366.4 ð ç« æ«éèš Summary
366.4.1 ð äžå¥è©±çžœçµ
Low back pain (LBP) = ~ 80% lifetime prevalence + leading cause of disability worldwide; neck pain ~ 30-50% annual; classification by duration â acute < 6 weeks, subacute 6-12, chronic > 12; ~ 85% non-specific (mechanical) â diagnosis without imaging in absence of red flags; specific causes â disc herniation (radiculopathy L5-S1/L4-L5 most common), spinal stenosis (neurogenic claudication relieved by flexion âshopping cart signâ), spondylolisthesis, vertebral compression fracture (osteoporosis, steroids), malignancy (metastasis breast/lung/prostate/kidney/thyroid + multiple myeloma), infection (spinal epidural abscess triad back pain + fever + neuro deficit but only 13% all 3 + osteomyelitis + discitis), inflammatory (ankylosing spondylitis HLA-B27 + bilateral sacroiliitis + bamboo spine + young < 45 + inflammatory pain morning stiffness > 30 min improved by exercise), cauda equina syndrome EMERGENCY; red flags get imaging + workup â Cancer (age > 50, history, weight loss, night pain), Infection (fever, IVDU, immunosuppression, bacteremia), Fracture (trauma, steroids, osteoporosis), Cauda equina (saddle anesthesia + urinary retention + bilateral leg weakness + bowel dysfunction + â rectal tone â urgent MRI + decompress within 48 hr), Cord compression (UMN signs); nerve root patterns memorize â L4 (anterior thigh, knee jerk â, quad weakness), L5 (lateral leg, dorsum foot, foot drop, great toe extension), S1 (posterior leg, lateral foot, plantarflexion, ankle jerk â); cervical C5 (deltoid biceps reflex), C6 (biceps brachioradialis reflex thumb), C7 (triceps reflex middle finger), C8 (hand intrinsics); imaging â no imaging acute non-specific LBP < 6 weeks without red flags; MRI best for disc/cord/nerve/abscess/tumor; mechanical vs inflammatory back pain â mechanical (any age, < 30 min stiffness, no rest pain, improved by rest) vs inflammatory (< 45, > 30 min, rest pain, exercise improves); neurogenic vs vascular claudication â neurogenic (normal pulses, relieved by flexion sitting) vs vascular (decreased pulses, relieved by standing still); treatment â stay active (bed rest worse) + NSAIDs first-line + muscle relaxants short-term + PT + CBT; interventional epidural steroid (radicular) + facet RFA + spinal cord stimulator; surgery for cauda equina + progressive neuro deficit + refractory radiculopathy > 6 weeks + spinal stenosis with disability + tumor/infection/instability; emerging: suzetrigine NaV1.8 inhibitor FDA 2025 for acute pain may reduce opioid use post-surgeryã
366.4.2 ð æ²»ç粟èŠ
- Acute non-specific LBPïŒstay active (bed rest worse) + NSAIDs + heat/cold + early mobilization; muscle relaxant cyclobenzaprine 5-10 mg HS à 1-2 weeks; acetaminophen limited evidence
- Chronic LBPïŒNSAIDs + duloxetine 60-120 mg + TCAs + PT + CBT + exercise programs; gabapentinoids for radicular pain; avoid chronic opioids
- Radicular painïŒNSAIDs + gabapentin/pregabalin + duloxetine + epidural steroid injection for persistent
- Spinal stenosisïŒNSAIDs + PT (flexion-based exercises) + epidural steroid + decompressive laminectomy for disabling
- Cauda equina syndromeïŒurgent MRI + neurosurgical decompression within 48 hr (sphincter function may not recover with delay)
- Spinal epidural abscessïŒsurgical drainage + IV antibiotics ⥠6 weeks (vancomycin + ceftriaxone empiric, target by culture)
- Vertebral compression fracture (osteoporotic)ïŒpain control + bracing + early mobilization + kyphoplasty for select refractory + osteoporosis treatment
- Ankylosing spondylitisïŒNSAIDs first-line (continuous use preferred) + TNF inhibitors (adalimumab, etanercept) + IL-17 inhibitors (secukinumab, ixekizumab) + JAK inhibitors (upadacitinib) for inadequate response
- Trigeminal neuralgia â see Ch364
- Surgical indicationsïŒcauda equina (emergency) + progressive neuro deficit + refractory radiculopathy > 6 weeks + spinal stenosis with disability + tumor + infection (with decompression need) + structural instability
366.4.3 ð¯ ç§é«åž«çèåæé
- ~ 85% non-specific LBP â no imaging in acute (< 6 weeks) without red flags; stay active + NSAIDs + PT first-line
- Red flags (memorize): Cancer (age > 50, history, weight loss, night pain) + Infection (fever, IVDU, immunosuppression) + Fracture (trauma, steroids, osteoporosis) + Cauda equina (EMERGENCY) + Cord compression (UMN signs)
- Cauda equina syndrome EMERGENCY: saddle anesthesia + urinary retention (most sensitive) + bilateral leg weakness/numbness + bowel dysfunction + â rectal tone â urgent MRI + neurosurgical decompression within 48 hr (delays â permanent sphincter dysfunction)
- Lumbar nerve root patterns: L4 (anterior thigh, quad, knee jerk); L5 (lateral leg, dorsum foot, foot drop tibialis anterior, great toe extension â no reflex); S1 (posterior leg, lateral foot, plantarflexion, ankle jerk)
- Cervical nerve root patterns: C5 (deltoid + biceps reflex); C6 (biceps + brachioradialis reflex + thumb); C7 (triceps reflex + middle finger); C8 (hand intrinsics + little finger)
- Spinal stenosis (neurogenic claudication): older + bilateral leg pain with walking/standing + relieved by flexion (shopping cart sign) + normal pulses; distinguished from vascular claudication
- Spinal epidural abscess: triad back pain + fever + neuro deficit (but only 13% all 3) + IVDU/immunosuppression/bacteremia + â ESR/CRP â MRI gadolinium + surgical drainage + IV antibiotics ⥠6 weeks
- Ankylosing spondylitis / axial SpA: young (< 45 onset) + inflammatory back pain (morning stiffness > 30 min, improved by exercise) + bilateral sacroiliitis + HLA-B27 â NSAIDs first-line + TNF inhibitors + IL-17 inhibitors + JAK inhibitors for inadequate response
- Mechanical vs inflammatory back pain distinction: mechanical (any age + < 30 min stiffness + no rest pain + improved by rest) vs inflammatory (< 45 + > 30 min + rest pain + exercise improves)
- Surgical indications: cauda equina (emergency) + progressive neuro deficit + refractory radiculopathy > 6 weeks + spinal stenosis with disability + tumor/infection/instability; avoid chronic opioids â multimodal best