LOW BACK PAIN

I. Epidemiology

1. 60-90% lifetime prevalence; 5% annual incidence

II. Natural history

1. 40-50% of pts with lbp improve in 1 wk; 90% resolve without MD intervention
2. 95% "functional recovery" at 6mos, but 31% "not completely better" at 6 mos (Carey et al., NEJM 1995); 62% have one or more relapses during 1yr f/u. Functional improvement, thus, is quicker than resolution of pain, and some improvement is common as well as return to work.

III. Examination

1. With pt standing, inspect

1. Popliteal creases & hip angle to see if legs same length
2. Spine for scoliosis (best examined with pt leaning back
3. If trunk is tilted could be "pseudoscoliosis" from splinting

2. Check is movement induces pain (range of motion is less sig. than motion reproducing sx)

1. Flexion
2. Extension
3. Tilt to R. & L. by running hand down leg

3. Strength

1. Heel walking to test tibialis strength
2. Toe raises while balancing with one hand on table to test gastroc strength
3. Squats with feet flat to check hip flexion/extension as well as gastroc flexibility
4. Check gluteus strength by attempting to raise heel with pt supine against their resistance

4. Check hip/SI joint

1. ROM with forceful flexion with knee bent, leaning on pt; n.b. if other hip flexes when you flex one hip, indicates tightness of hip flexors!
2. Figure-of-four test
3. Internal rotation of hip by "rolling" it with pt supine also tests piriformis flexibility

5. Sensation testing L3-5, S1
6. Check for "spasm" = painful contraction which won't resolve when mm. placed in shortened position
7. SLR: get sciatic tightening at about 45'. "Pos" means reproduction of radicular pain, i.e. down the leg.
8. Palpate vertebrae for tenderness

IV. Treatment of low back pain

1. Bedrest

1. In a systematic review of randomized trials of bedrest for treatment of low back pain or sciatica, bedrest was associated with slightly worse outcomes in terms of pain relief and return to functional status vs. no bed rest; for sciatica there was no difference (Spine 30:542, 2005--AFP)

2. Exercise

1. Some randomized studies have failed to show a benefit to nonspecific physical therapy in acute LBP
2. With exercises favoring non-pain-causing movements (extension vs. flexion), outcomes are improved
3. Stretching may be important
4. 187 pts 18-60yo with back pain from 1mo-6mo duration and no previous PT randomized to "usual tx" vs. 2x/wk exercise classes x 4wks (stretching, strengthening, and low-impact aerobics); at 1y f/u, sig. more pts in the exercise group had decreased disability (BMJ 319:279, 1999--AFP)
5. Exercise added to "usual care" vs. "usual care" alone was ass'd with sig. improvements in disability scores at 3mos but not at 12mos in a randomized trial in 1,334 pts with low back pain (BMJ 329:1377, 2004--abst)
6. Spine stabilization: strengthening spine after resolution of sx
   1. Strength training, esp. extensors (pts with back pain tend to have weakness)
   2. "Dynamic stabilization training," e.g. balance exercises

3. Yoga
   1. In a study in 101 pts with uncomplicated low back pain x 3-15mos randomized to viniyoga classes 75min Qwk x 12wks, exercise classes by a physical therapist Qwk x 12wks, or self-care books, at 12wks the yoga group had sig. less back-related dysfunction than the other 2 groups; ditto at 26wks, also at 26wks yoga pts had fewer sx and less medication use for back pain (Ann. Int. Med. 143:849, 2005--JW)
4. Physical therapy
   1. "McKenzie" method--no sig. benefit at 3mos in one randomized trial (see above under "Spine Manipulation")
   2. In a study of 286 pts with low back pain x > 6wks randomized to a course of PT vs. a single session of evaluation and advice from a physical therapist, at disability scores at 12mos were not sig. diff. in the two groups (BMJ 329:708, 2004--abst)
5. Massage therapy

1. In a 10wk randomized trial of 262 pts with low back pain > 6wks, massage therapy (up to 10 weekly visits) ass'd with sig. lower disability scores at 10wks compared with acupuncture or self-care education alone, but not at 1y (Arch. Int. Med. 161:1081, 2001--JW)

5. Spine manipulation

1. Some benefit from spine manipulation among those with no lower limb neuro findings or sciatic sx
2. 321 adults with acute LBP (but many with previous episodes) but no sciatica randomized to McKenzie PT vs. chiropractic maniuplation (max 9 sessions over 1mo) vs. educational booklet. At 1mo, chiropractic group had sig. reduction in sx scores c/w booklet group; PT group had nonsig. reduction in sx scores c/w booklet group. No diff. at 3mo, 1y, and 2y (NEJM 339:1021, 1998--AFP)
3. 178 pts 20-59yo with LBP x 3wks-6mos but no evidence of nerve-root compression or systemic disorders were randomized to osteopathic spinal manipulation (8 visits over 12wks) or "standard" care by an allopathic physician. No diff. in sx or functional status at 12wks, though osteopathy groups were given fewer scrips for NSAIDs (NEJM 341:1426, 1999--JW)
4. Spinal manipulation  added to "usual care" vs. "usual care" alone was ass'd with sig. improvements in disability scores at 3mos and 12mos in a randomized trial in 1,334 pts with low back pain (BMJ 329:1377, 2004--abst)

7. Multidisciplinary rehabilitation programs (PT, psychotherapy, etc.)
   1. In a systematic review of 10 randomized trials of multidisciplinary rehabilitation programs for chronic low back pain (> 3mos) involving total 1964 pts, higher-intensity programs (> 100h therapy) had sig. greater improvements in function than lower-intensity programs (< 30h therapy) (BMJ 322:1511, 2001--JW)
8. Transcutaneous electrical nerve stimulation (TENS)

8. Percutaneous electrical nerve stimulation (PENS)--acupuncture-like needles inserted in soft tissue or mm. and attached to a low-voltage power source
   1. 60 pts with low back pain due to "degenerative disc disease" randomized to one of the 4 tx's below, 3x/wk x 3wks. PENS was sig. more effective than other tx's at decreasing pain, decreasing use of nonopioid pain meds, andincreasing physical activity, quality of sleep, and overall well-being (JAMA 281:818, 1999)
      1. PENS
      2. Sham-PENS
      3. TENS
      4. Exercise therapy
9. Acupuncture
   1. In a systematic review of systematic reviews of grand total of 20 studies, methodologic quality was generally poor, but there was some evidence that acupuncture is more effecitve than no treatment or sham treatments, and less effective than massage (Ann. int. Med. 138:898, 2003)
   2. In a study in 241 adults with nonspecific low back pain x 4-52wks randomized to acupuncture (10 treatments) vs. "usual care" x 3mos.  At 2y, the active-tx group had sig. lower pain scores. (BMJ 333:623, 2006--JW)

11. Botulinum toxin injections
    1. 31 pts with chronic low back pain (> 6mos, mean duration 7y), with unilateral predonimance of pain, randomized to IM injections of botulinum toxin A vs. saline at 5 lumbar paravertebral sites. At 8wks, % of pts with > 50% improvement in pain was 60% in botulinum group vs. 12.5% with placebo (sig.); 6 of 10 BT responders noted decrease in effect at 6mos (Neurol. 56:1290, 2001--JW)

12. Antidepressants
    1. In a systematic review of 7 randomized trials of oral antidepressants for chronic low back pain, tricyclics were associated with significant reductions in pain, but SSRI's were not (Spine 28:2540, 2003--AFP)
13. Systemic Corticosteroids
    1. In a study in 87 pts with nonradicular low back pain randomized to methylprednisolone 160mg IM x 1 vs. placebo, at 1wk and 1mo, there were no sig. diffs. in pain scores. (J. Emerg. Med. 31:365, 2006--JW)

V. Lumbar disc herniation

1. Natural hx

1. 75% of pts recover within 6mos; 17% undergo surgery
2. With herniated disc + sciatica, surgical vs. "conservative" tx, after 1y surgery group did better, no diff. at 4y; positive correlation between physical activity & favorable results.
3. Pain probably doesn't come from nerve compression alone; inflammation & neurogenic mediators may be a greater cause of sciatica
4. Contrary to popular belief, prolonged nerve root compression has not been shown to cause permanent neurologic damage

2. Treatment

1. Surgery

1. Indications

1. Cauda equina sd
2. Progressive neurologic deficit
3. Intractable pain in appropriate distribution
4. "Failed conservative treatment in appropriate patient"
5. Maybe persistent though nonprogressive neurol. deficit

2. Radiologic findings alone do not constitute an indication--a significant # of asymptomatic individuals will have abnormal CT, myelograms (25-35%), e.g. bulging or degenerative disk

3. Risks of surgery:

1. Infection (about 3%)
2. Increases risk of subsequent surgery (15-20% of pts will have a repeat operation)
3. Post-op deconditioning is common but intensive PT may prevent
4. Risks of gen. anesthesia

4. Outcome of surgery

1. Generally good relief of pain (46-90% depending on study)
2. Good prognostic factors: no previous back surgery, presence of neurol. signs, only brief sciatica, not planning heavy work after surg., only brief pre-op unemployment, young, well-educated
3. In a study in 472 pts with lumbar radicular pain and corresponding findings of disk herniation on imaging studies randomized to diskectomy vs. non-operative care (PT, home exercise, analgesics), over 2y f/u there were no sig. diffs in pain, physical function, or disability.  However, over 40% of each group crossed over (i.e. some surgery-assigned pts improved and surgery was cancelled and some non-surgery-assigned pts ended up having surgery) ("Spine Patient Outcomes Research Trial" ("SPORT"); JAMA 296:2441, 2006--JW)
4. In a study in 283 pts with severe sciatica due to a herniated lumbar disc x 6-12wks randomized to early microdiscectomy (within 2wks of randomization) vs. conservative tx, the surgical group had sig. greater improvements in disability and pain at 4wks and 12wks but there was no sig. diff. in these outcomes at 1y (NEJM 356:2245, 2007--JW)

2. Nonsurgical therapy

1. Uncontrolled studies in pts with evidence of disc herniation (radiologic, EMG, neurol. signs), have shown good improvement with nonsurgical therapy in sx (>85% satisfactory improvement) as well as radiologic evidence of herniation
2. Therapies used

1. "Back school"
2. Spine stabilization
3. Bedrest-no direct evidence for efficacy
4. Pain meds
5. Abd. strengthening

3. Epidural steroid injections & sympathetic nerve root block

1. Uncontrolled studies show successful (per pt) outcomes in about 85%
2. 158 pts with herniated disk at L3-4, L4-5, or L5-S1 level on CT and pain for > 4 wks (but < 1y), as well as signs/sx of nerve root impingement, randomized to up to 3 epidural injections of methylprednisolone or saline over 6 weeks. At 3 weeks and 3mos, no sig. diff in sx (about 30% and 55% in each group had marked improvement at each of those times) (NEJM 336:1634, 1997)

4. Selective nerve-root steroid injections (injecting needle placed adjacent to affected nerve route under fluoroscopic guidance
   1. Nerve root injections with bupivacaine-betamethasone vs. bupivacaine alone ass'd with sig. less surgical intervention (29% vs. 67%) over avg. 2y f/u in a study of 55 pts with lumbar radicular pain and radiographically confirmed nerve-root compression not responsive to 6wks of conservative tx (J. Bone Joint Surg. Am. (82-A:1589, 2000--JW)

5. Percutaneous Electrical Nerve Stimulation ("PENS")
   1. 32g acupuncture-like needles inserted into subcutaneous soft tissue and used to transmit mild electrical current
   2. 60pts with LBP due to "degenerative disk disease" randomized to PENS, TENS, or exercise 3x/wk x 8wks; sig. less pain scores in PENS group (JAMA 281:818, 1999--JW)

3. Comparisons of surgical vs. other treatment

1. 126 pts with LBP & radicular signs & SLR, nonrandomized; compared surg. vs. no surgery: surgical group better at 1y, no diff. at 4y (Weber 1983)
2. Another nonrandomized study of 340 pts, 1y f/u, with sciatica showed 91% pts with sig. improvement with surgery vs. 82% pts with sig. improvement in non-operative group (Alaranta 1990)
3. 583 pts, nonrandomized, followed for 7y; 80% of non-surgically treated and 88% of surgically treated had little or no pain at f/u (Hakelius 1970)
4. 100 pts with a large herniation of a lumbar nucleus pulposus w/o improvement after 6wks of noninvasive tx randomized to epidural steroid injection vs. discectomy; over 3y f/u, discectomy pts had sig. higher incidence of improvement in sx (at every time point measured) (J. Bone Joint Surg 86:670, 2004--abst)

VI. Spinal stenosis

1. Physiology
   1. Narrowing of spinal  canal
   2. Can be congenital or acquired, the  latter typically from DJD but also  Paget's disease, trauma, ankylosing  spondylitis, etc.

2. Symptoms

1. Vague low back pain, worse with  activity, relieved by rest, often worse  with spinal flexion.
2. Neurogenic claudication"--pain and  paresthesias posterolateral LE's, not  necessarily symmetric
3. Sx don't correlate well w/degree of  compression seen on imaging studies
4. Sx may be due to decreased blood  flow rather than mechanical  compression

3. Treatment
   1. Analgesics
   2. Conditioning
   3. Epidural  steroids
   4. Decompression laminectomy
      1. In a study in 300 pts with lumbar degenerative spondylolisthesis with spinal stenosis causing neurogenic claudication or radicular pain, randomized to decompressive laminectomy w/fusion vs. no surgery, no diff. in intention-to-treat analysis in disability or pain at 2y, but in as-treated analysis, 2y outcomes were sig. better in surgery recipients (NEJM 356:2257, 2007--JW)