An adult with chronic low back pain >6 weeks who has not improved with activity modification, physical therapy, NSAIDs, and a short opioid trial—when is surgery indicated, what imaging should be obtained, which operative options are appropriate for disc herniation, spinal stenosis, or instability, and what pre‑ and postoperative management is recommended?

Surgical Indications for Chronic Low Back Pain

Surgery for chronic low back pain without radiculopathy should be reserved for highly selected patients after at least 6 weeks of failed conservative management, with Level II evidence showing no significant clinical difference between intensive rehabilitation with cognitive therapy versus lumbar fusion. 1

Initial Conservative Management Requirements

Before considering surgery, patients must complete a comprehensive trial of:

• Activity modification (not bed rest—patients should remain active) for at least 6 weeks 1, 2
• Physical therapy with structured exercises, ideally including cognitive-behavioral components 1
• NSAIDs as first-line pharmacologic management 1, 2
• Short-term opioid trial for severe pain (evidence suggests preoperative opioids may positively influence postoperative outcomes) 3
• Muscle relaxants for associated spasms 2

When Imaging Is Indicated

Immediate Imaging Required (Red Flags)

Obtain MRI immediately without waiting 6 weeks if any of the following are present: 1, 4

• Cauda equina syndrome (urinary retention/incontinence, bilateral weakness, saddle anesthesia) 1, 4
• Progressive neurological deficits (e.g., worsening motor weakness such as foot drop) 1, 4
• Suspected malignancy (history of cancer, unexplained weight loss, age >50 with new onset pain) 1, 4
• Suspected infection (fever, IV drug use, recent infection, immunosuppression) 1, 4
• Significant trauma with neurological symptoms 4

Delayed Imaging After Conservative Failure

• MRI lumbar spine without contrast is the preferred imaging modality after 6 weeks of failed conservative therapy, but only if the patient is a potential surgical candidate 1, 4
• CT scan is a reasonable alternative when MRI delays exceed 2-4 weeks and the patient requires timely evaluation for potential intervention 4
• Plain radiographs may be considered for suspected compression fracture (osteoporosis, steroid use, elderly patients) or to assess segmental motion in spondylolisthesis 1, 4

Critical pitfall: Routine imaging in acute low back pain (<6 weeks) without red flags provides no clinical benefit and leads to unnecessary interventions, as disc abnormalities are present in 29-43% of asymptomatic individuals 1, 4

Surgical Indications by Pathology

Disc Herniation with Radiculopathy

Surgical discectomy is appropriate when: 1, 2

• Radicular symptoms persist beyond 6 weeks of conservative management 1, 4
• MRI confirms nerve root compression correlating with clinical symptoms 1, 4
• Patient has disabling pain preventing normal activities 2
• Progressive motor deficits are present (immediate indication) 4

Operative approach: Simple discectomy/sequesterectomy without fusion is the standard procedure 1, 2

Critical pitfall: Lumbar fusion is not recommended for routine disc herniation and should be reserved only for documented instability, severe degenerative changes in manual laborers, or significant chronic axial back pain 1, 2

Spinal Stenosis

Surgery is indicated when: 1

• Neurogenic claudication significantly limits walking distance and quality of life 1
• Conservative management fails after 6 weeks 1
• MRI confirms canal stenosis correlating with symptoms 1

Operative approach: Decompressive laminectomy with or without fusion depending on stability 1

Chronic Axial Low Back Pain (No Radiculopathy, No Stenosis)

This is the most controversial indication with the weakest evidence. 1

Surgery may be considered only when ALL of the following criteria are met: 1, 5, 6

• At least 6 weeks (preferably 3 months) of failed intensive conservative management including cognitive-behavioral therapy 1, 2
• Clearly identifiable pain source on imaging (e.g., inflammatory disc signal on MRI, documented instability on flexion-extension films) 6, 7
• Absence of psychological disorders or active treatment of such disorders 6
• No active workers' compensation claims (associated with poor outcomes) 6
• Realistic patient expectations after extensive counseling 8
• Disabling pain preventing work and activities of daily living 6

Level II evidence shows: 1

• Lumbar fusion provides similar outcomes to intensive rehabilitation programs with cognitive therapy
• Lumbar fusion is superior to traditional physical therapy alone
• Only 5% of chronic low back pain patients are appropriate surgical candidates after thorough evaluation 5

Operative options for degenerative disc disease: 1, 8

• Posterolateral instrumented fusion
• Anterior lumbar interbody fusion (ALIF)
• Posterior lumbar interbody fusion (PLIF)
• Transforaminal lumbar interbody fusion (TLIF)

Expected outcomes: 50-93% clinical success rates in literature, with spondylolisthesis having the best outcomes; only 30% return to work 6

Pre-operative Management

• Biopsychosocial assessment to identify psychosocial risk factors (job dissatisfaction, depression, somatization) that predict poor outcomes 1, 2
• Confirm imaging-clinical correlation—symptoms must match anatomic findings 4, 2
• Patient education regarding realistic expectations, natural history, and surgical risks 1, 8
• Optimize medical comorbidities (diabetes, smoking cessation, weight management) 8
• Consider diagnostic/therapeutic epidural steroid injections under fluoroscopic guidance for radiculopathy—may avoid surgery or serve as prognostic indicator 2

Post-operative Management

• Early mobilization within 24-48 hours post-operatively 2
• Physical therapy beginning immediately post-operatively, focusing on core strengthening and functional restoration 2
• Multimodal pain management avoiding prolonged opioid use 2
• Gradual return to activities over 6-12 weeks depending on procedure 2
• Monitoring for complications including infection, hardware failure, adjacent segment degeneration 8
• Multidisciplinary rehabilitation to maximize functional outcomes and prevent chronic disability 2

Critical Pitfalls to Avoid

• Do not operate without 6 weeks of conservative therapy unless red flags are present 1, 4
• Do not rely on imaging alone—84% of patients with imaging abnormalities before symptom onset have unchanged or improved findings after symptoms develop 1
• Do not add fusion to routine discectomy—this increases complexity and complications without proven benefit 1, 2
• Do not proceed with surgery in patients with active psychological disorders or secondary gain issues without addressing these first 6
• Do not order MRI for acute low back pain without radiculopathy or red flags—this leads to unnecessary interventions 1, 4