• Information
  1. Character and Definitions
  2. Pathophysiology and Etiology of Back Pain
  3. Expanded Differential Diagnoses
  4. Initial Evaluation
  5. Pain Symptoms Signaling Serious Disease
  6. Neurologic Examination
  7. Evaluation for Serious Disease
  8. Spondyloarthropathy
  9. Spinal Stenosis
  10. Treatment of Acute LBP
  11. Overview of Treatments for Non-Acute LBP

A. Character and Definitions

1. General term refers to pain centered over lumbosacral junction
2. Epidemiology
   1. Lifetime prevalence ~75%
   2. Annual incidence ~5-15%
   3. 15-30% point prevalence
   4. Fifth most common complaint leading patients to seek medical attention
3. 90% of cases will resolve within 4-12 weeks
   1. This is independent of type of doctor who evaluates/treats pain
   2. Primary care practitioners provide least expensive care
   3. Vertebral fractures from osteoporosis are very common causes in older women
   4. Focus comprehensive evaluations on patients at risk for serious nonmechanical causes
   5. 10% of LBP which does not resolve within 3 weeks is often very slow to resolve
4. 1% have "Sciatica"
   1. Pain in distribution of lumbar nerve root
   2. Often accompanied by neurosensory ± motor deficits
   3. Usually due to herniated nucleus pulposus
   4. Increasing incidence with age up to age 65, when incidence declines
5. Risk Factors for Serious Nonmechanical Causes of LBP
   1. Onset age > 50 years
   2. Morning stiffness or severe pain, better on motion
   3. Pain when lying down, or pain waking patient up at night
   4. Other constitutional symptoms (such as weight loss, fevers, night sweats)
   5. See below: Evaluation

B. Pathophysiology and Etiology of Back Pain [1]

1. Normal Anatomy [1]
   1. Functional spinal unit is the key structural element involved
   2. Comprises 2 adjacent vertebral bodies, 2 posterior facet joints, intervertebral disk, and surrounding ligamentous structures
   3. Intervertebral disk absorbs energy and distributes weight evenly across spinal segments, while allowing movement of body
   4. Progressive degenerative changes occur across all parts of the spinal unit with aging and injury
2. Early Degenerative Changes
   1. Synovitis (joint inflammation) is earliest change infacet joints
   2. This can progress to degradation of articular surfaces, caupsular laxity, and subluxation, and finally to enlargement of artcular processes (facet hypertrophy)
   3. Intervertebral disk degeneration begins with loss of hydration of nucleus pulposus
   4. This is followed by tears in the annuls fibrosis (internal disk disruption)
3. Mechanisms of LBP
   1. LBP can arise from impingement on any sensory area of spinal unit
   2. local anatomical disruptions lead to "mechanical" causes of LBP
   3. Extrinsic causes lead to "non-mechanical" causes of LBP
   4. Precise neuroanatomical cause in <20% of patients [19]
   5. Pain may originate from facet joints or annulus fibrosis
   6. Internal disruption of annulus can lead to gelatinous central nucleus pulposus extending beyond disk margin causing disk herniation
   7. "Herniated disk" is actually herniated nucleus pulposus (HNP)
   8. HNP extending to region adjacent to spinal nerve causes inflammation
   9. This inflammation causes pain, presenting as acute radicular (spinal root) pain
   10. Hypertrophy of facet joints and ligamentous structure calcifcation reduces size of intervertebral foramina (radicular pain) or central spinal canal (spinal stenosis)
4. Mechanical Causes of LBP [19]
   1. Fibrositis (ligament and tendon pull)
   2. Muscle Pull (without myositis), "Lumbago" (lumbar strain and sprain)
   3. Degenerative Disc Disease or Disk Herniation (nucleus pulposus)
   4. Vertebral Fractures (usually osteoporotic)
   5. Sciatica (usually mechanical) or Pseudosciatica
   6. Fibromyalgia
   7. Pyriformis Syndrome
   8. Spinal Stenosis - spinal column narrowing with vascular compromise, claudication
   9. Mutations in collagen IX linked to back pain in ~5% of patients with sciatica
5. Risk Factors for Mechanical Causes
   1. Heavy listing and twisting
   2. Body vibration
   3. Obesity
   4. Poor conditioning
   5. Collagen IX gene R103W mutation (Trp3 allele) is a ~3X risk factor for lumbar disk disease [24]
   6. However, LBP is common in patients who have none of these risk factors
   7. Back belts do not appear to prevent back pain and injury [14]
6. Nonmechanical Causes
   1. Infection (see below)
   2. Neoplasia - local and metastatic including ovarian cancer [3]
   3. Spondyloarthropathy - ankylosing spondylitis and others (sacroileitis)
   4. Pancreatitis
   5. Aortic Dissection
   6. Abdnominal Aortic Aneurysm (AAA) [10]
   7. Hemorrhage - retroperitoneal
   8. Renal Stones or pyelonephritis or perinephric abscess

C. Expanded Differential Diagnoses

1. Sciatica
   1. Compression of lumbar nerve roots
   2. Herniated disk (nucleus pulposus) or degenerated disk
   3. Lateral or foraminal stenosis
   4. Intraspinal tumor or infection
   5. Extraspinal plexus compression
   6. Piriformis syndrome
   7. Lumbar canal stenosis
2. Infection
   1. Abscess - epidural or soft tissue
   2. Osteomyelitis
   3. Bacterial Endocarditis (SBE) - ~15% of patients with SBE will present with LBP
   4. Prostatitis
   5. Pyomyositis
3. Neoplasia
   1. Local - osteosarcoma, lymphoma, oligodendroglioma, soft tissue sarcoma
   2. Metastatic - lung, prostate, breast, kidney, colon cancers, others
4. Pseudosciatica
   1. Osteoarthritis
   2. Trochanteric bursitis
   3. Meralgia paresthetica
   4. Diabetic amyotrophy
   5. Vascular Claudication - pseudoclaudication

D. Initial Evaluation [13,25,26]

1. Focused history and physical exam to properly categorize patient [12]
   1. Nonspecific LBP
   2. LBP potentially associated with radiculopathy or spinal stenosis
   3. LBP potentially associated with another spinal cause (potentially serious cause)
2. Approximately 90% of patients with LBP will have a non-serious cause
3. Absence of markers of serious causes, called "red flags", will allow conservative therapy
   1. Patients without these markers can be treated conservatively for 2 weeks
   2. No further diagnostic evaluation is necessary [26]
4. Symptoms and Signs of Potentially Serious Conditions
   1. Systemic symptoms - fever, chills, night sweats, weight loss
   2. Smokers have increased risk for cancers and vascular disease
   3. Major Trauma
   4. Minor Trauma in elderly or patient with known cancer
   5. Subacute or chronic progression unrelated to known back strain
   6. Age >50 or <20
   7. Patient with known cancer
   8. Intravenous drug abuse or recent serious infection or immunosuppression
   9. Pain worse in supine position (compared with sitting)
   10. Severe pain at night or of character described below ("Pain Symptoms")
   11. Any sensory or motor abnormality on exam (excluding pain)
   12. Bowel or bladdery dysfunction
   13. Anal sphincter laxity
   14. Pain increases on walking or running, subsides quickly when sitting - spinal stenosis
5. Set of criteria were developed to examine patients with back pain
   1. These criteria are used to identify true back pain versus malingering
   2. Five criteria are listed here with their inappropriate responses suggesting malingering
   3. Tenderness - inappropriate: superficial, nonanatomic tenderness to light touch
   4. Distraction - inappropriate: discrepancy with findings made without distraction
   5. Simulation - inappropriate:
   6. Vertical loading on head produces back pain
      1. Passive rotation of shoulders and pelvis in same plane causes back pain
   7. Regional Disturbances - inappropriate: give-way weakness, nondermatomal sensory loss
   8. Overreaction, verbalization, tremor, during testing
6. Radiography
   1. Routine imaging or other diagnostic modality recommended only for severe or progressive neurologic deficits present or when serious underlying condition suspected [12]
   2. Rapid MRI may be no better than plain radiographs in uncomplicated LBP patients [5]
   3. In patients unlikely to have serious cause, MRI early in course of evaluation not helpful [13]
   4. MRI detects more anatomic abnormalities and may increase inappropriate surgery rates [5]
   5. CT or MRI scan is preferred diagnostic modality to rule out serious causes
   6. MRI recommended in patients >50 years, for those considering surgery or epidural glucocorticoid injection, or with systemic symptoms [12]
   7. Plain radiographs are of little or no value in LBP
   8. Diagnostic (not provocative) diskography can identify symptomatic disks prior to surgery; provocative diskography is not recommended for evaluation of LBP [1,13]

E. Pain Symptoms Signaling Serious Disease

1. Writhing Pain: abdominal, vascular Process
2. Unrelenting Pain at Night: cancer, infection (osteomyelitis)
3. Evolving Neurologic Deficit
   1. Epidural Abscess - evolving neurologic deficits required
   2. Epidural Hemorrhage
   3. Osteomyelitis - evolving neurologic deficits uncommon
4. Pseudoclaudication (pain on walking, better on sitting): consider spinal stenosis
5. Better with activity, worse with rest and in morning: consider spondyloarthropathy

F. Neurologic Examination

1. Nerve Root Pain
   1. L3-L4: Motor L4, Knee Inversion; Sensory: Medial Ankle
   2. L4-L5: Motor L5, Extend 1ST Toe; Sensory: Foot Dorsum
   3. L4-S1: Motor S1, Ankle Eversion; Sensory: Lateral Foot
2. Motor Weakness (expanded)
   1. L2-3: hip flexion
   2. L5-S1: hip extension and ankle plantar flexion
   3. L3-4: knee extension
   4. L4-5: knee flexion and ankle dorsiflexion

G. Evaluation for Serious Disease

1. Blood count, ESR, SPEP, Ca2+, Alkaline Phosphatase (bone etiology), Urinalysis
2. L-S XRays no longer indicated (very high radiation dose, insensitive)
3. Bone Scan - 99mTc may be helpful to detect diffuse disease
4. CT versus MRI: CT Better for Bone; MRI better for Vascular / Soft Tissue
5. Nearly 20% of patients without symptoms will have a herniated disk by CT or MRI
6. About 35% of patients with LBP will have herniated disk (65% disk bulges) by MRI [5]
7. Overall, MRI is generally better for evaluation of potentially serious LBP causes

H. Spondyloarthropathy

1. Most patients are males <40 years old with high incidence of HLA-B27+
2. Insidious Onset, Duration >3 months
3. Morning Stiffness, better as day progresses
4. Pain relieved with exercise
5. Related entities
   1. Ankylosing spondylitis: ~95% of Caucasian pts are HLA-B27+
   2. Psoriatic arthritis: ~85% have skin disease, usually severe, at presentation
   3. Inflammatory Bowel Disease Associated Arthritis
   4. Reactive Arthritis: Chalmydia, Enteropathic bacteria
   5. Reiter's Syndrome: conjunctivitis, arthritis (usually sacroiliitis) and urethritis

I. Spinal Stenosis (Neurologic Claudication) [8,20]

1. Patients with spinal stenosis have decreased blood to cauda equina and claudication
2. History and Physical Examination are critical for diagnosis
   1. Generalized leg pain, ± numbness and weakness
   2. Exacerbation with walking
   3. Often relieved by spinal flexion
   4. Physical exam should focus on lower extremity neurological changes
   5. These include sensory, vibratory, reflex, and strength evaluations
   6. However, findings on physical exam are rarely dramatic
3. MRI Scan - diagnostic gold standard, showing reduced dural cross-sectional area
4. Treatment
   1. Pain Medications - NSAIDs, other analgesics
   2. Narcotics may be given for 2-3 weeks during flare-ups
   3. Best long term treatment may be aerobic exercise for mild / moderate symptoms
   4. Epidural steroid injections may be helpful
   5. Acupuncture [23] and/or Chirpractic care may be considered
   6. Surgical laminectomy is usually last resort but is superior to nonsurgical therapy [35]
   7. Surgical candidates with symptoms for at least 12 weeks without spondylolisthesis did better on all outcomes with decompression surgery than those treated nonsurgically [35]
   8. Surgical benefits persisted from 3 months to 2 years [35]
   9. In spinal stenosis with degenerative spondylolisthesis, surgery provided greater pain and function improvement in 2 years compared with nonsurgical treatment [8]

J. Treatment of Acute LBP (Muscle Strain / Sciatica) [1,13,22]

1. Overview [12]
   1. Rule out (serious) causes of LBP as described above
   2. Continue ordinary activities as tolerated is best therapy versus exercise or bedrest
   3. Bed rest has no clear benefit for sciatica and may be detrimental
   4. Physical activity generally appears beneficial
   5. Application of heat or cold may provide some symptomatic benefit
   6. Pain medications as discussed below
   7. Massage is effective for persistent back pain [22]
   8. Electrical nerve stimulation therapy (see below)
   9. Osteopathic spinal manipulation may be of some use
   10. Overall, recommend patient education, light exercises and/or yoga, mild pain medicines, and continued normal activities
2. Non-Pharmacologic Therapy [15]
   1. Physical activity
   2. Cognitive-behavioral therapy
   3. Spinal manipulation
   4. Interdisciplinary rehabilitation
   5. For acute LBP, only superficial heat has shown clear benefit [15]
3. Physical Activity
   1. Light exercises following acute episode as pain subsides are recommended
   2. Physical therapy or chiropractic manipulation are marginally better than education
   3. Physical therapy and chiropractic manipulation cost over 2.5X as much as education
   4. Individualized exercise therapy for chronic or subacute LBP shows modest benefits in adults [29,30]
   5. Exercise therapy for acute back pain no better than education or no treatment [30]
   6. Yoga appears superior to book-guided self-care, possibly better than light exercise [21]
   7. Physical treatments are not superior to a brief pain-management program for LBP [9]
4. Osteopathic Spinal Manipulation [15]
   1. Osteopathic spinal manipulation is no better than any standard LBP therapy but may be considered [22,28]
   2. Osteopathic spinal manipulation had similar outcomes to medical treatment at 12 weeks, with less use of physical therapy and medications [22]
   3. Spinal manipulation or diclofenac no better than placebo in patients receiving acetaminophen and light exercises [16]
   4. A prediction rule for likely response to spinal manipulation has been devised and should be considered in selecting patients with LBP [7]
5. Pharmacologic Therapy for Muscle Strains [33]
   1. Acetaminophen or NSAIDs may be effective for sciatica component [16]
   2. NSAIDs and muscle relaxants improve acute LBP; less reliable for chronic LBP
   3. Diclofenac (NSAID) no benefit in addition to acetaminophen for acute LBP [16]
   4. Anti-cholinergic: Cyclobenzaprine (Flexeril®) - muscle relaxant activity; 5-10mg po tid
   5. Muscle Relaxants (see below)
   6. Methocarbamol (Robaxin®) - 500-750mg po bid-tid prn
   7. Generally avoid opiates; if needed, acute use only
   8. Chronic use of opiates for LBP associated with substance abuse, addiction [11]
6. Muscle Relaxants (Anti-Spasmotics)
   1. Baclofen (Lioresal®) - oral or intrathecal is available
   2. Carisoprodal (Soma®) - 350mg po tid, may cause drowsiness
   3. Tizanidine (Zanaflex®) [34] - 4mg po qhs initially, may lower blood pressure
   4. Benzodiazepines (clonazepam, diazepam) may be better tolerated, but less effective [34]
   5. Dantrolene (Dantrium®) - probably less effective than other agents
   6. All of these agents cause mental slowing and can affect judgement
7. Glucocorticoid Injection (Epidural) [6]
   1. Tmprovement in HNP (herniated disk) when used within 3-6 weeks of pain onset [1]
   2. Improvement at 2 months versus placebo suggests longer term benefits
   3. Did not change need for surgery at 12 months (about 25% of cases)
   4. Permits more rapid return to normal activity and work than placebo injections
   5. In inflammatory disease (ankylosing spondylitis), may be more effective
   6. Methylprednisolone 80mg or triamcinolone 50-80mg usually given usually with anesthetic
   7. Initial injection may require ~7 days for effect; repeat in 3-4 weeks
   8. Third injection usually given if good pain relief not achieved after 2 injections
   9. Anesthetic is usually lidocaine 0.5% or bupivacaine 0.25%
   10. Contraindicated in patients on anticoagulants, local infection, prominent motor deficits
   11. Increased risk of infection in diabetics
   12. Avoid in patients with severe spinal stenosis on imaging study
8. Electrical Nerve Stimulation
   1. Transcutaneous electrical nerve stimulation (TENS)
   2. Percutaneous electrical nerve stimulation (PENS)
   3. These are usually used for ~30 minutes, 3-5 times per week
   4. PENS may be more effective than TENS and exercise therapy for short term LBP relief

K. Overview of Treatments for Non-Acute LBP

1. Chronic LBP
   1. Acupuncture has shown efficacy in chronic LBP; data in acute LBP inconclusive [23]
   2. Exercise reduces chronic LBP and should be performed as tolerated
   3. Spinal manipulation is effective but problems, mainly with cervical manipulation, occur [4,22]
   4. Radiofrequency lesioning of dorsal root ganglia of no benefit for lumbosacral radicular pain [27]
   5. For lumbar disk herniation, surgery or non-surgical intervention had similar outcomes at 2 years, but many patients crossed-over therapy assignment [31,32]
   6. Spinal decompression machines or standard mechanical traction machines are not clearly better than other therapies for herniated or compressed disks []
   7. Spinal stenosis difficult to treat without surgery, but flexion exercise such as bicycling used [20]
   8. Avoid use of opiates chronically; increased substance abuse and addiction [11]
2. Surgery
   1. Surgical Diskectomy, Decompression, Fusion for Disk Disease
   2. Surgery (discectomy) appears to be effective for lumbar disc herniation (prolapse)
   3. Early lumbar disk surgery provided faster leg pain relief but not at 1 year in patients with severe sciatica that had not resolved in 6-12 weeks [18]
   4. Chemonucleolysis with chympapain is also used for prolapse; surgery is superior
   5. Degenerative lumbar spondylosis treated with laminectomy or spinal fusion
   6. Spinal Stenosis procedures - decompression such as laminectomy beneficial [8,20,35]
   7. Drainage - Hemorrhage and Abscess
3. Tumors on Spinal Cord
   1. In most cases, this is a medical emergency
   2. Irradiation or surgical decompression, or both
   3. High dose glucocorticoids may be used to reduce swelling
   4. Severe pain, requires opiate treatment
4. Abscess or Osteomyelitis
   1. Surgical debridement is generally required
   2. Antibiotics (intravenous) must be given aggressively
   3. Pain control usually requires opiates, at least initially

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