import { OnePagerSummary, ExamWarning, InfoCardGrid, InfoCard, MnemonicCard, EvidenceCard, VivaScenarioSection, VivaScenario, ExamCheatSheet, ContentSection, ExamPearl, SafetyAlert, NumberHighlightRow, NumberHighlight, Tabs, Tab, ComparisonTable } from '@/components/mdx' **Location**: Crosses anteromedial portal site subcutaneously, 1-2cm medial to patellar tendon. **Protection**: Keep AM portal close to tendon edge, vertical skin incision, use outside-in technique with spinal needle localization. **Location**: Passes through popliteal hiatus in posterolateral corner of lateral meniscus. **Protection**: Recognize hiatus as normal anatomy, do not resect or repair this area, protect tendon during lateral posterior horn work. **Location**: Wraps around fibular neck posterolaterally, approximately 2-3cm from lateral joint line. **Protection**: Avoid posterolateral portal placement beyond safety zone, controlled lateral meniscus resection, avoid excessive lateral compartment distension. **Location**: Opposing joint surfaces of medial and lateral compartments. **Protection**: Use blunt trocar for portal creation under direct visualization, careful instrument handling, avoid excessive shaver pressure against cartilage, systematic final inspection. **Location**: Attaches to peripheral border of medial meniscus, especially posterior horn. **Protection**: Controlled resection of posterior horn, avoid aggressive peripheral dissection, maintain meniscocapsular junction, use valgus stress to open space without excessive force. ## Meniscal Tear Classification ### By Location (Vascularity Zones) **Red-Red Zone (Peripheral 0-3mm)** - Excellent blood supply from meniscocapsular junction - High healing potential - **Repair candidate** if tear pattern suitable - Examples: peripheral longitudinal tears, meniscocapsular separations **Red-White Zone (Middle 3-5mm)** - Moderate vascularity - Variable healing potential - Consider repair in young patients with appropriate patterns - May augment with biological adjuncts (fibrin clot, PRP) **White-White Zone (Central >5mm)** - Avascular zone - Minimal healing potential - **Meniscectomy indicated** for symptomatic tears - Repairs fail in this zone ### By Tear Pattern **Vertical Longitudinal** - Parallel to circumferential collagen fibers - Most biomechanically favorable for repair - Can progress to bucket handle if unstable - Young patients: repair preferred if peripheral **Bucket Handle** - Complete longitudinal tear with displaced fragment - Causes mechanical locking - Inner fragment flips into notch - <40 years: attempt repair; >40 degenerative: resect unstable fragment only **Horizontal Cleavage** - Splits meniscus into superior and inferior leaves - Often degenerative etiology - Resect unstable leaf to stable rim - Cannot be repaired **Radial** - Perpendicular to circumferential fibers - Disrupts hoop stress transmission - Difficult to repair (biomechanically unfavorable) - Root tears (radial at meniscal attachment) may warrant repair in younger patients **Complex Degenerative** - Multiple tear patterns - Flap tears, fraying, maceration - No repair potential - Resect unstable tissue to stable contoured rim ### Indications for Partial Meniscectomy **Absolute Indications** - Symptomatic meniscal tear in white-white zone - Complex degenerative tear pattern not amenable to repair - Failed previous meniscal repair - Displaced bucket handle in older patient (>50 years) with degenerative changes **Relative Indications** - Horizontal cleavage tear with unstable flap - Radial tear in central avascular zone (not root) - Peripheral tear in elderly patient with low functional demands - Concurrent ligament reconstruction with irreparable meniscal tear **Contraindications** - Repairable tear in young active patient (repair should be attempted) - Asymptomatic meniscal tear (meniscectomy does NOT prevent OA) - Advanced arthritis (meniscectomy worsens symptoms) - Unrealistic patient expectations ## Functional Anatomy of Menisci ### Biomechanical Function **Load Transmission** - Menisci transmit 50-70% of knee load in extension - 85% of load in 90° flexion - Loss of meniscal function increases contact stress 2-3 fold - Each 10% tissue loss increases OA risk proportionally **Secondary Stabilizers** - Resist anteroposterior translation - Particularly important in ACL-deficient knee - Posterior horn medial meniscus critical for preventing anteromedial rotatory instability (AMRI) **Proprioception** - Mechanoreceptors throughout meniscus - Joint position sense - Loss may contribute to post-meniscectomy instability symptoms ### Blood Supply & Vascularity **Peripheral Vessels** - Superior medial genicular artery (medial meniscus) - Superior lateral genicular artery (lateral meniscus) - Inferior genicular arteries contribute - Perimeniscal capillary plexus from capsular attachment **Vascular Penetration** - Outer 10-30% vascularized (red-red zone: 0-3mm) - Middle zone transitional (red-white: 3-5mm) - Inner 70% avascular (white-white: >5mm) - Children: more extensive vascularity (better repair potential) - Age 50+: vascularity significantly reduced ### Structural Anatomy **Medial Meniscus** - C-shaped (more semicircular) - Firmly attached to capsule (less mobile) - Deep MCL fibers attach to peripheral border - Anterior horn: attaches anterior to ACL - Posterior horn: most commonly torn region, technically challenging access **Lateral Meniscus** - More circular (nearly O-shaped) - Loosely attached to capsule (more mobile) - **Popliteal hiatus**: normal gap in posterolateral peripheral attachment (8-10mm opening) - Popliteus tendon passes through hiatus (DO NOT repair or resect) - Anterior horn: attaches lateral to ACL - Posterior horn: posterior to PCL, meniscofemoral ligaments (Humphrey anterior, Wrisberg posterior) ### Portal Anatomy & Safe Zones **Anterolateral Portal** - 1cm proximal to joint line - Immediately lateral to patellar tendon - Primary viewing portal - Lateral inferior genicular artery typically 1-2cm anterior to portal **Anteromedial Portal** - 1cm proximal to joint line - Immediately medial to patellar tendon (within 5mm) - Primary working portal - **Infrapatellar branch of saphenous nerve** crosses 1-2cm medial to portal (injury causes painful neuroma) **Accessory Portals (if needed)** - Posteromedial: posterior to MCL, medial to semimembranosus, above joint line - Posterolateral: risks popliteal neurovascular structures (rarely used) - Central transpatellar tendon: for meniscal repair ## Meniscectomy Technique Modifications ### Instrument Selection **Basket Forceps** - **Upbiters**: Superior surface tears, medial meniscus femoral surface - **Downbiters**: Inferior surface tears, tibial surface - **Straight**: Anterior horn, body region - **Retrobiters**: Posterior horn access - **Technique**: Small controlled bites (2-3mm), don't pull large fragments (risk of excessive resection) **Motorized Shaver** - **Full radius**: Final contouring, smoothing rim - **Aggressive (whisker)**: Synovial debridement, not meniscus - **Suction control**: Essential for visualization - **Technique**: Smooth sweeping motions, avoid prolonged pressure on cartilage ### Posterior Horn Access Techniques **Standard Technique** - Figure-of-4 positioning (flexion, external rotation, valgus stress for medial) - 30° arthroscope from anterolateral portal - Work systematically from anterior to posterior - **Limitation**: Posterior horn visualization challenging **70° Arthroscope** - Improved posterior visualization - Especially useful for posterior horn medial meniscus - May be necessary for root tear assessment - Learning curve required **Posteromedial Accessory Portal** - Indications: Far posterior medial meniscus tears, posterior root tears, ramp lesions - Position: Behind MCL, medial to semimembranosus, palpate posteromedial corner - **Technique**: Use spinal needle localization, direct visualization from AL portal during creation - **Risks**: Saphenous nerve, vein medially; protect with careful technique **Pie-Crusting Capsule** - Controversial technique - Creates small capsular releases to improve access - **Avoid**: Risk of iatrogenic instability, not necessary in most cases ### Special Situations **Bucket Handle Tears** - **Assessment**: Can fragment be reduced and stabilized? Check vascularity zone - **Young patient** (<40 years) + peripheral location: attempt repair - **Older patient/degenerative**: resect displaced fragment only, preserve stable peripheral rim - **Technique**: May need to reduce fragment first to properly assess tear pattern and location **Root Tears** - **Medial posterior root**: Biomechanically equivalent to total meniscectomy (catastrophic) - **Young patients**: Consider root repair (transtibial pullout or suture anchor) - **Older patients**: Partial meniscectomy has poor outcomes; counsel regarding OA progression - **Identification critical**: Often missed on initial examination **Discoid Lateral Meniscus** - Congenital variant (3-5% population) - Tear in discoid meniscus: **saucerization** (reshape to normal anatomy) NOT total meniscectomy - Goal: stable peripheral rim, normal meniscal width - Preserve as much tissue as possible while creating stable configuration **Ramp Lesions** - Posterior horn medial meniscus separation from capsule (meniscocapsular junction) - Associated with ACL injuries (17-40%) - **Must examine from posteromedial compartment** (can't see from standard anterolateral viewing) - If found: repair indicated (peripheral vascular tissue) ## Key Evidence & Outcomes ### Natural History & Long-term Outcomes **Osteoarthritis Risk** - Meniscectomy increases OA risk 6-14 fold at 20-year follow-up - **Dose-dependent**: Each 10% meniscus removed increases load 5% - Total meniscectomy: 50% symptomatic OA at 10 years, 90% at 20 years - Partial meniscectomy: 40% symptomatic OA at 15-20 years - Degenerative tears: OA risk exists pre-operatively; surgery may accelerate **Functional Outcomes** - 80-90% good/excellent results at 2 years (short-term) - Results deteriorate over time as OA develops - Younger patients: better short-term function, higher long-term OA risk - Athletes: 85% return to sport, but 50% experience OA by 10-15 years post-operatively ### Landmark Studies **METEOR Trial (2016)** - Meniscal tear in degenerative knee with no OA - Arthroscopic partial meniscectomy vs PT alone - **Result**: NO significant difference at 12 months - Changed practice: non-operative treatment now first-line for degenerative tears **ESSKA Consensus (2016)** - Meniscal surgery should be reserved for: - Mechanical symptoms (locking, catching) - Failed conservative management (3-6 months) - MRI-confirmed unstable tear pattern - Avoid surgery for: incidental tears, stable tears, advanced OA **Systematic Reviews** - Young patients + traumatic tears: surgery beneficial - Middle-aged + degenerative tears: PT equivalent or superior to surgery - Presence of mechanical locking: surgery more likely beneficial - Advanced OA (KL grade 3-4): surgery harmful ### Surgical Factors Affecting Outcomes **Amount of Tissue Removed** - Minimal resection (saucerization only): Better outcomes - Subtotal meniscectomy: Significantly worse OA progression - **Save maximum stable tissue** - single most important technical factor **Limb Alignment** - Varus alignment + medial meniscectomy: Accelerated medial OA - Valgus alignment + lateral meniscectomy: Accelerated lateral OA - Consider HTO in young patients with meniscectomy + malalignment **Timing of Surgery** - Early surgery (<3 months): Higher failure rate (inflammatory component) - Delayed surgery (>12 months): Muscle atrophy, secondary changes - Optimal: 3-6 months conservative treatment before considering surgery ### Comparative Effectiveness **Meniscectomy vs Repair** - Repair: preserves meniscal function, prevents OA - Repair failure rate: 10-30% depending on tear pattern and zone - Failed repair can convert to meniscectomy (no harm from repair attempt) - **Young patients**: strongly favor repair when possible **Arthroscopic vs Open** - Arthroscopic: standard of care - Lower infection rates, faster recovery, better visualization - Open rarely indicated (extensive work, concurrent procedures) ## Rehabilitation Protocol ### Immediate Post-operative (0-2 Weeks) **Goals** - Control pain and swelling - Achieve full extension immediately (loss of extension = major complication) - Regain functional ROM (0-120°) - WBAT with normal gait **Protocol** - **Weight-bearing**: Full WBAT immediately, crutches for comfort 1-3 days - **ROM**: Begin immediately day 1, focus on achieving/maintaining full extension - **Exercises**: Ankle pumps, quadriceps sets, straight leg raises - **Ice/Elevation**: 20 minutes every 2-3 hours for first 48 hours - **NO brace needed** (unlike meniscal repair) **Warning Signs** - Loss of extension beyond 5° (arthrofibrosis risk) - Increasing pain/swelling after day 3 (infection, hemarthrosis) - Calf pain/swelling (DVT - rare but check) ### Early Phase (2-4 Weeks) **Goals** - Full ROM (equal to contralateral) - Eliminate effusion - Quadriceps strength >70% of contralateral - Normal gait without aids **Protocol** - Wean crutches by day 7-10 - Progressive resistance exercises (leg press, hamstring curls) - Closed-chain exercises (mini-squats, step-ups) - Stationary cycling (low resistance, high repetition) - Pool exercises if available (reduced load, improved ROM) ### Return to Activity Phase (4-6 Weeks) **Goals** - Quadriceps strength >90% of contralateral - No effusion with activity - Pass functional tests - Sport-specific training **Protocol** - Progress to plyometrics (jumping, landing) - Sport-specific drills - Running program (gradual progression) - Agility and cutting exercises **Return to Sport Criteria** - Full painless ROM - No effusion after exercise - Quadriceps strength ≥90% of contralateral (isokinetic testing if available) - Functional hop tests >90% (single leg hop, triple hop, crossover hop) - Sport-specific training completed - Typically 4-6 weeks for isolated meniscectomy ### Long-term Considerations **Activity Modification** - Avoid high-impact activities (long-term joint preservation) - Consider sports modification (reduced cutting/pivoting) - Weight management critical (every 1kg increases medial compartment load 2-4kg) **Surveillance** - Annual review for OA symptoms (younger patients) - Consider HTO if developing OA with malalignment - Maintain strength training (quadriceps protection) ## Outcome Measures ### Short-term Success (2 Years) - Resolution of mechanical symptoms: 85-95% - Return to sport: 85-90% - Patient satisfaction: 80-90% - KOOS improvement: 20-30 points ### Long-term Outcomes (10-20 Years) - Radiographic OA: 40-50% (KL grade 2+) - Symptomatic OA: 20-40% - Conversion to TKA: 10-20% by 20 years - Worse outcomes: more tissue removed, varus/valgus malalignment, age <40 at surgery ### Prognostic Factors **Favorable** - Minimal tissue resection - Neutral alignment - Traumatic tear in younger patient - Absence of chondral damage at surgery - Maintained quadriceps strength post-operatively **Unfavorable** - Extensive resection (>50% meniscus) - Varus or valgus malalignment - Degenerative tear pattern - Concomitant chondral injury (especially Grade 3-4) - Age >50 years - BMI >30 **Patient Position**: Supine with leg holder allowing 0-120° flexion. Tourniquet optional (often not needed). Lateral post at mid-thigh for valgus/varus stress. Non-sterile assistant helpful. **Surgical Approach**: Standard arthroscopic anterolateral (viewing) and anteromedial (working) portals **Incision**: Two small stab incisions for arthroscopic portals (5mm each) ### Step 1: Positioning & Setup Positioning & Setup: Supine, leg in holder allowing full flexion to extension. Lateral post at mid-thigh level for applying valgus/varus stress. Tourniquet high on thigh (inflated only if needed for visualization). Ensure full ROM available - inability to extend indicates locked tear requiring urgent reduction. Confirm appropriate patient, side, consent. Prophylactic antibiotics (single dose Cefazolin 2g or per local protocol). **Technical Tip**: EXAM KEY: 'Leg holder must allow full ROM 0-120°. Lateral post allows me to apply valgus stress for medial compartment and varus for lateral. I rarely use tourniquet - bloodless field not essential and tourniquet increases post-operative pain, DVT risk, and may impair meniscal vascularity assessment.' - Restricted ROM if holder too tight (prevents adequate visualization of all compartments) - Tourniquet complications if unnecessarily used (thigh pain, nerve injury, DVT risk) - Portal placement errors without proper knee position (30° flexion optimal for initial portal) - Wrong site surgery if timeout not performed with patient awake ### Step 2: Portal Placement - Anterolateral (AL) Portal Placement - Anterolateral (AL): ANTEROLATERAL PORTAL (viewing portal): Nick skin only with #11 blade 1cm proximal to joint line, immediately lateral to patellar tendon (within 5mm of edge). Insert 18G needle to insufflate joint with 20-30mL saline. Use blunt trocar with 30° arthroscope inside. Aim for intercondylar notch with gentle pressure - feel "pop" as trocar penetrates capsule. Knee in 30° flexion for initial entry. **Technical Tip**: EXAM KEY: 'AL portal is my VIEWING portal. It's 1cm above joint line and immediately lateral to tendon edge. Critical: I use an 18G needle first to insufflate joint with saline - this distends capsule away from cartilage preventing iatrogenic chondral injury. Then blunt trocar pointing 45° toward notch. Never use sharp trocar - unacceptable chondral damage risk.' - Too distal (at or below joint line) creates acute angle limiting access to posterior horns and increases articular cartilage damage risk - Too proximal (>2cm) makes instrumentation difficult, limits working angles - Sharp trocar penetration causes iatrogenic chondral damage (seen in up to 5% with poor technique) - Lateral inferior genicular artery runs 1-2cm anterior to standard portal (bleeding rare but possible) ### Step 3: Portal Placement - Anteromedial (AM) Portal Placement - Anteromedial (AM): ANTEROMEDIAL PORTAL (working portal): Established under direct arthroscopic visualization from AL portal using OUTSIDE-IN technique. Use 18G spinal needle from proposed site 1cm proximal to joint line, immediately medial to patellar tendon (within 5mm). Watch needle enter joint arthroscopically - confirm optimal trajectory to reach posterior horn of both menisci. Adjust needle position until perfect. Then make skin nick and insert cannula over switching stick under direct vision. **Technical Tip**: EXAM KEY: 'AM portal is my WORKING portal. This is the single most important technical step. I NEVER create this portal blind. Spinal needle localization under direct arthroscopic visualization is mandatory. I adjust needle position until trajectory is perfect - too medial limits access to lateral compartment, too high limits posterior horn access. Once positioned perfectly, only then make skin incision and insert cannula. This prevents articular damage and optimizes working angles.' - Blind portal placement causes articular cartilage damage in 3-5% (completely preventable with proper technique) - Too medial (>1cm from tendon) - difficult instrumentation, saphenous nerve injury risk - Fat pad entrapment creates visualization problems and requires debridement - Infrapatellar branch saphenous nerve crosses 1-2cm medial to ideal portal site (vertical incision reduces neuroma risk) ### Step 4: Systematic Diagnostic Arthroscopy Systematic Diagnostic Arthroscopy: SYSTEMATIC 13-POINT EXAMINATION (critical - don't skip): 1) Suprapatellar pouch (loose bodies, synovitis), 2) Medial gutter (plica, loose bodies), 3) Medial compartment with valgus stress (chondral damage grading), 4) Medial meniscus ANTERIOR HORN, 5) Medial meniscus BODY, 6) Medial meniscus POSTERIOR HORN (probe peripheral attachment - ramp lesion?), 7) Intercondylar notch (ACL, PCL integrity), 8) Lateral compartment with varus stress, 9) Lateral meniscus ANTERIOR HORN, 10) Lateral meniscus BODY, 11) Lateral meniscus POSTERIOR HORN (identify popliteal hiatus), 12) Lateral gutter, 13) Patellofemoral joint (track patella through ROM, trochlear and patellar chondral surfaces). Document ALL findings - 40% have concurrent pathology. **Technical Tip**: EXAM KEY: 'Systematic examination is mandatory - I use identical 13-point sequence every case. Critical areas commonly missed: 1) Ramp lesions (medial meniscus posterior horn separation from capsule at meniscocapsular junction - associated with ACL tear), 2) Root tears (radial tear at meniscal attachment - biomechanically catastrophic), 3) Chondral damage (changes management/prognosis), 4) Lateral meniscus popliteal hiatus (normal, not pathology). I probe the entire peripheral attachment of both menisci - meniscocapsular separation is repairable.' - Missing concurrent meniscal tear (opposite compartment or different zone same meniscus - 15% incidence) - Missing root tear (medial posterior root appears subtle but is biomechanically equivalent to total meniscectomy) - Missing ramp lesion (seen in 17-40% of ACL tears, requires posteromedial viewing to identify) - Mistaking popliteal hiatus for lateral meniscus tear (if you repair/resect this you create popliteus dysfunction) - Missing chondral damage (affects prognosis and treatment decisions) ### Step 5: Tear Assessment & Classification Tear Assessment & Classification: PROBE examination of tear: 1) ZONE - measure from peripheral capsular attachment: Red-Red vascular (0-3mm), Red-White middle (3-5mm), White-White avascular (>5mm). 2) PATTERN - Vertical longitudinal (repairable), Bucket handle (displaced longitudinal), Horizontal cleavage (superior/inferior leaves), Radial (perpendicular to circumference), Complex degenerative (multiple patterns). 3) STABILITY - probe test: flips up? reducible? stable to tension? 4) SIZE - length of tear, percentage of meniscus involved. 5) ASSOCIATED INJURIES - ACL tear? chondral damage? This classification determines REPAIR vs RESECTION. **Technical Tip**: EXAM KEY: 'Systematic assessment determines management. DECISION TREE: Red-Red or Red-White + Vertical/Bucket Handle + Young patient (<40) + Stable/Reducible = ATTEMPT REPAIR. White-White + Complex degenerative + Older patient = RESECTION. The grey zone: Red-White peripheral tears in middle-aged patients - consider patient age, activity level, alignment, concurrent injuries. When in doubt in a young patient - favor repair attempt. Failed repair converts to meniscectomy but gives patient best chance at meniscal preservation.' - Misclassifying repairable tear as irreparable in young patient (major error - eliminates chance of preservation) - Missing root tear component (appears as radial tear at attachment - requires different treatment) - Inadequate assessment of reducibility in bucket handle (reducible tears have better repair outcomes) - Failing to assess entire circumference (unstable tissue may extend beyond obvious tear) ### Step 6: Meniscectomy Technique - General Principles Meniscectomy Technique - General Principles: FUNDAMENTAL PRINCIPLES: 1) Resect ONLY unstable, torn, non-functional tissue, 2) Leave MAXIMUM amount of stable meniscus (every 10% lost increases OA risk), 3) Create SMOOTH, stable, contoured rim without steps or sharp edges, 4) Preserve peripheral meniscocapsular attachment. INSTRUMENTS: Basket forceps primary tool (upbiters for superior surface, downbiters for inferior surface, straight for body, retrobiters for posterior horn). Motorized shaver for final contouring only. Work systematically from mobile torn fragment toward fixed stable tissue. SMALL CONTROLLED BITES (2-3mm) - large bites risk excessive uncontrolled resection. **Technical Tip**: EXAM KEY: 'The goal is NOT to remove the tear - the goal is to create a stable functional meniscal remnant. I resect to a stable smooth rim that mimics normal meniscal contour, leaving absolutely maximum tissue. Basket forceps for resection - I take small 2-3mm bites working systematically. Large bites seem faster but result in excessive uncontrolled tissue loss. Shaver is for final smoothing only - if you use shaver as primary resection tool you will over-resect. Every study shows amount of tissue removed correlates directly with OA risk - preserve maximum stable tissue.' - Excessive resection (subtotal or total meniscectomy in young patient is catastrophic error - dramatically accelerates OA) - Using motorized shaver as primary resection tool (leads to over-resection - basket forceps give better control) - Leaving unstable flap or step-off (creates new tear initiation point, causes persistent symptoms) - Disrupting peripheral meniscocapsular attachment (converts repairable peripheral tear to irreparable) ### Step 7: Medial Meniscus Resection Medial Meniscus Resection: MEDIAL MENISCUS technique: Position knee in FIGURE-OF-4 (flexion, external rotation, foot resting on opposite knee). Apply VALGUS stress with lateral post to open medial compartment - improves visualization and working space. Viewing from AL portal, working from AM portal. Anterior horn and body straightforward. POSTERIOR HORN most technically challenging - work systematically from body toward posterior. Upbiter for superior (femoral) surface tears, downbiter for inferior (tibial) surface. May need to flex knee 70-90° to visualize far posterior. Protect peripheral attachment to avoid MCL injury. Consider posteromedial portal if visualization inadequate. **Technical Tip**: EXAM KEY: 'Medial meniscus posterior horn is the most commonly torn region and technically most difficult. Figure-of-4 position with valgus stress opens space. I work systematically from anterior (easy visualization) toward posterior (difficult). For far posterior horn I may need: 1) Increased knee flexion 70-90°, 2) 70° arthroscope for better angle, or 3) Posteromedial accessory portal. Critical: the peripheral attachment zone (red-red) is intimately associated with deep MCL fibers - aggressive peripheral resection can damage MCL causing medial instability. Preserve peripheral rim.' - MCL injury from aggressive posterior horn peripheral dissection (causes medial instability - major complication) - Inadequate visualization of posterior horn leading to incomplete resection and retained unstable fragment (15% of failures) - Missing posterior root tear (often subtle, requires probing root attachment with knee in extension) - Excessive tissue removal (medial meniscus more important for load transmission in varus knee - preserve maximum) ### Step 8: Lateral Meniscus Resection Lateral Meniscus Resection: LATERAL MENISCUS technique: Apply VARUS stress to open lateral compartment. Recognize POPLITEAL HIATUS (normal posterolateral 8-10mm gap in peripheral attachment where popliteus tendon passes through) - this is NORMAL ANATOMY, NOT pathology, DO NOT REPAIR OR RESECT. Protect popliteus tendon running through hiatus. Lateral meniscus more mobile than medial (weaker peripheral attachments). Anterior horn, body, posterior horn systematic resection. Be aware of common peroneal nerve proximity posterolaterally (2-3cm from joint line wrapping around fibular neck) - avoid excessive posterolateral work. Lateral discoid meniscus: saucerize to normal contour, don't perform total meniscectomy. **Technical Tip**: EXAM KEY: 'POPLITEAL HIATUS is the most important lateral meniscus anatomy. It's a normal 8-10mm opening in the posterolateral peripheral attachment where the popliteus tendon runs from lateral femur to posterior tibia. Novice surgeons mistake this for a tear and attempt repair - this is a critical error causing popliteus dysfunction and posterolateral pain. Confirm normal anatomy: hiatus located in posterior third, popliteus tendon visible running through it. In lateral meniscus tears, protect the popliteus tendon during posterior horn work. Iatrogenic popliteus injury causes posterolateral corner dysfunction.' - Popliteus tendon injury during posterior horn resection (causes posterolateral instability and chronic pain - difficult to diagnose/treat) - Misinterpreting popliteal hiatus as pathological tear and attempting repair (creates popliteus dysfunction) - Common peroneal nerve proximity posterolaterally (injury causes foot drop - catastrophic complication) - Excessive lateral meniscectomy in discoid meniscus (total meniscectomy wrong - should saucerize to normal contour) ### Step 9: Contouring & Final Shaping Contouring & Final Shaping: After basket forceps resection of unstable tissue, use motorized SHAVER (full radius blade) to smooth and contour remaining meniscus. Goal: create smooth transition from residual meniscus rim to capsular attachment - NO STEPS, sharp edges, or abrupt transitions (these create stress concentrations and new tear initiation points). Final rim should mimic normal meniscal contour (smooth gradual curve). Test with PROBE - rim must be completely stable to tension, no catches, no flips with stress. Smooth superior surface (femoral contact) and inferior surface (tibial contact) equally. Avoid overshaving. **Technical Tip**: EXAM KEY: 'Shaver is final step for smoothing only - not primary resection tool. I use sweeping motions to create smooth contour matching normal meniscal shape. Critical: avoid steps or sharp edges - these are stress concentrators where new tears initiate. The final rim should transition smoothly from thickest (peripheral) to thinnest (inner edge) without abrupt changes. I probe aggressively - if the rim has any instability I've left a symptomatic flap that will cause persistent symptoms. Completely stable smooth rim is the goal.' - Overshaving (shaver too aggressive or prolonged use) leading to excessive resection beyond unstable tissue - Leaving sharp edges or steps (create stress concentrations where re-tearing occurs - 10% of failures) - Aggressive shaving near capsule causes bleeding, synovitis, and risks peripheral attachment disruption - Shaver contact with articular cartilage (causes chondral injury - keep shaver blade parallel to cartilage surface) ### Step 10: Final Arthroscopic Check Final Arthroscopic Check: SYSTEMATIC FINAL INSPECTION: 1) Probe meniscal rim circumferentially - must be completely stable with no catches, 2) Visualize smooth contour - no steps or flaps, 3) Check opposite meniscus again (ensure no missed tear), 4) Inspect ACL/PCL (ensure no iatrogenic injury), 5) Examine articular cartilage all compartments (document any chondral injury), 6) Check for loose fragments (in gutters, suprapatellar pouch - cause locking), 7) Run through all 13 compartments again. Document final appearance with saved images/video. Ensure complete hemostasis. **Technical Tip**: EXAM KEY: 'Final systematic check using same 13-point examination sequence. I probe the meniscal rim aggressively - any instability means incomplete resection and persistent symptoms. Most importantly: look for loose meniscal fragments - these migrate to gutters and cause mechanical symptoms (locking, catching) that patients attribute to failed surgery. Suprapatellar pouch and medial gutter are common locations. I document final appearance with saved arthroscopic images - medicolegal record and confirms complete resection. Zero tolerance for retained unstable tissue or loose bodies.' - Retained loose meniscal bodies (10-15% if not systematically searched) causing persistent locking/catching symptoms - Unstable rim not identified (inadequate probing) leading to continued tearing and early failure - Iatrogenic chondral injury unrecognized (changes prognosis, may require counseling about OA risk) - Incomplete resection with residual unstable flap (most common cause of persistent symptoms post-meniscectomy) ### Step 11: Irrigation & Closure Irrigation & Closure: Copious irrigation (2-3 liters lactated Ringer's) to remove all meniscal debris, blood, and particulate matter. Deflate joint by releasing inflow. Evacuate fluid through portals with suction. Close portals: single interrupted 3-0 or 4-0 nylon suture each portal (not necessary to close capsule - too small). Inject local anesthetic (20mL 0.25% bupivacaine) into intra-articular space and portal sites for post-operative analgesia. Apply sterile adhesive dressing. Wool and crepe or compression stocking. NO drain needed for isolated meniscectomy. **Technical Tip**: EXAM KEY: 'Thorough irrigation is important - retained meniscal fragments cause persistent synovitis and pain. I use 2-3 liters minimum. Local anesthetic injection intra-articular and at portal sites provides excellent early pain control - patients mobilize better with reduced pain. Simple portal closure with single nylon suture - no need for deep closure, portals are small. Drains are not indicated for isolated arthroscopic meniscectomy - increase infection risk and pain without benefit. Compression dressing reduces swelling.' - Portal site hematoma if inadequate hemostasis (rare but causes pain and delayed recovery) - Retained meniscal fragments if irrigation inadequate (chronic synovitis) - Portal site infection if non-sterile technique (0.01-0.1% rate - very rare but serious) - Inadequate analgesia delaying mobilization (local anesthetic injection is simple, effective adjunct) ### Step 12: Immediate Post-Operative Assessment Immediate Post-Operative Assessment: Recovery room checks: 1) FULL EXTENSION achieved (inability to fully extend is major complication requiring intervention), 2) Neurovascular status intact (pulses, capillary refill, sensation, motor function), 3) Compartments soft (compartment syndrome rare but catastrophic if missed), 4) Minimal pain (if severe pain investigate). Immediate mobilization: WBAT with crutches for comfort, no brace required. ROM exercises begin day 1 - focus on maintaining/achieving full extension. Discharge criteria: pain controlled, full extension, able to straight leg raise, independent mobility. Physiotherapy referral for supervised rehabilitation protocol. **Technical Tip**: EXAM KEY: 'The single most important immediate post-operative assessment is EXTENSION. Patient must achieve full extension (0°) immediately - any loss beyond 5° indicates high risk of arthrofibrosis and requires aggressive intervention. Unlike meniscal repair, meniscectomy patients are WBAT immediately with no brace - I encourage early mobilization and ROM. Crutches for comfort only (1-3 days). Early movement prevents stiffness and hastens recovery. Failure to achieve full extension is the most common cause of poor outcome - address immediately with aggressive extension exercises, prone hangs, extension splinting if necessary.' - Loss of extension (flexion contracture) is most common major complication (2-5%) - requires early recognition and aggressive treatment - Unrecognized neurovascular injury (common peroneal nerve especially with lateral work, saphenous nerve with medial portals) - Compartment syndrome (extremely rare <0.01% but catastrophic - high index of suspicion if severe pain, tense compartments) - Inadequate pain control delaying mobilization and ROM (early movement critical to prevent stiffness) **IMMEDIATE (Day 0-2)**: Full weight-bearing as tolerated immediately. Crutches for comfort only (1-3 days). ROM exercises begin day 1 - critical focus on achieving and maintaining full extension (0°). Ice 20 minutes every 2-3 hours. Elevation. Compression dressing. Analgesia: paracetamol + NSAID (unless contraindicated). Remove dressing day 2-3. **EARLY (Week 1-2)**: Wean crutches by day 7-10 (normal gait pattern). Progress ROM - goal full ROM (0-135°) by week 2. Begin strengthening: quadriceps sets, straight leg raises, calf raises, stationary cycling (low resistance). Physiotherapy 2-3x weekly. Suture removal day 10-14. **INTERMEDIATE (Week 3-4)**: Progressive resistance training: leg press, hamstring curls, step-ups. Closed kinetic chain exercises. Pool exercises if available. Goal: quadriceps strength >80% contralateral by week 4. No effusion with activities. Light activities of daily living unrestricted. **RETURN TO ACTIVITY (Week 4-6)**: Sport-specific training. Plyometrics (jumping, landing). Running program (gradual progression). Agility drills, cutting exercises. **Criteria for Return to Sport**: Full painless ROM, No effusion with exercise, Quadriceps strength ≥90% contralateral (isokinetic testing), Functional hop tests >90% (single, triple, crossover), Sport-specific drills completed pain-free. Usually 4-6 weeks for isolated partial meniscectomy. **LONG-TERM**: Activity modification (reduce high-impact loading). Weight management. Annual review for younger patients (OA surveillance). Quadriceps strengthening maintenance. Consider HTO if developing OA with malalignment. ## References 1. Beaufils P, Becker R, Kopf S, et al. Surgical management of degenerative meniscus lesions: the 2016 ESSKA meniscus consensus. Knee Surg Sports Traumatol Arthrosc. 2017;25(2):335-346. doi:10.1007/s00167-016-4407-4 - *ESSKA consensus on degenerative meniscal tears - evidence-based guideline recommending conservative management first-line, surgery only for mechanical symptoms after failed conservative treatment. Critical reference for management algorithm.* 2. Kise NJ, Risberg MA, Stensrud S, et al. Exercise therapy versus arthroscopic partial meniscectomy for degenerative meniscal tear in middle aged patients: randomised controlled trial with two year follow-up. BMJ. 2016;354:i3740. doi:10.1136/bmj.i3740 - *METEOR trial - landmark RCT showing no significant difference between PT and meniscectomy for degenerative tears at 2 years. Changed practice to favor conservative management.* 3. Petty CA, Lubowitz JH. Does arthroscopic partial meniscectomy result in knee osteoarthritis? A systematic review with a minimum of 8 years' follow-up. Arthroscopy. 2011;27(3):419-424. doi:10.1016/j.arthro.2010.08.016 - *Systematic review demonstrating 40-50% radiographic OA at mean 15 years post-meniscectomy, emphasizing long-term degenerative consequences.* 4. Papalia R, Del Buono A, Osti L, et al. Meniscectomy as a risk factor for knee osteoarthritis: a systematic review. Br Med Bull. 2011;99:89-106. doi:10.1093/bmb/ldq043 - *Comprehensive review showing dose-dependent relationship between amount of meniscus removed and OA progression - every 10% tissue loss increases degenerative risk.* 5. Herrlin SV, Wange PO, Lapidus G, et al. Is arthroscopic surgery beneficial in treating non-traumatic, degenerative medial meniscal tears? A five year follow-up. Knee Surg Sports Traumatol Arthrosc. 2013;21(2):358-364. doi:10.1007/s00167-012-1960-3 - *Five-year follow-up showing deteriorating outcomes over time after meniscectomy for degenerative tears, supporting conservative management for this indication.* 6. Chatain F, Adeleine P, Chambat P, Neyret P. A comparative study of medial versus lateral arthroscopic partial meniscectomy on stable knees: 10-year minimum follow-up. Arthroscopy. 2003;19(8):842-849. doi:10.1016/s0749-8063(03)00735-7 - *Long-term outcomes study showing 85% good/excellent results short-term but progressive OA development (50% at 10 years), worse with larger resections.* 7. LaPrade CM, James EW, Cram TR, et al. Meniscal root tears: a classification system based on tear morphology. Am J Sports Med. 2015;43(2):363-369. doi:10.1177/0363546514559684 - *Classification of meniscal root tears - critical to recognize as these are biomechanically equivalent to total meniscectomy and may warrant repair in younger patients.* 8. Ahn JH, Wang JH, Yoo JC, et al. A pull out suture for transection of the popliteus tendon during arthroscopic surgery: a technical note. Knee Surg Sports Traumatol Arthrosc. 2007;15(12):1417-1419. doi:10.1007/s00167-007-0395-4 - *Technical note on popliteal hiatus anatomy and popliteus tendon protection during lateral meniscus surgery - critical to prevent iatrogenic injury.* 9. Austin MS, Ghanem E, Joshi A, et al. The assessment of intraoperative prosthetic joint infection during revision total hip and knee arthroplasty: a systematic review. J Bone Joint Surg Am. 2008;90(Suppl 4):117-120. doi:10.2106/JBJS.H.01024 - *While focused on arthroplasty, provides evidence base for infection prevention principles applicable to all arthroscopic procedures including prophylactic antibiotics.* 10. Krych AJ, Reardon PJ, Johnson NR, et al. Non-operative management of medial meniscus posterior horn root tears is associated with worsening arthritis and poor clinical outcome at 5-year follow-up. Knee Surg Sports Traumatol Arthrosc. 2017;25(2):383-389. doi:10.1007/s00167-016-4359-8 *Five-year outcomes of non-operative management of medial meniscus posterior root tears showing progression to OA - supports consideration of root repair in appropriate candidates.*

Arthroscopic Partial Meniscectomy

Arthroscopic Partial Meniscectomy