Non-Specific Low Back Pain

I thought that this Review article, by Balague et al (2012), was a wonderful outline of where we are at with regards to Non-Specific Low Back Pain. I would recommend those interested read the article in detail as obviously the vast majority of information below is cited by the authors.

General Summary:

  • The lifetime prevalence of low back pain is reported to be as high as 84%, and the prevalence of chronic low back pain is about 23%, with 11-12% of the population being disabled by low back pain.
  • Mechanical factors, such as lifting and carrying, probably do not have a major pathogenic role, but genetic constitution is important.
  • The use of clinical imaging for diagnosis should be restricted.
  • The mechanism of action of many treatments is unclear, and effect sizes of most treatments are low.
  • Both patient preferences and clinical evidence should be taken into account for pain management, but generally self-management, with appropriate support, is recommended.
  • Surgery and overtreatment should be avoided.

MRI findings:

  • A systematic review with meta-analysis concluded that, at the individual level, none of the lesions (with the exception of Modic signs) identified by MRI could be established as the cause of low back pain because such MRI abnormalities are very common in:
    • people who are asymptomatic.
    • do not coincide with the development of low back pain and;
    • do not predict the response to evidence-based therapy for non-specific low back pain.

Mechanical factors:

  • Eight systematic reviews concluded that it was unlikely that the following factors were independently causative of low back pain:
    • Occupational sitting
    • Awkward postures
    • Standing
    • Walking
    • Manual handling or assisting patients
    • Pushing or pulling
    • Bending and twisting
    • Lifting or carrying

Obesity:

  • Findings from a meta-analysis show that people who are overweight or obese have an increased risk of low back pain, with the strongest association for care-seeking for low back pain, and for chronic low back pain.

Disuse or Physical De-conditioning:

  • Research evidence to suggest that disuse and physical deconditioning are directly associated with chronic low back pain, in either a causal or consequential manner, is scarce.

Smoking:

  • Cohort studies reveal a slight association between back pain and smoking status even when controlling for anxiety or mood disorders.

Genetics:

  • Twin studies show that both low back pain and disc degeneration have a genetic background.
  • Heritability estimates range from 30% to 46% for various types of back pain problem.

Differential Diagnosis:

  • Many practitioners maintain that different underlying causes (eg, facetogenic, discogenic, or sacroiliac) exist and can be identified.
    • Evidence to suggest that the characteristics that purportedly define subgroups can be identified with good accuracy, or that a specific type of management is available for each subgroup, is insufficient.

Predictors of Persistent Pain:

  • The most helpful baseline predictors of persistent disabling low back pain included:
    • Maladaptive pain coping behaviours.
    • Non-organic signs.
    • Functional impairment.
    • Low general health status.
    • Presence of psychiatric comorbidities.

Predictors of Recovery at 1 Year:

  • Low levels of fear avoidance
  • Low levels of functional impairment

Recovery Expectations:

  • Findings from other reports suggest that, within 3 weeks of the onset of non-specific low back pain, low recovery expectations can identify people at risk of a poor functional outcome up to 6 months later.

Prevention of Low Back Pain:

  • Generalised primary prevention does not seem to be a realistic aim in low back pain because the symptom is highly prevalent, with the strongest risk factor for future low back pain being previous low back pain and with a high proportion of teenagers having already had low back pain.
  • Most prospective studies have not been able to identify many strong and modifiable risk factors for true first time low back pain.
  • Findings from systematic reviews of trials into the prevention of low back pain show that only exercise interventions seem to be effective. Other interventions seem ineffective, including:
    • Stress management
    • Shoe inserts or insoles
    • Back supports
    • Ergonomics or back education
    • Reduced lifting programmes
    • Manual materials handling advice and training, with or without the use of assistive devices.

Classification of Back Pain:

  • The Red flags consistently reported in the published work include:
    • Weight loss
    • Previous history of cancer
    • Night pain
    • Age more than 50 years
    • Violent trauma
    • Fever
    • Saddle anaesthesia
    • Difficulty with micturition
    • Intravenous drug misuse
    • Progressive neurological disturbances
    • Systemic steroids.
  • Henschke and colleagues (see my Red Flag Post) showed that, using 25 red flag questions in a primary care setting, 80% of patients (942 of 1172) had at least one red flag; this finding contrasted with a prevalence of serious disease of 0·9% (11 of 1172).
  • Other research would suggest that if a thorough assessment has been undertaken, and if there are no red flags, one can be 99% confident that serious spinal disease has not been missed.
  • Four features are significantly associated with vertebral fracture:
    • Female sex
    • Age >70 years
    • Substantial trauma
    • Prolonged use of corticoids
  • For malignancy the following combination has been reported to have a perfect sensitivity and negative likelihood ratio, but only moderate specificity and positive likelihood ratio:
    • Age 50 years or older
    • History of cancer
    • Unexplained weight loss
    • Failure of conservative therapy.
  • Once serious disease has been ruled out, the next priority is to identify patients with radicular pain.
  • All other cases are classified as non-specific and the patient should be assessed for the severity of symptoms and functional limitations, and for risk factors for chronicity.
  • Dermatomal radiation, more pain on coughing, sneezing or straining, positive straight leg raising, and crossed straight leg raising can be used to predict nerve root compression on MRI.
  • Most patients seeking surgical treatment for lumbar stenosis, for example, do not have positive physical examination findings and have subjective symptoms only, such as pain during walking.

Management of Acute Low Back Pain:

  • Most clinical practice guidelines agree on the use of:
    • Reassurance
    • Recommendations to stay active
    • Brief education
    • Paracetamol
    • Non-steroidal anti-inflammatory drugs
    • Spinal manipulation therapy
    • Muscle relaxants (as second line drugs only, because of side-effects), and weak opioids (in selected cases).
  • Some reviews recommend topical pharmacological treatments and superficial heat application for pain relief.
  • Systemic corticosteroids are not recommended for acute low back pain.
  • Symptoms tend to improve after a short period of time, with or without treatment.

Management of Chronic Low Back Pain:

  • Primary Recommendations:
    • Brief education about the problem
    • Advice to stay active
    • Non-steroidal anti-inflammatory drugs
    • Weak opioids (short-term use)
    • Exercise therapy (of any sort)
    • Spinal manipulation.
  • Self-management strategies are receiving increasing attention as important components in the management of low back pain.
  • Secondary Recommendations:
    • Multidisciplinary rehabilitation
    • Adjunctive analgesics
    • Cognitive behavioural therapy
    • Strong opioids.
  • Antidepressants:
    • Second line treatment:
      • Showing a small to moderate benefit, although possibly no greater than placebo, and with a high risk of side-effects.
  • Pain Management Procedures:
    • Intradiscal electrothermal therapy, percutaneous intra-discal radiofrequency thermocoagulation, and radio- frequency facet joint denervation are generally not recommended.
  • Chronic disabling cases of non-specific low back pain:
    • Intensive multidisciplinary approaches are often recommended, although these are not necessarily available everywhere.
    • Group cognitive behavioural interventions in a primary care setting can have a sustained effect on troublesome subacute and chronic low back pain at low cost to the health-care provider.
  • Surgery:
    • The place for surgery is very limited and its overuse has been criticised.
    • Results from trials that compare intensive rehabilitation with spinal fusion surgery have shown:
      • Similar clinical improvement for the treatments at short and long-term follow-up.
      • More complications and lower cost-effectiveness for surgery.
  • Patients with chronic pain not responding to conservative treatment should be carefully reassessed to ensure that a structural lesion that might be an indication for surgery has not been overlooked. Otherwise, chronic refractory cases should be managed by pain specialists or with multidisciplinary programmes focused on chronic pain management.
  • Effects of Treatment:
    • Many specific treatments (eg, back strengthening exercises) that are designed to address a specific problem (eg muscular weakness or atrophy) turn out to show effectiveness unrelated to the extent of any specific physiological or anatomical changes (eg, of back strength or muscle size)
    • The effects are, instead, related to concomitant changes in beliefs, attitudes, and coping mechanisms.
    • Patients’ expectations are known to influence the outcome of treatment, with expectations being fulfilled the main determinant.
      • The impact of expectations on subjective outcome is related to the placebo effect.

Next post will cover some of the up-to-date research evidence with regards to treatment of lumbar pain.

References:

Balagué F, Mannion AF, Pellisé F, Cedraschi C. Non-specific low back pain. Lancet. 2012 Feb 4;379(9814):482-91.

About the Author:

Mark is a Specialist Musculoskeletal Physiotherapist who consults at both Insight Physiotherapy and Pain Options, in Perth, Western Australia. He specialises in the assessment and management of persistent/chronic musculoskeletal pain. In addition to his clinical role he maintains regular involvement in education of the profession having held a Teaching Fellow position at the University of Western Australia for 10 years and regularly presenting at courses and seminars through the Australian Physiotherapy Association and private education sector. Mark is also a Facilitator for the Australian College of Physiotherapists Specialisation Training Program and a Branch Councillor on the Western Australian Branch of the Australian Physiotherapy Association.

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