import { OnePagerSummary, ContentSection, ExamWarning, InfoCardGrid, InfoCard, EvidenceCard, ComparisonTable, VivaScenario, MnemonicCard, ExamCheatSheet, Tab, Tabs } from '@/components/mdx' **Knee arthroscopy** is the MOST COMMONLY performed orthopaedic procedure worldwide, with over 4 million procedures annually (AAOS 2023). Understanding portal anatomy is CRITICAL for safe arthroscopy and minimizing neurovascular complications. ### Standard Arthroscopic Portals **1. ANTEROLATERAL PORTAL (VIEWING PORTAL):** **Location:** - **1cm proximal to joint line** (superior to lateral tibial plateau) - **1cm lateral to patellar tendon** lateral border - Level with inferior pole of patella when knee flexed 90° **Function:** - **PRIMARY viewing portal** for diagnostic arthroscopy - Camera inserted through this portal for standard examination - Provides view of medial compartment (medial meniscus, medial femoral condyle, ACL, PCL, intercondylar notch) **Structures at Risk:** - **Lateral femoral cutaneous nerve** (lateral thigh sensation) - runs 5-8cm lateral to portal (usually safe) - **Lateral superior geniculate artery** - 2-3cm proximal to portal (safe with standard placement) - **Cartilage** - lateral femoral condyle or lateral tibial plateau (avoid high/low placement) **Safe Zone:** - Soft tissue triangle bounded by: Patellar tendon medially, Joint line inferiorly, Inferior patella pole superiorly **2. ANTEROMEDIAL PORTAL (WORKING PORTAL):** **Location:** - **1cm proximal to joint line** (superior to medial tibial plateau) - **1cm medial to patellar tendon** medial border - Level with inferior pole of patella when knee flexed 90° **Function:** - **PRIMARY working portal** for instruments (probes, shavers, graspers) - Provides access to lateral compartment (lateral meniscus, lateral femoral condyle) when viewing from anterolateral - Instrument portal for ACL tibial tunnel drilling (AM portal for tibial guide pin) **Structures at Risk (HIGHEST INJURY RISK):** - **Saphenous nerve infrapatellar branch** (medial knee/proximal leg sensation) - crosses DIRECTLY over portal site (2-7% injury rate - Mochizuki 2009) - **Medial superior geniculate artery** - 2-3cm proximal to portal (usually safe) - **Saphenous vein** - accompanies nerve (minor bleeding if injured) - **MCL superficial fibers** - 1-2cm medial to portal (avoid excessive medial placement) **Safe Zone:** - Keep portal 1cm medial to patellar tendon (NOT more medial - increases saphenous nerve risk) - Avoid extension inferior to joint line (risks tibial plateau cartilage) **3. SUPEROLATERAL (SUPRAPATELLAR) PORTAL:** **Location:** - **2-3cm proximal to superior pole of patella** - **1cm lateral to lateral patellar border** - In line with anterolateral portal (straight proximal extension) **Function:** - Access to **suprapatellar pouch** (remove loose bodies, synovectomy) - Outflow portal (continuous fluid drainage to maintain visualization) - Accessory viewing portal for patellofemoral assessment (chondromalacia patellae, trochlear dysplasia) **Structures at Risk:** - **Quadriceps tendon** - portal enters THROUGH quadriceps tendon (use sharp trocar to penetrate tendon cleanly) - **Suprapatellar plica** - may need to be released if thick/symptomatic **Safe Zone:** - Stay 1cm lateral to lateral patellar border (avoids vastus medialis muscle belly medially) **4. ACCESSORY ANTEROLATERAL PORTAL (MID-PATELLAR):** **Location:** - At level of **mid-patella** (NOT inferior pole like standard anterolateral) - **1cm lateral to patellar border** - 2-3cm proximal to standard anterolateral portal **Function:** - **Trans-patellar tendon drilling** for ACL tibial tunnel (avoids posterior cortex blowout) - Access to **posteromedial corner** (posterior horn medial meniscus) when viewing from standard anterolateral - Accessory working portal for **meniscus repair** (posterior horn lateral meniscus) **Structures at Risk:** - **Fat pad** (Hoffa's fat pad) - portal traverses fat pad (risk of post-operative anterior knee pain 5-10% - Jacobson 1988) - **Patellar tendon** - portal may nick lateral edge of tendon (usually no functional consequence) ### Posterior Arthroscopic Portals **5. POSTEROMEDIAL PORTAL:** **Location:** - **1cm proximal to joint line** - **1-2cm medial to medial border of patellar tendon** (posteromedial to MCL) - Anterior to posteromedial corner of knee **Function:** - Access to **posterior horn medial meniscus** (meniscus repair, meniscectomy) - Viewing portal for **posteromedial compartment** (posterior capsule, PCL femoral attachment) - Inside-out meniscus repair (needles exit through this portal - requires safety incision) **Structures at Risk (HIGH RISK):** - **Saphenous nerve and vein** - run 2-3cm medial to portal (2-7% injury risk - Mochizuki 2009) - **Medial head of gastrocnemius** - portal passes between MCL and gastroc (stay anterior to avoid muscle) - **Popliteal vessels and tibial nerve** - lie 15-20mm medial to portal (SAFE if portal kept anterior) **Safety Technique:** - Create portal with knee flexed 90° (posterior structures migrate posteriorly - increases safety clearance) - Use **spinal needle** localization first (visualize intra-articular needle tip from anterolateral viewing portal) - Direct portal **anteriorly and laterally** toward intercondylar notch (avoids posterior neurovascular structures) **6. POSTEROLATERAL PORTAL (SAFEST POSTERIOR PORTAL):** **Location:** - **1cm proximal to joint line** - **1-2cm lateral to lateral border of patellar tendon** (posterolateral to LCL) - Anterior to popliteus hiatus **Function:** - Access to **posterior horn lateral meniscus** (meniscus repair, meniscectomy - MOST COMMON indication) - Viewing portal for **posterolateral compartment** (posterior capsule, popliteus, arcuate ligament, PCL tibial attachment) - PCL reconstruction (tibial tunnel drilling for transtibial technique) **Structures at Risk:** - **Common peroneal nerve** - runs 8-10mm lateral to portal (0.4% injury risk - Allardyce 2013) - SAFEST of posterior portals - **Inferior lateral geniculate artery** - crosses portal site (1-3% injury causing hemarthrosis - Small 1985) - **Lateral head of gastrocnemius** - portal passes lateral to gastroc (minimal risk) - **Popliteal vessels** - lie 20-25mm medial to portal (SAFE) **Safety Technique:** - Posterolateral portal is **PREFERRED posterior portal** vs posteromedial (peroneal nerve 8-10mm lateral vs tibial nerve 5mm medial - Allardyce 2013) - Create with knee flexed 90° and slight internal rotation (peroneal nerve migrates laterally - increases safety clearance) - Use spinal needle localization + visualization from anterolateral portal - Direct portal **anteriorly and medially** toward intercondylar notch **7. CENTRAL TRANSPATELLAR PORTAL (RARELY USED):** **Location:** - Through **center of patellar tendon** - 0.5-1cm proximal to tibial tubercle **Function:** - **ACL femoral tunnel drilling** (central portal gives BEST angle for anatomic femoral tunnel via transtibial technique) - Access to **intercondylar notch** (notchplasty, ACL remnant debridement) **Structures at Risk:** - **Patellar tendon** - portal created THROUGH tendon (2-5% risk of patellar tendinopathy, anterior knee pain - Howell 1999) **Controversy:** - Most surgeons AVOID trans-patellar tendon portal (prefer accessory anterolateral for ACL femoral tunnel) due to patellar tendinopathy risk ### Portal Triangulation Principles **Optimal Viewing and Working Relationship:** - **Anterolateral (viewing) + Anteromedial (working)**: 60-70° angle for optimal instrument access to all compartments - **Anterolateral (viewing) + Posterolateral (working)**: 90-100° angle for posterior horn lateral meniscus repair - **Anteromedial (viewing) + Posterolateral (working)**: 120-130° angle for PCL femoral attachment visualization **Key Rule:** - Viewing and working portals should create **60-90° angle** for optimal triangulation (less than 60° = instruments conflict, greater than 90° = difficult manipulation) **Most commonly injured structure**: Infrapatellar branch of saphenous nerve (2-7% injury rate - Mochizuki 2009) **Anatomy**: - Crosses **DIRECTLY over** anteromedial portal site - Runs 10-15mm medial to patellar tendon at joint line - Oblique course: Proximal-medial to distal-lateral - Provides sensation to medial knee and proximal medial leg **Clinical consequences**: - Numbness over medial knee/leg (permanent in 30-40% cases) - Painful neuroma (10-15%) - Patient dissatisfaction despite successful arthroscopy **Prevention strategies**: 1. **Portal placement**: Keep 1cm (NOT MORE) medial to patellar tendon 2. **Incision size**: SMALL skin incision (5-7mm ONLY) - Avoid long transverse incisions (increase nerve transection risk) 3. **Incision direction**: Use VERTICAL (parallel to nerve course) NOT horizontal 4. **Capsule penetration**: SHARP trocar or blade - Clean cut vs blunt tearing (causes more nerve trauma) 5. **Portal switching**: Consider lateral viewing/medial working for medial compartment work (reduces anteromedial portal need) **Management if injured**: - Observation first-line (30-40% resolve by 12 months) - Neuroma excision if symptomatic beyond 12 months (70% improvement) **Safety comparison** (Allardyce 2013): - **Posterolateral portal**: SAFER (peroneal nerve injury 0.4%) - **Posteromedial portal**: Higher risk (tibial nerve injury 1-2%) **Anatomical clearance**: - Peroneal nerve: 8-10mm LATERAL to posterolateral portal (safer) - Tibial nerve: 5mm MEDIAL to posteromedial portal (higher risk) **Posterolateral portal safety techniques**: 1. **Positioning**: Knee flexed 90° with SLIGHT INTERNAL ROTATION - Peroneal nerve migrates laterally with internal rotation (Allardyce 2013) 2. **Needle localization FIRST**: - Spinal needle (18G) inserted first - Visualize needle tip intra-articularly from anterolateral viewing portal - Confirm position BEFORE creating portal with blade 3. **Portal direction**: ANTERIORLY and MEDIALLY toward intercondylar notch - Avoids posterior dissection toward peroneal nerve 4. **Capsule penetration**: BLUNT trocar or switching stick after initial capsule penetration - Reduces risk of penetrating beyond joint into neurovascular structures **Inferior lateral geniculate artery risk**: - Crosses posterolateral portal site (1-3% injury - Small 1985) - Causes hemarthrosis if injured - Management: Tamponade with pump pressure 50-60mmHg, radiofrequency cautery if persistent bleeding ### Patient Positioning **Setup:** - **Supine** position on operating table - **Leg holder** or **post** at lateral thigh (allows knee flexion/extension and varus/valgus stress) - **Foot of bed dropped** (allows knee to hang at 90° flexion for portal creation) - **Tourniquet** on proximal thigh (250-280mmHg for 60-90 minutes) - optional (most surgeons use arthroscopic pump pressure for hemostasis without tourniquet) - **Arthroscopic pump** pressure 40-50mmHg (higher pressure 50-60mmHg for posterior portal work or bleeding) ### Portal Creation Technique **STEP 1: ANTEROLATERAL PORTAL (FIRST PORTAL - VIEWING):** **Landmarks:** - Palpate **patellar tendon** medial and lateral borders - Palpate **joint line** (soft tissue depression between patella and tibial plateau) - Mark portal site: **1cm proximal to joint line, 1cm lateral to patellar tendon** **Technique:** 1. **Skin incision**: 5-7mm VERTICAL incision with #11 blade (vertical incision parallel to neurovascular structures) 2. **Penetrate subcutaneous tissue** with mosquito clamp or trocar (spread down to joint capsule) 3. **Penetrate joint capsule**: Use **sharp trocar** with 30° arthroscope inside (direct trocar anteriorly and slightly medially toward intercondylar notch) 4. **Visual confirmation**: Withdraw trocar, advance arthroscope - confirm intra-articular position (visualize fat pad, medial femoral condyle, or PCL) 5. **Inflow**: Connect arthroscopic pump to inflow port on camera sheath (40-50mmHg pressure) **STEP 2: ANTEROMEDIAL PORTAL (SECOND PORTAL - WORKING):** **Inside-Out Technique (SAFEST):** 1. **Spinal needle localization**: Insert 18G spinal needle through skin 1cm medial to patellar tendon, 1cm proximal to joint line 2. **Visualize needle tip** from anterolateral viewing portal (confirm needle enters joint in desired location - usually above medial tibial plateau, aimed at lateral compartment) 3. **Adjust needle position** if needed (too high/low/medial) until optimal position confirmed 4. **Mark skin** at needle entry site 5. **Remove needle**, make **5-7mm VERTICAL skin incision** at mark 6. **Penetrate joint capsule** with blade or trocar under direct visualization from anterolateral portal (watch blade enter joint - avoid crossing to lateral compartment prematurely) **Outflow Portal (Optional):** - Create **superolateral portal** for outflow (continuous drainage maintains visualization) - 2-3cm proximal to superior patella pole, 1cm lateral to lateral patellar border - Use sharp trocar through quadriceps tendon into suprapatellar pouch ### Systematic Diagnostic Arthroscopy (Order of Examination) **21-Point Examination (Outerbridge-Saunders Protocol):** **SUPRAPATELLAR POUCH (from anterolateral viewing):** 1. Suprapatellar plica (medial, lateral, central) 2. Suprapatellar synovium (synovitis, loose bodies) **MEDIAL COMPARTMENT (from anterolateral viewing, anteromedial working):** 3. Medial gutter (synovitis, loose bodies) 4. **Medial femoral condyle** (chondral lesions - Outerbridge classification) 5. **Medial meniscus anterior horn** (tears, fraying) 6. **Medial meniscus body** (horizontal, vertical, radial tears) 7. **Medial meniscus posterior horn** (root tears, posterior horn tears) 8. Medial tibial plateau (chondral lesions, osteophytes) **INTERCONDYLAR NOTCH (from anterolateral viewing):** 9. **ACL** (tear, degeneration, impingement) 10. **PCL** (tear, attenuation) 11. Intercondylar notch (notch stenosis, impingement lesions) **LATERAL COMPARTMENT (from anteromedial viewing, anterolateral working):** 12. Lateral gutter (synovitis, loose bodies) 13. **Lateral femoral condyle** (chondral lesions) 14. **Lateral meniscus anterior horn** (tears, fraying) 15. **Lateral meniscus body** (tears, cysts) 16. **Lateral meniscus posterior horn** (tears, popliteus hiatus assessment) 17. Lateral tibial plateau (chondral lesions) **PATELLOFEMORAL JOINT (from inferolateral or superomedial viewing):** 18. **Patella** (chondromalacia - Outerbridge grade, facet lesions) 19. **Trochlea** (trochlear dysplasia, chondral lesions) 20. Patellar tracking (assess with knee flexion/extension) **POSTERIOR COMPARTMENT (from posterolateral portal if indicated):** 21. Posterior horn menisci (medial/lateral), posterior capsule, PCL attachments ### Indications for Knee Arthroscopy **DIAGNOSTIC ARTHROSCOPY (Decreasing Indication):** - **MRI has largely REPLACED diagnostic arthroscopy** (90-95% accuracy for meniscus tears, ACL tears, chondral lesions - Ryzewicz 2007) - Reserved for: Equivocal MRI findings, mechanical symptoms (locking, catching) without clear diagnosis, acute traumatic hemarthrosis with suspected meniscus/cartilage injury **THERAPEUTIC ARTHROSCOPY (PRIMARY INDICATIONS):** **1. Meniscus Pathology:** - **Meniscus tears** with mechanical symptoms (locking, catching) or persistent pain - partial meniscectomy (resect unstable tear only, preserve stable rim) - **Meniscus root tears** (medial meniscus posterior root most common) - consider root repair vs meniscectomy (root repair better outcomes if repairable - LaPrade 2015) - **Meniscus repair** (inside-out, outside-in, all-inside techniques) for peripheral tears in vascular zone (outer 1/3 "red-red zone") in patients less than 40 years **2. Ligament Reconstruction:** - **ACL reconstruction** (primary, revision) - arthroscopic-assisted tunnel drilling, graft passage, fixation - **PCL reconstruction** (transtibial, tibial inlay) - less common, complex arthroscopic technique - **Multi-ligament reconstruction** (ACL + PCL, ACL + LCL, etc.) - usually arthroscopic-assisted with open component **3. Cartilage Procedures:** - **Chondral loose body removal** (osteochondritis dissecans, post-traumatic fragmentation) - **Microfracture** for focal chondral defects (less than 2cm²) - Outerbridge grade IV (bone exposed) - **Autologous chondrocyte implantation (ACI)** - arthroscopic-assisted membrane fixation - **Osteochondral autograft transfer (OATS/Mosaicplasty)** - arthroscopic harvest and implantation **4. Synovial Pathology:** - **Synovectomy** for inflammatory arthritis (rheumatoid arthritis, pigmented villonodular synovitis) - **Plica resection** (symptomatic medial plica causing medial knee pain and clicking) **5. Fracture Fixation:** - **Tibial plateau fractures** (Schatzker I-III) - arthroscopic-assisted reduction and percutaneous fixation - **Tibial eminence fractures** (ACL avulsion) - arthroscopic reduction and suture fixation **CONTRAINDICATIONS:** **Absolute:** - **Active infection** (septic arthritis, overlying cellulitis) - risk of seeding joint - **Severe arthrofibrosis** with inability to flex knee to 90° (inadequate working space) **Relative:** - **Advanced osteoarthritis** (Kellgren-Lawrence grade 3-4) - arthroscopic debridement NOT effective (Moseley 2002 - placebo-controlled trial showed no benefit) - **Unrealistic patient expectations** (expecting arthroscopy to 'cure' arthritis) - **Medical comorbidities** increasing anesthesia risk (optimize first) ### Outcomes by Procedure **Meniscectomy:** - **Symptom relief**: 80-85% patients have good-excellent outcomes at 2 years (reduced locking, catching, pain) - **Long-term**: 50-60% develop radiographic OA by 10-15 years (meniscectomy accelerates OA - Englund 2003) - **Extent of resection**: Greater resection = faster OA progression (preserve as much stable meniscus as possible) **Meniscus Repair:** - **Healing rate**: 70-85% for peripheral "red-red" zone tears (outer 1/3 with vascular supply) - **Failure rate**: 15-30% require revision meniscectomy (most failures within 2 years) - **Better outcomes**: Young age (less than 30 years), acute tears (less than 6 weeks), peripheral location, concomitant ACL reconstruction (ACL reconstruction increases meniscus repair healing by 10-15% - Wasserstein 2013) **ACL Reconstruction:** - **Graft survival**: 85-90% at 10 years for primary reconstruction (Barret 2011) - **Revision rate**: 8-12% (higher in young athletes less than 20 years - 15-20% revision rate) - **Return to sport**: 65-75% return to pre-injury sport level, 90% return to some sport activity **Chondral Procedures:** - **Microfracture**: 60-70% good-excellent outcomes at 2 years, deteriorates by 5 years (fibrocartilage vs hyaline cartilage) - **ACI/MACI**: 70-80% good-excellent outcomes sustained to 5-10 years (superior to microfracture for lesions greater than 2cm²) ### Portal-Related Complications **1. SAPHENOUS NERVE INJURY (2-7% - MOST COMMON):** **Clinical Manifestation:** - **Numbness** over medial knee and proximal medial leg (saphenous nerve distribution) - **Dysesthesia** (tingling, burning sensation) in 30-40% of cases - **Painful neuroma** (10-15%) at portal site - tender nodule palpable at anteromedial portal **Natural History:** - **Transient** (60-70% cases): Resolves by 6-12 months - **Permanent** (30-40% cases): Persistent numbness (usually well-tolerated if no neuroma pain) **Prevention:** - Keep anteromedial portal 10mm (NOT MORE) medial to patellar tendon medial border - **Vertical skin incisions** (parallel to nerve course) - reduces transection risk vs horizontal incisions - **Small portal size** (5-7mm) - large incisions (greater than 10mm) increase nerve exposure area - Sharp capsule penetration (clean cut vs blunt tearing which avulses nerve branches) **Management:** - **Observation** for 6-12 months (60-70% resolve spontaneously) - **Desensitization therapy** (massage with graded textures) for dysesthesia - **Neuropathic pain medications**: Gabapentin 300mg TDS (titrate to 900mg TDS), amitriptyline 25mg nocte - **Neuroma excision** if symptomatic beyond 12 months (painful tender nodule) - 70% symptom improvement **2. HEMARTHROSIS (1-3%):** **Mechanism:** - **Inferior lateral geniculate artery injury** during posterolateral or inferolateral portal creation (most common - Small 1985) - Synovial bleeding from aggressive synovectomy or fat pad resection - Inadequate hemostasis before tourniquet release **Clinical Manifestation:** - Progressive knee swelling in first 24-48 hours post-op - Tense effusion (50-150mL blood) - Pain, limited ROM **Prevention:** - Spinal needle localization for posterior portals - Direct portals ANTERIORLY toward intercondylar notch (avoids posterior dissection into geniculate arteries) - Cauterize bleeding vessels with radiofrequency ablation BEFORE completing procedure - Release tourniquet BEFORE wound closure, ensure hemostasis **Management:** - **Aspiration** (50-150mL blood typical) - provides symptom relief - **Re-arthroscopy** if persistent bleeding (greater than 200mL aspirated or re-accumulates rapidly) - identify and cauterize bleeding vessel - **Observation** if small volume (less than 50mL) - spontaneous resolution by 1-2 weeks **Outcome:** - 95% resolve with aspiration ± observation - Rarely requires open ligation or angiographic embolization **3. INFECTION (0.1-0.5%):** **Risk Factors:** - Diabetes (3× increased risk) - Obesity (BMI greater than 30) - Smoking - Prolonged procedure time (greater than 90 minutes) - Intra-articular corticosteroid injection within 3 months **Clinical Manifestation:** - **Septic arthritis** (acute infection): Fever, severe pain, tense effusion, warmth, erythema (onset 2-7 days post-op) - **Portal cellulitis** (superficial infection): Erythema around portal site, no systemic symptoms **Prevention:** - Pre-operative antibiotic prophylaxis (cephazolin 2g IV) within 60 minutes of incision - Strict sterile technique (draping, gown, gloves) - Minimize procedure time (complete diagnostic + therapeutic arthroscopy within 60-90 minutes) - Avoid intra-articular corticosteroid injection close to surgery date (delay 3 months if possible) **Management:** - **Septic arthritis**: - **Arthroscopic irrigation and debridement** (URGENT within 24 hours) - remove fibrinous debris, copious lavage (6-9L saline) - **Aspiration** for Gram stain and culture (obtain BEFORE starting antibiotics if possible) - **IV antibiotics** (empiric: flucloxacillin 2g QDS + gentamicin 4-6mg/kg daily, adjust based on culture results) - Duration: 2 weeks IV + 4 weeks PO (total 6 weeks) - **Portal cellulitis**: - Oral antibiotics (flucloxacillin 500mg QDS or cephalexin 500mg QDS for 7-10 days) - Local wound care (daily dressings) **Outcome:** - With early I&D (within 24-48 hours): 90-95% infection clearance, full recovery - Delayed treatment (greater than 3 days): 20-30% risk of chronic infection, chondral damage, reduced ROM **4. PERONEAL OR TIBIAL NERVE INJURY (0.4-1.2%):** **Mechanism:** - Direct trauma during posterior portal creation (posterolateral: peroneal nerve, posteromedial: tibial nerve) - Excessive posterior dissection beyond joint capsule into neurovascular structures **Clinical Manifestation:** - **Peroneal nerve palsy** (posterolateral portal injury 0.4% - Allardyce 2013): - **Foot drop** (ankle/toe dorsiflexion weakness - tibialis anterior, EHL, EDL) - **Steppage gait** (high stepping to clear foot) - **Sensory loss** over dorsum of foot and lateral leg - **Tibial nerve palsy** (posteromedial portal injury 1.2%): - **Calf weakness** (gastrocnemius, soleus - ankle/toe plantarflexion weakness) - **Intrinsic foot weakness** (FHL, FDL, lumbricals/interossei) - **Sensory loss** over plantar foot **Prevention:** - **Posterolateral portal PREFERRED** over posteromedial (peroneal nerve 8mm lateral vs tibial nerve 5mm medial - Allardyce 2013) - Knee flexed 90° + slight internal rotation for posterolateral portal (peroneal nerve migrates laterally) - **Spinal needle localization** MANDATORY - visualize needle tip intra-articularly BEFORE creating portal with blade - **Blunt trocar** or switching stick after initial capsule penetration (avoid sharp blade deep to capsule) - Direct portal ANTERIORLY toward intercondylar notch (avoid posterior dissection) **Management:** - **Immediate post-operative palsy** (recognized in PACU): - **Urgent MRI** to assess for hematoma compressing nerve (rare - less than 5% of cases) - If hematoma: Urgent decompression (evacuate hematoma, achieve hemostasis) - If NO hematoma: Observation (likely neurapraxia from direct trauma - 70-80% spontaneous recovery by 4-6 months) - **Dynamic splinting**: - **Peroneal palsy**: AFO (ankle-foot orthosis) to prevent foot drop, protect from tripping - **Tibial palsy**: Solid AFO for ankle stability (less common - tibial palsy usually less disabling than peroneal) - **Serial EMG** at 6-8 weeks (signs of reinnervation indicate recovery) - **Nerve exploration** if NO recovery by 6 months (neurolysis vs nerve grafting) - **Tendon transfers** if no recovery by 12 months: - **Peroneal palsy**: Tibialis posterior transfer to dorsum of foot (restores dorsiflexion) - **Tibial palsy**: Usually do NOT require transfer (compensatory mechanisms adequate) **Outcome:** - Neurapraxia (mild contusion): 90-95% complete recovery by 6 months - Axonotmesis (moderate crush): 60-70% recovery by 12 months - Neurotmesis (complete transection): Requires nerve repair or grafting (40-50% functional recovery)

Arthroscopic Portal Placement (Knee)

Arthroscopic Portal Placement (Knee)