Nonspecific Low Back Pain

Nonspecific Low Back Pain Glastonbury

The New England Journal of Medicine
May 5, 2022; Vol. 386; No. 18; pp. 1732-1740

Alessandro Chiarotto, P.T., Ph.D., and Bart W. Koes, Ph.D. This study cites 54 references.

Typical Nonspecific Low Back Pain (LBP) case presentation:

• Low back pain (LBP) and stiffness for weeks to months.
• The pain is worse getting up in the morning.
• A history of episodes of LBP that occurs after vigorous sports activities.
• Other medical history is unremarkable.
• Physical examination shows reduced lumbar flexion.
• There is tenderness on palpation of the lower back.
• There are no neurologic deficits.

KEY POINTS FROM THIS ARTICLE:

1) Low back pain, with or without leg pain, “is worldwide the most prevalent and most disabling of the conditions that are considered to benefit from rehabilitation.”

2) “Low back pain is classified as specific (pain and other symptoms that are caused by specific pathophysiological mechanisms of non-spinal or spinal origin) or nonspecific (back pain, with or without leg pain, without a clear nociceptive-specific cause).” [emphasis added]

• “Non-spinal causes of specific low back pain include hip conditions, diseases of the pelvic organs (e.g., prostatitis and endometriosis), and vascular (e.g., aortic aneurysm) or systemic disorders; spinal causes include herniated disk, spinal stenosis, fracture, tumor, infection, and axial spondyloarthritis.”
• “Lumbar disorders with radicular pain due to nerve-root involvement have a higher prevalence (5 to 10%) than other spinal causes; the two most frequent causes of such back pain are herniated disk and spinal stenosis.”

3) “There is some controversy regarding the term ‘nonspecific’ low back pain, since structures such as muscles, joints, or disks (or a combination of these) may be causing the pain but are not readily identified by means of history taking and physical examination.” [Key Point]

• “Some patients with nonspecific low back pain may have symptomatic spinal osteoarthritis; in contrast to osteoarthritis of the peripheral joints, there are no diagnostic criteria for spinal osteoarthritis.”

4) Nonspecific low back pain “accounts for approximately 80 to 90% of all cases of low back pain.” [Key Point]

5) Low back pain classification according to pain duration:

• Acute <6 weeks
  • Approximately 70% of patients with acute LBP will recover.
• Subacute 6 to 12 weeks
• Chronic >12 weeks
  • Approximately 30% of patients with chronic LBP will recover.

6) Natural History and Prognosis

• “Low back pain is increasingly understood to be a long-lasting condition with a variable course rather than isolated, unrelated episodes.”
• “New-onset episodes of low back pain generally abated substantially within 6 weeks, and by 12 months the average reported pain levels were low.”

7) “Diagnosis of nonspecific low back pain is made after specific disorders of spinal and non-spinal origin are ruled out.” [Important]

8) “The history should include attention to red flags (e.g., history of cancer or trauma, parenteral drug use, long-term glucocorticoid use, immunocompromise, fever, and unexplained weight loss), since their presence warrants consideration of an occult serious diagnosis (e.g., cancer, infection, or inflammatory disease) and close follow-up.”

9) “Older age (>70 years), trauma, and the prolonged use of glucocorticoids have been associated with a high specificity for and considerable increased probability of spinal fracture.”

10) “If a herniated disk is suspected, a positive ipsilateral straight-leg-raising test (in which pain results when the leg on the side of the back or leg pain is raised) is highly sensitive (in 92% of patients), and a positive contralateral straight-leg-raising test (in which pain is produced when the leg opposite the side of the back or leg pain is raised) is highly specific (in 90% of patients).”

11) “In the case of radiculopathy, a neurologic evaluation can rule out weakness, loss of sensation, or decreased reflexes; if any of these features are present, referral to a specialist may be indicated.”

12) “Other maneuvers on physical examination have generally low diagnostic accuracy for the identification of other sources of low back pain (i.e., facet joints, sacroiliac joints, and disks).” [Very Important]

13) “The Predicting the Inception of Chronic Pain (PICKUP) tool is a validated prediction model that estimates the risk of chronic low back pain on the basis of five measures (i.e., disability compensation, presence of leg pain, pain intensity, depressive symptoms, and perceived risk of persistent pain) among patients who have an initial episode of low back pain.”

14) Other screening questionnaires validated to predict chronic pain, disability, and work absenteeism include:

• The Subgroups for Targeted Treatment (STarT) back screening tool
• The Örebro Musculoskeletal Pain Questionnaire
• “The PICK-UP tool or the Örebro Musculoskeletal Pain Questionnaire may be used to evaluate the patient for risk of the episode becoming chronic.”

15) Imaging

• “Routine imaging is not recommended in patients with nonspecific low back pain.”
• Systematic reviews of observational studies have shown poor correlation between abnormal imaging findings and low back pain.
• In acute low back pain without radiculopathy, the use of early imaging (e.g., radiography, magnetic resonance imaging, or computed tomography) is not associated with improved patient outcomes at 1 year.
• “Imaging may be performed when informative red flags are present, when there is a neurologic deficit, or when persistent low back pain with or without nerve-root involvement does not abate with conservative care.”

16) “First-line treatments are currently represented by nonpharmacologic interventions, which should be prioritized before pharmacologic treatment is prescribed.” [Important]

• “Recent [low back pain] guidelines (e.g., those of the American College of Physicians) have moved away from pharmacotherapy (owing to limited efficacy and risk of adverse effects) in favor of initial nonpharmacologic care for both acute and chronic low back pain.” [Important]

17) “Patient education and advice to remain active should represent routine care for patients with acute low back pain.”

• “Patients should be encouraged to continue with regular activities,” even if there is some pain when engaging in them.

18) “Meta-analyses of randomized trials support the use of a few sessions of spinal manipulative therapy or acupuncture for the reduction of pain, although the certainty of evidence for spinal manipulative therapy is moderate and that for acupuncture is low.”

19) “Heat and massage therapy are without risks and are reasonable to try, although the benefit of these therapies is supported only by limited data.”

20) “Exercise therapy that is prescribed or planned by a health professional has not been shown to be effective in patients with acute low back pain.” [emphasis added]

• Exercise helps chronic low back pain and helps in reducing the risk of future episodes of low back pain.
• For chronic LBP, “most types of exercise had beneficial effects on alleviating pain and improving functioning.”
• “Pilates therapy (which is focused on isometric contractions of the core muscles, attention to body movement, and improved posture) and McKenzie therapy (which involves repeated movement directional exercises, postural training, and education about patients’ self-management of pain) resulted in reduced pain and improved functioning.”

21) Acetaminophen has not been effective for LBP.

22) “Caution is advised in the use of NSAIDs in older adults and in patients with coexisting conditions such as renal disease.”

23) “Muscle relaxant agents had no significant effect on pain or disability during longer follow-up and were associated with a higher risk of adverse events.”

24) “Given the lack of data and the associated risk of addiction, the use of opioids should be minimized.”

• “The use of opioids should be limited to very carefully selected patients and only for short periods of time with appropriate monitoring.”
• Tramadol is a “weak opioid.” [Important]

25) “Other therapies for chronic low back pain include spinal manipulative therapy, massage therapy, yoga, and multidisciplinary rehabilitation.”

26) “Invasive therapies, such as epidural glucocorticoid injections and surgery, are rarely indicated for nonspecific low back pain.”

27) If low back pain does not abate within 2 months after the first visit, it is recommended that a referral be made to a specialist.

28) Key Clinical Points on Nonspecific Low Back Pain from Authors:

• “Nonspecific low back pain is diagnosed on the basis of the exclusion of specific causes, usually by means of history taking and physical examination.”
• “Imaging is not routinely indicated in patients with nonspecific low back pain.”
• “Most patients with an acute episode of nonspecific low back pain will recover in a short period of time.”
• “Education and advice to remain active are recommended for patients with acute or chronic low back pain.”

COMMENTS FROM DAN MURPHY:

Chiropractic education and expert opinions emphasize the importance of history and examination to arrive at a diagnosis prior to initiating treatment (usually spinal adjusting) for low back pain. Adequate history and examination to rule-out disease (like fracture, cancer, infection) and/or a neuropathological process (like cauda equina syndrome or progressive muscular weakness/atrophy) is a good idea.

Yet, this study, from a top medical publication, reminds us that about 85% (“80% to 90% of all cases of low back pain”) of low back pain cases, a definitive diagnosis is not possible despite a thorough history and examination.

The Cauda Equina Syndrome components might include:

Cauda Equina Syndrome occurs when a low back disc problem puts pressure on the nerves that control bowel, bladder, and sexual function.

Representative symptoms include leaky bladder, or leaky bowels, or loss of sensation (numbness) around the pelvic sexual organs (the saddle area), or the inability to start/stop urination or to start/stop a bowel movement.

Cauda Equina Syndrome is a medical emergency because the nerves that control these functions can permanently die, and those functions may be lost or compromised forever. The standard approach is to surgically decompress the nerves, and the window to do so may be as short as 12-72 hours, depending.

This study also devalues the benefits of imaging, from x-rays to MRI, unless there are red flags, like a reasonable suspicion of a disease process (fracture, infection, cancer), progressive weakness and/or atrophy, or an unacceptable clinical response after about 2 months of conservative management.