Nontraumatic Low Back Pain

Sarah McPhersonOct. 3, 2002

Why is it important?

• High disease prevalence

• most expensive cause of work-related disability

• wide variations in medical care

Sickness days appear to be increasing

Waddell, G. Ann Rheum Dis. 1993;52:317-19

Practice patterns in the USA

• US National survey of 114 ER physicians

• answered questionnaire of case vignettes

• results reflect that practice pattern does not follow recommended guidelines or the medical literatureElam KC, J Emerg Med.1995;13(2):143-50

What causes low back pain?

• May originate from many spinal structures:– ligaments– facets– periosteum– muscles– fascia– blood vessels– nerve roots– anulus fibrosus

• ~ 85% no pathoanatomical diagnosis

Important questions to ask

• Is there a systemic disease that is the source for the pain?

• Is there any indication that surgical evaluation is required?

• How can I provide the best symptomatic relief?

• Can I help to prevent chronicity or recurrence?

What are the indications for further imaging?

AHCPR guidelines for the ordering of radiographs:

Possible Fracture: Possible tumor or infection:major trauma > 50yrsminor trauma age >50 < 20 yrschronic steroid use history of cancerosteoporosis constitutional symptoms

recent bacterial infectioniv drug useimmunosuppressionsupine painnocturnal pain

Problems with the AHCPR guidelines

• There has been no prospective validation therefore we do not know the sensitivity or specificity

• following the guidelines would increase utilization by ~ 200% Suarez-Almazor. JAMA .1997 277(22). 1782-86

• plain radiographs are not sensitive for the diseases that require specific therapy– 23% epidural abscess, 25% disc space infection, 68% bone

tumor, 90% vertebral osteomyelitisLiang, M. Arch Intern Med. 1982, 142: 1108-12

• radiation dose of lumbar radiographs 40X > than CXRWhalen, JP.Dis Mon. 1982;28:73

What about MRI?

• Advantages:– highly sensitive for the detection of infection,

tumors, nerve root compression, spinal stenosis

• Disadvantages:– imaging may not correlate with clinical disease

• 25% of asymptotic patients have disc herniation• 50% healthy young adults will have bulging or

degenerative discs on MRI Jarvik, J.Radiology.1997;204(2):447-54

– cost effectiveness

So when should you order an MRI?

• No validated clinical guidelines

• Recommendations:– clinical suggestion of underlying infection– clinical suggestion of underlying cancer– persistent neurologic deficit– evidence of cauda equina syndrome

When is surgical evaluation required?

• Cauda equina syndrome (surgical emergency)– bladder or bowel dysfunction (usually urinary

retention)– numbness to perineum and medial thighs (saddle

distribution)– bilateral leg pain, weakness and numbness

• progressive or severe neurologic deficits• persistent neuromotor deficit after 4-6 weeks• persistent sciatica for 4-6 weeks (not low back

pain alone)Deyo, RA. NEJM. 2001; 344(5): 363-70

Pharmaceutical treatment of LBP

AHCPR Guidelines:– Recommended medications:

• Acetominophen• NSAIDs

– “Optional” medications:• muscle relaxants• opioids for < 2 weeks

– Recommended against:• opioids > 2 weeks• phenylbutazone• oral steroids• colchicine• antidepressants

Evidence for NSAIDs

• NSAID vs Placebo– 9 RCT (5 high quality, 4 low)– heterogeneity between studies with respect to

dosing, mode of administration and type of NSAID

RESULTS:– NSAIDs provide better pain control than placebo– improved global improvement in patients treated

with NSAIDs– decreased need for additional analgesia in NSAID

groupsvan Tulder, MW. Spine 2000;25:2501-13

Evidence for NSAIDs

• NSAID vs Acetominophen– 5 RCT (1 high quality, 4 low)RESULTS:– 2 low quality studies showed no difference– 1 low quality and 1 high quality showed

superiority of NSAID for pain control

Bottom line: Conflicting evidence but NSAIDs appear more effective than

acetominophenvan Tulder, MW. Spine 2000;25:2501-13

Evidence for NSAIDs

• NSAID + muscle relaxant– 3 RCT (1 high quality, 2 low quality)

Results:– all 3 studies showed combined therapy to

be better than NSAID alone but results not statistically significant

van Tulder, MW. Spine.2000;25:2501-13

Evidence for NSAIDs

• Comparisons of different NSAID types– 24 trials– looked at ibuprofen, indomethacin,

diclofenac, ketorolac, tenoxicam, piroxicam, naproxen

RESULTS:– equal efficacy

Evidence for NSAIDs

• NSAID vs COX-2– RCT– N = 104– nimesulide vs ibuprofenResults:– no difference in pain or stiffness scores – no difference in side effectsPohjolainen, T. Spine 2000; 25(12):1579-85

What about muscle relaxants

• 14 RCT (8 high quality, 6 low quality)• 8 high quality:

– 5 showed improvement in pain intensity, 3 no difference

• many different muscle relaxants studied (cylcobenzaprine, tizanidine, diazepam, baclofen, butabarital)

• all appear to have equal efficacy however good studies with head to head comparisons are lackingvan Tulder, MW. Spine. 1997;22(18): 2128-56

Cyclobenzaprine (Flexeril)

• 14 RCT’s reviewed in meta-analysis• all studies but 2 treated for > 14 days• dosing was 10mg tid

• Outcomes measured: – local pain– muscle spasm– tenderness to palpation– range of motion– activities of daily living

Cyclobenzaprine - outcomes

• Moderate improvement for all outcome measures

• NNT = 3

Browning, R. Arch Intern Med. 2001; 161:1613-20

Cyclobenzaprine - Side effects

• 53% of patients experience at least one side effect compared with 28% in the placebo group

What if your patient prefers “natural” remedies?

• The efficacy of willow bark extract– RCT: high (240mg) and low dose(120 mg)

willow bark vs placebo– N = 210– outcomes measures VAS at 4 weeks, need of

break-through analgesia

– Results:high dose > low dose > placeboChrubasik, S. Am J Med.2000;109:9-14

Medical Management - What should you choose?

• Regular dosing of NSAID of your choice for 1-2 weeks

• addition of muscle relaxant (warn of side effects), acetominophen or a narcotic may be of benefit

• the optimal combo of meds and duration is not known

To rest or not to rest?

• current guidelines advocate bed rest for a maximum of 2 days for LBP and up to 2 weeks for sciatica

QUESTIONS:– Is there any evidence to suggest that

bed rest may improve recovery?– Is there any evidence that bed rest

may be harmful?

Bed rest has not been shown to be effective treatment for LBP

Systematic review:– 10 trial identified evaluating therapeutics of

bed rest– length of bed rest varied from 2-7 days– 8 trials showed no difference in pain scores or

activities of daily living– despite differences in length of rest, no trials

showed a difference or efficacy of bed rest

Waddell, G. Br J Gen Prac. 1997;47:647-52

Could bed rest actually have negative effects?

Bed rest vs Exercises vs ordinary activity?– RCT to 3 groups (N= 67,52,67)– outcome measures of duration & intensity of

pain, absence from work, ability to work, & Oswestry back disability index

– groups evaluated at 3 and 12 weeks– control group had less absenteeism, decrease

pain intensity scores and similar satisfaction to bed rest group

Malmivaara, A. NEJM.1995;332(6):351-55

3 week outcomes

Outcomes at 12 weeks

Bed rest for Sciatica

• RCT 2 weeks bed rest vs normal activity• N = 92 & 91• outcome measures: global assessment

of function, pain scores, absenteeism, surgical requirements

• evaluated at 3 and 12 weeks

Vrooman, PCAJ. NEJM.1999;340(6):418-23

Bed rest for sciatica

Results:– 10 % lost to follow-up– mean # days in bed 22hr vs 10 hrs– no difference in outcome measures at 3 or 12

weeks

• Bed rest is definitely not more effective in treating sciatica

• Is it harmful? - this study does not answer that & no other studies were found in my review

Physiotherapy and exercise programs

Systematic Review – 1991– 16 studies identified– Only 4 high quality studies– Different types of therapy studied– Chronic and acute LBP

– 10 studies reported no difference between treatment and nontreatment groups

– 6 studies reported positive results in the PT group

Koes, BW. BMJ. 1991;302:1572-6

What is the role of physiotherapy?

• Since 1991 5 more studies looking at PT for acute LBP

Positive Studies– 1 study identified– Retrospective review of randomly selected

patients with acute LBP– Looked at 3 groups (immediate PT, start at

2-7 days or Pt started at 8-179days)– Delayed therapy group had increased

absenteeism and more physician visits

What is the role of physiotherapy?

• 4 negative studiesCherkin et al , NEJM. 1998; 339(15) 1021-9:

– prospective RCT McKenzie PT vs chiro vs educational booklet

– N = 323, LBP < 7 days– PT and chiro group had less “bothersome”

symptoms at 4 weeks but not at 12 weeks– no difference in Roland disability scores,

absenteeism or recurrences at 1 or 2 years– PT and chiro costs similar, both +++ more

expensive than educational booklet

What is the role of physiotherapy?

Faas, A et al. Spine 1995;20(8):941-7:– prospective RCT– no treatment vs PT vs sham PT– N= 473, LBP < 3 weeks– Outcomes:

• higher absenteeism in PT group• no difference in releif from symptoms• no decreased duration of pain episodes

– follow-up at 1,2,4 and 12 months

What is the role of physiotherapy?

Dettori, JR et al. Spine. 1995;20(21):2303-12:– prospective RCT– flexion vs extension exercises vs no exercises– N = 152, LBP < 7 days– Outcomes:

• no difference in pain scores• no difference in disability scores• no difference time to return to work• ~60% recurrence rate at 6-12 months in all categories

– follow-up at 1,2& 4 weeks, and at 6-12 months

What is the role of Physiotherapy?

• Does not appear to decrease acute symptoms

• does not appear to decrease recurrence of back pain

• despite the literature, physiotherapists are convinced from experience that it works

What about spinal manipulation?

• Meta-analysis of 7 studies• LBP 2-4 weeks• improvement in pain at 2-3

week post onset of treatment (50% vs 67%)

• difference gone within weeks to months

• studies did not look at disability scores or work absenteeism

Shekelle, PG.Ann Intern Med. 1992;117(7): 590-8

Is there a role for Acupuncture?

• Number of studies have been done looking at the role in chronic LBP (> 3 months)

• no studies looking at acupuncture acutely

• appears to be beneficial in reduction of pain, improved activity, and decreased analgesic requirements

Ernst, E. Arch Intern Med. 1998;158:2235-41Christer, C. Clin J pain. 2001;17(4): 296-305Ghoname, E. JAMA. 1999;281(7): 818-23

Overview of non pharmaceutical interventions

• Bed rest is not helpful and is probably harmful

• Physiotherapy does not appear to reduce symptomatology or prevent recurrence

• spinal manipulation may reduce short term symptoms but loses its effect in the long term

• accupuncture appears to be helpful in chronic LBP

Factors predicting chronicity

• ~ 10% of all LBP becomes chronic• Risk factors include:

– psychosocial issues primarily• fear avoidance model• depression• poor coping skills• chronic daily stress• poor job satisfaction

– clinical• large disc protrusionWilliams, R. Arch Phys Rehab Med. 1998;79:366-73Burton, K. Spine. 1995;20(6): 722-8Hasenbring, M. Spine. 1994: 19(24): 2759-65Klenerman, L. Spine. 1995: 20(4): 478-84

Can we influence the path to chronicity?

• Prospective study of high risk patients– treatment of risk factor based cognitive behavioral

intervention vs electromyographic biofeedback (relaxation techniques) vs no intervention

– improved pain reduction, decreased immobility in daily life, decreased depression immediately post intervention and at 6 months

– high risk patients with intervention had results similar to low risk patients

Hasenbring, M. Spine. 1999;24(23):2525-35

Can we influence Chronicity

• Prospective RCT educational booklet vs advice consistent with current guidelines

Can we influence chronicity

• Effects of the booklet– improvement in beliefs at 1 year– decreased fear avoidance beliefs– improved Roland disability scores– no difference in pain scores

Burton, K. Spine. 1999; 24(23): 2484-91

Can we influence patients returning to normal work?

• The sooner the recommendation to return to work is made, the more likely the patient will comply

• the probability of return to work decreases as length of time off work increases

• subjective pain ratings does not correlate with a person’s ability to accomplish physical activities

Hall, H. Spine. 1994; 19(18): 2033-37

Influencing return to work

• Prospective study looking at unrestricted return to work recommendations vs return to work with restricted duties– enrolled patients through their PT rehabilitation

program– part way thorough they enforced that all patients

be given unrestricted return to work instructions regardless of pain ratings

– OUTCOMES: • increased return to work in unrestricted group (84% vs

47%)Hall, H. Spine . 1994;19(18): 2033-37

Overall recommendations

• Regular NSAID +/- muscle relaxant/Tylenol

• Spinal manipulation likely shortens course of symptoms

• PT may be helpful • education emphasizing benign course of

disease and encouragement to decrease fear avoidance behaviors