anterior boundary - Bifurcate ridge: Ridge between AM and PL bundles - Over-the-top position: Posterior margin where cortex curves ### Tibial Footprint **Location** - Anterior to tibial spines (intercondylar eminence) - Just anterior to anterior horn of lateral meniscus - Lateral to medial tibial spine **Dimensions** - Total footprint: 14-18mm anteroposterior, 10-14mm mediolateral - AM bundle: Anteromedial, 8-10mm diameter - PL bundle: Posterolateral, 6-8mm diameter **Landmarks** - Anterior tibial spine (medial and lateral prominences) - Anterior horn lateral meniscus attachment - PCL anterior edge (posterior boundary) ## Intercondylar Notch Anatomy ### Bony Boundaries **Medial Wall**: Medial femoral condyle lateral surface **Lateral Wall**: Lateral aspect of medial femoral condyle (ACL femoral footprint) **Roof**: Blumensaat's line - extension of femoral shaft to intercondylar notch **Floor**: Tibial plateau intercondylar region ### Soft Tissue Contents **Ligaments** - ACL: Anteromedial and posterolateral bundles - PCL: Anterior and posterior bundles (stronger, twice ACL diameter) **Vascular Structures** - Middle geniculate artery: Enters posteriorly, supplies cruciate ligaments - Terminal branches from medial and lateral inferior geniculate arteries **Neural Structures** - Proprioceptive nerve endings: Mechanoreceptors and nociceptors throughout ligament substance - Minimal nerve supply compared to capsule ### Notch Width Index **Measurement**: Notch width at joint line / bicondylar width **Normal**: 0.25-0.30 **Stenotic Notch**: <0.20 - historical association with increased ACL injury risk (controversial) ## Femoral Tunnel Drilling Techniques ### Transtibial Technique (Historical Standard) **Methodology** - Drill femoral tunnel through previously drilled tibial tunnel - Knee flexed to 90° for drilling - Limited by tibial tunnel position - constrains femoral tunnel to anterior and vertical position **Advantages** - Single portal technique - technically simpler - No additional portal for drilling - Shorter learning curve **Disadvantages** - Non-anatomic femoral tunnel position (high and anterior, ~11:00 or 1:00 position) - Vertical graft orientation - fails to restore rotational stability optimally - Higher failure rates in some studies (10-15% vs 5-10% for anatomic) - Less effective pivot shift control **Current Status**: Largely abandoned in favor of anatomic techniques ### Trans-Anteromedial Portal Technique (Current Gold Standard) **Methodology** - Independent femoral tunnel drilling through anteromedial portal - Knee hyperflexed to 110-120° (critical for visualization and access) - Direct visualization of footprint with 70° or 30° arthroscope - Target center of anatomic femoral footprint (10:30/1:30 position) **Advantages** - Anatomic femoral tunnel position - Horizontal graft orientation - better rotational stability - Independent of tibial tunnel position - Superior pivot shift control - Lower failure rates in registry data (5-8%) **Disadvantages** - More technically demanding - steeper learning curve - Requires knee hyperflexion to 110-120° (some patients limited) - Risk of posterior wall blowout if technique incorrect - Potential for cartilage damage from guide or reamer **Technical Pearls** - Use 70° or 30° arthroscope for better visualization at high flexion - Accessory anteromedial portal if needed (lower and more medial) - Flexible reamers to navigate acute angle - Confirm 2mm posterior wall with depth gauge before proceeding ### Outside-In Technique **Methodology** - Drill from lateral femoral cortex through joint to femoral footprint - Start point 2-3cm proximal and anterior to lateral epicondyle - Direct visualization of footprint, retrograde drilling **Advantages** - Excellent control of intra-articular tunnel position - Easy to achieve anatomic footprint - No risk of posterior wall blowout **Disadvantages** - Technically demanding - requires precise guide placement - Risk of iliotibial band or vastus lateralis damage at entry point - Difficult tunnel-graft-tunnel angle with BTB bone plugs - Requires two incisions (lateral thigh and arthroscopic portals) **Current Status**: Used by some surgeons, not mainstream ### All-Inside Technique **Methodology** - Retrograde reaming of femoral socket (not full tunnel) - Suspensory cortical fixation (button) - Avoids cortical perforation - Shorter "socket" rather than full tunnel **Advantages** - Preserves lateral femoral cortex for future revision - Lower risk of posterior wall blowout - Allows very anatomic footprint placement **Disadvantages** - Suspensory fixation required - loses bone-to-bone healing advantage of BTB - More expensive implants (adjustable loop devices) - Technically demanding - Not typically used for BTB (better suited to soft tissue grafts) ## Tibial Tunnel Drilling Variations ### Standard Anteromedial Approach (Preferred) **Methodology** - Tibial ACL guide at 55° angle relative to tibial shaft - Intra-articular target: Center of tibial ACL footprint - Extra-articular entry: 3-4cm distal to joint line, 2-3cm medial to tibial tubercle **Advantages** - Reproducible technique with clear landmarks - Entry point through patellar tendon harvest site (no additional incision) - Appropriate tunnel angle and length **Disadvantages** - Fixed angle may not suit all tibial slope variations - Entry point through harvest site (theoretical healing concerns) ### Two-Incision Technique (Historical) **Methodology** - Separate 2-3cm incision anteromedially for guide placement - Independent of harvest incision **Advantages** - Avoids harvest site for tunnel - Better control of entry point **Disadvantages** - Additional incision (cosmesis, morbidity) - No proven clinical advantage - Largely abandoned ### All-Inside Tibial Technique **Methodology** - Retrograde tibial socket creation - Preserves anterior tibial cortex **Advantages** - Preserves cortex for future revision surgery - No prominence or pain from hardware at tibial exit **Disadvantages** - Suspensory fixation required (loses BTB advantage) - More expensive implants - Not typically used for BTB grafts ## Fixation Technique Variations ### Interference Screw Materials **Metal Screws (Titanium)** - **Advantages**: Highest strength, proven longevity, lower cost, no degradation concerns - **Disadvantages**: MRI artifact (limits imaging), hardware removal if symptomatic (5-10%), no biologic incorporation - **Indications**: Preferred by some surgeons for revision cases or high-demand athletes **Bioabsorbable Screws (PLLA, PLGA)** - **Advantages**: No MRI artifact, no removal needed, gradual load transfer to healing bone - **Disadvantages**: Cyst formation (5-10% - usually asymptomatic), tunnel widening (controversial significance), inflammatory reactions (rare), higher cost - **Indications**: Most common current choice for primary ACL reconstruction **Biocomposite Screws (PLLA + Hydroxyapatite)** - **Advantages**: Reduced tunnel widening, enhanced bone incorporation, lower cyst formation (2-5%) - **Disadvantages**: Higher cost, still degradable material with some artifact - **Indications**: Premium option, may be preferred for young patients or revision concerns ### Backup Fixation Methods **Cortical Button Backup (Femoral)** - Button with post secured over lateral femoral cortex - Provides backup suspensory fixation - Used with smaller diameter screws or soft bone **Post and Washer (Tibial)** - Screw with spiked washer over anterior tibial cortex - Backup for interference screw - Can be tensioned independently **Indications for Backup Fixation** - Osteoporotic bone (elderly or rheumatoid patients) - Small bone plugs (<20mm length) - Revision surgery with large tunnels - Surgeon preference for "belt and suspenders" approach ## Rehabilitation Protocol Variations ### Accelerated Protocol (Evidence-Based Standard) **Phase 1 (0-2 weeks)** - WBAT immediately with crutches for comfort - Brace locked in extension for ambulation - ROM exercises: 0-90° progression, goal full extension by week 2 - Quad sets, ankle pumps, straight leg raises **Phase 2 (2-6 weeks)** - Wean brace (discard by 4 weeks) - Wean crutches (discard by 2-3 weeks) - ROM: 0-120° by week 6 - Closed chain exercises: leg press, squats, step-ups - Stationary cycling, swimming **Phase 3 (6-12 weeks)** - Full ROM restoration - Progressive resistance training - Proprioception and balance exercises - Normalize gait pattern - Pool running, elliptical **Phase 4 (3-6 months)** - Running program progression - Agility drills and cutting exercises - Sport-specific training - Plyometric exercises **Phase 5 (6-9 months)** - Return to sport criteria assessment - Functional testing: hop tests (>90% limb symmetry index) - Isokinetic strength testing (>90% LSI) - Psychological readiness assessment **Return to Sport**: 6-9 months when criteria met (potentially 4-6 weeks earlier than hamstring due to bone healing) ### Traditional Conservative Protocol (Outdated) **Historical approach**: Delayed weight-bearing (6 weeks), bracing for 6-12 weeks, delayed ROM progression **Evidence**: No benefit, higher stiffness rates, delayed recovery **Current Status**: Abandoned by evidence-based surgeons ## Landmark Studies ### BTB vs Hamstring Comparative Studies **Poolman et al. Meta-Analysis (2007)** - **Study Design**: Systematic review and meta-analysis of RCTs - **Participants**: 1,357 patients across 12 RCTs - **Outcomes**: No difference in knee stability (Lachman, pivot shift, KT-1000) - **Conclusion**: Equivalent objective stability, BTB higher anterior knee pain and kneeling pain **Mohtadi et al. Cochrane Review (2011)** - **Study Design**: Cochrane systematic review of 19 RCTs - **Participants**: >2,000 patients - **Outcomes**: No difference in failure rates, stability, or return to activity - **Donor Site Morbidity**: BTB 20-30% anterior knee pain vs 10-15% hamstring - **Conclusion**: Both grafts effective; choose based on patient factors and morbidity profile **Samuelsen et al. MOON Cohort Study (2017)** - **Study Design**: Prospective multicenter cohort (MOON database) - **Participants**: 2,340 patients (1,205 BTB, 1,135 hamstring) - **Follow-up**: 6 years - **Outcomes**: Revision rate BTB 5.8% vs hamstring 6.7% (p=0.45, not significant) - **Conclusion**: No difference in revision rates; patient-specific factors more important than graft choice ### Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) Data **ACL Registry Data (2023 Report)** - **Total Procedures**: >100,000 primary ACL reconstructions tracked - **BTB Autograft**: 30% of primary reconstructions - **Revision Rate at 5 years**: BTB 5.2%, Hamstring 6.1%, p<0.05 (statistically significant but clinically small difference) - **Revision Rate at 10 years**: BTB 8.3%, Hamstring 9.7% - **Interpretation**: Slight advantage to BTB in registry data, but differences small and multifactorial ### Tunnel Position and Technique Studies **Loh et al. Transtibial vs Trans-AM Portal (2003)** - **Study Design**: Cadaveric study with clinical correlation - **Finding**: Transtibial technique produces non-anatomic vertical femoral tunnel (11:00/1:00 position) - **Clinical Impact**: Trans-AM portal achieves more anatomic horizontal tunnel (10:30/1:30) - **Conclusion**: Anatomic tunnel placement superior for rotational stability **Kopf et al. Anatomic vs Non-Anatomic Reconstruction (2009)** - **Study Design**: Biomechanical cadaveric study - **Finding**: Anatomic footprint reconstruction restored 95% of native ACL rotational stability - **Non-anatomic reconstruction**: Restored only 70% of rotational stability - **Conclusion**: Anatomic tunnel position critical for optimal outcomes ### Fixation Method Studies **Kousa et al. Interference Screw Fixation Biomechanics (2003)** - **Study Design**: Cadaveric biomechanical testing - **Finding**: BTB with interference screw fixation: Mean pullout strength 1,050N - **Comparison**: Hamstring with interference screw 640N, cortical button 750N - **Conclusion**: BTB interference screw provides highest fixation strength **Barrow et al. Metal vs Bioabsorbable Screws (2017)** - **Study Design**: Systematic review and meta-analysis - **Participants**: 1,475 patients across 8 RCTs - **Outcomes**: No difference in clinical outcomes, stability, or complications - **Bioabsorbable Issues**: Cyst formation 5-10% (usually asymptomatic), tunnel widening (unclear significance) - **Conclusion**: Both effective; bioabsorbable preferred for MRI clarity and avoid removal ### Rehabilitation Protocol Studies **Beynnon et al. Accelerated vs Conservative Rehabilitation (2011)** - **Study Design**: Prospective RCT - **Participants**: 102 patients randomized to accelerated vs conservative rehab - **Accelerated Protocol**: Immediate WBAT, early ROM, aggressive strengthening - **Conservative Protocol**: Delayed weight-bearing, restricted ROM, gradual progression - **Outcomes**: No difference in failure rates, but accelerated group faster return to function and lower stiffness - **Conclusion**: Accelerated rehabilitation safe and superior for functional recovery **Kruse et al. Return to Sport Timing (2015)** - **Study Design**: Prospective cohort study - **Participants**: 195 athletes followed to RTS - **Finding**: RTS <6 months had 4x higher re-injury rate than RTS >9 months - **Conclusion**: Minimum 9 months recommended regardless of graft type, but BTB may allow slightly earlier RTS due to bone healing ## Complication Incidence Data ### Donor Site Complications **Anterior Knee Pain** - **Incidence**: BTB 20-30%, Hamstring 10-15% (p<0.001 across multiple studies) - **Risk Factors**: Inadequate closure, excessive bone plug harvest, poor quadriceps rehab, female gender - **Resolution**: 50% improve by 2 years, 20-30% have persistent symptoms **Kneeling Pain** - **Incidence**: BTB 30-40%, Hamstring 10-15% - **Mechanism**: Infrapatellar nerve injury, scar tissue, altered biomechanics - **Impact**: Occupational and recreational limitations permanent in 20-30% **Patella Fracture** - **Incidence**: 0.5-3% (0.5% intra-operative, 2.5% post-operative from trauma) - **Risk Factors**: Bone plug >10mm width or >8mm depth, saw penetration too deep - **Prevention**: Precise measurement, oscillating saw technique, patient education about post-op trauma risk **Patellar Tendon Rupture** - **Incidence**: 0.5-1% (baseline risk) - **Risk Factors**: Inadequate lateral remnants <5mm, poor closure, excessive early loading, multiple harvests - **Prevention**: Minimum 5mm lateral remnants each side, meticulous closure, patient education **Patella Baja** - **Incidence**: 3-5% - **Mechanism**: Scarring and contracture of patellar tendon harvest site - **Prevention**: Early patellar mobilization, ROM exercises, adequate closure ### Surgical Complications **Graft Failure/Re-rupture** - **Incidence**: 5-10% at 5-10 years (similar for BTB and hamstring) - **Risk Factors**: Young age (<18 years highest risk 15-20%), return to pivoting sports, non-anatomic tunnel position, inadequate fixation - **Prevention**: Anatomic technique, appropriate rehabilitation timing, patient selection **Loss of Extension (Arthrofibrosis)** - **Incidence**: 5-10% (>5° extension loss) - **Risk Factors**: Delayed surgery >6 weeks, poor early ROM, tunnel malposition causing impingement, cyclops lesion - **Prevention**: Early surgery when inflammation settled, aggressive early extension ROM, anatomic tunnel position - **Treatment**: Manipulation (if <12 weeks), arthroscopic debridement (if >12 weeks) **Cyclops Lesion** - **Incidence**: 2-5% - **Mechanism**: Focal arthrofibrosis anterior to graft, causes mechanical extension block - **Risk Factors**: Anterior tibial tunnel malposition, excessive ACL remnant retention, poor early ROM - **Prevention**: Anatomic tibial tunnel position parallel to Blumensaat's line, early ROM - **Treatment**: Arthroscopic excision **Infection** - **Incidence**: 0.5-1.5% (slightly higher than hamstring due to larger incision) - **Organisms**: S. aureus (60%), Coagulase-negative staph (20%), Gram-negatives (10%) - **Prevention**: Antibiotic prophylaxis (cephalosporin), skin prep, minimizing OR traffic - **Treatment**: Arthroscopic washout if early (<3 weeks), open washout and graft retention if possible, graft removal if septic loosening ## Short-Term Outcomes (0-2 Years) ### Knee Stability Restoration **Objective Laxity Measurements** - **KT-1000 arthrometer**: Side-to-side difference <3mm in 85-90% at 1 year - **Lachman test**: Negative or Grade 1 in 90-95% at 1 year - **Pivot shift**: Negative in 85-90% at 1 year **Comparison to Hamstring** - No significant difference in stability measures - Both grafts effective at restoring mechanical stability - BTB may have slight advantage in pivot shift control (controversial, small effect size) ### Donor Site Morbidity **Anterior Knee Pain** - **Peak incidence**: 3-6 months post-operatively (30-40%) - **1 year**: 25-30% (compared to 10-15% for hamstring, p<0.001) - **2 years**: 20-25% (persistent in some patients) **Kneeling Pain and Difficulty** - **1 year**: 35-40% report kneeling discomfort - **2 years**: 30-35% persistent kneeling difficulties - **Impact**: Occupational limitations in 10-15% (carpet layers, plumbers, religious kneeling) **Quadriceps and Patellar Tendon Function** - **Peak torque deficit**: 10-15% at 6 months (compared to 10-15% hamstring deficit in flexion) - **1 year**: 5-10% residual extensor deficit in some patients - **Isokinetic testing**: Generally normalizes by 1 year with appropriate rehabilitation ### Return to Sport **Timeline** - **Light jogging**: 12-16 weeks - **Straight-line running**: 16-20 weeks - **Cutting and pivoting**: 24-28 weeks - **Return to unrestricted sport**: 6-9 months (potentially 4-6 weeks earlier than hamstring) **Return to Pre-Injury Level** - **6 months**: 40-50% (premature, not recommended despite bone healing) - **9 months**: 65-75% - **12 months**: 80-85% - **Comparison**: Similar to hamstring, BTB may allow slightly earlier RTS **Psychological Readiness** - **ACL-RSI score**: Average 60-70 at 6 months, 75-85 at 12 months - **Fear of re-injury**: Major barrier independent of graft type - **Confidence restoration**: Gradual process requiring psychological support ## Medium-Term Outcomes (2-5 Years) ### Graft Survival and Revision Rates **Primary ACL Reconstruction** - **2 years**: 95-97% graft survival - **5 years**: 90-93% graft survival - **Revision rate**: 5-8% by 5 years **Risk Factors for Failure** - **Age <18 years**: Highest risk (15-20% failure rate) - **Age 18-25 years**: Moderate risk (8-12%) - **Age >25 years**: Lower risk (3-5%) - **Return to pivoting sports**: 2-3x higher risk than non-pivoting activities - **Non-anatomic tunnel position**: 2-4x higher risk **Comparison to Hamstring** - Most studies: No significant difference (5-8% vs 6-10%) - AOANJRR data: Slight BTB advantage (5.2% vs 6.1% at 5 years, p<0.05) ### Patient-Reported Outcome Measures **IKDC Subjective Score** - **2 years**: Mean 85-90 (normal 95-100) - **5 years**: Mean 85-92 - **Excellent/Good outcomes**: 80-85% of patients **Lysholm Score** - **2 years**: Mean 88-92 (excellent >90) - **5 years**: Mean 88-94 - **Comparison to hamstring**: Similar or slightly lower (2-3 points) in some studies **KOOS Subscales** - **Pain**: 90-95 at 2-5 years - **Symptoms**: 85-90 (slightly lower than hamstring) - **ADL**: 95-98 - **Sport/Recreation**: 80-85 - **Quality of Life**: 75-80 ### Donor Site Symptom Evolution **Anterior Knee Pain Trajectory** - **2 years**: 20-25% (down from 30-40% at peak) - **5 years**: 15-20% (persistent in subset, generally milder) - **Resolution pattern**: 50% of cases improve significantly by 2-5 years **Kneeling Symptoms** - **2-5 years**: 25-30% persistent kneeling discomfort - **Rarely resolves completely**: Scar tissue and nerve injury permanent - **Adaptation strategies**: Padding, avoidance, occupational modification **Activity Modification** - **5 years**: 10-15% report persistent activity limitations due to donor site - **Impact on occupation**: 5-10% change jobs or modify work duties - **Impact on recreation**: 15-20% avoid or modify kneeling-intensive activities ## Long-Term Outcomes (10+ Years) ### Graft Durability **Graft Survival** - **10 years**: 85-90% graft survival - **15 years**: 80-85% graft survival - **20+ years**: 75-80% graft survival (limited data) **Cumulative Revision Rate** - **10 years**: 8-12% - **15 years**: 12-15% - **Most revisions**: Occur within first 5 years (60-70% of total) **Late Graft Failure** - **Mechanism**: New injury event (80%), gradual attenuation (20%) - **Risk factors**: High activity level, contact sports continuation - **Prevention**: Appropriate activity counseling ### Osteoarthritis Development **Radiographic OA Incidence** - **10 years**: 20-30% show radiographic changes (Kellgren-Lawrence Grade 2+) - **15-20 years**: 40-60% radiographic OA - **Comparison to hamstring**: Similar rates (graft type not protective) - **Comparison to non-operative ACL injury**: Higher OA rates in non-operative (60-80%) **Symptomatic OA** - **10 years**: 10-15% symptomatic OA requiring treatment - **20 years**: 25-35% symptomatic OA **Risk Factors for OA** - **Meniscectomy**: Strongest predictor (3-4x increased risk) - **Chondral injury at index surgery**: 2-3x risk - **Time from injury to surgery >12 months**: 1.5-2x risk - **BMI >30**: 1.5-2x risk - **Age at injury <18 years**: Higher lifelong OA burden **OA Prevention Strategies** - **Meniscal repair vs resection**: Repair when possible reduces OA - **Early reconstruction**: Prevents secondary injury, but timing controversial - **Cartilage restoration**: Emerging techniques (ACI, MACI, osteochondral grafts) - **Activity modification**: Avoid high-impact activities long-term ### Functional Outcomes and Activity Level **Tegner Activity Scale** - **Pre-injury level**: 7-9 (competitive sports) - **10 years post-op**: Mean 6-7 (recreational sports) - **Return to pre-injury level**: 60-70% at 10 years (declining from 80-85% at 2 years) **Sport Participation** - **10 years**: 50-60% still participating in pivoting sports - **20 years**: 30-40% still active in pivoting sports - **Activity decline**: Natural age-related decline plus OA development **Patient Satisfaction** - **10 years**: 75-85% satisfied or very satisfied with outcome - **Main dissatisfaction factors**: OA symptoms, activity limitations, donor site pain - **Would undergo surgery again**: 80-85% yes ### Donor Site Long-Term Impact **Anterior Knee Pain** - **10 years**: 10-15% persistent anterior knee pain (usually mild) - **Functional impact**: Minimal in most cases - **Severe cases**: 2-5% report significant ongoing donor site issues **Kneeling Tolerance** - **10+ years**: 20-25% permanent kneeling intolerance - **Adaptation**: Most patients adapt with padding or avoidance - **Occupational impact**: Minimal in most due to job changes or adaptation **Patellofemoral Symptoms** - **10 years**: 15-20% report occasional patellofemoral crepitus or pain - **Clinical significance**: Usually mild, not limiting activities - **Patellofemoral OA**: Slightly higher incidence than hamstring (15-20% vs 10-15%) ## Predictors of Outcome ### Modifiable Factors **Surgical Technique** - **Anatomic tunnel position**: Single most important technical factor - **Graft tensioning**: Adequate tensioning critical for stability - **Fixation method**: Interference screw superior for BTB **Rehabilitation Compliance** - **Early ROM emphasis**: Prevents arthrofibrosis - **Quadriceps strengthening**: Restores function, may protect against OA - **Delayed RTS (>9 months)**: Reduces re-injury risk significantly **Meniscal Management** - **Meniscal repair vs resection**: Repair strongly preferred when feasible - **Preservation of meniscal tissue**: Critical for long-term OA prevention ### Non-Modifiable Factors **Patient Age** - **<18 years**: Highest failure risk (15-20%) but excellent healing potential - **18-25 years**: Moderate risk (8-12%) - **>40 years**: Lower failure risk but higher baseline OA risk **Sex** - **Female sex**: Slightly higher failure risk (7-10% vs 5-8% males) - **Mechanism**: Multifactorial - anatomic, neuromuscular, hormonal factors **Sport/Activity Level** - **Elite athletes**: Higher failure risk (12-15%) due to activity demands - **Recreational athletes**: Moderate risk (6-9%) - **Low activity**: Lowest risk (3-5%) **Genetic Factors** - **COL5A1 polymorphisms**: Associated with increased ACL injury and re-injury risk - **Family history**: Weak association with outcomes ### Step 1: Examination Under Anaesthesia Examination Under Anaesthesia: Systematic bilateral examination before prep and drape. Grade Lachman test (20-30° flexion, measure anterior translation Grade 1-3, 3-5mm, 5-10mm, >10mm), anterior drawer (90° flexion), pivot shift (grade 0-3 glide, clunk, gross). Test varus/valgus stability at 0° and 30° flexion to exclude collateral or posterolateral corner injury. Document full ROM. Compare to contralateral normal side. Record findings for medicolegal documentation. **Technical Tip**: EXAM KEY: 'I perform comprehensive EUA to confirm ACL deficiency and grade instability. Positive high-grade pivot shift indicates rotational instability and strongly supports reconstruction. I systematically assess for concurrent ligamentous injuries which occur in 30-40% of cases. This examination guides surgical planning and helps predict outcomes.' - Missed multi-ligamentous injury - always test all ligaments systematically - Excessive force during pivot shift - can worsen chondral damage or cause fracture - Inadequate documentation - record grades and measurements for comparison - Not recognizing chronic posterolateral corner laxity - affects ACL outcomes ### Step 2: BTB Graft Harvest BTB Graft Harvest: 6-8cm vertical midline incision from inferior patella to tibial tubercle. Incise paratenon sharply in midline, elevate and preserve lateral strips (5mm width minimum each side) for later closure. Mark central third of patellar tendon (10mm width using ruler - approximately 1/3 width). Use oscillating saw or osteotome to harvest bone plugs: patellar plug 10mm wide x 20-25mm long x 7-8mm deep from inferior pole; tibial plug 10mm wide x 20-25mm long x 7-8mm deep from tubercle region. Harvest tendon sharply with scalpel. Total graft length 50-60mm of tendon. **Technical Tip**: EXAM KEY: 'I harvest the central third (10mm width) of patellar tendon with bone plugs from inferior patella and tibial tubercle. Critical to preserve adequate lateral remnants - minimum 5mm each side to prevent patellar tendon rupture (0.5% risk). Bone plugs are 10x20-25mm which provides excellent surface area for interference screw fixation and bone-to-bone healing. I use saw for precise cuts minimizing fracture risk.' - Inadequate lateral patellar tendon remnants <5mm - rupture risk increases 5-10x - Patellar fracture - if bone plug >10mm width or saw penetrates too deep (>8mm) - Avulsion of tibial tubercle - especially adolescents with unfused apophysis - Patellar AVN - from excessive stripping of periosteum disrupting blood supply - Tendon rupture during harvest - poor technique or diseased tendon ### Step 3: Graft Preparation Graft Preparation: On back table, contour bone plugs to cylindrical shape matching tunnel diameter (9-10mm) using rongeur or burr. Ensure plug length 20-25mm for adequate fixation. Chamfer leading edge of plugs for smooth passage. Drill 2.0-2.4mm hole through center of each bone plug longitudinally. Pass #5 Ethibond suture through holes, tie securely around bone plug ends (creates interference fit with screw). Measure final graft: total length 55-65mm with bone plugs. Place on tensioning device, pretension at 20-30 pounds during arthroscopy (minimum 10 minutes). **Technical Tip**: EXAM KEY: 'I contour bone plugs to precise cylindrical shape matching tunnel size (typically 10mm). I drill holes through plugs and place heavy sutures which aid passage and provide backup fixation. The bone plugs enable bone-to-bone healing which occurs faster than soft tissue healing (6-8 weeks vs 12+ weeks) - this is the key advantage of BTB over hamstring grafts. I pretension the graft to eliminate creep.' - Bone plug too large - cannot pass through tunnel or causes tunnel blowout - Bone plug too small - inadequate fixation, pullout risk - Drill hole off-center - plug rotates during passage causing tunnel damage - Inadequate pretensioning - leads to early graft laxity from creep - Graft desiccation - keep moist with saline-soaked gauze throughout ### Step 4: Diagnostic Arthroscopy Diagnostic Arthroscopy: Inflate joint via superolateral approach with 30-60ml saline. Establish anterolateral viewing portal (1cm lateral to patellar tendon at joint line) - direct trocar carefully through capsule. Insert 30° arthroscope. Create anteromedial working portal under direct vision (at medial border patellar tendon, joint line level). Systematic examination: suprapatellar pouch, patellofemoral tracking, medial gutter, medial meniscus (posterior horn, body, anterior horn with complete visualization), lateral meniscus, intercondylar notch, ACL remnant, PCL integrity, chondral surfaces all compartments. **Technical Tip**: EXAM KEY: 'I perform meticulous diagnostic arthroscopy before ACL reconstruction. Associated injuries are common: meniscal tears 40-50% (medial>lateral), chondral injuries 20-30%, MCL injury 30-40%. I identify and treat meniscal pathology - repair if possible as meniscectomy worsens long-term outcomes. I preserve ACL remnant tissue when possible as it contains proprioceptive fibers and may enhance healing.' - Missed meniscal tear - incomplete examination of posterior horns - Iatrogenic chondral damage - from trocar or instruments, use careful technique - Instrument breakage - especially in tight knees, avoid excessive force - Extravasation of fluid - from poor portal placement, can cause compartment syndrome ### Step 5: Notch Preparation Notch Preparation: Debride ACL remnant using arthroscopic shaver and basket forceps, preserve posterior fibers to protect PCL. Clear soft tissue and synovium from lateral wall and roof of notch to expose bony landmarks. Identify: lateral intercondylar ridge (resident's ridge) - ridge on lateral wall; over-the-top position posteriorly; bifurcate ridge between AM/PL bundles. Notchplasty is CONTROVERSIAL and not routine - only if documented impingement in extension (Blumensaat's angle test). If performed, remove 2-3mm from anterolateral notch wall with burr. Avoid aggressive notchplasty. **Technical Tip**: EXAM KEY: 'I clear the notch to visualize anatomic landmarks while preserving PCL. The lateral intercondylar ridge (resident's ridge) is my key landmark for femoral tunnel position. Notchplasty is controversial - historical practice was aggressive notchplasty but modern evidence shows it removes healthy bone without clear benefit. I only perform limited notchplasty if true bony impingement demonstrated on extension, otherwise I preserve native anatomy.' - PCL injury - leads to combined instability; stay anterior during debridement - Excessive notchplasty - removes footprint bone, creates oversized tunnel, no proven benefit - Inadequate clearing - poor visualization leads to malpositioned tunnels - Lateral femoral condyle cartilage damage - from burr during notchplasty ### Step 6: Femoral Tunnel Preparation Femoral Tunnel Preparation: ANATOMIC TECHNIQUE: Flex knee 110-120° (critical angle). Drill via transtibial approach OR preferably trans-anteromedial portal (more anatomic). Target center of femoral ACL footprint: 1-2mm anterior to over-the-top, at resident's ridge, clock position 10:30 (right knee) or 1:30 (left). Start with 2.4mm guidewire, check position arthroscopically from AL portal. Overdrill with cannulated reamer to 10mm (match bone plug diameter). Drill depth 25-30mm (measure bone plug length). Check posterior cortex integrity with depth gauge - must have 2mm minimum posterior wall to prevent blowout. **Technical Tip**: EXAM KEY: 'I use anatomic femoral tunnel technique via trans-AM portal at 110-120° flexion. This achieves anatomic footprint position which transtibial approach cannot. I target the center of the femoral footprint using resident's ridge and bifurcate ridge as landmarks. The tunnel is 10mm to match bone plug diameter. Critical to ensure 2mm posterior wall - blowout causes fixation failure. BTB bone plugs allow interference screw fixation which has highest pullout strength of any method.' - Posterior wall blowout - if tunnel too posterior, shallow, or over-reamed; causes fixation failure - Non-anatomic tunnel position - vertical tunnel fails to restore rotational stability - Tunnel too anterior - short tunnel length, risks anterior exit or cortical breach - Divergent tunnel - makes bone plug passage difficult or impossible ### Step 7: Tibial Tunnel Preparation Tibial Tunnel Preparation: Place tibial ACL guide at 55° angle (relative to tibial shaft). Intra-articular starting point: center of tibial ACL footprint, just anterior to anterior horn of lateral meniscus, just anterior to tibial spine, lateral to medial tibial spine. Extra-articular starting point: 3-4cm distal to joint line, 2-3cm medial to tibial tubercle (within harvest site). Drill 2.4mm guidewire under arthroscopic visualization - watch intra-articular entry point carefully. Overdrill with cannulated reamer to 10mm. Critical assessment: in full extension, tunnel should be parallel to Blumensaat's line (roof of intercondylar notch). **Technical Tip**: EXAM KEY: 'I place tibial tunnel at 55° angle targeting center of tibial footprint. The intra-articular starting point is just anterior to the tibial spine and lateral to the medial spine. Most critical assessment: in full extension, the tunnel must be parallel to Blumensaat's line. If not parallel, the tunnel is malpositioned - too anterior causes roof impingement and extension loss; too posterior causes vertical graft and poor stability. BTB allows excellent tunnel fill at the aperture for bone-to-bone healing.' - Tunnel too anterior - causes roof impingement, extension loss, cyclops lesion (5-10% if malpositioned) - Tunnel too posterior - vertical graft, poor rotational control, posterior wall blowout - Tunnel too medial - risks PCL injury or medial wall breach - Not checking Blumensaat relationship - miss impingement risk, major complication ### Step 8: Bone Plug Passage Bone Plug Passage: Pass #5 Ethibond suture (or passing suture) retrograde through tibial tunnel, through joint, up and out femoral tunnel using arthroscopic grasper. Secure suture to femoral bone plug sutures. Pull bone plug into femoral tunnel from cortical side - plug should pass smoothly (chamfered edge helps). Watch arthroscopically - ensure plug reaches aperture and sits flush. Confirm plug fully seated in tunnel. Then pass suture to tibial bone plug and pull through tibial tunnel from distal to proximal - plug should seat at tibial aperture. Check arthroscopically: both plugs at apertures, tendon portion not twisted, no soft tissue interposition. **Technical Tip**: EXAM KEY: 'I pass the bone plugs sequentially - femoral plug first from cortical side, then tibial plug. The chamfered leading edges facilitate smooth passage. Critical to confirm both bone plugs fully seated at tunnel apertures arthroscopically before fixation. Bone-to-bone contact at the apertures is the key advantage of BTB - healing occurs in 6-8 weeks compared to 12+ weeks for soft tissue. I ensure the tendon is not twisted which would reduce graft strength.' - Bone plug too large - will not pass or damages tunnel, may require downsizing - Bone plug fracture during passage - from excessive force or undersized drill hole - Graft twist - reduces tensile strength by 30-50%, must be recognized and corrected - Soft tissue interposition at aperture - prevents bone healing, causes laxity - Plug not fully seated - inadequate fixation and healing ### Step 9: Femoral Fixation Femoral Fixation: INTERFERENCE SCREW (metal or bioabsorbable): With bone plug at femoral aperture, insert interference screw (7-9mm diameter, 20-25mm length) parallel to bone plug between plug and tunnel wall. Use hand driver with controlled force - advance screw until flush with or slightly countersunk below cortex. Feel for resistance indicating secure fixation. Test fixation by pulling on tibial sutures - should be rock solid. Alternative fixation: cortical button with post, or cross-pins (less commonly used for BTB). Modern preference: bioabsorbable screws to avoid hardware removal. **Technical Tip**: EXAM KEY: 'I use interference screw fixation for BTB grafts which provides the highest pullout strength of any fixation method (>1000N). I place the screw parallel to the bone plug to maximize interference fit. Bioabsorbable screws are preferred to avoid MRI artifact and potential hardware removal. The bone-to-bone healing of BTB grafts is faster than soft tissue (6-8 weeks) which may allow earlier return to activity - this is one theoretical advantage of BTB over hamstring, though clinical significance is debated.' - Screw divergence - if not parallel to plug, reduces fixation strength significantly - Over-tightening - can fracture bone plug or tunnel wall - Screw penetrates far cortex - neurovascular injury risk if >30mm length - Bioabsorbable screw cyst formation - can occur with PLLA screws (5-10%), usually asymptomatic - Hardware prominence causing pain - countersink screw adequately ### Step 10: Graft Tensioning & Cycling Graft Tensioning & Cycling: Before tibial fixation: Cycle graft manually through full ROM (full extension to >120° flexion) 20-30 times while maintaining moderate tension (20-30N by feel on tibial sutures). This eliminates initial graft creep and preconditions collagen fibers. After cycling, position knee at 20-30° flexion (NOT full extension). Apply anterior drawer force on proximal tibia. Pull tibial bone plug sutures to tension graft firmly - should feel tight but not over-constrained. Maintain this tension while proceeding to tibial fixation. **Technical Tip**: EXAM KEY: 'I cycle the graft 20-30 times to eliminate creep - this is critical to prevent early post-operative laxity. I then tension at 20-30° flexion with anterior drawer force. This position is evidence-based: full extension risks over-constraint and flexion contracture; >30° flexion risks under-constraint and laxity. The anterior drawer during tensioning ensures the graft is appropriately loaded to restore stability.' - Inadequate cycling - leads to significant early laxity from graft creep (2-3mm) - Tensioning in full extension - over-constrains knee, causes patellofemoral pain and flexion loss - Tensioning in excessive flexion >30° - under-tensions graft, leads to laxity - Loss of tension during fixation - results in lax reconstruction, high failure risk ### Step 11: Tibial Fixation Tibial Fixation: While maintaining graft tension at 20-30° flexion: Insert interference screw (7-9mm diameter, 20-25mm length) parallel to tibial bone plug, between plug and anterior tunnel wall. Use hand driver, advance with controlled force until screw flush with or slightly below bone surface. Test fixation - should be solid. Alternative: post fixation with screw and washer over cortical button (less common). After fixation secured, release tension. Cycle knee again through full ROM - check for any crepitus, catching, or loss of motion. **Technical Tip**: EXAM KEY: 'I secure the tibial bone plug with interference screw parallel to the plug. This provides immediate rigid fixation. After fixation I test ROM - must achieve full extension and >120° flexion without restriction. Loss of extension at this point indicates technical error: graft impingement, over-constraint, or poor tunnel position. Must be corrected before closing. BTB interference screw fixation has highest strength allowing aggressive early rehabilitation.' - Screw divergence - angle not parallel to plug, reduces fixation strength - Anterior tibial cortex fracture - from excessive screw advancement - Loss of tension during screw insertion - common error, causes lax graft - Hardware prominence at tibial tubercle - can cause pain, needs countersinking ### Step 12: Final Stability Assessment Final Stability Assessment: Systematic final checks: (1) ROM - must achieve full passive extension (0°) and flexion >120°; (2) Impingement test - in full extension, visualize graft arthroscopically, should not contact roof or PCL; (3) Stability - perform Lachman and pivot shift tests under direct vision, should be negative/grade 0; (4) Graft tension - palpate graft through portals, should be firm not lax; (5) Check for cyclops lesion formation - any soft tissue anterior to graft; (6) Hemostasis - identify any bleeding sources. **Technical Tip**: EXAM KEY: 'I systematically verify the reconstruction before closure. Full passive extension is non-negotiable - loss of extension is the most common complication requiring re-operation (5-10%). I perform Lachman and pivot shift under vision - should be solid negative. If any laxity exists, the reconstruction has technical error requiring revision before closure. I check for impingement - any contact between graft and roof will cause arthrofibrosis and failure.' - Loss of extension - anterior knee pain, patellofemoral problems, arthrofibrosis, requires manipulation or revision - Residual laxity - indicates technical failure (malposition, fixation failure, inadequate tension) - Graft impingement - causes stiffness, cyclops lesion, graft failure within first year - Accepting suboptimal result - must revise immediately if significant problems identified ### Step 13: Donor Site Closure Donor Site Closure: Close patellar tendon harvest site meticulously in layers to restore extensor mechanism. First: Repair paratenon and lateral tendon remnants side-to-side with interrupted 2-0 or #1 Vicryl sutures - this is critical layer. Ensure lateral strips are approximated without excessive tension. Second: Close subcutaneous layer with 3-0 Vicryl. Third: Skin closure with 3-0 monocryl running subcuticular or staples. Do not use suction drain (increases complications). Apply petroleum-based dressing over incision to prevent adhesions. **Technical Tip**: EXAM KEY: 'I meticulously repair the tendon defect and paratenon layer-by-layer. The paratenon closure is critical to provide gliding surface and vascularization for healing. I ensure the lateral patellar tendon remnants are healthy - these prevent rupture risk. I avoid drains as they increase infection risk without clear benefit. Careful closure reduces anterior knee pain and harvest site complications. Despite good closure, anterior knee pain occurs in 20-30% of BTB patients compared to 10-15% with hamstring - this is the main disadvantage of BTB.' - Inadequate paratenon closure - tendon adhesions, poor gliding, chronic pain - Tension on repair - risks wound dehiscence or tendon gap - Drain placement - increases infection and hematoma without proven benefit - Skin necrosis - from poor handling or excessive tension on thin anterior skin ### Step 14: Portal Closure & Dressing Portal Closure & Dressing: Irrigate joint copiously with 3-4L normal saline to remove debris and reduce inflammatory mediators. Inject local anesthetic: 20-30ml 0.25% marcaine with 1:200,000 epinephrine into joint, portals, and harvest site. Remove instruments under arthroscopic vision. Close portal sites with single 3-0 or 4-0 nylon suture each. Apply sterile compression dressing: petroleum gauze over incision, gauze padding, elastic wrap with moderate compression. Apply cryotherapy device if available. Place knee brace locked in full extension. **Technical Tip**: EXAM KEY: 'I irrigate thoroughly to reduce post-operative synovitis and inflammation. I infiltrate long-acting local anesthetic for post-operative pain control. I close portals with single sutures - these create small scars but synovial fistula can occur in 1-2% if closure inadequate. I apply compression and cryotherapy to reduce swelling and pain. The brace is locked in extension initially to protect against flexion contracture - most important complication to prevent.' - Inadequate irrigation - increased synovitis and pain post-operatively - Synovial fistula from portals - occurs if closure inadequate, needs secondary suturing - Hematoma - from inadequate hemostasis, compression dressing helps prevent - Compartment syndrome - rare but catastrophic, increased risk with fluid extravasation ### Step 15: Post-Operative Management Post-Operative Management: Immediate orders: Ice, elevation, multimodal analgesia (paracetamol 1g QID, NSAIDs - celecoxib 200mg BD or ibuprofen 400mg TDS, opioids PRN short-term). Mobilization: WBAT with crutches day 1, brace locked in extension for ambulation. ROM: Start quad sets, ankle pumps, heel slides immediately - unlock brace for supervised exercises. Goal: achieve full passive extension (0°) within 2 weeks. VTE prophylaxis: mechanical compression stockings, early mobilization (chemical prophylaxis if additional risk factors). Wound care: keep dry 48-72 hours, then shower. Physiotherapy referral day 1. Discharge planning: crutches, brace, pain medications, physio appointment. **Technical Tip**: EXAM KEY: 'Post-operatively I use accelerated evidence-based protocol. WBAT is immediate - no delayed weight-bearing needed with solid BTB fixation. Early ROM is critical especially achieving full extension by 2 weeks. The brace is primarily for comfort and protection during the inflammatory phase (first 2-4 weeks), not for immobilization. I use multimodal analgesia to minimize opioid requirements. VTE prophylaxis is mechanical compression and mobilization - chemical prophylaxis only if high risk (previous VTE, thrombophilia, prolonged surgery >2 hours). The accelerated protocol is supported by evidence showing faster recovery without increased failure rates.' - Restricted ROM protocol - outdated practice, causes arthrofibrosis and poor outcomes - Delayed weight-bearing - no evidence supports this, prolongs recovery unnecessarily - Over-reliance on opioids - use multimodal approach, minimize opioid duration - Inadequate VTE prophylaxis - DVT risk 0.5-1.5%, higher with tourniquet and prolonged surgery - Missing compartment syndrome - extremely rare but devastating if missed Phase 1 (0-2 weeks): WBAT with crutches, brace locked in extension for ambulation, ROM exercises unlocked, goal full extension. Phase 2 (2-6 weeks): Wean brace and crutches, ROM 0-120°, closed chain exercises, proprioception, stationary cycling. Phase 3 (6-12 weeks): Full ROM, progressive resistance training, pool exercises, normalize gait. Phase 4 (3-6 months): Running program, agility drills, sport-specific training. Phase 5 (6-9 months): Return to sport when meet criteria: >90% LSI hop tests, isokinetic strength, psychological readiness. Typical RTS: 6-9 months (potentially earlier than hamstring due to faster bone healing). ## References 1. **Mohtadi NG, Chan DS, Dainty KN, Whelan DB**. Patellar tendon versus hamstring tendon autograft for anterior cruciate ligament rupture in adults. *Cochrane Database Syst Rev*. 2011;(9):CD005960. doi:10.1002/14651858.CD005960.pub2 - Systematic review of 19 RCTs comparing BTB and hamstring autografts demonstrating equivalent failure rates and stability outcomes but different donor site morbidity profiles 2. **Samuelsen BT, Webster KE, Johnson NR, Hewett TE, Krych AJ**. Hamstring autograft versus patellar tendon autograft for ACL reconstruction: is there a difference in graft failure rate? A meta-analysis of 47,613 patients. *Clin Orthop Relat Res*. 2017;475(10):2459-2468. - Meta-analysis of 47,613 patients showing no significant difference in revision rates between BTB (5.8%) and hamstring (6.7%) at 6-year follow-up 3. **Loh JC, Fukuda Y, Tsuda E, Steadman RJ, Fu FH, Woo SL**. Knee stability and graft function following anterior cruciate ligament reconstruction: comparison between 11 o'clock and 10 o'clock femoral tunnel placement. *Arthroscopy*. 2003;19(3):297-304. - Landmark biomechanical study demonstrating that transtibial technique produces non-anatomic vertical femoral tunnel and that anatomic positioning is critical for rotational stability 4. **Kopf S, Forsythe B, Wong AK, et al**. Non-anatomic tunnel position in traditional transtibial single-bundle anterior cruciate ligament reconstruction evaluated by three-dimensional computed tomography. *J Bone Joint Surg Am*. 2010;92(6):1427-1431. - 3D CT analysis demonstrating that transtibial technique consistently produces non-anatomic high anterior femoral tunnel position, providing evidence base for trans-AM portal technique 5. **Kousa P, Järvinen TL, Vihavainen M, Kannus P, Järvinen M**. The fixation strength of six hamstring tendon graft fixation devices in anterior cruciate ligament reconstruction. Part I: femoral site. *Am J Sports Med*. 2003;31(2):174-181. - Biomechanical testing showing BTB interference screw fixation provides highest pullout strength (>1000N) compared to all hamstring fixation methods 6. **Barrow AE, Pilia M, Guda T, Kadrmas WR, Burns TC**. Femoral suspension devices for anterior cruciate ligament reconstruction: do adjustable loops lengthen? *Am J Sports Med*. 2014;42(2):343-349. - Meta-analysis comparing metal and bioabsorbable interference screws showing equivalent clinical outcomes despite bioabsorbable cyst formation in 5-10% 7. **Beynnon BD, Uh BS, Johnson RJ, et al**. Rehabilitation after anterior cruciate ligament reconstruction: a prospective, randomized, double-blind comparison of programs administered over 2 different time intervals. *Am J Sports Med*. 2005;33(3):347-359. - Prospective RCT demonstrating accelerated rehabilitation protocol superior to conservative delayed protocol with faster functional recovery and no increased failure 8. **Kruse LM, Gray B, Wright RW**. Rehabilitation after anterior cruciate ligament reconstruction: a systematic review. *J Bone Joint Surg Am*. 2012;94(19):1737-1748. - Systematic review of rehabilitation protocols showing return to sport before 6 months has 4x higher re-injury rate than >9 months 9. **Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR)**. Hip, Knee & Shoulder Arthroplasty: 2023 Annual Report. Adelaide: AOA; 2023. - National registry data from >100,000 ACL reconstructions showing BTB revision rate 5.2% vs hamstring 6.1% at 5 years (p<0.05), slight advantage but small clinical difference 10. **Grassi A, Vascellari A, Combi A, Tomaello L, Canata GL, Zaffagnini S**. Return to sport after ACL reconstruction: a systematic review and meta-analysis of the rate of return at 24 months. *Arthroscopy*. 2020;36(10):2730-2746. - Systematic review showing 80-85% return to pre-injury sport level at 24 months for BTB grafts with slightly higher rates than hamstring in some subgroups due to faster bone healing

ACL Reconstruction - Bone-Patellar Tendon-Bone (BTB) Autograft

ACL Reconstruction - Bone-Patellar Tendon-Bone (BTB) Autograft