Low-back Pain

DDx Low-Back Pain

• Serious (RED FLAGS)
  Note: As per a 2023 Cochrane systemic review individual red flags have poor diagnostic accuracy

  • Cord Compression (Urinary/Fecal incontinence/retention, saddle anesthesia, motor weakness/numbness)

  • Infectious - Discitis/epidural abscess/pyelonephritis (Fever, IV drug use, severe, recent surgery,  recent infection, immunocomprised)

  • Metastatic Cancer (Hx, weight loss, age>50, persist, night pain, pain at rest)

  • Vertebral Fracture (Osteoporosis, steroid use, age, trauma)

  • Ruptured AAA (pulsations)

  • Spondyloarthritis (Improvement with exercise, pain at night (with improvement upon getting up/activity), insidious onset, age <40 years, no improvement at rest, inflamamtory arthritis, enthesitis, uveitis, psoriasis, family history)

• Radicular pain (leg pain, sensory loss, reduced reflex, myotomal weakness)

  • Intervertebral disc herniation

• Neurogenic claudication (Bilateral buttock/thigh/leg pain, pseudoclaudication)

  • Central spinal canal stenosis

• Non-specific (mechanical)

• Beyond lumbar spine

  • Gyne

  • Renal (kidney stones)

  • GI

  • Hip joint

Physical Exam

• Vitals (Temperature)

• Gait/Posture

  • Heel-toe, Squat and Rise

• Spine

  • Abnormalities

  • ROM

    • Schober's test (marks at 5cm below L5 and 10cm above, flexion should increase distance from 15 to >20cm)

  • Vertebral Tenderness

• Waddell's Signs (Non-organic)

  • Superficial or nonanatomic tenderness

  • Simulation test

    • Axial loading

    • Rotation of shoulder/Pelvis in same plane

  • Distraction

    • Discrepency between sitting and supine straight leg raise

  • Regional disturbances

    • Cogwheel (give-way) weakness

    • Nondermatomal sensory loss

  • Overreaction

• Straight Leg Raise

• Motor/Sensory (Saddle anesthesia, sphincter tone)

  • DF ankle, EHL

• Reflexes

• Joint above and below (eg. hip)

  • FABER for SI joint

Investigations rarely needed initially unless (multiple) red flags

• CBC, ESR (tumor, infection)

• SPEP (multiple myeloma)

• X-ray (fractures)

• X-ray or CT Sacroiliac joints (ankylosing spondylitis)

  • HLA-B27 antigen (ankylosing spondylitis)

• MRI (cauda equina)

Treatment

Acute or subacute low back pain  

• Nonpharmacologic treatment

  • Superficial heat (moderate-quality evidence)

  • Massage, acupuncture, or spinal manipulation (low-quality evidence)

  • Maintain activity and re-assurance (95% improve in 6 weeks)

• Pharmacologic treatment

  • Topical NSAIDs

  • NSAIDs (eg. ibuprofen 600mg PO QID) or skeletal muscle relaxants (eg. cyclobenzaprine 10mg PO TID) (moderate-quality evidence) 

Chronic low back pain 

• Nonpharmacologic treatment 

  • Exercise, multidisciplinary rehabilitation, acupuncture, mindfulness-based stress reduction (moderate-quality evidence)

  • Tai chi, yoga, motor control exercise, progressive relaxation, electromyography biofeedback, low-level laser therapy, operant therapy, cognitive behavioral therapy, or spinal manipulation (low-quality evidence)

• Pharmacologic treatment

  • First-line: NSAIDs

  • Second-line

    • Rubafacients, eg. Capsaicin cream 0.025% topical QID

    • SNRIs, eg. Duloxetine 30-60mg PO daily

    • TCAs, eg. Amitriptyline 25mg PO daily

    • Gabapentinoids, eg. Gabapentin 300mg PO TID

  • Avoid opioids and cannabinoids unless benefits outweigh risks