import { OnePagerSummary, ExamWarning, InfoCardGrid, InfoCard, MnemonicCard, EvidenceCard, VivaScenarioSection, VivaScenario, ExamCheatSheet, ContentSection, ExamPearl, SafetyAlert, NumberHighlightRow, NumberHighlight, Tabs, Tab, ComparisonTable } from '@/components/mdx' **Location**: Bundle of nerve roots extending from conus medullaris (L1-L2 level) to sacral foramina. Float freely in CSF within dural sac. At L4-5 level, contains L5, S1, S2, S3, S4, S5 roots descending to respective exit levels. **Protection**: Gentle dural retraction only when absolutely necessary. Avoid direct instrumentation within canal. Bipolar cautery on low power (15-20W) and away from dura. Confirm adequate bony decompression before retraction. **Location**: Enters canal from level above, descends through lateral recess at disc level, exits at level below. At L4-5, L5 traversing root enters from L4 vertebra, descends through L4-5 lateral recess medial to L5 pedicle, exits through L5-S1 foramen. Located 3-5mm lateral to midline dura. **Protection**: Identify before retraction. Use nerve hook gently. Minimal retraction force (less than 10mm displacement, less than 30 minutes duration). Adequate lateral recess decompression eliminates need for aggressive retraction. Intermittent technique. **Location**: Exits neural foramen at SAME level as disc. At L4-5, L4 root exits through L4-5 foramen lateral to L4 pedicle, superior to disc. DRG (dorsal root ganglion) lies within foramen in superior-anterior quadrant. Located 15-20mm lateral from posterior midline. **Protection**: During foraminotomy, undercut facet from medial to lateral (away from nerve). Stay inferior to pars interarticularis. Preserve more than 50% of facet joint. Use angled curette to feel DRG before bone removal. Avoid direct instrumentation of DRG - exquisitely sensitive. **Location**: Outermost meningeal layer containing CSF, arachnoid, and nerve roots. Runs from foramen magnum to S2. In lumbar spine, lies immediately anterior to ligamentum flavum in epidural space, immediately posterior to PLL. Thickness 0.5-1mm (thinner than cervical/thoracic). Often adherent to hypertrophied flavum in stenosis. **Protection**: Angled 45-degree Kerrison when removing ligamentum flavum. Advance superior-lateral (away from dura). Sharp dissection with microscissors if dura adherent to flavum rather than blunt stripping. Identify dura early before aggressive bone removal. Lower bipolar power (15-20W). **Location**: Valveless venous network in epidural space, running longitudinally along posterior vertebral body and within lateral recess. Connects to segmental veins laterally. Engorged and hypertrophied in chronic stenosis due to increased collateral flow. **Protection**: Subperiosteal dissection preserves muscle layers. Bipolar cautery on low power (15-20W). Hemostatic agents (Gelfoam, Surgicel, thrombin-soaked cottonoids) for oozing. Patient positioning with abdomen free-hanging reduces venous pressure. Patience - tamponade effect over 5-10 minutes often controls bleeding. ### Indications for Lumbar Decompression **Neurogenic Claudication Criteria:** - Leg pain (bilateral or unilateral) worse with walking/standing, relieved by sitting/forward flexion - Distance limitation (less than 500m typical, variable between patients) - Failed conservative treatment: 3-6 months of PT, medications (NSAIDs, gabapentin), epidural steroid injections - Significant functional limitation affecting quality of life (shopping, activities of daily living) - MRI correlation with anatomical stenosis matching clinical symptoms **Progressive Neurological Deficit:** - Motor weakness in lower extremities (foot drop, knee buckling) - Sensory deficit in dermatomal distribution - Bladder/bowel dysfunction (rare presentation but urgent indication) - Cauda equina syndrome (emergency indication) **Imaging Requirements:** - MRI lumbar spine demonstrating stenosis (central canal diameter less than 10mm, lateral recess less than 3mm, foraminal height less than 15mm) - Schizas classification Grade C or D (severe stenosis) has best surgical outcomes - Correlation between imaging findings and clinical symptoms essential - Flexion-extension radiographs if spondylolisthesis suspected (assess mobility) **Contraindications - Relative:** - Predominantly axial back pain without radicular component (poor surgical outcome predictor) - Mild symptoms not limiting function - Lack of imaging correlation with clinical picture - Psychosocial factors: active litigation, secondary gain, severe depression, catastrophizing - Medical comorbidities requiring optimization: uncontrolled diabetes (HbA1c more than 8%), active smoking (4-week cessation recommended), severe cardiac disease, coagulopathy **Contraindications - Absolute:** - Active spinal infection (pyogenic discitis, epidural abscess) - Medical instability precluding anesthesia - Patient refusal or unrealistic expectations **Patient Selection Pearls**: SPORT stenosis trial showed surgery superior to conservative treatment at 2-4 years for patients with anatomical stenosis and neurogenic claudication. However, patient selection is critical - surgery relieves LEG symptoms (claudication, radiculopathy) better than BACK pain. Patients with predominantly axial pain have poor outcomes. Psychosocial screening identifies high-risk patients: litigation, workers compensation, depression, catastrophizing, opioid dependence all predict poor outcomes regardless of technical surgical success. Set realistic expectations - improvement not cure, 60-80% good/excellent outcomes at 1 year, 50-70% sustained at 4+ years. ### Evidence Base **SPORT Stenosis Trial:** - Multicenter RCT: surgery vs conservative treatment for lumbar stenosis - Surgery group: significant improvement in ODI, SF-36, leg pain scores at 2 years, sustained at 4 years - Conservative group: some improvement but inferior to surgery - Crossover analysis (intention-to-treat confounded): as-treated analysis showed larger surgical benefit - Conclusion: Surgery superior for appropriately selected patients with stenosis and neurogenic claudication **SLIP Trial (Spondylolisthesis):** - Multicenter RCT: decompression alone vs decompression + fusion for degenerative spondylolisthesis - Decompression + fusion: superior outcomes in ODI, SF-36, less reoperation at 4 years - Decompression alone: 25% required fusion for progression/instability by 4 years - Conclusion: Fusion recommended for spondylolisthesis (grade 1 or higher, or mobile on flex-ex) **Swedish Spine Register Data:** - Large registry study (5,000+ patients) - Stenosis surgery outcomes: 60-70% satisfied at 1 year, 50-60% at 5 years - Predictors of good outcome: leg pain dominant, severe stenosis on imaging, younger age, non-smoker - Predictors of poor outcome: back pain dominant, mild stenosis, psychosocial factors ### Bony Anatomy **Vertebral Structure:** - Vertebral body: anterior weight-bearing structure, bounded posteriorly by posterior longitudinal ligament (PLL) - Pedicles: connect vertebral body to posterior elements, lateral walls of spinal canal - Lamina: posterior roof of spinal canal, extends from pedicle to spinous process medially - Facet joints (zygapophyseal joints): superior articular process of inferior vertebra articulates with inferior articular process of superior vertebra - Pars interarticularis: bone bridge between superior and inferior articular processes, vulnerable to fracture during foraminotomy - Spinous process: midline posterior projection, attachment for interspinous and supraspinous ligaments **Three-Column Spine Concept (Denis):** - Anterior column: anterior longitudinal ligament, anterior 2/3 vertebral body, anterior annulus - Middle column: posterior 1/3 vertebral body, PLL, posterior annulus (CRITICAL for stability) - Posterior column: pedicles, lamina, facets, spinous processes, posterior ligamentous complex - Decompression affects posterior column primarily - preserve facet joints for stability **Facet Joint Orientation:** - Lumbar facets: more sagittal/vertical orientation (45-60 degrees from coronal plane) - Function: resist anterior shear forces (prevent spondylolisthesis), allow flexion-extension - Decompression principle: preserve more than 50% to maintain anti-shear function - Biomechanics: facets provide 20-25% of segmental stability, disc 60%, ligaments 15% ### Neural Anatomy - Three Zones **Zone 1: Central Canal (Dural Compression)** - Contents: dura, arachnoid, CSF, cauda equina (L5, S1, S2, S3, S4, S5 roots at L4-5 level) - Normal diameter: 15-25mm on axial MRI (measured at pedicle level) - Stenosis: less than 10mm (relative), less than 8mm (absolute), Schizas Grade C-D - Compression from: ligamentum flavum hypertrophy (posterior), disc bulge (anterior), facet hypertrophy (lateral) - Clinical: neurogenic claudication (bilateral leg symptoms, positional relief) **Zone 2: Lateral Recess (Traversing Root Compression)** - Boundaries: medial (dura/thecal sac), lateral (pedicle), anterior (vertebral body/disc), posterior (superior articular process/facet) - Contents: traversing nerve root (descends one level before exiting) - At L4-5: L5 root traverses lateral recess, exits L5-S1 foramen - Normal diameter: 5-8mm on axial MRI (lateral recess height) - Stenosis: less than 3mm (significant), less than 2mm (severe) - Compression from: facet hypertrophy (posterior), disc bulge (anterior), ligamentum flavum (medial) - Clinical: radiculopathy in distribution of traversing root (L5 radiculopathy at L4-5 level) **Zone 3: Foramen (Exiting Root and DRG Compression)** - Boundaries: superior (pedicle of level above), inferior (pedicle and disc of level below), anterior (vertebral body), posterior (facet joint and pars) - Contents: exiting nerve root, DRG (dorsal root ganglion in superior-anterior quadrant), radicular arteries - At L4-5 foramen: L4 root exits (root number matches level above disc) - Normal dimensions: height 15-20mm (sagittal), width 8-10mm (axial) - Stenosis: height less than 15mm, width less than 8mm - Compression from: disc height loss (reduces foraminal height), facet hypertrophy (posterior), osteophytes (anterior) - Clinical: radiculopathy in distribution of exiting root (L4 radiculopathy at L4-5 level) - DRG sensitivity: DRG is exquisitely sensitive structure - direct trauma causes severe dysesthesia and burning pain ### Ligamentous Anatomy **Ligamentum Flavum (Yellow Ligament):** - Composition: 80% elastin (yellow color), 20% collagen - Location: connects laminae of adjacent vertebrae, forms posterior wall of spinal canal - Normal thickness: 2-3mm - Stenosis hypertrophy: 5-8mm (can double or triple in thickness) - Pathophysiology: chronic mechanical stress, inflammation, fibrosis, calcification (10-15% cases) - Clinical significance: OFTEN PRIMARY cause of stenosis (more than disc bulge) - Surgical importance: complete removal essential for adequate decompression **Other Key Ligaments:** - Interspinous ligament: connects spinous processes, preserved in laminotomy techniques - Supraspinous ligament: runs along tips of spinous processes, may preserve in midline-sparing techniques - Intertransverse ligaments: between transverse processes, not involved in decompression - Posterior longitudinal ligament (PLL): anterior to dura, may ossify (OPLL - requires different surgical approach) ### Vascular Anatomy **Epidural Venous Plexus (Batson's Plexus):** - Valveless venous network in epidural space - Longitudinal veins along posterior vertebral body - Transverse connections at each level - Connections to segmental veins laterally - Engorged in chronic stenosis (collateral flow from chronic compression) - Surgical significance: primary source of intraoperative bleeding, controlled with bipolar cautery, hemostatic agents, patient positioning **Arterial Supply:** - Segmental arteries from aorta at each level - Radicular arteries accompany nerve roots through foramina - Artery of Adamkiewicz: major anterior radicular artery (T8-L1), supplies anterior spinal artery - Surgical caution: avoid excessive cautery or traction on radicular arteries (risk of root ischemia) ### Positioning (Critical for Success) **Prone Position Setup:** - **Frame Options**: Wilson frame (most common - allows lumbar flexion adjustment), Jackson table (radiolucent - optimal for fluoroscopy), Andrews frame (chest/pelvis support) - **Hip Flexion**: 30-45 degrees hip flexion (accomplished by frame adjustment) - Opens interspinous space 3-5mm per level - Increases lumbar flexion - Widens interlaminar window for easier surgical access - **Abdomen Free-Hanging**: Essential to reduce epidural venous pressure - Check ventilation parameters after positioning (peak pressures should not increase) - Palpate abdomen to ensure no compression - Reduces intraoperative bleeding significantly - **Arm Position**: Less than 90 degrees shoulder abduction - Prevents brachial plexus stretch injury (C5-C6 roots most vulnerable) - Padding at elbows (ulnar nerve) - **Pressure Point Protection**: Chest rolls or frame padding, knee padding, ankle padding, eye protection (tape or pads), face protection (padded headrest or prone view pillow) - **Final Check**: All pressure points padded, eyes protected, no abdominal compression, adequate ventilation, stable position ### Incision and Exposure **Fluoroscopic Level Identification:** 1. Palpate iliac crests (Tuffier's line) - usually L4-5 level (70% of patients) 2. Mark estimated level on skin 3. MANDATORY fluoroscopy with spinal needle on skin BEFORE incision 4. AP and lateral views to confirm level 5. Count from C7 (if cervical visible) AND from sacrum (if transitional anatomy suspected) 6. Document level confirmation in operative note **Skin Incision:** - Midline posterior incision - Length: 3-5cm per level for traditional laminectomy (e.g., 6-10cm for L4-5 + L5-S1 two-level) - Centered over stenotic levels (confirmed with fluoroscopy) - Incise skin, subcutaneous tissue sharply **Fascial Incision:** - Identify thoracolumbar fascia (thick white glistening layer) - Palpate spinous processes through fascia to confirm midline - Incise fascia sharply in midline with monopolar cautery or scalpel - May encounter interspinous ligament (midline avascular plane) **Subperiosteal Muscle Dissection:** - Use Cobb elevator or monopolar cautery - Dissect paravertebral muscles (multifidus, longissimus) laterally off spinous processes and laminae - STAY SUBPERIOSTEAL (minimizes bleeding, preserves muscle attachments) - Expose lateral to facet joints bilaterally (15-20mm from midline each side) - Identify key landmarks: spinous processes, laminae, facet joints, pars interarticularis - Place self-retaining retractors (Taylor or Weitlaner) ### Laminectomy Technique (Traditional) **Bony Work - Central Decompression:** 1. **Spinous Process**: May preserve or remove depending on technique - Traditional laminectomy: remove with rongeur - Some surgeons preserve for midline structure stability 2. **Lamina Removal**: - Use high-speed burr (diamond or cutting burr) to thin lamina to eggshell thickness - Burr from lateral to medial, superficial to deep - Once thin, use Kerrison rongeur to remove bone - Remove entire lamina from medial aspect of one facet to medial aspect of contralateral facet - Superior to inferior: remove from superior edge of inferior lamina to inferior edge of superior lamina 3. **Facet Preservation**: CRITICAL - preserve more than 50% of facet joint - Remove only medial 1/3 of facet (5-8mm from medial border) - Measure with ruler or estimate visually (typical facet width 15-20mm, remove less than 10mm) - Protect pars interarticularis (do not violate) **Ligamentum Flavum Removal - KEY STEP:** 1. **Identification**: Thick (5-8mm in stenosis), yellow, elastic ligament between laminae 2. **Entry Point**: Safest at inferior-medial corner (furthest from dura) 3. **Technique**: - Use angled 45-degree Kerrison rongeur - Enter epidural space carefully (dura lies 2-3mm anterior to flavum) - Advance Kerrison superior-lateral direction (away from dura) - Remove flavum completely from medial facet to medial facet - If flavum adherent to dura (common in stenosis), use sharp dissection with microscissors to separate 4. **Confirmation**: Dura should be visible, translucent, with visible vessels 5. **Test for Elasticity**: Flavum 'springs back' when touched (elastic), dura does not (differentiation) **Central Canal Decompression Assessment:** - **Dural Pulsation**: OBJECTIVE ENDPOINT - Should see rhythmic pulsation transmitted from CSF and cardiac cycle - Absence suggests: residual anterior compression, proximal CSF obstruction, severe stenosis - If non-pulsatile: explore further (remove more bone anteriorly, check adjacent levels, consider anterior pathology) ### Lateral Recess and Foraminal Decompression **Lateral Recess (Traversing Root):** 1. **Identify Traversing Root**: Use nerve hook to palpate root in lateral recess (medial to pedicle, 3-5mm lateral to dura) 2. **Medial Facet Undercut**: - Use angled Kerrison or curette - Remove medial 1/3 of facet (5-8mm) - this decompresses lateral recess - Preserve more than 50% of facet total (measure carefully) 3. **Disc Bulge**: If significant disc bulge compressing lateral recess, consider discectomy 4. **Confirmation**: Traversing root should mobilize freely - Pass ball-tip probe around root 360 degrees (gently) - Root should have normal color (pink/white, not cyanotic blue/purple) **Foraminotomy (Exiting Root) - If Indicated:** - **Indications**: Foraminal stenosis on MRI (diameter less than 10mm axial, height less than 15mm sagittal), inability to pass probe through foramen, intraoperative visualization of compressed exiting root - **Technique**: 1. Undercut facet from medial to lateral (away from nerve and DRG) 2. Remove superior articular process of inferior vertebra 3. Stay inferior to pars interarticularis (superior boundary of foramen) 4. Use angled curette to feel for DRG in superior-anterior foramen before bone removal 5. PRESERVE more than 50% of facet joint total 6. Gentle technique - DRG extremely sensitive to trauma - **Confirmation**: Should be able to pass probe through foramen alongside exiting root ### Multi-Level Decompression **Approach for Multiple Stenotic Levels:** 1. Decompress all clinically and radiographically significant levels 2. Common patterns: L3-4 + L4-5 (most common), L4-5 + L5-S1, skip lesions (L3-4 + L5-S1) 3. Use same systematic technique at each level (central, lateral recess, foraminal if needed) 4. Mark each level with methylene blue on spinous process to prevent wrong-level work 5. Consider fusion if 3+ levels or facet preservation compromised ### Hemostasis **Epidural Venous Bleeding Control:** - Bipolar cautery: LOW POWER (15-20W) to avoid thermal injury to dura/roots - Hemostatic agents: Gelfoam or Surgicel packing (leave in place, absorbs over time) - Thrombin-soaked cottonoids: place and hold pressure for 5-10 minutes (tamponade) - Patient positioning: ensure abdomen free-hanging (reduces venous pressure) - Patience: allow tamponade effect over 5-10 minutes before declaring uncontrolled bleeding - Floseal hemostatic matrix: some surgeons use for persistent oozing **Irrigation:** - Copious irrigation with 2-3L warm saline - Removes blood clots, bone dust, debris - Reduces inflammation and postoperative pain - Prevents arachnoiditis from particulate matter ### Closure **Layered Watertight Technique:** 1. **Fascial Layer**: Most critical for preventing CSF leak - Interrupted or running 0 or 2-0 absorbable suture (Vicryl, PDS) - Ensure watertight closure even if no recognized dural tear - Optional: Valsalva test before fascial closure (increase ventilator pressure to 30-40cmH2O, observe for CSF leak) 2. **Subcutaneous Layer**: 2-0 or 3-0 absorbable, obliterate dead space 3. **Skin**: Subcuticular 3-0 or 4-0 absorbable (Monocryl - best cosmesis), OR staples (faster, easier removal at 7-14 days), OR interrupted nylon 4. **Dressing**: Sterile dressing (Tegaderm or gauze + tape) ### Decompression Alone vs Decompression Plus Fusion **Indications for Decompression ALONE:** - Stenosis without spondylolisthesis - Stable spondylolisthesis grade 1 (less than 25% slip) with NO mobility on flexion-extension (less than 3mm translation) - Single or two-level stenosis with adequate facet preservation (more than 50% maintained) - No significant scoliosis requiring correction - First-time surgery (not revision) **Indications for Decompression PLUS FUSION:** 1. **Pre-existing Spondylolisthesis**: - Grade 2 or higher (more than 25% slip) - absolute indication - Grade 1 with MOBILITY on flex-ex radiographs (more than 3mm translation or more than 10 degrees angular motion) - SLIP trial evidence: decompression + fusion superior outcomes, less reoperation 2. **Iatrogenic Instability**: - More than 50% facet removal bilaterally (intraoperative decision) - Pars interarticularis fracture during surgery - Complete facetectomy (rare, if required for exposure) 3. **Scoliosis**: - Degenerative scoliosis (Cobb angle more than 20 degrees) with coronal imbalance - Progressive curve requiring correction - Rotatory listhesis (spondylolisthesis in coronal plane) 4. **Multi-Level Extensive Decompression**: - Three or more levels (controversial - some surgeons fuse, others don't) - Biomechanical concern for destabilization with extensive posterior element removal 5. **Revision Surgery**: - Recurrent stenosis after previous decompression-only (instability developed) - Progression of spondylolisthesis after prior surgery **Fusion Technique Options:** - Posterolateral fusion: bone graft along transverse processes and facets - TLIF (Transforaminal Lumbar Interbody Fusion): cage via transforaminal approach, unilateral approach - PLIF (Posterior Lumbar Interbody Fusion): cage via bilateral approach between nerve roots - Instrumentation: pedicle screw fixation for all fusions (provides rigid stabilization) ### Laminectomy vs Laminotomy vs Minimally Invasive Techniques **Traditional Laminectomy (Complete):** - Remove entire lamina from medial facet to medial facet - Indications: severe central stenosis (Schizas C-D), multi-level stenosis, revision surgery with epidural scarring - Advantages: wide decompression, excellent visualization, can address central + lateral + foraminal stenosis - Disadvantages: more tissue disruption, longer recovery, theoretical destabilization (if facets not preserved) **Bilateral Laminotomy (Interlaminar Window):** - Create interlaminar window by removing inferior portion of superior lamina and superior portion of inferior lamina - Preserve midline structures: spinous process, interspinous ligament, supraspinous ligament - Indications: focal stenosis (single level), primarily ligamentum flavum hypertrophy, younger patients where motion preservation desired - Advantages: preserves midline tension band, less destabilization theoretically - Disadvantages: limited lateral exposure, difficult for foraminal stenosis **Unilateral Laminotomy for Bilateral Decompression (ULBD):** - Minimally invasive approach: unilateral exposure, decompress both sides via undercutting - Technique: approach from one side, undercut spinous process and contralateral lamina to reach opposite lateral recess - Indications: bilateral stenosis without severe central component, suitable anatomy - Advantages: less tissue trauma, faster recovery, preserves midline structures - Disadvantages: technically demanding, learning curve, limited visualization, may miss pathology on contralateral side **Tubular Minimally Invasive (MIS) Approach:** - Dilators and tubular retractor for focal decompression - Indications: focal single-level stenosis, selected patients - Advantages: minimal tissue disruption, outpatient potential, faster recovery - Disadvantages: steep learning curve, limited field of view, higher complication rate during learning phase, expensive equipment **Surgeon Choice Factors:** - Extent and severity of stenosis (MRI grading) - Number of levels involved - Patient age and activity level - Surgeon experience and training - Patient preference after informed discussion ### Management of Intraoperative Complications **Durotomy Recognition and Repair:** 1. **Recognition**: Clear fluid in field (CSF), may see neural tissue if large tear 2. **Extend Exposure**: Expose dura above and below tear for adequate visualization 3. **Primary Repair**: - 6-0 or 7-0 non-absorbable suture (Prolene, Nurolon) - Simple interrupted sutures for small tears (less than 5mm) - Running technique for larger tears (more than 5mm) - Ensure watertight closure 4. **Adjuncts**: - Fibrin glue overlay (DuraSeal, Tisseel) - If tear too large for primary repair: dural patch (autograft - fascia lata, or allograft - collagen matrix) 5. **Valsalva Test**: Anesthesia increases ventilator pressure to 30-40cmH2O, observe for leak 6. **Postoperative**: Flat bed rest 24-48h (controversial, commonly done), watertight fascial closure critical **Nerve Root Injury:** - If recognized: immediate cessation of causative action, assess root viability - Document in operative note (preoperative vs intraoperative deficit) - Postoperative: serial neurological exams, neuropathic pain medications (gabapentin, pregabalin), physiotherapy - Most temporary injuries (neuropraxia) recover over 6-12 weeks - Permanent injury (rare): requires multidisciplinary pain management, orthotics for foot drop **Excessive Facet Removal:** - If more than 50% removed bilaterally (recognized intraoperatively): ADD FUSION at index surgery - Do not close and observe - fusion at index surgery prevents late instability - Document reasoning in operative note ### Immediate Postoperative Management (First 24 Hours) **Recovery Room Monitoring:** - Neurovascular checks every 4 hours for 24 hours - Lower extremity motor function: ankle dorsiflexion (L4-5), great toe extension (L5), ankle plantarflexion (S1) - Sensory: check all dermatomes (L1-S1) - Bladder function: monitor for urinary retention (post-void residual less than 200mL normal) - Sacral sensation: check perianal sensation (cauda equina screening) - **RED FLAGS** requiring urgent MRI: - New or worsening bilateral leg weakness - Saddle anesthesia (S2-S5 distribution) - Urinary retention developing postoperatively (more than 200mL post-void residual) - Progressive motor deficit - **ACTION**: Urgent MRI to rule out epidural hematoma, if confirmed re-explore immediately **Pain Management:** - Multimodal analgesia protocol: - Acetaminophen 1000mg PO/IV Q6h (scheduled, not PRN) - Gabapentin 300mg PO TID (start preop, continue postop - reduces opioid requirement) - Opioids as needed: oxycodone 5-10mg PO Q4h PRN, or PCA hydromorphone if severe pain - Local anesthetic: some surgeons infiltrate wound with bupivacaine 0.25% at closure - **AVOID NSAIDs if fusion performed** (impair bone healing) - Target pain control allowing mobilization (pain score 3-4/10 acceptable) **DVT Prophylaxis:** - **Mechanical**: TED stockings, sequential compression devices (SCDs) - apply immediately postop, continue until fully ambulatory - **Chemical**: Risk-stratified approach - Low risk (age less than 40, healthy, short surgery): mechanical only - Moderate risk (age 40-60, 1-2 risk factors): mechanical + consider chemical - High risk (age more than 60, malignancy, prior VTE, prolonged immobility): mechanical + chemical - Agent: enoxaparin 40mg SQ daily, start 12-24h postop (balance VTE vs bleeding risk) - Timing: earlier start (12h) reduces VTE, later start (24h) reduces hematoma risk - surgeon judgment - **Early mobilization**: most important VTE prevention - out of bed same day or POD1 **Bladder Management:** - Monitor voiding: should void within 6-8 hours postop - Bladder scan if unable to void: post-void residual less than 200mL normal - **Urinary retention (5-10% incidence)**: - Causes: epidural anesthesia effect (if used), narcotic effect, neurogenic bladder, spinal cord/cauda equina injury - Management: bladder scan (if more than 400mL, straight catheterization), avoid indwelling Foley if possible (infection risk) - Most retention resolves within 48h - if persistent, indwelling catheter and urology consult **Drain Management (If Used):** - Subfascial drain (Jackson-Pratt or Blake) - NOT epidural - Low-pressure suction - Monitor output: typically 50-200mL first 24h - Remove when output less than 50mL per day (usually POD1-2) - Note: Drain use is controversial - surgeon preference ### Hospital Stay and Mobilization **Day of Surgery (POD0):** - Log roll technique for position changes (initial 24h, then unrestricted) - Out of bed to chair with assistance if pain controlled (some surgeons same day, others POD1) - Diet: clear fluids initially, advance as tolerated - Continue multimodal analgesia **Postoperative Day 1:** - Neurovascular assessment continues Q4h - **Mobilization with physiotherapy**: KEY to recovery - Out of bed, ambulate in hallway with walker/stick as needed - Goal: walk 50-100m on POD1 - Early mobilization reduces: DVT risk, pulmonary complications, deconditioning, length of stay - Transition to oral pain medications if tolerating PO - Remove urinary catheter if placed (reduce infection risk) - Drain removal if output less than 50mL **Discharge Criteria (POD1-3):** - Pain controlled with oral medications (score less than 4/10 at rest) - Ambulating independently or with minimal assistance (walker acceptable) - Tolerating diet without nausea/vomiting - Adequate bladder function (voiding spontaneously, post-void residual less than 200mL) - No signs of infection (afebrile, wound clean and dry) - Adequate home support or discharge to rehabilitation facility - Understanding of red flag symptoms requiring urgent return ### Outpatient Recovery (Weeks 1-6) **Activity Restrictions:** - **Week 1-2**: Light activities only - Walking encouraged (start 10-15 minutes TID, increase gradually) - Avoid prolonged sitting initially (less than 30 minutes at a time) - No bending, lifting, twisting (BLTs) - No driving while on opioids - **Week 3-6**: Gradual increase - No heavy lifting (more than 10kg) for 6 weeks - May increase walking distance progressively - May drive if off opioids and comfortable (check insurance policy) - Sedentary work: return at 2-4 weeks - Light duty work: return at 4-6 weeks - Heavy labor: return at 12 weeks **Wound Care:** - Keep dressing clean and dry for 48-72h - May shower after 72h (let water run over wound, pat dry, no soaking/submersion) - Staples/sutures: remove at 7-14 days (outpatient clinic or GP) - Monitor for infection signs: increasing pain, redness, warmth, drainage, fever **Physiotherapy:** - **Initial 6 weeks**: Gentle range of motion, walking program - **After 6 weeks**: Core strengthening program - Lumbar stabilization exercises (multifidus, transversus abdominis activation) - Gradual progression to resistance training - Goal: return to normal activities by 12 weeks **Medications:** - Continue gabapentin 300-900mg TID for 6 weeks (neuropathic pain, helps nerve recovery) - Wean opioids as rapidly as possible (target off by 2-4 weeks) - Acetaminophen for background pain control - Avoid NSAIDs if fusion performed (until fusion confirmed on imaging at 3-6 months) ### Follow-Up Schedule **Week 2**: Wound check, staple/suture removal **Week 6**: Clinical assessment - neurological exam, symptom improvement, activity tolerance **Month 3**: Clinical assessment, consider imaging if concerns **Month 6-12**: Final assessment, imaging if fusion performed (assess fusion status) **Expected Outcomes:** - Neurogenic claudication: improvement over 6-12 weeks (gradual, not immediate) - Radiculopathy: may worsen initially (surgical irritation), then improve over 6-12 weeks - Motor deficit: recovery variable (axonotmesis may take 6-12 months) - Success rate: 60-80% good/excellent outcomes at 1 year for appropriate indications - Durability: 50-70% sustained benefit at 4+ years (some deterioration over time from natural degeneration) **Red Flags for Urgent Return:** - New or worsening bilateral leg weakness - Urinary retention or incontinence - Saddle anesthesia - Fever more than 38.5°C with wound drainage (infection) - Severe uncontrolled pain despite medications (hematoma, infection) - Wound leak of clear fluid (CSF leak) - Increasing swelling at wound (hematoma, seroma, pseudomeningocele) ## References 1. Weinstein JN, Tosteson TD, Lurie JD, et al. Surgical versus nonsurgical therapy for lumbar spinal stenosis. N Engl J Med. 2008;358(8):794-810. (SPORT stenosis trial - Level I evidence for surgical superiority) 2. Försth P, Ólafsson G, Carlsson T, et al. A Randomized, Controlled Trial of Fusion Surgery for Lumbar Spinal Stenosis. N Engl J Med. 2016;374(15):1413-1423. (SLIP trial - fusion vs decompression alone for spondylolisthesis) 3. Schizas C, Theumann N, Burn A, et al. Qualitative grading of severity of lumbar spinal stenosis based on the morphology of the dura mater on magnetic resonance images. Spine. 2010;35(21):1919-1924. (Schizas classification system) 4. Ghogawala Z, Dziura J, Butler WE, et al. Laminectomy plus fusion versus laminectomy alone for lumbar spondylolisthesis. N Engl J Med. 2016;374(15):1424-1434. (RCT supporting fusion for spondylolisthesis) 5. Abumi K, Panjabi MM, Kramer KM, Duranceau J, Oxland T, Crisco JJ. Biomechanical evaluation of lumbar spinal stability after graded facetectomies. Spine. 1990;15(11):1142-1147. (Biomechanics of facet preservation - 50% threshold) 6. Ciol MA, Deyo RA, Howell E, Kreif S. An assessment of surgery for spinal stenosis: time trends, geographic variations, complications, and reoperations. J Am Geriatr Soc. 1996;44(3):285-290. (Large epidemiological study of outcomes) 7. Jones AA, Stambough JL, Balderston RA, Rothman RH, Booth RE Jr. Long-term results of lumbar spine surgery complicated by unintended incidental durotomy. Spine. 1989;14(4):443-446. (Natural history and management of durotomy) 8. Epstein NE. Identification of ossification of the posterior longitudinal ligament extending through the dura on preoperative computed tomographic examinations of the cervical spine. Spine. 2001;26(2):182-186. (Relevance for anterior compression assessment) 9. Atlas SJ, Keller RB, Wu YA, Deyo RA, Singer DE. Long-term outcomes of surgical and nonsurgical management of lumbar spinal stenosis: 8 to 10 year results from the Maine Lumbar Spine Study. Spine. 2005;30(8):936-943. (Long-term outcomes data) 10. Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR). Hip, Knee & Shoulder Arthroplasty: 2023 Annual Report. Adelaide: AOA; 2023. (Australian context for arthroplasty complications, DVT rates, infection rates applicable to spinal surgery)

Lumbar Decompression for Spinal Stenosis

Lumbar Decompression for Spinal Stenosis