low back pain (LBP)

Etiology

• myofascial
  • muscle strain
  • insertion tendonitis
• discogenic, radiculopathy, sciatica
  • herniated nucleus pulposus
  • degenerative disc
• osteoarthritis: including facet joints
• spondylolisthesis
  • spondylolysis: pain on extension of lumbar spine, young athletes
• spinal stenosis (see lumbar spinal stenosis)
  • congenital
  • acquired
• fracture
  • vertebral compression fracture)
    • traumatic
    • pathologic
  • osteoporotic sacral fracture
• sacroiliac joint pain
• inflammatory or rheumatologic disease
  • ankylosing spondylitis
  • lumbar adhesive arachnoiditis
• infiltrative disease
  • infection
  • malignancy (see bone neoplasm)
  • Paget's disease
• psyschosocial component ?
• risk factors for chronic low back pain
  • obesity, female, age > 65 years, low educational status, demanding physical occupations, depression, anxiety

Epidemiology

• low back pain afflicts 90% of people over their lifetime;
  • 80% of cases resolve within 30 days with conservative management
  • a precise diagnosis is found in <10% of cases
• no association with rain
• Covid-19 lockdowns increased the prevalence & intensity of chronic low back pain

Clinical manifestations

• discogenic back pain
  • relieved by back rest, aggravated by activity
  • episodic attacks, generally resolving in 4 weeks
  • minimal morning stiffness
  • back movement limited only with acute flares
• symptoms of sciatica
• back pain due to muscle spasm generally worsens with sitting
• pain from the spine is poorly localized
• pain from abdominal, thoracic & pelvic viscera may refer dorsally
• signs/symptoms of serious etiologies (see complications)
  • bowel & bladder incontinence
  • saddle anesthesia
  • pain that is worse in the supine than upright position
• runners with low back pain 2.5 time more likely to have knee pain
• point tenderness over the lumbar spine suggests vertebral fracture
• STarT Back Screening Tool may help stratify risk

* see Complications: for *red flags*

Laboratory

• testing generally reserved for patients whose symptoms do not improve or worsen after 6 weeks of conservative therapy
• electromyelography: tests peripheral nerve function
• blood tests
  • ESR or CRP
  • serologic tests for rheumatologic diseases

Radiology

• radiographs
  • routine imaging is not cost-effective
  • can reveal
    • fractures
    • spondylolysis
    • lytic lesions
    • degenerative disc disease
      • loss of disc space height (61%)
    • facet degeneration (34%)
  • along with neurologic exam can rule out most serious causes of low back pain, but does not by itself rule out cancer or infection
  • indicated in:
    • trauma
    • major risk factors for cancer
    • neurologic deficits
    • 4-6 weeks of conservative management without improvement
    • adolescents, adults > 50 years of age (probably not)
  • not indicated
    • within 6 weeks on onset in absence of red flags
    • not necessarily indicated for referral
    • monitoring of patient' progress
• bone scan
  • can reveal
    • inflammatory processes
    • infiltrative processes
    • occult fractures
    • active spondylosis
  • highly sensitive for ruling out serious pathology
• computed tomography (CT)
  • for red flags & patients who may require surgery
  • MRI unavailable (MRI is superior to CT)
• magnetic resonance imaging (MRI)
  • for red flags & patients who may require surgery
  • disc bulges (61%)
  • disc herniation (33%)
  • spinal stenosis (20%)
  • suspicion of osteomyelitis or bony metastases*
  • LS spine abnormalities on MRI are often meaningless
  • no benefit for patients without pathologic features or red flags suggesting a need for surgery
  • MRI signal changes in the vertebral bone marrow known as Modic changes may be noted in patients with chronic low back pain
    • Modic type 1: edema
    • Modic type 2: fatty
    • Modic tyoe 3: sclerotic
  • spinal cord compression:
    • administer dexamethasone 1st, then MRI of entire spine
• symptoms & functional disability correlated poorly with objective anatomical tests
• routine imaging in the evaluation of low-back pain
  • does not change outcomes regardless of age
  • increases risk of lumbar surgery 13-fold
  • increases risk of opioid prescription (RR=1.2)
  • slightly worsens, rather than improves pain scores
  • increases health care costs

* more comon than primary bone cancers

Complications

• early guideline non-concordant care associated with risk of transition from acute to chronic low back pain

red flags

• cauda equina syndrome
  • urinary retention is most common presentaton
  • bowel & bladder incontinence
  • saddle anesthesia (diminished perineal sensation)
  • bilateral lower extremity motor deficits
• cancer:
  • pain that is worse in the supine than upright position &/or no relief with bedrest
  • history of cancer$ &/or unexplained weight loss
  • pain lasting 1 month or not improving after 1 month of therapy
  • age > 50 years
• osteomylelitis
  • fever
  • preceding urinary tract infection
  • skin infection
  • injection drug use
• vertebral fracture
  • long-term corticosteroid use
  • age > 50 years, osteoporosis
  • presence of contusions or abrasions# (trauma)
• herniated disk: symptoms of sciatica
• lumbar spinal stenosis: age > 50 years
• ankylosing spondylitis or other rheumatologic disorder
  • morning stiffness
  • pain not relieved with supine
  • pain persisting > 3 months
  • involvement of other joints
• other progressive motor weakness

* red flags need re-evaluation; predictive value low

# best predictive value for vertebral fracture (62%)

$ best predictive value for spinal malignancy (33%)

Management

• conservative initial approach
  • 90% of patients will be better in 4-6 weeks; most patients with be better in 3 months
  • nonpharmacologic therapies 1st line
    • heat, massage, acupuncture, spinal manipulation [[68]
  • heat, ice, ultrasound
  • relative rest, early return to activity
    • bedrest not helpful
  • physical therapy
    • physical therapy for chronic low back pain (not acute pain)
      • combine with cognitive-behavorial therapy (CBT) best for benefit of physical function & alleviating fear of movement
    • massage therapy may be helpful (MKSAP17)
      • very little confidence that massage is an effective treatment; update on Cochrane review cited by
    • weekly massage for 10 weeks of marginal benefit
    • early physical therapy of no benefit
    • 30-60% of patients benefit with clinical improvement
    • prolonged physical therapy not indicated unless in support of active treatment plan
  • exercise: benefit to risk ratio is favorable
    • therapeutic aquatic exercise better than physical therapy
      • long-term effect up to 12 months
    • isometric & motor control trunk training most effective in patients < 40 years of age
  • yoga may be of benefit
    • yoga equivalent to stretching
    • yoga non-inferior to physical therapy
    • yoga improves function but not pain
  • psychosocial interventions
    • resolution of pyschosocial stressors
    • cognitive-behavorial therapy (CBT)
      • benefits persist after 2 years
      • CBT combined with physical therapy best for benefit of physical function & alleviating fear of movement
      • telephone-based interactive voice-response CBT noninferior to in-person CBT
      • EaseVRx FDA-approved Nov 2021
    • artificial intelligence driven cognitive behavioral therapy may be effective
    • mindfulness meditation, mindfulness-based stress reduction
      • may be associated with sustained reductions in pain
      • no sustained functional improvement
      • functional improvement
      • better than usual care, noninferior to CBT
      • benefits not as persistent as CBT (< 2 years)
  • pharmaceutical agents
    • muscle relaxants & NSAIDs effective in reducing pain & disability for acute low back pain after about 1 week of use
    • non-steroidal anti-inflammatory drugs (NSAIDs)
      • 1st line for subacute or chronic low back pain not responsive to non-pharmacologic measures
      • only a small % of patients benefit
      • toradol 60 mg IM may be useful for acute, severe pain
    • muscle relaxants (cyclobenzaprine 10-20 mg TID)
      • may have some benefit in 1/3 of patients
  • of modest short-term benefit at best
  • alternative to NSAID for subacute low back pain
    • • of no benefit when added to NSAID
      • avoid long-term use
    • acetaminophen
      • no better than placebo
      • when combined with NSAIDs, better than NSAIDs alone
    • antidepressants
      • tricyclic antidepressants; 25 mg amitriptyline QD may be of some benefit
      • SSNRI: duloxetine (Cymbalta), venlafaxine, tramadol - benefit unlikely to be clinically significant - benefit for chronic back pain (moderate-certainty evidence)
      • antidepressants not effective
    • opiates
      • opiates of no benefit when added to NSAID
      • minimal benefit of opiates for chronic low back pain
      • no better than placebo at 6 weeks
      • long-term pain management contraindicated in absence of psychosocial assessment
      • off-label epidural Depo-Medrol is increasing as doctors limit opioid prescribing
      • tramadol no better than other opioids
    • cannabis reduces opioid use & improve both pain & function
      • multiple routes of cannabis use more strongly associated with reduced opioid use
    • diazepam of no benefit added to naproxen
    • prednisone (oral glucocorticoid) of no benefit
    • anticonvulsants of no benefit
      • gabapentin marginally better than placebo
      • prebabalin less effective than NSAID or antidepressant
      • gabapentin & prebabalin associated with risk of drowsiness, dizziness, & nausea
      • topiramate of no benefit but without adverse effects
• 3 months of amoxicillin of no benefit in patients with chronic low back pain & Modic changes (see Radiology .., MRI)
  • • increased spending on pharmaceuticals has not resulted in corresonding improvement in functional status
    • placebo of benefit even when people know its a placebo
• multidisciplinary rehabilitation better than usual care
  • physical therapy
    • heat, electrotherapeutic modalities, stretching, strengthening, manual therapy
  • psychological assessment
    • addressing psychosocial factors of little benefit (component of multidisciplinary rehabilitation)
  • social assessment
  • vocational assessment
  • multidisciplinary biopsychosocial rehabilitation program for patient who fail to show for physical therapy
  • person-specific motor skill training in functional activities limited because of chronic low back pain may improve function
• osteopathic or chiropractic manipulation (spondylolisthesis)
  • no evidence of clinically meaningful benefit or harm
  • GSR8 interpretion: 'as effective as combination of analgesia, physical therapy & stretching'
  • modest benefit for pain & function in adults with acute low back pain
  • questionable benefit for low back pain
• other modalities
  • traction, transcutaneous electrical nerve stimulation (TENS), diathermy, acupuncture have no proven benefit
  • acupuncture may be of benefit
    • electroacupuncture of marginal benefit; no benefit for pain
  • facet joint &/or intradiscal corticosteroid injection not recommended
  • insufficient evidence to support use of injection therapy
    • specific subgroups of patients may respond to a specific type of injection therapy
  • an early feasibility study (20 patients, meeting abstract), hydrogel injected into spinal discs reduced chronic low back pain by 67%
• non-specific back pain persisting > 4 weeks
  • see UK BEAM trial
  • psychosocial evaluation for issues interfering with recovery
• firmer mattress not necessarily better
• lumbar supports or braces not indicated for long-term treatment of low back pain
• surgery:
  • indications:
    • persistent radiculopathy due to lumbar disk herniation
    • painful lumbar spinal stenosis
    • cauda equina syndrome
    • neurologic deficits
    • spinal cord compression
      • 1st step is to administer dexamethasone, then MRI of entire spine
  • otherwise
    • spinal fusion surgery of uncertain value [9, 13]
    • outcomes at 1 year similar for surgery vs medical management
      • complications more common with surgery vs medical management
• radiofrequency denervation
  • of no benefit in treatment of low back pain arising from facet joints, sacroiliac joints, &/or intervertebral disc disease
  • lumbar facet blocks predict response to radiofrequency denervation
• implantation of a spinal cord stimulator for intractable back or leg pain
  • FDA approves spinal cord stimulation devices for chronic low back pain in patients who have had surgery or are not eliible for surgery
• email discussion group participation improved symptoms
• some good results for individual herbal medicines in short-term individual trials, but no good pooled estimates of benefit
• prevention
  • lumbosacral corset or lumbosacral orthosis may help prevent back injury (not helpful for treatment)
    • lumbar supports or braces not indicated for prevention of low back pain
  • exercise of benefit in preventing low back pain
  • general exercise better than back muscle exercises
  • motor control exercises which aim to strengthen deep trunk muscles through isolated contractions may be of benefit
  • weight loss
  • modified workplace ergonomics
  • lifelong fitness

Notes

• adherence to guidelines for management of low back pain is suboptimal

More general terms

• back pain

Additional terms

• causes of myofascial back pain
• indications for radiographs in patients with acute low back pain
• STarT Back Screening Tool
• United Kingdom back pain exercise and manipulation (UK BEAM) randomised trial

Patient information

low back pain patient information