Arthroscopic ACL Reconstruction - Hamstring Autograft (Anatomic AM Portal Technique)

Patient Position: Supine on standard operating table with operative leg in arthroscopic leg holder (allows full flexion to at least 130 degrees for hyperflexion during femoral tunnel drilling). Non-operative leg in lithotomy stirrup position or abducted and supported on leg holder. Operative leg hip flexed 30-45 degrees, externally rotated 10-15 degrees for comfortable access to medial knee. Thigh tourniquet applied high and proximal on thigh (rarely inflated - only if bleeding obscures visualization after attempting epinephrine infiltration with local anesthetic). Ensure leg holder allows easy adjustment of flexion angle throughout case (will need hyperflexion 110-120 degrees for femoral tunnel drilling, then various flexion angles for graft passage and fixation). Position patient on table to allow full knee flexion without leg holder contacting table edge or foot dropping off end. Fluoroscopy C-arm positioned on contralateral side if using fluoroscopic guidance for tunnel positioning (optional - most surgeons use arthroscopic visualization alone). Back table prepared for graft preparation (sizing tubes ranging 7-10mm, graft board with tensioning device to apply calibrated tension, suture materials including #2 non-absorbable braided suture for whipstitch, passing sutures).

Surgical Approach: Arthroscopic approach via standard anterolateral (AL) and anteromedial (AM) portals for visualization and instrumentation. Anteromedial longitudinal 3-4cm incision on proximal medial tibia for hamstring graft harvest and tibial tunnel exit point.

Incision: Portal incisions: (1) Anterolateral portal - 1cm proximal to joint line, just lateral to lateral border of patellar tendon (soft spot palpable with knee flexed 90 degrees). Standard 5mm skin incision. Entry point through lateral soft spot avoiding fat pad. (2) Anteromedial portal - established under direct arthroscopic visualization after AL portal created and arthroscope inserted. Position 2-3cm medial to medial border of patellar tendon, at joint line level. Use spinal needle under arthroscopic guidance to identify ideal trajectory before making portal (insert needle from proposed site, visualize trajectory arthroscopically, confirm needle can reach lateral wall of intercondylar notch and posterior horn of lateral meniscus). Adjust position until optimal trajectory confirmed. Make 5mm skin incision and create portal with trocar under arthroscopic visualization. Harvest incision: (3) Anteromedial tibial incision - vertical orientation parallel to tibial shaft, 3-4cm length, starting 2-2.5cm distal to joint line (palpate joint line with knee flexed), centered 2cm medial to tibial tubercle (landmarks: medial border of patellar tendon medially to tibial tubercle laterally - incision in between closer to tubercle). This incision serves dual purpose: hamstring graft harvest and tibial tunnel exit point.

Step 1: Hamstring Graft Harvest and Preparation

Hamstring Graft Harvest and Preparation: Position knee in 90 degrees flexion with foot flat on bed (relaxes hamstrings and pes anserinus tendons). Make 3-4cm vertical incision on anteromedial proximal tibia: start 2-2.5cm below joint line, 2cm medial to tibial tubercle (palpate tibial tubercle and medial patellar tendon border, mark midpoint). Incise skin and subcutaneous tissue carefully - IDENTIFY and PROTECT saphenous nerve (runs in subcutaneous fat medially, 1-2cm medial to incision) and infrapatellar branch (crosses incision site obliquely from superomedial to inferolateral, emerges 8-10cm above joint line). If nerve branches visualized, gently retract medially with vessel loop or Penrose drain. Use blunt finger dissection in subcutaneous layer rather than sharp dissection to reduce nerve injury risk. Incise sartorius fascia longitudinally (shiny white fascia overlying pes anserinus, easily identified). Identify PES ANSERINUS tendons beneath sartorius fascia (three tendons: gracilis most superficial and superior, semitendinosus deeper and inferior, sartorius most superficial and anterior): (1) Gracilis - most superficial and superior, appears as thin white rounded tendon approximately 3-4mm diameter; (2) Semitendinosus - deeper and inferior to gracilis, broader and thicker tendon approximately 5-6mm diameter. Palpate to differentiate (gracilis more superficial mobile, semitendinosus deeper). Bluntly dissect around each tendon with finger or small curved clamp (pass clamp around tendon separating from surrounding tissue). FREE TENDONS from surrounding tissue by finger dissection posteriorly (release posterior attachments and adhesions - critical for adequate stripping length). CRITICAL: Identify and divide any ACCESSORY DISTAL BANDS (semitendinosus often has 2-3 distal slips inserting separately on tibia - failure to release these accessory bands causes premature stripping with inadequate graft length). Use right-angle clamp to pass around each tendon proximally. Clamp each tendon with Kocher clamp or snap tendon stripper and transect at distal tibial insertion with scalpel (cut 1-2cm from tibial attachment to preserve enough distal stump for instrument grip). Pass closed tendon stripper (8mm diameter cylindrical stripper) over each freed tendon, advancing proximally along tendon while maintaining firm tension on distal end. Strip each tendon with steady firm pull (not yanking motion - slow steady pressure), protecting posterior structures by keeping stripper pressed against posterior tibia (do not allow stripper to migrate posteriorly into popliteal fossa where vascular structures located 3-4cm posterior). Typically strips to approximately 25-30cm length (may feel subtle 'pop' as muscle-tendon junction releases). Harvest both gracilis and semitendinosus tendons. Expected combined length greater than 24cm (minimum to create adequate quadruple-strand graft with sufficient length for tunnels and fixation - if less than 24cm may need to consider alternative graft or triple-strand technique). GRAFT PREPARATION (back table by assistant or surgeon): Clean each tendon of all muscle fibers and fascial tissue using scalpel and moist gauze (remove all non-tendinous tissue - muscle compromises graft strength). Measure each tendon length with ruler (typical 26-30cm each). Create QUADRUPLE-STRAND construct: fold gracilis tendon in half (creates 2 strands), fold semitendinosus in half (creates 2 strands), align all 4 free ends together (creates graft with 4 parallel strands - combined cross-sectional area provides strength). Whipstitch both ends with #2 non-absorbable braided suture (Fiberwire, Ethibond, TigerWire) using locking Krackow or baseball stitch pattern - minimum 2.5cm whipstitch length for each end (longer whipstitch distributes load and prevents pullout during tensioning). Alternative: running locked whipstitch technique. Ensure sutures tight and secure. SIZE GRAFT: Pass graft through cylindrical sizers (start at 7mm, progress through 7.5mm, 8mm, 8.5mm, 9mm, 10mm until graft no longer passes easily) - record final diameter that graft passes through. Ideal diameter 8-9mm (studies show less than 7mm has higher failure rate up to 2-3x, especially in young athletes; greater than 9mm acceptable and may be stronger but can be difficult to pass through tunnels). If less than 8mm diameter, consider triple-strand technique (fold one tendon in half, leave other straight creating 3 strands) or switching to BTB graft in high-demand athlete. Attach graft to TENSIONING BOARD: secure one end to fixed point on board, attach other end to weight typically 20-25 pounds / 90-110 Newtons (or use spring mechanism with calibrated tension). Allow graft to pre-tension for 10-15 minutes while performing arthroscopy and diagnostic evaluation (eliminates initial creep from tendon viscoelasticity - critical step). This pre-tensioning eliminates 1-2mm of initial graft elongation that would otherwise occur post-operatively causing laxity. Keep graft moist with saline-soaked sponge while on tensioning board.

Step 2: Arthroscopic Portal Establishment and Diagnostic Arthroscopy

Arthroscopic Portal Establishment and Diagnostic Arthroscopy: Establish ANTEROLATERAL (AL) PORTAL first as primary viewing portal. Landmarks: 1cm proximal to joint line, just lateral to lateral edge of patellar tendon (soft spot palpable when knee flexed 90 degrees - depression lateral to patellar tendon). Infiltrate with local anesthetic with or without epinephrine (20ml 0.5 percent ropivacaine with 1:200,000 epinephrine - provides post-operative pain control and reduces intra-operative bleeding). Make 5mm vertical or transverse skin incision with #11 blade. Use sharp trocar or switching stick to penetrate capsule with knee flexed 90 degrees (aim toward intercondylar notch, feel 'pop' as trocar penetrates capsule and enters joint). Remove trocar and insert 30-degree arthroscope with inflow attached (gravity inflow or pump set to 40-60mmHg pressure). Perform SYSTEMATIC DIAGNOSTIC ARTHROSCOPY (follow consistent sequence every case to avoid missing pathology): (1) SUPRAPATELLAR POUCH - extend knee fully and advance scope proximally above patella into suprapatellar pouch. Inspect for loose bodies (osteochondral fragments, meniscal fragments), synovitis (thickened inflamed synovium suggests inflammatory arthritis or chronic ACL tear), visualization of quadriceps tendon (normally white glistening tendon), evaluate effusion character (hemarthrosis acute ACL injury, clear chronic, purulent suggests infection). (2) PATELLOFEMORAL JOINT - slowly flex and extend knee while viewing patellofemoral articulation. Track patella through range of motion. Assess articular cartilage of patella (medial facet, lateral facet, central ridge) and trochlea (medial facet, lateral facet, central groove) using Outerbridge classification (grade 0 normal, grade 1 softening, grade 2 superficial fissures, grade 3 deep fissures to subchondral bone, grade 4 exposed bone). Note any chondral lesions, tracking abnormalities, tilt or subluxation. (3) MEDIAL COMPARTMENT - slowly flex knee to approximately 30-40 degrees and apply valgus stress to open medial compartment (assistant pushes knee laterally or use valgus stress device). Visualize MEDIAL MENISCUS systematically: posterior horn (most common tear location with ACL injury - trapped during pivot shift mechanism), body, anterior horn. Probe meniscus at each segment with arthroscopic probe - assess stability and integrity. Look for vertical longitudinal tears (run parallel to circumferential fibers, bucket-handle configuration if displaced), radial tears (perpendicular to fibers), horizontal cleavage tears (split meniscus into superior and inferior leaves, degenerative pattern), meniscal root avulsions (detachment from tibial insertion). Test meniscal stability with probe (firmly attached at periphery equals normal, mobile fragment suggests tear). Assess medial tibial plateau and medial femoral condyle cartilage. (4) INTERCONDYLAR NOTCH - identify ACL remnant. Confirm ACL RUPTURE by visualizing disrupted fibers, empty footprints, "empty notch" sign. Assess stump location (femoral avulsion versus mid-substance tear versus tibial avulsion - mid-substance most common 70 percent), stump quality (acute tear with good quality hemorrhagic remnant versus chronic tear with poor quality friable stump), identify femoral and tibial footprints. Visualize PCL - should be intact and tight when knee flexed (bowstring appearance). Check PCL integrity with posterior drawer. Note lateral femoral condyle and posterior lateral tibial plateau bone bruising (contusion from pivot shift mechanism - hallmark of ACL injury). (5) LATERAL COMPARTMENT - extend knee slightly and apply varus stress to open lateral side (push knee medially). Visualize LATERAL MENISCUS systematically: posterior horn, popliteal hiatus (normal gap between posterior horn and body where popliteus tendon passes - do not mistake for tear), body, anterior horn. Lateral meniscus tears less common than medial with ACL injury but assess thoroughly. Use probe to test stability. Identify lateral recess, popliteus tendon (shiny white cord running posterolaterally), lateral meniscotibial ligament. Assess LCL insertion site, lateral capsule integrity. Assess lateral tibial plateau and lateral femoral condyle cartilage. (6) MEDIAL GUTTER - flex knee and advance scope medially posterior to medial femoral condyle. Recheck medial meniscus posterior horn from different viewing angle (better visualization of peripheral tears). Visualize posteromedial capsule. Establish ANTEROMEDIAL (AM) PORTAL under direct arthroscopic visualization (viewing from AL portal with knee flexed 90 degrees). Use spinal needle (18-gauge) to identify ideal trajectory - insert needle from proposed site (2-3cm medial to medial border of patellar tendon, at joint line level), advance into joint under arthroscopic visualization. Aim for center of joint with ability to reach lateral wall of intercondylar notch (for femoral tunnel drilling) and posterior horn of lateral meniscus (for instrumentation). Ideal AM portal position: just medial to medial edge of patellar tendon (2-3cm medial), at joint line level (avoid too high which causes intra-articular fat pad obstruction, avoid too low which limits access to posterior structures). Test trajectory with spinal needle - should reach posterolateral aspect of lateral wall (10-11 o'clock position on right knee) when knee hyperflexed to 110-120 degrees. Once trajectory confirmed with needle, remove needle and make 5mm skin incision at needle entry site. Penetrate capsule with trocar under arthroscopic visualization (watch trocar enter joint). This AM portal serves as primary WORKING PORTAL for all instrumentation and critical portal for femoral tunnel drilling (AM portal technique). DOCUMENT all pathology found (ACL tear, meniscal tears, cartilage lesions, other findings) - dictate findings or record in operative note for accurate documentation.

Step 3: Meniscal Pathology Management (If Present)

Meniscal Pathology Management (If Present): If meniscal tear identified on diagnostic arthroscopy, address BEFORE proceeding with ACL reconstruction (meniscal repair healing improved with stable knee from ACL reconstruction). DECISION: REPAIR versus RESECTION. INDICATIONS FOR REPAIR (favor repair whenever possible - meniscus preservation prevents osteoarthritis): (1) Peripheral location - RED-RED ZONE (outer one-third within 3-4mm of capsule, excellent blood supply from perimeniscal capillary plexus) or RED-WHITE ZONE (middle one-third 4-6mm from capsule, intermediate vascularity). WHITE-WHITE zone (inner one-third, avascular) cannot heal - resect unstable fragments only. (2) Tear pattern - vertical longitudinal (parallel to circumferential fibers, bucket-handle configuration) - IDEAL for repair with 85-90 percent healing rate. Radial tears (perpendicular to circumferential fibers) harder to repair with lower healing (50-60 percent) but consider if peripheral (radial tears disrupt hoop stress mechanism). Horizontal cleavage tears (degenerative pattern splitting meniscus horizontally) - typically resect (poor healing 20-30 percent). Complex multiplanar tears - usually resect (poor healing). (3) Tear acuity - acute traumatic tears in young patients heal better (80-90 percent) than chronic degenerative tears in older patients (50-60 percent). (4) Concomitant ACL reconstruction - dramatically improves meniscal repair healing rates from 60-70 percent (isolated meniscal repair) to 85-90 percent (repair with ACL) due to stable knee environment reducing shear forces and hemarthrosis providing fibrin clot and growth factors. CONTRAINDICATIONS TO REPAIR: Chronic degenerative tears (frayed edges, poor tissue quality), white-white zone central location (avascular, no healing potential), complex multiplanar tears (difficult to repair, poor outcomes), extensive meniscal damage (greater than 50 percent destroyed, insufficient remaining meniscus), poor tissue quality (thinned, attenuated), patient factors (non-compliant with protected rehabilitation, elderly sedentary). REPAIR TECHNIQUE using ALL-INSIDE devices (most common contemporary technique): (1) PREPARE tear site - use motorized shaver or meniscal rasp to FRESHEN/ABRADE edges of tear on both superior and inferior leaves (remove fibrocartilage surface layer exposing underlying vascular tissue, promotes bleeding and healing response). Use rasp or curette to abrade adjacent synovial capsule (enhance vascularity and bleeding). Some surgeons make small trephination holes across tear with spinal needle (channel blood from capsule into tear site promoting fibrin clot formation). Apply fibrin clot (take blood from arthroscopic portal, inject into tear site to provide scaffold for healing). (2) REDUCE displaced fragments - use arthroscopic probe, meniscal grasper, or spinal needle to reduce displaced bucket-handle fragment back to anatomic position (align edges perfectly for healing). Hold reduction with probe while inserting repair device. (3) SELECT all-inside meniscal repair device (pre-loaded sutures with anchors deployed extra-articularly on capsular side): FasT-Fix (Smith and Nephew - two anchors connected by suture), Omnispan (Arthrex - adjustable suture bridge), Sequent (ConMed - bio-absorbable anchors), Crossfix (Cayenne Medical - knotless adjustable), Ultra FasT-Fix (self-adjusting implant). (4) INSERT device through working portal (typically AM portal for medial meniscus, AL portal for lateral meniscus). Insert device needle through meniscus body on superior surface, pass across tear, exit on capsular (peripheral) side of meniscus on inferior surface. DEPLOY anchors on extra-articular capsular side (outside meniscus in synovial tissue - anchors grab capsule). Withdraw device needle leaving suture across tear connecting anchors. (5) TENSION and TIE suture - pull suture to bring tear edges together (reduce tear), tie arthroscopic knot or use self-locking mechanism depending on device (most modern devices self-adjust and lock). Place MULTIPLE repair devices along length of tear spaced 4-5mm apart (typical tear requires 2-4 devices depending on length - 1-2cm tear needs 2 devices, 3-4cm bucket-handle needs 4 devices). Start posteriorly and work anteriorly. (6) CHECK stability of repair with probe - meniscus should be stable to probing, tear edges well-opposed and reduced. No gap at repair site. ALTERNATIVE TECHNIQUES: INSIDE-OUT repair (gold standard for posterior horn tears, provides strongest repair but requires posteromedial or posterolateral safety incisions with retractors to protect neurovascular structures - more invasive, risk of nerve injury): Pass long flexible needles with sutures from inside joint through meniscus and capsule to outside, retrieve sutures through safety incision, tie over capsule extra-articularly. Requires posteromedial incision for medial meniscus (protect saphenous nerve and vein) or posterolateral incision for lateral meniscus (protect common peroneal nerve, popliteal vessels). OUTSIDE-IN repair (for anterior horn tears accessible from anterior): Pass sutures from outside through capsule and meniscus to inside joint, retrieve intra-articularly, tie arthroscopically or extra-articularly. POST-OPERATIVE IMPLICATIONS of meniscal repair: Requires MODIFIED REHABILITATION protocol - (1) Limit deep flexion greater than 90 degrees for first 6 weeks (protects posterior horn repairs from excessive hoop stress), (2) Protected weight-bearing with crutches for 4-6 weeks (partial weight-bearing 20-50 percent or toe-touch depending on surgeon preference and tear location), (3) Hinged brace locked at 0-90 degrees for 4-6 weeks (prevents excessive flexion), (4) Delayed return to impact activities (running 4-5 months versus 3-4 months isolated ACL), (5) Delayed return to sport (12-15 months versus 9-12 months isolated ACL), (6) Repair failure rate 10-15 percent with protected rehabilitation (versus 20-40 percent if not protected) - manifests as recurrent mechanical symptoms (catching, locking, pain) requiring subsequent meniscectomy. Counsel patient on importance of compliance with protected rehabilitation to maximize repair healing.

Step 4: ACL Remnant Debridement and Notchplasty (If Needed)

ACL Remnant Debridement and Notchplasty (If Needed): GOAL: Adequately debride ACL remnant to visualize anatomic femoral and tibial footprints for accurate tunnel placement, while potentially preserving some remnant for proprioception and vascularity if using remnant-preserving technique. Use motorized shaver (4.0-5.5mm aggressive full-radius blade) and radiofrequency ablation device. Viewing from AL portal, working through AM portal. IDENTIFY KEY ANATOMIC LANDMARKS for femoral footprint: (1) LATERAL INTERCONDYLAR RIDGE (also called Resident's Ridge) - vertical bony ridge on lateral wall of intercondylar notch (medial aspect of lateral femoral condyle), marks ANTERIOR border of femoral ACL footprint. Easily palpated with probe. (2) OVER-THE-TOP POSITION - most posterior-superior point on lateral wall where lateral femoral condyle curves over posteriorly to become posterior condyle (no articular cartilage at this transition point). Marks POSTERIOR boundary of femoral footprint. Identified by passing probe over top of condyle posteriorly (probe drops off posterior edge into posterior fossa). (3) BIFURCATE RIDGE - subtle horizontal ridge separating anteromedial (AM) bundle footprint (inferior) from posterolateral (PL) bundle footprint (superior) on femoral side - can be subtle or absent, not always visualized. (4) LATERAL FEMORAL CONDYLE articular cartilage margin - marks superior/proximal boundary of footprint (femoral footprint located 2-3mm distal to inferior edge of weight-bearing articular cartilage). DEBRIDE ACL REMNANT: Remove torn ACL fibers with motorized shaver using aggressive cutting technique (shaver toward tissue) - remove stump from intercondylar notch to expose footprints. Consider preserving some tibial stump if good quality and not obscuring view (remnant-preserving technique may provide proprioception and vascularity benefits, though evidence mixed). Use radiofrequency ablation device to shrink and remove soft tissue and achieve hemostasis (stop bleeding for better visualization). Goal is clear visualization of both FEMORAL and TIBIAL footprints without obscuring tissue. TIBIAL FOOTPRINT identification: Located on tibial plateau posterior to anterior horn of lateral meniscus, anterior and slightly lateral to PCL tibial insertion, medial to lateral tibial spine, centered approximately at junction of anterior one-third and posterior two-thirds of tibia in AP dimension. Classic teaching: 7mm anterior to posterior tibial cortex on lateral fluoroscopic view (though arthroscopic visualization more accurate). Can mark footprint center with electrocautery tip or microfracture awl for reference during tibial tunnel drilling. ASSESS INTERCONDYLAR NOTCH WIDTH: Flex knee to 90 degrees and view intercondylar notch from AL portal. Assess if notch is narrow/stenotic which may cause graft impingement on lateral wall or roof. Historic teaching: Perform routine notchplasty on all ACL reconstructions. MODERN approach: Notchplasty often NOT needed if using anatomic tunnel position with AM portal femoral tunnel technique (creates more posterior oblique tunnel with less impingement risk than anterior vertical tunnel from old transtibial technique). INDICATIONS FOR NOTCHPLASTY (selective, not routine): (1) Obvious notch stenosis on MRI or arthroscopy (Blumensaat line to intercondylar notch width ratio less than 0.2 on lateral X-ray indicates stenosis), (2) Visible graft impingement on lateral wall during ROM testing (simulate graft with probe - if probe rubs on lateral wall during extension to flexion ROM, indicates impingement requiring notchplasty), (3) Narrow notch preventing adequate footprint visualization (cannot see entire femoral footprint due to tight space). NOTCHPLASTY TECHNIQUE (if indicated): Use motorized burr (4.0-5.5mm round or oval burr) or osteotome. Remove bone from LATERAL WALL of intercondylar notch (medial aspect of lateral femoral condyle) - NOT from medial wall (lateral aspect of medial femoral condyle) or roof (distal femur). Remove bone CONSERVATIVELY - goal is relieve impingement without creating massive defect, not create wide notch. Remove anterior osteophytes if present (common in chronic ACL deficiency). Typical bone removal: 3-5mm width from lateral wall. Use burr with high speed and light pressure avoiding plunging (control burr carefully to prevent skipping onto articular cartilage or diving too deep). Work from anterior to posterior along lateral wall. CHECK IMPINGEMENT after notchplasty: Test with knee in full extension (bring knee to 0 degrees while viewing from AL portal) - use probe to simulate where graft will be positioned, check clearance between graft position and lateral wall/roof. Probe should not contact lateral wall or roof throughout ROM from full extension to 90 degrees flexion. AVOID EXCESSIVE NOTCHPLASTY: Over-resection weakens lateral femoral condyle (can lead to lateral wall fracture during tunnel drilling 1-2 percent), risks posterior cortex blowout if burring too far posterior (removes bone posterior to femoral footprint compromising posterior wall of femoral tunnel), removes bone stock needed for femoral tunnel (adequate bone required for tunnel and fixation). Contemporary trend: MINIMAL or NO notchplasty with anatomic AM portal technique (90 percent of cases do not require notchplasty - only perform if clear indication for impingement or visualization). Final check: Visualize both femoral and tibial footprints clearly marked and ready for tunnel drilling.

Step 5: Femoral Tunnel Creation - Anatomic Anteromedial Portal Technique

Femoral Tunnel Creation - Anatomic Anteromedial Portal Technique: This step is CRITICAL for ACL reconstruction success determining anatomic graft position and long-term outcomes. Goal: Create femoral tunnel with intra-articular aperture positioned at CENTER of native ACL femoral footprint (specifically AM bundle footprint center) for anatomic graft orientation and function. TECHNIQUE: ANTEROMEDIAL PORTAL technique for independent femoral tunnel drilling (NOT transtibial technique which is outdated and non-anatomic). POSITIONING: Flex knee to 110-120 degrees of hyperflexion (relaxes superficial capsular fibers improving access to posterior footprint on lateral wall, opens intercondylar notch allowing better visualization and instrumentation). May need assistant to hold knee in hyperflexion or use foot support. Alternative: figure-4 position (knee flexed 90 degrees, hip flexed 45 degrees and abducted, foot externally rotated creating frog-leg position). FEMORAL FOOTPRINT IDENTIFICATION (viewing from AL portal, working through AM portal with knee hyperflexed): Footprint located on LATERAL WALL of intercondylar notch (medial aspect of lateral femoral condyle). Use probe to identify BOUNDARIES: Anterior boundary equals Resident's ridge (lateral intercondylar ridge - easily palpable vertical ridge), Posterior boundary equals over-the-top position (most posterior-superior point where condyle curves posteriorly - probe drops off edge, target position is 6-7mm ANTERIOR to this critical measurement), Superior boundary equals articular cartilage margin (inferior edge of weight-bearing cartilage - target position is 2-3mm INFERIOR to cartilage edge to avoid creating chondral defect), Inferior boundary equals roof of intercondylar notch. CLOCK FACE REFERENCE system: Viewing lateral wall en face (looking directly at wall) with knee flexed. RIGHT KNEE equals 10-11 o'clock position (12 o'clock equals superior/proximal, 3 o'clock equals posterior, 6 o'clock equals inferior/distal, 9 o'clock equals anterior). Target center of AM bundle footprint at 10:30 position. LEFT KNEE equals 1-2 o'clock position (mirror image of right knee - 12 o'clock equals superior, 9 o'clock equals posterior, 6 o'clock equals inferior, 3 o'clock equals anterior). Target 1:30 position. This represents POSTEROLATERAL position on lateral wall (posterior and low on footprint). CENTER OF FOOTPRINT marking: Use arthroscopic ruler or depth gauge to measure 6-7mm anterior to over-the-top position (critical measurement - less than 6mm risks posterior wall blowout, greater than 7mm creates anterior non-anatomic tunnel), measure 2-3mm inferior to articular cartilage margin. Mark center point with electrocautery tip or microfracture awl creating small divot for reference (helps guide wire placement). GUIDEWIRE PLACEMENT using offset femoral guide: Insert offset femoral guide through AM portal with knee in hyperflexion. Offset guide has adjustable tip offset (typically 6-7mm offset) allowing guidewire to exit on lateral femoral cortex. Position guide tip at marked center of footprint (10:30 right knee, 1:30 left knee). Guide should sit flush against lateral wall. Angle guide to aim from AM portal entry through marked footprint center toward lateral femoral cortex (will exit on lateral thigh). Alternative: use flexible curved reamer system (FlipCutter, Retro-Drill) which reams from inside-out without needing outside-in guidewire. CRITICAL CHECKPOINT before drilling guidewire: Confirm position arthroscopically - guide tip should be at marked center (6-7mm anterior to over-the-top measured with ruler, 2-3mm inferior to cartilage, centered between resident's ridge anteriorly and over-the-top posteriorly). If position incorrect, adjust guide before drilling. Can use second spinal needle through AM portal to mark ideal position and compare to guide position. DRILL GUIDEWIRE: Once position confirmed, drill 2.4mm smooth guidewire through guide from inside (footprint center) toward outside (lateral femoral cortex) - will exit on lateral thigh. Advance wire until tip penetrates lateral cortex and exits skin (may feel subtle give as wire penetrates cortex). Remove guide leaving wire in place. CONFIRM WIRE POSITION arthroscopically: Wire should enter joint at marked footprint center (10-11 o'clock right knee). If wire malpositioned (too anterior toward 11-12 o'clock or too posterior toward 9-10 o'clock or too superior toward cartilage), REMOVE wire and re-drill correctly (do not proceed with malpositioned wire - will create non-anatomic tunnel with poor outcomes). Can check wire position with lateral fluoroscopy (wire should be posterior in intercondylar notch, 6-7mm from over-the-top). MEASURE FEMORAL TUNNEL LENGTH: Use depth gauge over guidewire - insert depth gauge through AM portal, pass over wire to lateral femoral cortex, measure from intra-articular aperture (footprint center) to lateral cortex. Need MINIMUM 25-30mm tunnel length for adequate fixation (short tunnels less than 25mm risk button pulling through cortex or inadequate screw purchase). Ideal 30-35mm length. Record length (will need for selecting fixation devices). If tunnel too short (less than 25mm from small patient or wire angled too obliquely), may need to adjust wire angle or accept short tunnel and plan fixation accordingly (use longer button loop or interference screw femoral fixation). REAM FEMORAL TUNNEL using cannulated reamer over guidewire: Select cannulated reamer matching graft diameter (typically 8mm or 9mm if graft is 8-9mm diameter, some surgeons ream 0.5mm larger for easier graft passage). For outside-in technique: Insert acorn-shaped reamer from outside (lateral femoral cortex) over wire toward inside (joint). Acorn reamer creates smooth rounded tunnel aperture preventing graft abrasion on sharp bone edges. Advance reamer to pre-marked depth on reamer (based on tunnel length measurement) - typical depth 30-35mm from lateral cortex. Use power drill on low speed setting (not high speed which generates heat). Watch reamer enter joint arthroscopically from AL portal (should see reamer appear at marked footprint center). Ream to full depth. Alternative for inside-out flexible reamer: Advance flexible curved reamer through AM portal over guidewire, ream from inside toward outside (self-drilling and reaming). CRITICAL during reaming: Preserve POSTERIOR WALL integrity - must maintain 1-2mm bone thickness of posterior femoral cortex. Watch for posterior wall breakthrough arthroscopically (should not see reamer penetrate posteriorly into posterior fossa). If posterior wall intact, can use interference screw or button fixation. If posterior wall blowout occurs (see reamer or probe pass through posterior wall into fossa), requires button fixation relying on lateral cortex only (cannot use interference screw). Check posterior wall after reaming with probe or depth gauge (pass probe along posterior tunnel wall - should feel solid bone, probe should not pass through wall into posterior space). REMOVE BONE DEBRIS from tunnel: Back reamer out slowly while still rotating (clears bone chips from tunnel and flutes). Use motorized shaver to remove remaining bone debris from tunnel aperture and joint. Irrigate copiously with arthroscopic pump. FINAL CHECK of femoral tunnel: Pass probe through tunnel from joint to lateral cortex - should feel smooth cylindrical tunnel, intact posterior wall (probe does not pass through posteriorly), tunnel positioned at anatomic footprint center (10-11 o'clock right knee), tunnel length 30-35mm adequate for fixation, tunnel diameter matches graft (passes probe of same diameter as graft easily). Record femoral tunnel parameters (length, diameter, position) in operative note.

Step 6: Tibial Tunnel Creation - Anatomic Footprint Technique

Tibial Tunnel Creation - Anatomic Footprint Technique: GOAL: Create tibial tunnel with intra-articular aperture positioned at CENTER of native ACL tibial footprint for anatomic graft position and optimal biomechanics. TIBIAL FOOTPRINT ANATOMY: Located on tibial plateau posterior to anterior horn of lateral meniscus, anterior and slightly lateral to PCL tibial insertion, medial to lateral tibial spine. In AP dimension: Center of footprint at junction of anterior 43 percent and posterior 57 percent of tibial width (classic teaching says 7mm anterior to PCL insertion). In mediolateral dimension: Centered or slightly lateral (not purely medial). Shape is oval/elliptical oriented anteroposterior. VISUALIZATION: View from AL portal with knee flexed 90 degrees, working instruments through AM portal. Use motorized shaver and radiofrequency ablation to remove soft tissue and clearly visualize footprint (should see exposed bone of tibial plateau). Use arthroscopic ruler or depth gauge to measure from anterior horn of lateral meniscus (reference point) to center of footprint (typically 5-7mm posterior to anterior horn attachment). Can mark center with electrocautery tip creating small divot. GUIDEWIRE PLACEMENT: Use tibial ACL guide (external guide positioned on anterior tibia with intra-articular arm positioned at footprint center). Typical tibial guide angles: 50-55 degrees from horizontal (creates oblique tunnel from anterior tibial cortex to posterior footprint on plateau). More vertical angles (60-70 degrees) create anterior footprint position risking graft impingement and roof blowout (avoid). Flatter angles (40-45 degrees) create posterior footprint position risking PCL injury and posterior cortex blowout (avoid). Ideal 50-55 degrees balances anatomic position with safety. EXTERNAL GUIDE POSITION: Place guide on ANTEROMEDIAL aspect of proximal tibia (NOT anterior midline). Entry point should be 3-4cm distal to joint line (below tibial tubercle apophysis in skeletally immature, at tubercle level in skeletally mature) and medial enough to avoid lateral cortex blowout but not so medial that tunnel too oblique. Mark skin incision site (if not already incised). Incise skin 1.5cm vertical or longitudinal (protect infrapatellar branch of saphenous nerve which crosses anterior tibia obliquely - subcutaneous nerve providing sensation to anterior knee, injury causes numb area but no functional deficit, dissect bluntly to identify and protect). Develop subcutaneous tissues down to periosteum of tibia. Place guide sleeve through incision onto anterior tibial cortex. INTRA-ARTICULAR GUIDE ARM: Pass intra-articular arm of tibial guide through AM portal into joint. Position tip of guide at marked center of tibial footprint (viewing from AL portal). Confirm position: 5-7mm posterior to anterior horn of lateral meniscus, anterior and lateral to PCL, centered on footprint, not impinging on PCL or posterior horn of medial meniscus. Typical footprint center corresponds to "7mm anterior to PCL" measurement on lateral fluoroscopy (though arthroscopic visualization more accurate than fluoroscopy). CRITICAL CHECKPOINT: Verify guide arm position arthroscopically before drilling wire - should be at anatomic footprint center, not too anterior (would cause roof impingement) or too posterior (would risk PCL injury), not too medial or lateral. Can use second spinal needle as marker to compare positions. DRILL GUIDEWIRE: With guide stabilized (assistant holds external guide firmly against anterior tibia, surgeon controls intra-articular arm position), drill 2.4mm smooth guidewire from outside (anterior tibia) toward inside (joint) through guide from anterior tibial cortex through footprint center exiting posteriorly on tibial plateau. Watch wire advance arthroscopically (should emerge exactly at marked footprint center). COMMON ERROR: Wire position migrates medially or laterally during drilling if guide not held firmly (wire skives off bone) - maintain firm pressure on guide throughout drilling. Advance wire fully until tip well beyond posterior cortex of tibia (into soft tissues posteriorly) to prevent wire pullback during reaming. CONFIRM WIRE POSITION arthroscopically: Intra-articular wire exit should be at marked footprint center (5-7mm posterior to anterior horn lateral meniscus, anterior and lateral to PCL, centered mediolaterally). If malpositioned, REMOVE wire and re-drill (do not proceed with malpositioned wire). Can confirm with lateral fluoroscopy (wire should emerge at junction of anterior one-third/posterior two-thirds of tibia or 7mm anterior to posterior tibial cortex). MEASURE TIBIAL TUNNEL LENGTH: Use depth gauge over guidewire measuring from anterior tibial cortex (entry point) to posterior cortex (exit point on tibial plateau). Typical tibial tunnel length 40-50mm depending on patient size and tunnel angle. Record measurement (needed for interference screw length selection - screw should be 5-10mm shorter than tunnel to avoid screw prominence). REAM TIBIAL TUNNEL: Select cannulated reamer matching graft diameter (typically 8-9mm if graft is 8-9mm diameter). Some surgeons ream 0.5mm larger for easier graft passage, others match exactly for tighter fit. Insert cannulated reamer over guidewire from outside (anterior tibia incision) toward inside (joint) using power drill on low speed. Advance reamer slowly with steady pressure watching arthroscopically as reamer emerges at footprint center. Ream to full depth until reamer exits posteriorly on tibial plateau (should see reamer break through into joint at marked footprint). CRITICAL during reaming: Avoid OVER-REAMING - stop once reamer aperture fully emerges at footprint (do not advance further or will enlarge aperture excessively creating keyhole defect). Watch for PCL proximity (reamer should not contact or abrade PCL fibers - if PCL at risk, may need to adjust wire position more anteriorly or laterally). Maintain straight trajectory (do not angle reamer or will create elliptical tunnel). BACK REAMER OUT while still rotating (clears bone chips from tunnel). Remove guidewire. DEBRIS REMOVAL: Use motorized shaver through AM portal to remove bone debris from tibial tunnel aperture and joint. Use suction through anterior tibial incision to clear tunnel of bone chips and blood. Irrigate copiously. TUNNEL MEASUREMENT with dilator: Pass graduated dilator probe through tibial tunnel from outside to inside confirming tunnel diameter (should accept probe matching graft size), measuring tunnel length (40-50mm typical), checking for smooth cylindrical tunnel without sharp edges at aperture that could abrade graft. APERTURE EDGES: Inspect arthroscopically - tibial tunnel aperture should have smooth rounded edges (not sharp bone spicules that would abrade graft fibers causing graft failure over time from repetitive microtrauma). If sharp edges present, use rasp or curette to smooth edges, or use motorized burr to chamfer edges creating beveled transition from tunnel to joint. FINAL CHECK: Pass switching stick or looped suture through tibial tunnel from outside to inside (emerges in joint at footprint center) - will use this to pass graft later. Confirm tibial tunnel position anatomic (center of footprint), adequate length (40-50mm), appropriate diameter (matches graft), smooth aperture (no sharp edges), does not impinge on PCL or menisci, does not communicate with femoral tunnel (separate independent tunnels). Record tibial tunnel parameters (length, diameter, position) in operative note.

Step 7: Graft Passage into Joint

Graft Passage into Joint: GOAL: Pass prepared hamstring graft through tibial tunnel into joint and subsequently through femoral tunnel for fixation without damaging graft or introducing infection. TIMING: Perform graft passage after BOTH tunnels created (femoral and tibial) and measured. PREPARATION: Have graft ready on back table in moist sponge soaked with saline or antibiotic solution (keep graft hydrated throughout - do NOT allow graft to dry which weakens collagen fibers). Ensure sutures secure at both ends (typically 5-6 whipstitches creating 15-20mm suture-tendon interface preventing suture pullout), measure final graft length with sutures (record in operative note). PASSING SUTURE PLACEMENT: Thread passing suture (typically No. 2 or No. 5 braided non-absorbable suture or heavy silk suture or thick looped suture) through tibial tunnel from OUTSIDE (anterior tibia) to INSIDE (joint) using long suture passer or looped wire or passing rod. Watch arthroscopically as passing suture emerges from tibial tunnel aperture into joint. Pull passing suture fully through until suture exits anteriorly through anterior tibial incision (now have passing suture loop extending from tibial incision through tunnel into joint). GRAFT ATTACHMENT TO PASSING SUTURE: Remove graft from sterile field maintaining sterility. Attach FEMORAL END of graft (end with femoral fixation device - typically suspensory button already attached with adjustable loop or fixed loop, or end intended for femoral tunnel if using interference screw) to passing suture. Use square knot or surgeon's knot securely tying graft sutures to passing suture (ensure knot will not come loose during passage). Alternative: If using button fixation, button suture loops serve as passing suture (no separate passing suture needed - pull button loops to pass graft). GRAFT PASSAGE TECHNIQUE: Assistant or surgeon slowly pulls passing suture from anterior tibial incision (outside) while second surgeon feeds graft into tibial tunnel from back table and monitors arthroscopically. CRITICAL: Graft must pass smoothly through tunnel without twisting, bunching, or catching on tunnel edges. Watch arthroscopically as graft emerges from tibial tunnel aperture into joint (should see graft advance steadily without resistance). If graft catches or bunches (common at tunnel aperture if edges sharp), STOP pulling - may need to release tension, smooth tunnel edges with rasp or curette, re-attempt passage. Continue pulling until entire graft length passes through tibial tunnel into joint with femoral end of graft positioned intra-articularly (ready for femoral tunnel passage). CONFIRM GRAFT ORIENTATION: Ensure graft not twisted 180 degrees or 360 degrees (twisted graft weakens biomechanical properties reducing ultimate failure load by 20-30 percent and creates abnormal stress distribution leading to accelerated failure). Arthroscopically visualize graft in joint (should be smooth and uniform without visible twisting - can see suture pattern should be consistent). If twisted, pull graft back out and re-pass correctly oriented. NEXT STEP PREPARATION: Position femoral end of graft at entrance of femoral tunnel (use probe or grasper through AM portal to guide graft toward femoral tunnel opening on lateral wall of intercondylar notch). For BUTTON FIXATION: Pass button and suture loops through femoral tunnel first (button will deploy on lateral femoral cortex extra-articularly), then pull graft up into tunnel. For INTERFERENCE SCREW femoral fixation: Pass graft directly into femoral tunnel, advance graft to full depth, then insert screw alongside graft.

Step 8: Femoral Fixation

Femoral Fixation: GOAL: Securely fix femoral end of graft in femoral tunnel with fixation strong enough to allow early rehabilitation without fixation failure or graft pullout during healing phase (minimum 6-12 weeks until graft-bone healing provides biological fixation). TWO main femoral fixation methods: (1) SUSPENSORY BUTTON FIXATION (Endobutton, TightRope, RetroButton) - current most common method 60-70 percent of surgeons. (2) INTERFERENCE SCREW fixation (bioabsorbable or metal screw inserted alongside graft in tunnel). BUTTON FIXATION TECHNIQUE (if using button): Graft attached to button with adjustable loop or fixed loop suture construct on back table during preparation. Button already connected to graft femoral end. PASS BUTTON through femoral tunnel: Use button passing pin or suture to pull button and graft together from joint (intra-articular position) through femoral tunnel toward lateral femoral cortex (extra-articular position). Watch arthroscopically and palpate lateral thigh as button advances (can feel button traverse tunnel). Continue pulling until button fully exits femoral tunnel onto lateral femoral cortex. FLIP BUTTON: Once button clears tunnel, button designed to flip 90 degrees lying flat against lateral cortex (continuous outline button design like Endobutton flips automatically when tensioned, adjustable loop buttons like TightRope require specific flipping maneuver). Confirm button flip: (1) Arthroscopically - should see graft advance into femoral tunnel as button seats on cortex, (2) Palpate lateral thigh - feel button lying flat against cortex (distinct hard edge under skin), (3) Fluoroscopy - lateral view shows button parallel to femoral shaft on lateral cortex. TENSION GRAFT: Pull on tibial end of graft from anterior tibia while cycling knee through ROM (flexion-extension 0-120 degrees repeated 20-30 cycles) to tension graft and remove slack from fixation construct. Tensioning important for adjustable loop buttons (loop tightens as graft pulled reducing loop length and seating graft firmly in tunnel). Fixed loop buttons already at set length. FINAL SEATING: Ensure button flat against lateral cortex with graft pulled to appropriate tension (typically 20-30 pounds tension or moderate pull). Knee flexed to 20-30 degrees during tibial fixation (some surgeons prefer full extension 0 degrees or 15 degrees - controversy regarding optimal knee angle, generally 15-30 degrees flexion accepted). Button fixation ADVANTAGES: Does not require intact posterior femoral cortex (works even with posterior wall blowout), provides very strong fixation (typically 800-1200N pullout strength exceeding native ACL strength), allows graft length adjustment with adjustable loop (can modify graft position by pulling to change loop length), less risk of graft laceration compared to interference screw (no screw threads cutting fibers). DISADVANTAGES: Button prominence on lateral thigh (10-20 percent patients feel button under skin, rarely painful or bothersome), theoretical concern for graft toggle or windshield wiper effect (graft motion within tunnel before graft-bone healing - may enlarge tunnel though clinical significance debated), higher cost than interference screw. INTERFERENCE SCREW FEMORAL FIXATION TECHNIQUE (alternative to button): Graft passed into femoral tunnel to full depth (usually leaving 5mm of graft extending beyond tunnel into joint for later tensioning). Select interference screw size: Diameter should be SAME as tunnel diameter (8mm tunnel uses 8mm screw, 9mm tunnel uses 9mm screw), or 1mm larger (9mm screw in 8mm tunnel - not commonly used as risks damaging graft from compression). Length should be 5-10mm SHORTER than tunnel length (femoral tunnel 30mm uses 20-25mm screw - shorter screw prevents screw prominence beyond lateral cortex and reduces risk of screw diverging into joint or out posterior cortex). Material: Bioabsorbable (PLLA, PLGA copolymers) most common current practice (gradual resorption over 12-24 months replaced by bone, eliminates hardware, avoids interference with future surgery like revision or TKA), metal (titanium) alternative (stronger pullout but permanent, can interfere with MRI imaging artifact, may complicate revision surgery if needed years later). SCREW INSERTION: Insert cannulated screw over guidewire OR use non-cannulated screw with self-drilling/self-tapping design. Position screw ALONGSIDE graft (not through graft center which would lacerate fibers). Use screw driver to advance screw into femoral tunnel parallel to graft and tunnel axis. CRITICAL: Screw should compress graft against tunnel wall (wedging graft between screw threads and bone creating friction fixation). Advance screw to depth where screw head sits flush with lateral femoral cortex or slightly recessed (not prominent which could irritate soft tissues or cause pain). Typical depth: Insert until resistance increases indicating screw fully seated (do not over-tighten which can strip screw or break screw especially bioabsorbable screws which weaker than metal). SCREW FIXATION ADVANTAGES: Lower cost than button, avoids prominence on lateral cortex (screw head recessed), may provide better graft-bone healing (compression at graft-bone interface enhances healing though evidence mixed). DISADVANTAGES: Requires intact posterior femoral cortex (posterior wall blowout contraindication for interference screw as screw relies on posterior wall for purchase), risk of graft laceration from screw threads (can weaken graft by cutting fibers if screw malpositioned through graft center or over-advanced), bioabsorbable screws can break during insertion (brittle material fractures if excessive torque 5-15 percent breakage rate, usually not clinically significant), screw divergence (screw does not follow tunnel axis and exits posteriorly or into joint - serious complication requiring screw removal and re-fixation). CONFIRM FEMORAL FIXATION SECURITY: Test fixation by pulling on tibial end of graft with moderate force (20-30 pounds tension) - graft should not pull out of femoral tunnel or show excessive motion. Cycle knee through ROM 20-30 times (0-120 degrees flexion-extension) to remove slack and pre-condition graft. Arthroscopically visualize femoral tunnel aperture (should see graft filling tunnel without gaps, no graft pullout or toggle with ROM). FINAL CHECKPOINT before tibial fixation: Femoral fixation secure (button flipped on lateral cortex or interference screw seated at appropriate depth), graft tensioned appropriately (no slack in construct), knee can achieve full ROM (0 degrees extension to 130 degrees flexion without graft over-constraint or impingement), graft positioned anatomically in femoral tunnel (centered at AM bundle footprint 10-11 o'clock).

Step 9: Graft Tensioning and Knee Cycling

Graft Tensioning and Knee Cycling: GOAL: Remove slack from graft construct, pre-tension graft to physiologic level, cycle knee through ROM to precondition graft before tibial fixation eliminating creep (gradual lengthening under load). RATIONALE: All grafts exhibit CREEP when first loaded (viscoelastic property of collagen - under constant load tendon gradually elongates over time reaching new equilibrium length after 20-30 load cycles). If tibial fixation performed before cycling, graft will creep post-fixation causing LAXITY (graft elongates creating increased knee translation and positive pivot shift). By cycling BEFORE tibial fixation, induce creep pre-fixation then fix graft at post-creep length eliminating post-operative laxity from creep. TECHNIQUE: With femoral fixation secure (button flipped and seated, or interference screw inserted), pull on tibial end of graft from anterior tibial incision applying 15-30 pounds tension (moderate firm pull - can use tensiometer for precise measurement but most surgeons estimate by feel). While maintaining tension on graft, cycle knee slowly through full ROM: 0 degrees full extension to 120-130 degrees flexion, repeated 20-30 cycles (each cycle equals extension to flexion back to extension). Watch arthroscopically during cycling: Graft should tighten and relax with knee motion (tight in extension for AM bundle component, relatively relaxed in deep flexion - normal biomechanics), graft should fill femoral and tibial tunnels throughout ROM without gapping (no space between graft and tunnel walls), graft should NOT contact or impinge on roof of intercondylar notch or lateral wall during extension (if impingement present indicates notchplasty needed or tibial tunnel too anterior - address before proceeding). After 20-30 cycles, graft will have undergone creep and reached equilibrium length (additional cycles produce no further lengthening). Maintain tension on tibial end of graft preparing for tibial fixation. OPTIMAL KNEE POSITION FOR TIBIAL FIXATION: Controversy exists regarding ideal knee flexion angle for tibial fixation. OPTIONS: (1) FULL EXTENSION 0 degrees - historic approach, rationale: ACL tightest in full extension so fixing graft in extension ensures adequate restraint to anterior translation throughout ROM, prevents post-operative flexion contracture. (2) 15-30 DEGREES FLEXION - most common current practice, rationale: Neutral position where graft isometric (equal tension throughout ROM without over-constraint), prevents over-tensioning graft (full extension can over-tighten graft causing graft stress, loss of flexion from over-constraint, graft failure), allows slight graft relaxation in deep flexion (physiologic). (3) 20 DEGREES FLEXION with anterior drawer reduced - some surgeons apply POSTERIOR force to tibia while knee flexed 20 degrees pushing tibia posteriorly to reduce any anterior subluxation then fix graft with tibia reduced (ensures ACL graft replacing anterior translation restraint). EVIDENCE: Multiple studies show NO significant difference in outcomes regardless of fixation angle within 0-30 degree range (all positions provide equivalent laxity, IKDC scores, return to sport). Avoid fixing in FLEXION greater than 30 degrees (causes graft over-constraint in extension potentially limiting extension or over-stressing graft) or EXTENSION less than 0 degrees (hyperextension can over-tension graft). Current CONSENSUS: 15-30 degrees flexion accepted standard. MAINTAIN KNEE POSITION: Use assistant or positioning device to hold knee at chosen angle (typically 20-30 degrees flexion), confirm angle visually and with goniometer, maintain position during tibial fixation (do not allow knee to move which would alter graft tension). FINAL TENSION ON GRAFT before tibial fixation: Pull tibial end of graft with 15-30 pounds force (moderate firm pull) removing all slack - graft should be taut but not over-tensioned (excessive tension greater than 50 pounds can damage graft or cause over-constraint).

Step 10: Tibial Fixation

Tibial Fixation: GOAL: Securely fix tibial end of graft in tibial tunnel with fixation strong enough to allow early rehabilitation protocols without pullout or failure during healing phase (6-12 weeks until graft-bone healing provides biological fixation). With knee held at chosen position (typically 20-30 degrees flexion) and graft tensioned (15-30 pounds moderate pull on tibial graft end), perform tibial fixation. TWO main tibial fixation methods: (1) INTERFERENCE SCREW fixation (bioabsorbable or metal screw inserted alongside graft in tibial tunnel) - most common method 70-80 percent surgeons. (2) FIXATION OVER BONE BRIDGE or on anterior tibia with post screw, spiked washer, or button (backup fixation). INTERFERENCE SCREW TIBIAL FIXATION TECHNIQUE: Select interference screw: Diameter same as tibial tunnel (8mm tunnel uses 8mm screw, 9mm tunnel uses 9mm screw) or 1mm larger (9mm screw in 8mm tunnel for tighter interference - less common), Length should be 25-35mm (typical tibial tunnel depth 40-50mm so screw 5-15mm shorter than tunnel preventing screw from penetrating too deep and exiting posterior tibial cortex risking popliteal vessel or nerve injury). Material: Bioabsorbable (PLLA or PLGA copolymers) most common current practice (gradual resorption over 12-24 months replaced by bone, eliminates retained hardware, avoids interference with future imaging or surgery), Metal (titanium) alternative (stronger, permanent but MRI artifact and may complicate future surgery). PREPARATION: Ensure graft under tension (15-30 pounds pull on sutures attached to tibial graft end protruding from anterior tibial incision), knee held at fixation angle (20-30 degrees flexion typically). INSERT SCREW through anterior tibial incision into tibial tunnel: Position screw ALONGSIDE graft (eccentric placement - screw on one side of tunnel, graft on opposite side creating interference wedge effect between screw threads and tunnel bone). Do NOT insert screw through center of graft (would lacerate fibers weakening graft). Use screw driver to advance screw into tibial tunnel parallel to tunnel axis and graft. CRITICAL TECHNIQUE: Screw should wedge graft against opposite tunnel wall (compression fixation). Advance screw slowly with controlled torque watching for: (1) Screw advancement (should progress steadily into tunnel at rate of 1-2mm per full screw driver rotation), (2) Graft position (graft should stay alongside screw not wrap around screw which indicates graft twisting or poor screw position), (3) Resistance (steady moderate resistance indicates screw engaging bone and compressing graft - sudden loss of resistance suggests posterior cortex penetration or screw divergence). DEPTH: Advance screw until screw head sits flush with anterior tibial cortex or slightly recessed 2-3mm (recessed reduces palpability and irritation over anterior tibia). Typical depth 25-35mm from anterior cortex. AVOID over-advancing: Screw deeper than 35-40mm risks penetrating posterior tibial cortex (popliteal vessels and tibial nerve located just posterior to tibia separated only by popliteus muscle and thin posterior capsule - screw penetration can cause catastrophic vascular or nerve injury). Use depth markings on screw driver or pre-measured depth stop to control advancement. CONFIRM FIXATION: After screw inserted, release tension on graft sutures - graft should remain in place without pullout (screw compression holds graft). Pull on sutures with moderate force (10-20 pounds) testing fixation security (graft should not pull out - if pulls out indicates inadequate screw purchase and need to revise fixation with larger screw or backup fixation). Cycle knee through ROM 10-20 cycles confirming graft stays fixed without motion. BACKUP TIBIAL FIXATION (if using): Some surgeons add BACKUP fixation on anterior tibia for extra security especially with soft bone, large diameter grafts, or revision surgery. Options: (1) POST SCREW with spiked washer - screw with large spiked washer inserted into anterior tibia adjacent to tibial tunnel over graft sutures securing sutures to bone (creates backup fixation point if interference screw fails). (2) SUTURE BUTTON - button similar to femoral button deployed on anterior tibia cortex with graft sutures passed through button (suspensory tibial fixation mirroring femoral technique). (3) SCREW AND WASHER over bone bridge - if tibial tunnel has bone bridge anterior to tunnel (interference screw in tunnel, bone bridge anterior to tunnel exit site), can place screw with washer over bone bridge securing graft sutures to bridge (historical technique less common now). HYBRID FIXATION (interference screw plus backup): Provides maximum fixation strength (600-1000N combined pullout strength exceeding physiologic ACL loads), redundancy if one fixation fails (backup prevents catastrophic failure), but added complexity and cost. Not routinely necessary for primary ACL reconstruction with good bone quality and proper technique (interference screw alone provides adequate 400-800N fixation strength). Consider hybrid in: Revision ACL with bone loss or tunnel widening (compromised bone quality reducing screw holding), very large diameter grafts (greater than 10mm where single screw may not provide adequate compression), osteoporotic or poor quality bone (elderly patient or rheumatoid arthritis patient where bone weak). FINAL ASSESSMENT after tibial fixation: (1) Graft fixed securely at both femoral and tibial ends (no pullout with moderate tension test), (2) Knee achieves full ROM - 0 degrees full extension (non-negotiable must achieve full extension before closing or have extension loss complication post-op) to 120-130 degrees flexion (normal physiologic flexion), (3) Stability tests negative - Lachman test NEGATIVE (no anterior tibial translation or firm endpoint grade 0-1 maximum acceptable, grade 2-3 indicates under-tension or fixation failure requiring revision), Pivot shift test NEGATIVE (no pivot or clunk grade 0-1 acceptable, grade 2-3 indicates inadequate stability needing revision), (4) Graft appearance good arthroscopically (fills tunnels, no impingement, no twisting, smooth without fraying), (5) No complications (no vascular injury, no nerve injury, no graft damage).

Step 11: Final Assessment and ROM Confirmation

Final Assessment and ROM Confirmation: GOAL: Confirm ACL reconstruction successfully completed with adequate stability, full ROM, proper graft position and tension, no complications before closing and ending procedure. This final assessment critical quality checkpoint - identification of problems now allows correction before closing, missing problems leads to post-operative complications and possible revision surgery. SYSTEMATIC FINAL CHECKS: (1) FULL EXTENSION ACHIEVEMENT (MOST CRITICAL CHECKPOINT - extension loss is NEVER acceptable): Bring knee to full extension 0 degrees (may need assistant to apply extension force or place bump under heel allowing gravity extension). CONFIRM full extension: Visually assess knee extended flat on bed (no flexion contracture visible), use goniometer measuring 0 degrees extension (not 5 degrees or 10 degrees - must be true 0 degrees full extension matching contralateral knee), arthroscopically visualize graft position in terminal extension (graft should NOT impinge on anterior roof of intercondylar notch or lateral wall - should have 2-3mm clearance minimum), feel extension endpoint (should be firm bony endpoint indicating full extension, soft springy endpoint suggests mechanical block preventing full extension from impingement or over-constraint). IF EXTENSION LOSS PRESENT (cannot achieve 0 degrees): MUST identify cause and correct before closing - DO NOT accept extension loss "will improve with therapy" (will NOT improve if mechanical cause, leads to quadriceps shutdown, patellofemoral pain, arthritis, poor outcome, possible litigation). CAUSES of extension loss and MANAGEMENT: (a) GRAFT IMPINGEMENT on roof or lateral wall (most common cause) - graft too anterior or inadequate notchplasty. CORRECTION: Perform or extend notchplasty removing bone from anterior roof or lateral wall creating clearance (typically need 2-3mm minimum clearance), confirm clearance arthroscopically after notchplasty (see graft clear roof throughout extension), re-test extension achieving 0 degrees. (b) GRAFT OVER-CONSTRAINT from excessive tension - graft fixed too tight preventing extension. CORRECTION: Release tibial fixation, reduce graft tension (less pull on tibial graft end), re-fix tibia with appropriate tension, re-test extension. (c) CYCLOPS LESION from inadequate ACL stump debridement - residual anterior stump creates nodule. CORRECTION: Debride remaining ACL stump or fibrous tissue using motorized shaver and radiofrequency device removing anterior soft tissue blocking extension, re-test extension. (d) HEMARTHROSIS - large blood clot in joint creates stiffness. CORRECTION: Irrigate joint copiously evacuating blood and clots, re-test extension. (e) FEMORAL TUNNEL TOO ANTERIOR - creates vertical graft prone to impingement. CORRECTION: May need to abandon reconstruction and re-drill femoral tunnel posteriorly (major revision intra-operatively but necessary if tunnel critically malpositioned), or perform aggressive notchplasty accepting suboptimal graft position. NEVER LEAVE OR WITH EXTENSION LOSS - this single checkpoint prevents most common ACL reconstruction complication (extension loss). (2) ADEQUATE FLEXION: Flex knee to 120-130 degrees (normal physiologic flexion) confirming no mechanical block or over-constraint limiting flexion. IF FLEXION LIMITED (cannot achieve 120 degrees): Identify cause: (a) Graft over-tensioned - release tibial fixation and re-fix with less tension. (b) Pain or muscle guarding - adequate anesthesia should eliminate pain allowing full passive flexion (if not, may need deeper anesthesia or muscle relaxation). (c) Adhesions from prolonged case or manipulation - debride adhesions arthroscopically (rare during initial reconstruction, more common in revision or repeat arthroscopy). Typical accept minimum 120 degrees flexion before closing (mild flexion limitation less problematic than extension loss - flexion usually improves with therapy while extension loss does not). (3) STABILITY TESTING: Perform LACHMAN TEST - patient supine with knee 20-30 degrees flexion, stabilize distal femur with one hand, pull proximal tibia anteriorly with other hand assessing anterior tibial translation and endpoint. EXPECTED result: NEGATIVE Lachman (no anterior translation or firm endpoint grade 0), or trace anterior translation with firm endpoint (grade 1 acceptable). UNACCEPTABLE: Grade 2 (5-10mm anterior translation with soft endpoint) or grade 3 (greater than 10mm anterior translation with no endpoint) indicates inadequate graft tension or fixation failure - MUST revise before closing (release and re-fix tibia with more tension, or check femoral fixation if button not flipped or screw diverged). Perform PIVOT SHIFT TEST - patient supine completely relaxed under anesthesia (muscle guarding must be eliminated for valid test), flex hip 20-30 degrees, internally rotate tibia, apply valgus stress to knee, slowly flex knee from full extension toward 90 degrees feeling for "clunk" or "shift" of lateral tibial plateau reducing from subluxed to reduced position. EXPECTED result: NEGATIVE pivot shift (no clunk or shift, smooth motion throughout flexion arc grade 0), or trace shift barely palpable (grade 1 acceptable). UNACCEPTABLE: Grade 2 (moderate clunk felt but not visible) or grade 3 (gross clunk visible and felt "jump sign") indicates inadequate rotational stability from graft malposition (femoral tunnel too anterior) or under-tension - requires revision (check femoral tunnel position, check graft tension, may need to abandon and re-drill femoral tunnel if critically anterior, or increase tibial tension if under-tensioned). NOTE: Pivot shift test most sensitive and specific test for ACL function (better predictor of functional stability than Lachman or drawer) - positive post-operative pivot shift correlates with poor functional outcomes and patient dissatisfaction. (4) ARTHROSCOPIC INSPECTION: View graft from AL and AM portals systematically: Femoral tunnel aperture - graft should fill tunnel completely without gaps (tight graft-bone interface), graft positioned at anatomic footprint center (10-11 o'clock right knee), no graft fraying or damage visible, graft does not pull out of tunnel with ROM (stable fixation). Intra-articular graft course - graft should be smooth and uniform without twisting (suture pattern runs straight along graft confirming no twisting), graft tensioned appropriately (taut in extension relaxes slightly in flexion normal biomechanics), graft does not impinge on PCL or menisci during ROM. Tibial tunnel aperture - graft fills tunnel completely, smooth tunnel edges without sharp corners abrading graft, no graft fraying, graft stable without pullout. General joint inspection - no loose bodies or debris from bone or graft preparation, menisci intact without iatrogenic injury, articular cartilage intact without damage from instrumentation, ligaments intact (MCL, LCL, PCL visualized and intact), adequate hemostasis (no active bleeding from soft tissues, capsule, or bone). (5) FINAL ROM UNDER DIRECT VISUALIZATION: Cycle knee through full ROM (0 degrees extension to 130 degrees flexion) 10-20 times while viewing arthroscopically confirming: Graft clears intercondylar notch roof and lateral wall throughout ROM (no impingement at any flexion angle), graft does not contact or abrade on PCL during flexion-extension cycles, graft remains in tunnels without pullout (stable fixation), graft behavior physiologic (tightens in extension, relaxes in flexion). (6) DOCUMENT ALL FINDINGS: Record in operative note: Femoral tunnel position (clock face position measured - example "10:30 right knee"), femoral tunnel length and diameter (example "32mm length, 8mm diameter"), femoral fixation method and device (example "Endobutton CL button fixation, button flipped confirmed"), tibial tunnel position (anatomic footprint center, relation to PCL and meniscus), tibial tunnel length and diameter (example "45mm length, 8mm diameter"), tibial fixation method and device (example "8mm x 28mm bioabsorbable PLLA interference screw"), final graft tension (example "20 pounds tension at 20 degrees flexion"), final ROM achieved (example "0 degrees extension to 135 degrees flexion full ROM"), final stability testing (example "Lachman negative grade 0, pivot shift negative grade 0"), any complications or intra-operative events (example "none" or describe issue and management). (7) PREPARE FOR CLOSURE: Irrigate joint with copious saline (3-5 liters minimum removing all debris, bone chips, blood), remove all instruments from joint, perform final arthroscopic sweep visualizing all compartments clear, deflate tourniquet (if used) and achieve hemostasis (cauterize bleeding vessels, ensure no active arterial or venous bleeding), remove arthroscope.

Step 12: Wound Closure and Dressing

Wound Closure and Dressing: GOAL: Close all incisions with appropriate technique preventing infection, minimizing scarring, ensuring hemostasis. TOURNIQUET DEFLATION (if tourniquet used): Release tourniquet before closure allowing vascular reperfusion and identification of bleeding requiring cautery. Wait 5-10 minutes after deflation for blood pressure to equilibrate and identify arterial bleeders (small vessels may not bleed under tourniquet but bleed once tourniquet released). Use electrocautery to cauterize any bleeding vessels in subcutaneous tissues or capsule (bipolar cautery preferred near nerves to avoid thermal spread, monopolar cautery adequate for larger vessels). Achieve complete hemostasis before closure (no active bleeding visible minimizes post-operative hemarthrosis and hematoma formation). ANTERIOR TIBIAL INCISION CLOSURE (graft harvest site and tibial tunnel incision): Typically single 3-5cm longitudinal or oblique incision on anteromedial proximal tibia. DEEP LAYER closure (fascia/periosteum layer if violated): Close periosteum over tibial tunnel with interrupted absorbable sutures (2-0 or 3-0 Vicryl or Monocryl) reducing dead space and preventing soft tissue herniation into tunnel (periosteal closure not critical - many surgeons skip this layer). SUBCUTANEOUS LAYER: Close deep dermis/subcutaneous tissues with interrupted or running absorbable sutures (3-0 or 4-0 Vicryl or Monocryl) approximating skin edges and eliminating dead space (reduces hematoma risk and improves cosmesis). SKIN CLOSURE options: (1) SUBCUTICULAR running absorbable suture (4-0 or 5-0 Monocryl most common) - buried subcuticular stitch providing good cosmesis without need for suture removal (suture absorbs over 8-12 weeks by which time wound healed), (2) Non-absorbable interrupted or running sutures (4-0 or 5-0 nylon or Prolene) - traditional method requiring suture removal 10-14 days post-op, slightly higher tensile strength during healing but cosmesis equivalent to absorbable, (3) Skin staples - fastest closure technique (each staple takes 2-3 seconds) used commonly for speed especially in long cases, requires staple removal 10-14 days, cosmesis slightly inferior to suture (small puncture marks at each staple site), higher infection risk (staples create more tissue trauma than sutures), (4) Skin adhesive (Dermabond, surgical glue) - cyanoacrylate glue applied topically over approximated skin edges creating waterproof seal, no need for removal (glue peels off in 7-14 days as epidermis sheds), excellent cosmesis, but requires dry field (any bleeding prevents adhesion) and well-approximated edges (does not provide any closure force - only seals already-closed wound). PREFERENCE: Most surgeons use subcuticular absorbable suture for balance of cosmesis, strength, and convenience (no removal needed). STERI-STRIPS application: Apply adhesive strips perpendicular to incision over skin closure (whether sutured or glued) providing additional wound edge approximation and support (reduces tension on healing skin edges preventing dehiscence). Leave steri-strips in place 7-14 days (will peel off naturally or remove at first post-op visit). PORTAL CLOSURES (arthroscopic portals - anterolateral and anteromedial portals): Small 5-8mm incisions typically closed simply. OPTIONS: (1) Single interrupted absorbable suture (4-0 Monocryl) approximating skin edges sufficient for small portal, (2) Skin adhesive applied over portal without suture (adequate for 5mm portals if edges well-approximated), (3) Leave open (some surgeons leave portals open allowing drainage and close spontaneously - outdated practice higher infection risk, not recommended). MODERN STANDARD: Single suture or skin adhesive for all portals. LATERAL THIGH INCISION (if using suspensory femoral button fixation): Tiny 5-10mm incision over lateral femoral cortex where button deployed. Close with single interrupted absorbable suture (4-0 Monocryl) or skin adhesive. May leave lateral incision open if very small (less than 5mm) though suture closure preferred for infection prevention. DRAIN PLACEMENT decision: CONTROVERSIAL - no consensus. Options: (1) NO DRAIN - most common current practice (60-70 percent surgeons do not use drain), rationale: Modern arthroscopic technique with copious irrigation and good hemostasis creates minimal bleeding post-operatively making drain unnecessary, drains may increase infection risk by creating portal for bacterial entry, drains cause patient discomfort and limit mobility. Evidence: Multiple RCTs show no difference in hemarthrosis, pain, or outcomes with versus without drain in routine ACL reconstruction. (2) INTRA-ARTICULAR DRAIN placed through portal exiting joint and brought out through skin (10-12 Fr suction drain like Hemovac or Blake drain) - used by some surgeons especially if hemostasis suboptimal or patient on anticoagulation. Remove drain 24 hours post-op. (3) DRAIN OVER TIBIAL TUNNEL in subcutaneous plane (not intra-articular) preventing hematoma at tibial incision. CURRENT RECOMMENDATION: No drain for routine primary ACL reconstruction in healthy patient with good hemostasis (drain not beneficial and potentially harmful). Consider drain if: patient on anticoagulation (higher bleeding risk), revision ACL with extensive dissection (more bleeding expected), hemostasis suboptimal at end of case despite cautery (persistent oozing). DRESSING APPLICATION: STERILE TECHNIQUE throughout. FIRST LAYER (contact layer): Apply sterile non-adherent dressing directly on incisions (Telfa or Adaptic non-stick pad prevents dressing from adhering to wound allowing painless dressing changes). SECOND LAYER (absorbent layer): Apply sterile gauze pads (4x4 inch gauze) over non-adherent layer absorbing any drainage or bleeding (typically 4-8 gauze pads covering anterior knee including portal sites, tibial incision, and lateral thigh if present). COMPRESSION LAYER: Apply elastic bandage wrap (Ace wrap or Coban) over gauze with MODERATE circumferential compression (gentle compression reduces post-operative swelling and hemarthrosis without causing vascular compromise or compartment syndrome). Start wrap at ankle and spiral proximally to mid-thigh covering entire knee and calf. Ensure compression not excessive (should be able to insert 1-2 fingers under wrap edge indicating adequate perfusion). IMMOBILIZATION decision: (1) NO BRACE (unlocked ROM allowed immediately) - increasingly common modern approach for hamstring autograft ACL reconstruction (40-50 percent surgeons), rationale: Strong fixation allows immediate ROM without protection, early motion prevents stiffness and improves outcomes, no evidence that bracing improves stability or reduces failure rates. (2) HINGED KNEE BRACE locked in extension 0 degrees - traditional approach still used by many surgeons (50-60 percent), rationale: Protects reconstruction during early healing phase preventing excessive stress on graft, prevents flexion contracture by maintaining full extension, provides patient psychological confidence (feels protected). BRACE PROTOCOL if using: Locked in extension 0 degrees for first 24-48 hours (ensures extension maintained while nerve block wearing off and pain high), then unlock brace allowing 0-90 degrees ROM for weeks 1-2 (protected motion preventing hyperextension or excessive flexion), advance ROM in brace to 0-120 degrees weeks 3-4, discontinue brace weeks 4-6 once quadriceps control adequate and extension stable. EVIDENCE: Multiple Level 1 RCTs comparing bracing versus no bracing show no difference in outcomes (ROM, strength, stability, return to sport all equivalent). CONCLUSION: Bracing optional based on surgeon preference and patient factors (unlocked ROM allowed with strong fixation in compliant patient, consider brace for large patient, heavy manual labor occupation, or patient with poor compliance where protection beneficial). CRYOTHERAPY (ice therapy): Apply ice over dressing for first 24-72 hours post-op for pain control and edema reduction (ice reduces metabolic demand, vasoconstriction decreases bleeding and swelling, analgesic effect). Can use ice bags, cold therapy device (Cryocuff, Game Ready), or ice machine with circumferential wrap. Apply 20 minutes every 2-3 hours while awake for first 2-3 days. ELEVATION: Elevate operative leg above heart level for first 24-48 hours reducing venous pooling and edema (prop leg on pillows with ankle above heart, not just foot on stool which insufficient elevation). FINAL INSTRUCTIONS before patient leaves OR: Document and communicate to recovery room nurses and patient/family: (1) Weight-bearing status (typically weight-bearing as tolerated with crutches for comfort, full weight-bearing allowed if no meniscal repair), (2) ROM restrictions (none if unlocked, or 0-90 degrees if braced), (3) Dressing instructions (keep dressing clean and dry for 48-72 hours, may shower after 72 hours with waterproof covering, remove outer wrap at 48 hours leaving sterile gauze on incisions), (4) Pain management (prescribed opioid analgesics for 3-5 days post-op, transition to acetaminophen or NSAIDs, ice therapy), (5) DVT prophylaxis (early mobilization, ankle pumps, consider aspirin 325mg daily for 14 days in high-risk patient), (6) Follow-up appointment (typically 7-14 days post-op for wound check and early rehab assessment), (7) Warning signs requiring urgent contact (fever greater than 38.5C indicating possible infection, excessive swelling or pain out of proportion indicating compartment syndrome, loss of distal pulses or foot numbness indicating vascular or nerve injury, wound drainage or erythema suggesting infection, inability to straight leg raise indicating quadriceps rupture).

Phase 1 (0-2 weeks): Goals - control swelling, achieve full extension (0°), flexion to 90°, quadriceps activation. Weight-bearing as tolerated with crutches, unlock brace for exercises. Exercises: quadriceps sets hourly, straight leg raise when quad control adequate, heel slides, patellar mobilization, prone hangs for extension. Cryotherapy and elevation. No active hamstring exercises yet to protect healing graft.

Phase 2 (2-6 weeks): Goals - full ROM (0-130°), normalize gait, progress strengthening. Wean crutches and brace. Closed-chain exercises: wall sits, mini squats 0-60°, step-ups. Begin cycling (high seat, low resistance). Pool walking week 4. Proprioception training: single-leg balance, wobble board. Continue quad emphasis.

Phase 3 (6-12 weeks): Goals - normalize strength, functional activities. Full ROM maintained. Progress squats to 90°, lunges, step-downs. Begin open-chain quads week 8-12. Begin hamstring strengthening week 8. Swimming. Advanced proprioception with perturbation training.

Phase 4 (12-24 weeks): Goals - running program, sport-specific training. Straight-line running progression starting week 12-16. Plyometrics: double-leg then single-leg jumping. Agility drills: cutting, figure-8. Sport-specific drills. Isokinetic testing at 4 months.

Phase 5 (6-12 months): Return to sport when ALL criteria met: minimum 9 months, quad/hamstring LSI greater than 90%, hop testing LSI greater than 90%, full ROM, no effusion/pain, psychological readiness (ACL-RSI greater than 56), sport-specific training complete. Progressive RTS: non-contact training, limited contact, full practice, competition. Optimal RTS 12 months for elite athletes.

References

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