Mechanical Back Pain 

Updated: Jan 24, 2017
Author: Debra G Perina, MD; Chief Editor: Trevor John Mills, MD, MPH 

Overview

Background

Mechanical low back pain is one of the most common patient complaints expressed to emergency physicians in the United States accounting for more than 6 million cases annually. Approximately two thirds of adults are affected by mechanical low back pain at some point in their lives, making it the second most common complaint in ambulatory medicine and the third most expensive disorder in terms of health care dollars spent surpassed only by cancer and heart disease.[1, 2]

The image below illustrates a herniated nucleus pulposus at multiple levels, one of the causes of low back pain.

Magnetic resonance image of the lumbar spine. This Magnetic resonance image of the lumbar spine. This image demonstrates a herniated nucleus pulposus at multiple levels.

See Back Pain: Find the Cause, Watch for the Comeback, a Critical Images slideshow, to help diagnose and manage this common problem.

Low back pain reportedly occurs at least once in 85% of adults younger than 50 years, and 15-20% of Americans have at least one episode of back pain per year. Of these patients, only 20% can be given a precise pathoanatomic diagnosis. Low back pain affects men and women equally. The onset most frequently occurs in people aged 30-50 years. Low back pain is the most common and most expensive cause of work-related disability in the United States.[3, 2] Smokers appear to have an increased incidence of back pain compared with nonsmokers. Furthermore, the incidence of current smoking and the association with low back pain is higher in adolescents than in adults.[4]

The American College of Radiology (ACR) has published appropriateness criteria for low back pain, including the following[5] :

  • Uncomplicated acute low back pain and/or radiculopathy are benign, self-limited conditions that do not warrant any imaging studies.
  • MRI of the lumbar spine should be considered for those patients presenting with red flags raising suspicion for a serious underlying condition, such as cauda equine syndrome, malignancy, or infection.
  • In patients with a history of low-velocity trauma, osteoporosis, or chronic steroid use, initial evaluation with radiographs is recommended.
  • In the absence of red flags, first-line treatment for chronic low back pain remains conservative therapy with both pharmacologic and nonpharmacologic (eg, exercise, remaining active) therapy.
  • If there are persistent or progressive symptoms during or following 6 weeks of conservative management and the patient is a surgery or intervention candidate or diagnostic uncertainty remains, MRI of the lumbar spine has become the initial imaging modality of choice in evaluating complicated low back pain.
  • MRI is the imaging procedure of choice in patients suspected of cord compression or spinal cord injury.
  • Patients with recurrent low back pain and history of prior surgical intervention should be evaluated with contrast-enhanced MRI.

Pathophysiology

Many causes of mechanical low back pain exist. The most common causes are age-related degenerative disc and facet processes and muscle- or ligament-related injuries. Discussion in this article is limited to musculoskeletal causes. These can be divided into nerve root syndromes, musculoskeletal pain syndromes, and skeletal causes.

Nerve root syndromes

Classic nerve root syndrome is characterized by radicular pain arising from nerve root impingement due to herniated discs. A similar syndrome can also be produced by inflammation and irritation, which may explain why patients whose presentation is consistent with this diagnosis respond to conservative therapies.

Impingement pain tends to be sharp, well localized, and can be associated with paresthesia, whereas irritation pain tends to be dull, poorly localized, and without paresthesia. Impingement is associated with a positive straight leg raising sign (ie, shooting pain down contralateral leg with leg raising), while irritation is not. Neurologic deficits and pain radiation below the knee are rarely seen in irritation alone and are most commonly found with impingement.[6]

The cause of impingement syndrome is most commonly herniated discs, but it may also be caused by spinal stenosis, spinal degeneration, or cauda equina syndrome.

Herniated discs are produced as spinal discs degenerate. After growing thinner, the nucleus pulposus herniates out of the central cavity against a nerve root. Intervertebral discs begin to degenerate by the third decade of life, and herniated discs are found on autopsy in one third of adults older than 20 years. Only 3% of these, however, are symptomatic.[7] The most common locations for herniation are L4, L5, and S1.[8]

Spinal stenosis occurs when disc spaces decrease as intervertebral discs lose moisture and volume with age. Even minor trauma under these circumstances can cause inflammation or nerve root impingement, which can produce classic sciatica pain without disc rupture. The pain can often be bilateral.[9]

Spinal degeneration is caused by alterations in the hygroscopic quality of the nucleus pulposus. This process progresses to annular degeneration. Coupled with progressive posterior facet disease, this process leads to spinal canal or foraminal encroachment. These retrogressive and proliferative changes in the disc anteriorly and the joints posteriorly produce clinical symptoms and radiographic findings termed 3-joint complex degeneration. Spinal degeneration has 3 distinct stages, as follows:

  • Dysfunction with complaints of pain only

  • Instability with advanced degeneration, pseudospondylolisthesis, and neurologic abnormalities

  • Stabilization with morning stiffness and with prolonged standing or walking, producing radicular pain

Cauda equina syndrome is produced by massive midline extrusion of nuclear material or tumor into the spinal canal, which compresses the caudal sac. The classic presentation is bilateral sciatica, with lower extremity bowel or bladder dysfunction present in 90% of patients. Urinary retention is initially observed and followed by overflow incontinence. Perineal or perianal anesthesia is present in 60-80% of patients.[10]

Musculoskeletal pain syndromes

Musculoskeletal pain syndromes that produce low back pain include myofascial pain syndromes and fibromyalgia.

Myofascial pain is characterized by pain and tenderness over localized areas (trigger points), loss of range of motion in the involved muscle groups, and pain radiating in a characteristic distribution but restricted to a peripheral nerve. Relief of pain is often reported when the involved muscle group is stretched.

Fibromyalgia results in pain and tenderness on palpation of 11 of 18 trigger points, one of which is the low back area, as classified by the American College of Rheumatology. Generalized stiffness, fatigue, and muscle ache are reported.

Other skeletal causes

Other skeletal causes of low back pain include osteomyelitis, sacroiliitis, and malignancy.

Osteomyelitis results from infectious processes involving the bones of the spine, while sacroiliitis results from inflammatory changes in the sacroiliac joints. This pain presents over the sacroiliac joints and radiates to the anterior and posterior thighs. This pain is usually worse at night and is exacerbated by prolonged sitting or standing.

Malignant tumors of the spine can be primary or metastatic. Most primary spinal tumors are found in patients younger than 30 years and usually involve the posterior vertebral elements. Metastatic tumors are found mostly in patients older than 50 years and tend to occur in the anterior aspects of the vertebral body.[11] Metastatic disease is more common than primary tumors of the spine, and thoracic spine metastatic lesions are more common than lumbar. Caution is advised, in that these traditional "red flags" have sufficient evidence in detecting spinal malignancy if based on the presence of a single red flag. However, the presence of more than 2 of these together should increase suspicion for the need for further workup.[12]

Epidemiology

 

Mechanical low back pain is one of the most common patient complaints expressed to emergency physicians in the United States accounting for more than 6 million cases annually. Global studies have shown that low back pain is one of the most common complaints experienced by physicians in most countries.[13, 2]

According to the Nationwide Inpatient Sample (NIS), approximately 183,151 patients with a primary diagnosis of low back pain were discharged from US hospitals between 1998 and 2007. During this period, an average of 65% of these patients were admitted through the ER, with a significant increase from 1998 (54%) to 2005 (71%). Multivariate analysis showed that uninsured patients (OR 2.1, 95% CI 1.7-2.6, P<0.0001) and African American patients (OR 1.5, 95% CI 1.2-1.7, P<0.0001) were significantly more likely to be admitted through the ER than private insurance patients or Caucasian patients, respectively.[14]

Most etiologies of mechanical low back pain are not life threatening; however, significant morbidity is associated with chronic low back pain syndromes. A significant number of patients are unable to return to their normal daily routines or function in a productive work environment secondary to low back pain.[3]  Most cases of back pain treated in the emergency department are not true emergencies, with the exception of cauda equina syndrome. Patients who have cauda equina syndrome must undergo surgical decompression as soon as possible or face permanent neurologic damage.

Low back pain is a common complaint in adults of all ages, and it is becoming an increasing complaint in children and adolescents. A study following children from age 14 years into adulthood suggests that obesity in childhood, particularly in females, is a risk factor for later hospitalization for sciatica. This study also reported an increased risk of hospitalization for sciatica in males who smoked at a young age.[15]

Prognosis

The prognosis is good for most patients who present with mechanical back pain.[16, 17]  Overall, 70% of patients feel better in 1 week; 80%, in 2 weeks; and 90%, in 1 month. Only 10% of all patients with low back pain have long-term problems.

A significant functional overlay or component of secondary gain is present in a subgroup of patients, who also account for the majority of office visits with low back pain complaints (see Causes section).

Recurrence is common and seen in up to 40% of patients within 6 months. Prevention methods should be discussed with patients with low back pain along with encouragement to monitor them when the acute period has resolved.

Psychosocial factors such as presence of posttraumatic stress disorder, use of a lawyer, presence of other chronic illnesses, and lower education levels appear to be positive predictors of development of chronic back pain in patients who sustain an initial injury to their back. Chronic back pain development was not associated with age, gender, occupation, or severity of original injury.

A systematic review by Chou and Shekelle found that the following factors were most helpful for predicting which patients would experience persistent disabling low back pain: maladaptive pain coping behaviors, nonorganic signs, functional impairment, general health status, and presence of psychiatric comorbidities. Factors related to the patient's work environment, baseline pain, and presence of radiculopathy are less useful for predicting worse outcomes.[18]

Patient Education

Patient education focuses on prevention and includes the following:

  • Promoting weight loss where indicated

  • Performing back strengthening exercises

  • Teaching proper lifting technique

  • Increasing overall physical conditioning

Back belts, which are commonly worn in occupations with heavy lifting, have not been proven to prevent back injury.

For patient education resources, see the Bone Health Center; Back, Ribs, Neck, and Head Center; and Muscle Disorders Center, as well as Back Pain, Chronic Pain, and Sciatica.

 

Presentation

History

A thorough history and physical examination is paramount to arrive at a diagnosis, and initially imaging is often unnecessary.[6]  Patients most often complain of pain in the lumbosacral area. Determine whether pain is exacerbated by movement or by prolonged sitting or standing; the duration of pain; and whether the pain is relieved by lying down.

Establish if pain was sudden in onset or gradual over days or months, and determine whether pain is worse in the morning or at night. Find out if the patient can identify a precipitating event such as lifting or moving furniture. Explore the presence of systemic symptoms such as fever, weight loss, dysuria, cough, and bowel or bladder problems.

Inquire about current medications that may produce symptomatology. Chronic steroids may predispose to infection or compression fractures. Anticoagulants may result in a bleed or hematoma.

Any history of new-onset bowel or bladder dysfunction (eg, urinary hesitancy, overflow incontinence) with back pain is suggestive of cauda equina syndrome. This is particularly true if other, new neurologic deficits are also present.

The existence of traditional red flags for occult vertebral fractures, such as advancing age, long-term steroid use, spinal point tenderness, and minor trauma, appear to be relatively poor indicators if used individually. The presence of 2 or more of these should raise the index of suspicion for the clinician.[19]

Physical

Physical examination of a patient with back pain should include range of motion and a thorough neurologic examination, including assessment of peripheral motor function, sensation, and deep tendon reflexes.[20]

Perform straight leg testing with the patient in a supine position. Record response to raising each leg. An approximation of the test may also be performed with the patient sitting and each leg straightened at the knee. An elevation of the leg to less than 60° is abnormal. The straight leg test result is positive only if the pain radiates to below the knee and not merely in the back or the hamstrings. This is the single best test for determining radiculopathy due to disc herniation with a high sensitivity and moderate specificity.[21]

Perform an abdominal examination to exclude intra-abdominal pathology.

Men older than 50 years should be given a rectal examination to assess prostate size and exclude prostatitis. Also perform a rectal examination on any patient who may have cauda equina syndrome to assess rectal tone and perineal sensation. If cauda equina syndrome is suspected, urinary catheterization for a postvoid residual or bedside ultrasonography of the bladder may be helpful to assess for urinary retention. Perform a rectal examination, if necessary, in younger males who are febrile and have urinary complaints.

 A pelvic examination should be done in females complaining of menstrual abnormalities or vaginal discharge.

Patients with true herniated discs may not present with any findings other than a positive straight leg raising test. Classic presentation includes numbness in a dermatomal distribution corresponding to the level of disc involved, with findings of motor weakness and reflex loss as described below. Herniated discs have different presentations depending on the location as follows:

  • At L4: Pain along the front of the leg; weak extension of the leg at the knee; sensory loss about the knee; loss of knee-jerk reflex

  • At L5: Pain along the side of the leg; weak dorsiflexion of the foot; sensory loss in the web of the big toe; no reflexes lost

  • At S1: Pain along the back of the leg; weak plantar flexion of the foot; sensory loss along the back of the calf and the lateral aspect of the foot; loss of ankle jerk

  • L5 and S1: These nerve roots are involved in approximately 95% of all disc herniations.

Spinal stenosis may be present when evidence of degenerative joint disease is present on radiographic studies. Patients with this disease process often complain of progressive pain down the lateral aspect of the leg during ambulation (pseudoclaudication). This pain results from neurologic compression rather than actual arterial insufficiency, which produces true claudication. In cases of spinal stenosis, the straight leg test result is often negative.

The stoop test helps distinguish true claudication from pseudoclaudication. Patients with true claudication sit down to rest when pain occurs, while patients with pseudoclaudication attempt to keep walking by stooping or flexing the spine to relieve the stretch on the sciatic nerve.

Sacroiliitis usually presents with pain over the involved joints and no peripheral neurologic findings.

Osteomyelitis may be subacute or acute. Clinical findings are nonspecific, and the patient may be afebrile on presentation. Classic presentation includes pain on palpation of the vertebral body, elevated sedimentation rate, and complaints of pain out of proportion to physical findings. Patients particularly at risk for development of osteomyelitis include patients who have undergone recent back surgery, intravenous (IV) drug users, patients with immunosuppression, and those with a history of chronic pelvic inflammatory disease (PID).

Causes

Certain clinical clues can help differentiate between causes. Generally, impingement syndromes produce positive straight leg raising tests, whereas pure irritation does not. To assess for a functional disorder as the cause of low back pain, consider the following:

Mechanical low back pain is a common complaint in patients with functional disorders. In addition, a functional overlay or component of secondary gain may be present in some patients with true organic pathology.[22] The degree of psychosocial issues affecting the patient's condition may be assessed by the following:

  • Patient may receive compensation for injury.

  • Patient has pending litigation.

  • Patient dislikes job.

  • Patient has symptoms of depression.

  • Patient caused the accident resulting in back pain.

  • Physical clues that help identify patients with significant functional overlay or component of secondary gain include the following: findings of nonanatomic motor or sensory loss, nonspecific tenderness or generalized tenderness over the entire back, and overly dramatic behavior and loss of positive straight leg raising test when patient is distracted

  • A particularly useful test is to have patients hold their wrists next to their hips and turn their body from side to side. This test gives the illusion that you are testing spinal rotation, but no actual stress is placed on any muscles or ligaments. Any complaint of pain during this maneuver is strongly suggestive of a functional overlay or component of secondary gain in the presentation.

 

DDx

 

Workup

Laboratory Studies

Consider performing a urinalysis if the problem is not clearly musculoskeletal or an exacerbation of chronic back pain.

Perform a complete blood count (CBC) and erythrocyte sedimentation rate (ESR) if the patient is febrile or if an epidural or spinal abscess, or osteomyelitis is suspected. While ESR has moderate specificity, the sensitivity is relatively high in cases of abscess, and it can be used as a screening test.

Preform cogulation studies is patient is on an anticoagulant

Other laboratory studies are rarely needed unless a disorder other than back pain is strongly suspected.

Imaging Studies

The American College of Radiology (ACR) has come up with appropriateness criteria for low back pain, including the following[5] :

  • Uncomplicated acute low back pain and/or radiculopathy are benign, self-limited conditions that do not warrant any imaging studies.
  • MRI of the lumbar spine should be considered for those patients presenting with red flags raising suspicion for a serious underlying condition, such as cauda equine syndrome, malignancy, or infection.
  • In patients with a history of low-velocity trauma, osteoporosis, or chronic steroid use, initial evaluation with radiographs is recommended.
  • In the absence of red flags, first-line treatment for chronic low back pain remains conservative therapy with both pharmacologic and nonpharmacologic (eg, exercise, remaining active) therapy.
  • If there are persistent or progressive symptoms during or following 6 weeks of conservative management and the patient is a surgery or intervention candidate or diagnostic uncertainty remains, MRI of the lumbar spine has become the initial imaging modality of choice in evaluating complicated low back pain.
  • MRI is the imaging procedure of choice in patients suspected of cord compression or spinal cord injury.
  • Patients with recurrent low back pain and history of prior surgical intervention should be evaluated with contrast-enhanced MRI.

Lumbosacral spine series are expensive and expose the reproductive organs to significant radiation. Annually, 7-8 million such tests are obtained, but most have little value in directing therapy, particularly among adults younger than 50 years. Osteophytes are the most frequently seen abnormality of plain films followed by intervertebral disc space narrowing. Both increase with age. Disc space narrowing appears to be more frequent in women. Disc space narrowing at 2 or more levels is strongly associated with back pain pathology.[23]

Unless a history of traumatic injury or systemic illness is present, such films should be obtained only for suspicion of malignancy or infection. Malignant involvement of vertebral bodies can be evident on plain film when as little as 30% of the vertebral body has been replaced. Other indications that suggest the need for radiographic imaging include chronic steroid use and acute onset of pain in patients older than 50 years or in the pediatric age group. The physician may also consider obtaining radiographs in patients whose cases involve (or potentially involve) litigation or for patients seeking compensation.

CT and MRI are generally considered the studies of choice for more precise imaging of the vertebrae, paraspinal soft tissues, discs, or spinal cord. CT images cortical bone with higher resolution and can delineate some fractures better than MRI.[24]  MRI is generally the preferred imaging modality for detecting disc, cord, or soft tissue abnormalities. See the image below.

Magnetic resonance image of the lumbar spine. This Magnetic resonance image of the lumbar spine. This image demonstrates a herniated nucleus pulposus at multiple levels.

Ultrasonography may be useful if the differential diagnosis includes appendicitis, a pathologic pelvic process, or abdominal aneurysm.

True emergencies that necessitate imaging include the following:

  • Patients with a history of malignancy and new evidence of nerve entrapment

  • Patients with back pain associated with paralysis or gross muscle weakness

  • Patients with bilateral neurologic deficits associated with bowel or bladder function loss

  • Patients on anticoagulants with sudden onset of back pain

  • Patients in whom an epidural hematoma or epidural abscess is suspected

  • Postoperative patients with a recent lumbar laminectomy or hip replacement

Improvement occurs in almost all patients within 4-6 weeks, except those with infection, occult malignancy, or systemic illness. If pain fails to significantly improve or resolve in this time frame, imaging is always indicated.[25]

Other Tests

Perform the straight leg raising test with the patient in a supine position. Record the response to raising each leg. An approximation of the test may be performed with the patient sitting and each leg straightened at the knee. The examiner should take care to make sure that the quadriceps muscle is relaxed while passively raising the leg to ensure that the sciatic nerve is being adequately stretched during the testing. If the quadriceps is contracted, it will take the pressure off the sciatic nerve and may give a false-negative result.

The stoop test helps distinguish true claudication from pseudoclaudication. Patients with true claudication sit down to rest when pain occurs, while patients with pseudoclaudication attempt to keep walking by stooping or flexing the spine to relieve the stretch on the sciatic nerve.

 

Treatment

Prehospital Care

If the patient's back pain is from a traumatic injury, full spinal precautions using a long backboard for spinal immobilization should be used for extrication if needed and left in place during transport, unless there is extended transport times where risk of skin breakdown exists, particularly in older patients. If transport is going to be prolonged, it is reasonable to log roll the patient onto a soft stretcher if enough personnel are available to do so while maintaining spinal precautions.

If no history of trauma is present, spinal precautions is not necessary, as the patient may experience significant exacerbation of pain by lying on a rigid board. If the patient is brought into the emergency department on a rigid board, they should be removed from the board at the first opportunity.

If a rigid board is necessary, the patient may be made more comfortable by supporting the lower extremities with a pillow or blanket.

Emergency Department Care

If new neurologic deficits are noted accompanied by bowel or bladder dysfunction one should suspect cauda equina syndrome. This is a true emergency, and emergency imaging is mandated. MRI is the preferred imaging modality in this situation.[26] If cauda equina syndrome is strongly suspected, the practitioner should consider giving dexamethasone without delay to prevent further loss of neurologic function while pursuing confirmatory testing.

Conservative therapy is the mainstay of treatment, as even those with true sciatica generally respond.[27] Ultimately, only 2% of patients with sciatica and 4-6% of patients with true disc herniation require surgery. Conservative therapy traditionally includes the following:

Bed rest, once the cornerstone of treatment, is no longer widely recommended. A growing body of evidence suggests that even brief bed rest is not necessary except in patients with true sciatica. In this case, the supine position decreases pressure on the spinal cord itself and is useful for the first 2-3 days. Early mobilization with gentle range of motion and strengthening exercises are recommended for patients with nonsciatic back pain.[28]  Early return to work on light duty or restricted activity leads to better long-term outcomes.

Pharmacologic therapy primarily involves both anti-inflammatory medication and muscle relaxants. Opioid medications may be used initially to gain relief in acute illness or injury, but should be used sparingly.

Athough opioids may provide modest short-term pain relief, their long-term use is associated with increased functional impairment. Literature review of randomized, controlled trials using the GRADE methodology showed that evidence of long-term efficacy is lacking and that any short-term effect is likely not to be clinically important within recommended dosing.[29]

Steroids, while highly recommended by some practitioners, lack prospective confirmation of their value. Some physicians may prescribe a single burst or short course of oral steroids, which can be beneficial, particularly in those with a significant degree of inflammation. Epidural steroid injection may also bring significant short-term relief, but this treatment is not without adverse effects and has not been shown to provide lasting benefit.[30]  Unless the patient is allergic to the medicine or it is otherwise contraindicated, severe low back pain can be improved significantly with a combination of nonsteroidal anti-inflammatory drugs (NSAIDs) and muscle relaxants. Opioid narcotics should be used sparingly and only in the acute phase for the first several days. Comparative studies between opioids and nonsteroidal anti-inflammatory drugs have not shown any differences in pain or function after the first few days of therapy. Long-term management with opioids is not indicated.[31]

Use of hot or cold compresses has never been proven scientifically to speed symptom resolution, but some patients may experience brief relief. Gentle flexion/extension exercises are helpful.[32, 33]  Spinal traction is ineffective.

Evidence-based clinical practice guidelines from the American Pain Society (APS) for patients with chronic low back pain describe the use of interventional diagnostic tests and therapies, surgeries, and interdisciplinary rehabilitation.[34]  

Practice guidelines for nonradicular pain include the following:

  • Interdisciplinary rehabilitation emphasizing cognitive-behavioral approaches should be considered for patients who do not respond to usual interventions.

  • Provocative discography (injecting material into a disc nucleus in an attempt to reproduce the patient's typical pain) is not recommended.

  • Facet joint corticosteroid injection, prolotherapy (repeated injections of irritant material to stimulate an inflammatory response), and intradiscal corticosteroid injection are not recommended.

  • Persistent disabling symptoms and degenerative spinal changes should prompt discussion and shared decision-making regarding surgery or interdisciplinary rehabilitation (evidence is insufficient to weigh the risks and benefits of vertebral disc replacement in these patients).

Practice guidelines for persistent radiculopathy include the following:

  • For patients with herniated discs, the use of epidural steroid injection should be discussed.

  • For patients with herniated discs and disabling leg pain from spinal stenosis, surgical options should be discussed.

  • For patients with persistent pain after surgery, the risks and benefits of spinal cord stimulation should be discussed.

Consultations

ED consultation with a specialist is necessary for patients who present with acute cauda equina syndrome, demonstrate intractable pain, or have evidence of a serious etiology (eg, epidural abscess, hematoma, or tumor), or where a social situation makes hospitalization necessary.

Whether orthopedic or neurosurgical consultation is chosen depends on local custom and resources.

Other medical consultation may be needed if the cause of back pain is not mechanical.

Medical Care

Outpatient follow-up is generally managed by the patient's private physician. Patients with true sciatica or nerve root findings may also require consultation with an orthopedic surgeon or a neurosurgeon.

Spinal manipulation is not recommended. Rubinstein et al, in an evidence based review of published literature, did not support any significant benefits from spinal manipulation.[35]

Short-term physical therapy with gentle exercises may be of some benefit.

  • Short-term physical therapy has not been proven significantly more effective than self-care with instructions by the physician. However, patients appear to prefer therapy to self-care when surveyed.

  • Sertpoyraz et al compared isokinetic and standard exercise programs for chronic low back pain. Pain, mobility, disability, psychological status, and muscle strength was measured. Forty patients were randomly assigned to a program that took place in an outpatient rehabilitation clinic. Results showed an equal effect in the treatment of low back pain, with no statistically significant difference found between the two programs.[33]

  • Cost-benefit ratio should be considered prior to physical therapy referral from the ED.

Studies of back pain patients in England suggest that a stratified management approach including prognostic screening, and a treatment approach targeting primary care efficiency and physiotherapy, leads to greater health gains for patients with back pain. Significant improvements were noted in the stratified management group at both 4- and 12-month follow-up with respect to physical and emotional wellbeing, pain intensity, work days missed, and quality of life.[36]

Inpatient care for low back pain is typically not required. Patients with cauda equina syndrome, epidural abscess, spinal tumor, systemic illnesses, or those with poor social support should be admitted for further evaluation and management.

Time-sensitive transfer to other facilities may be necessary in patients with suspected or known cauda equina syndrome or epidural hematoma or abscess, or if emergent MRI or a needed consultant is not available at the treating hospital. All suspected cauda equina patients should receive dexamethasone before transfer. Suspected or known epidural abscess patients should receive empiric antibiotics against staphlococcus, streptococcus, and gram-negative bacilli; and in suspected or known epidural hematomas in patients on anticoagulants, the anticoagulant agent should be reversed if possible before transport to avoid delays in treatment.

Patients with compressive tumors or abscesses should be transferred to a center that has a spine surgeon who can provide decompression in a timely manner if unavailable at the treating hospital.

Prevention

Back muscle strengthening exercises have value in preventing future episodes of low back strain.[37]

Weight loss in overweight patients results in less strain on back muscles.

Practicing proper lifting techniques results in less back strain.

General overall improvement of physical conditioning can decrease low back pain exacerbations.[38]

 

Guidelines

Guidelines Summary

A summary of recommendations from the American College of Radiology (ACR) include the following[5] :

  • Uncomplicated acute low back pain and/or radiculopathy are benign, self-limited conditions that do not warrant any imaging studies.

  • MRI of the lumbar spine should be considered for those patients presenting with red flags raising suspicion for a serious underlying condition, such as cauda equina syndrome, malignancy, or infection.

  • In patients with a history of low-velocity trauma, osteoporosis, or chronic steroid use, initial evaluation with radiographs is recommended.

  • In the absence of red flags, first-line treatment for chronic low back pain remains conservative therapy with both pharmacologic and nonpharmacologic (eg, exercise, remaining active) therapy.

  • If there are persistent or progressive symptoms during or following 6 weeks of conservative management and the patient is a surgery or intervention candidate or diagnostic uncertainty remains, MRI of the lumbar spine has become the initial imaging modality of choice in evaluating complicated low back pain.

  • MRI is the imaging procedure of choice in patients suspected of cord compression or spinal cord injury.

  • Patients with recurrent low back pain and history of prior surgical intervention should be evaluated with contrast-enhanced MRI.

Practice guidelines for nonradicular pain include the following[34] :

  • Interdisciplinary rehabilitation emphasizing cognitive-behavioral approaches should be considered for patients who do not respond to usual interventions.

  • Provocative discography (injecting material into a disc nucleus in an attempt to reproduce the patient's typical pain) is not recommended.

  • Facet joint corticosteroid injection, prolotherapy (repeated injections of irritant material to stimulate an inflammatory response), and intradiscal corticosteroid injection are not recommended.

  • Persistent disabling symptoms and degenerative spinal changes should prompt discussion and shared decision-making regarding surgery or interdisciplinary rehabilitation (evidence is insufficient to weigh the risks and benefits of vertebral disc replacement in these patients).

Practice guidelines for persistent radiculopathy include the following[34] :

  • For patients with herniated discs, the use of epidural steroid injection should be discussed.

  • For patients with herniated discs and disabling leg pain from spinal stenosis, surgical options should be discussed.

  • For patients with persistent pain after surgery, the risks and benefits of spinal cord stimulation should be discussed.

 

Medication

Medication Summary

The goal of pharmacotherapy is to reduce pain and inflammation.

Nonsteroidal anti-inflammatory agents (NSAIDs)

Class Summary

NSAIDs are most commonly used to relieve mild to moderate pain. Although the effectiveness of NSAIDs tends to be patient specific, ibuprofen is usually the DOC for initial therapy. Other options include flurbiprofen, ketoprofen, and naproxen.

Ibuprofen (Ibuprin, Advil, Motrin)

DOC to treat mild to moderate pain if no contraindications exist.

Inhibits inflammatory reactions and pain by decreasing prostaglandin synthesis.

Naproxen (Anaprox, Naprelan, and Naprosyn)

For relief of mild to moderate pain; inhibits inflammatory reactions and pain by decreasing activity of cyclooxygenase, which results in a decrease of prostaglandin synthesis.

Muscle relaxants

Class Summary

These agents reduce tonic somatic motor activity of the muscle.

Carisoprodol (Soma)

Short-acting medication that may have depressant effects at spinal cord level.

Skeletal muscle relaxants have modest short-term benefit as adjunctive therapy for nociceptive pain associated with muscle strains and, used intermittently, for diffuse and certain regional chronic pain syndromes. Long-term improvement over placebo has not been established.

Cyclobenzaprine (Flexeril)

Skeletal muscle relaxant that acts centrally and reduces motor activity of tonic somatic origins influencing both alpha and gamma motor neurons.

Structurally related to tricyclic antidepressants and thus carries some of the same liabilities.

Analgesics

Class Summary

Pain control is essential to ensure patient comfort, to promote pulmonary toilet, and to aid physical therapy regimens. Many analgesics have sedating properties that benefit patients who have sustained injuries.

Acetaminophen (Tylenol, Panadol, Aspirin Free Anacin)

DOC for pain in patients with documented hypersensitivity to aspirin or NSAIDs, in those with upper GI disease, or in those who are taking oral anticoagulants.

Hydrocodone bitartrate and acetaminophen (Vicodin ES)

A drug combination indicated for the relief of moderate to severe pain.

Tramadol (Ryzolt, Ultram, Ultram ER)

Tramadol binds to receptors in the brain (opioid receptors) that are important for transmitting the sensation of pain from throughout the body.

Duloxetine (Cymbalta)

Potent inhibitor of neuronal serotonin and norepinephrine reuptake. Indicated for chronic musculoskeletal pain, including discomfort from osteoarthritis and chronic lower back pain.[27]