What is the recommended assessment and treatment approach for an adult patient with no significant medical history presenting with low back pain?

Assessment of Low Back Pain

Conduct a focused history and physical examination to categorize the patient into one of three groups: nonspecific low back pain (85% of cases), back pain with radiculopathy/spinal stenosis, or back pain with a specific serious spinal cause—this categorization drives all subsequent management decisions. 1

Critical Red Flags Requiring Urgent Imaging and Specialist Consultation

Screen immediately for these high-risk features that demand urgent MRI and specialist evaluation:

• Cauda equina syndrome: Bowel/bladder dysfunction, urinary retention, saddle anesthesia, or loss of anal sphincter tone 1, 2
• Malignancy indicators: History of cancer (increases probability to 9%, positive likelihood ratio 14.7), unexplained weight loss (positive likelihood ratio 2.7), age >50 years (positive likelihood ratio 2.7), or failure to improve after 1 month (positive likelihood ratio 3.0) 1, 3
• Spinal infection: Fever, recent infection, IV drug use, or immunocompromised status 1, 3
• Severe neurological compromise: Rapidly progressive or severe motor/sensory deficits 1, 2
• Significant trauma: Major trauma in young patients or minor trauma (fall, heavy lifting) in patients with osteoporosis 2, 4

If any red flags are present, obtain immediate MRI (superior to CT due to better soft tissue visualization and no radiation) and arrange urgent specialist consultation. 2, 3

Essential History Components

Obtain these specific details to guide categorization:

• Pain location and radiation: Localized back pain versus radiating leg pain following dermatomal distribution (suggests radiculopathy) 1, 3
• Neurological symptoms: Sciatica, motor weakness, numbness, or pseudoclaudication (leg symptoms with walking that improve with sitting/forward flexion, suggesting spinal stenosis) 1, 3
• Symptom frequency and duration: Constant versus intermittent, acute (<4 weeks), subacute (4-12 weeks), or chronic (>12 weeks) 1, 2
• Previous episodes and treatment response: What has been tried and what worked 1
• Midline tenderness: May indicate vertebral compression fracture (especially with osteoporosis/steroid use) or vertebral infection if accompanied by fever 2

Physical Examination Priorities

• Neurological examination: Test motor strength, sensory function, and reflexes corresponding to nerve root levels 2
• Straight leg raise test: Assess for radiculopathy 2
• Gait assessment: Observe for neurogenic claudication patterns 1
• Spinal palpation: Check for midline tenderness suggesting fracture or infection 2

Psychosocial Risk Assessment

Screen for "yellow flags" that predict progression to chronic disabling pain—these factors often predict outcomes more strongly than anatomical findings:

• Depression, anxiety, catastrophizing, fear-avoidance beliefs 1, 2
• Job dissatisfaction, passive coping strategies 2
• Use the STarT Back tool at 2 weeks to risk-stratify patients (low, medium, or high risk) for targeted resource allocation 2

Diagnostic Imaging Strategy

Do not order routine imaging for nonspecific low back pain without red flags—this is a strong recommendation to avoid unnecessary radiation exposure and costs. 1, 2, 3

• No imaging initially: For nonspecific low back pain without red flags 1, 2
• Plain radiography: Consider only after 4-6 weeks of persistent symptoms without improvement, or if risk factors for compression fracture exist 2
• Immediate MRI or CT: Required if red flags present, with MRI preferred 2, 3
• MRI for surgical candidates: If persistent radiculopathy and patient is candidate for surgery or epidural steroid injection 1

Diagnostic Categorization and Next Steps

Nonspecific Low Back Pain (85% of cases)

• Localized pain without specific identifiable cause and no red flags 1, 3
• Management: Reassurance, education about expected self-limited course, maintain activity (avoid bed rest), and self-care options 1, 2
• First-line nonpharmacologic: Superficial heat, massage, acupuncture, or spinal manipulation 2
• Pharmacologic if desired: NSAIDs or acetaminophen (up to 4g daily), skeletal muscle relaxants for short-term use 2

Back Pain with Radiculopathy/Spinal Stenosis

• Radiculopathy (4% of cases): Radiating leg pain following dermatomal distribution with corresponding motor/sensory deficits 3
• Spinal stenosis (3% of cases): Neurogenic claudication with leg pain/weakness on walking/standing, relieved by sitting or spinal flexion 3
• Management: Consider MRI if surgical candidate or for epidural steroid injection 1

Back Pain with Specific Spinal Cause

• Includes cancer (0.7%), compression fracture (4%), spinal infection (0.01%), ankylosing spondylitis (0.3-5%), cauda equina syndrome (0.04%) 1, 3
• Management: Urgent imaging, laboratory studies (CBC, ESR, CRP), and specialist consultation 3

Follow-Up Timing

• Reevaluate at 1 month if symptoms persist without improvement 1, 2
• Earlier reassessment for patients >65 years, signs of radiculopathy/stenosis, or worsening symptoms 2
• Consider imaging at 4-6 weeks if not previously performed and symptoms persist despite conservative management 2
• Referral consideration after 3 months minimum of failed conservative therapy, or earlier if progressive neurologic deficits 2

Common Pitfalls to Avoid

• Delaying imaging when red flags are present can lead to permanent disability, especially with cauda equina syndrome 3
• Over-imaging uncomplicated cases exposes patients to unnecessary radiation and costs without clinical benefit 2, 3
• Attributing pain to imaging findings without clinical correlation leads to misdiagnosis—remember that radiologic abnormalities are common in asymptomatic persons 3, 5
• Ignoring psychosocial factors that predict chronicity more strongly than anatomical findings 3
• Prescribing prolonged bed rest worsens outcomes—patients should stay as active as possible 2