An Evidence-Based Approach To The Evaluation And Treatment Of Low Back Pain In The Emergency Department

Table of Contents

 

1. Abstract
2. Case Presentation
3. Introduction
4. Critical Appraisal Of The Literature
5. Epidemiology
6. Pathophysiology
   1. Definitions
7. Differential Diagnosis
   1. Epidural Abscess
   2. Abdominal Aortic Aneurysm
   3. Cauda Equina Syndrome
   4. Spinal Epidural Hematoma
8. Prehospital Care
9. Emergency Department Evaluation
10. Diagnostic Studies
    1. Imaging
    2. Emergency Department Ultrasound
    3. Laboratory Testing
11. Treatment
    1. Measuring Effectiveness Of Treatment
    2. Pharmacologic Treatment
       1. Acetaminophen
       2. Nonsteroidal Anti-Inflammatory Drugs
       3. Muscle Relaxants
       4. Topical Medications
       5. Neuropathic Pain Medications
       6. Antidepressants
       7. Opioid Analgesics
       8. Systemic Steroids
    3. Nonpharmacologic Treatment For Acute And Chronic Lower Back Pain
       1. Bed Rest
       2. Education And Back Schools
       3. Behavioral Therapy
       4. Exercise Therapy And Yoga
       5. Massage
       6. Heat
       7. Transcutaneous Electrical Nerve Stimulation
       8. Acupuncture
       9. Spinal Manipulation
    4. Surgical Treatment Of Back Pain
       1. Fusion
       2. Surgery For Radiculopathy
       3. Decompressive Surgery For Spinal Stenosis
12. Special Circumstances
    1. The Pediatric Patient
13. Controversies And Cutting Edge
14. Disposition
15. Summary
16. Risk Management Pitfalls For Low Back Pain
17. Time- And Cost-Effective Strategies
18. Case Conclusion
19. Clinical Pathway For Management Of Low Back Pain In The Emergency Department
20. Tables and Figures
    1. Table 1. Relevant Practice Guidelines For Low Back Pain
    2. Table 2. Differential Diagnosis For Lower Back Pain
    3. Table 3. Red Flag History And Physical Examination Findings
    4. Table 4. Affected Nerve Roots And Their Corresponding Neurologic Examination Findings
    5. Table 5. The Waddell Signs And Score
    6. Table 6. Low Back Pain Interventions%2C Summary Of Evidence Level And Grade
    7. Figure 1. General Anatomy Of The Lumbar Spine
    8. Figure 2. Summary Of Neurologic Examination At L4-S1 Levels
    9. Figure 3. Osteomyelitis And Abscess
    10. Figure 4. Posterior Disc Herniation
    11. FIgure 5. Sample of Discharge Instructions
21. References

Abstract

Low back pain is the most common musculoskeletal complaint that results in a visit to the emergency department, and it is 1 of the top 5 most common complaints in emergency medicine. Estimates of annual healthcare expenditures for low back pain in the United States exceed $90 billion annually, not even taking lost productivity and business costs into account. This review explores an evidence-based rationale for the evaluation of the patient with low back pain, and it provides guidance on risk stratification pertaining to laboratory assessment and radiologic imaging in the emergency department. Published guidelines from the American College of Physicians and American Pain Society are reviewed, with emphasis on best evidence for pharmacologic treatments, self-care interventions, and more invasive procedures and surgery in management of low back pain. Utilizing effective and proven strategies will avoid medical errors, provide better care for pa- tients, and help manage healthcare resources and costs.

Key Words: low back pain, herniated disc, sciatica, cauda equina syndrome, radiculopathy, NSAID, acetaminophen, muscle relaxant, opioid, fusion, discectomy, laminectomy, epidural steroid injection

Case Presentation

A 45-year-old man presents after 7 days of pain in his lower back. He reports that it began the day after he started at a new job site. The pain initially improved with ibupro- fen, but he woke up this morning with a severe exacerba- tion of the pain. He denies a fall or other trauma, and he states that the pain radiates from his left buttock to his left foot. He has had intermittent back pains in the past, but he never required any imaging or interventions. Employed in the construction industry, he has a history of hypertension and is going through a divorce. He is afebrile, has a benign abdominal exam, and displays an antalgic gait. He has intact patella and Achilles reflexes, and he has a positive left straight-leg raise sign and crossed straight-leg raise sign. Strength and sensation, including the perineum, are intact and symmetrical. The patient insists that he needs an MRI and requests a note for 2 weeks off from work...

As you are considering your first patient’s requests, a 27-year-old woman is placed in the next room, also com- plaining of lower back pain. You review her past visits and see that she has been to the ED several times in the past 6 months for various complaints, including headache, tooth- ache, and pain after an assault. She has had pain in her up- per lumbar area for 1 week, and it is exacerbated with any change in body position. She has no pain in her legs and no weakness or numbness, although she says that it feels as if her back is swollen. She insists she has never had back problems in the past, and there has been no trauma. She has a normal heart and lung exam and no abdominal tender- ness. There is no costovertebral angle tenderness, and she seems tender around the L1 area. You write a prescription for NSAIDs and go off to see your next patient. When you return to finish your evaluation, you note that the patient had a fever of 38.9°C. She has already left the ED, and the phone number she left is disconnected; however, before the end of your shift, she is returned to the ED by EMS, with a fever of 39.4°C. You have a sinking feeling that maybe you were too quick to judge this patient’s complaint...

Introduction

Low back pain is the most common musculoskel- etal complaint that is evaluated in the emergency department (ED), and it affects most adults at some point in their lives.¹ The Edwin Smith papyrus, a collection of Egyptian documents from 1600 BC, and one of the oldest medical texts, describes 48 patient cases. It includes a patient with a pulled vertebra and recommends “...you have to put him stretched out... ” Unfortunately, this was patient case number 48, the last scroll, and the rest of the scroll is missing; hence the medical field has been without clear guid- ance for this condition for over 3500 years.² In the intervening time, we have developed extraordinary tools to noninvasively visualize spinal anatomy,and we have elucidated a molecular mechanism of neurotransmission, yet we are still challenged by the many elements that constitute how humans feel and interpret pain. Interspersed between the patients with musculoskeletal back pain are patients with back pain who are at risk for permanent neurologic or even life-threatening sequela because they are harboring lesions that require timely diagnosis and treatment. By utilizing a focused approach, the ED clinician will be able to identify these “red flag” symptoms in patients and initiate a workup. This is- sue of Emergency Medicine Practice reviews the prog- ress to date on developing a standardized, focused approach and guides the clinician to rationally and cost-effectively evaluate the patient presenting with low back pain symptoms.

Critical Appraisal Of The Literature

The study of low back pain is plagued by the fact that it is not a single pathologic entity. In addition, pain is a subjective complaint that can be measured only indirectly, and these measurements are influenced by cognitive and behavioral factors as well as secondary gains. There are many back pain treatments available, and the randomized controlled trials available do not necessarily compare 1 treatment with placebo; instead, 1 treatment is compared with a multitude of other interventions, adding difficulty to making pooled data samples that are typical of systematic reviews and meta-analyses. There are long-term studies available, however, and the natural history of low back pain is very well described, so, for the most part, prognostic conclusions are well supported.

A literature search was performed utilizing PubMed, as well as Ovid MEDLINE® and the Co- chrane Database of Systematic Reviews from 1990 to the present. Search terms included low back pain and back pain, and these terms were joined with imaging medication classes (NSAID, acetaminophen, muscle relaxant, opioid), as well as specific therapies (fusion, diskectomy/discectomy, laminectomy, epidural steroid, injection, acupuncture, spinal manipulation), and were limited to English literature and human studies. Papers with prospective randomized methodologies were initially reviewed, and references most frequently mentioned in the discussion sections of these papers were reviewed as well. These searches produced guidelines by the American College of Physicians in association with the American Pain Society³ as well as recommendations from the National Health Service in the United Kingdom,⁴ an imaging guideline from the American College of Radiology,⁵ and opioid prescription guidelines from the Ameri- can College of Emergency Physicians.⁶ (See Table 1.)

Risk Management Pitfalls For Low Back Pain

1. “I didn’t realize that he had a prior history of melanoma that was resected 2 years ago.” Red flag signs, symptoms, and history are essential in the management of these patients. While some of these syndromes (eg, cauda equina syndrome, epidural abscess) are uncommon in the general population, they become a real possibility in the patient with metastatic cancer or in the patient who injects drugs.
2. “My 70-year-old male patient with back pain had syncope in the waiting room and was rushed to the trauma bay. I thought the systolic pressure of 70 mm Hg was just an error, as the repeat was 120 mm Hg.” More thought needs to be given to older patients with back pain, as their symptoms may be arising not from typical muscular/discogenic/degenerative joint disease sources; they may be harboring a leaking abdominal aortic aneurysm or metastatic cancer. Consider systemic symptoms such as weight loss, fever, abdominal pain, and syncope as well as risk for peripheral vascular disease.
3. “I remember seeing this patient 4 times this past year for toothache and headache. Now he has back pain! He does have a fever this time though, very clever!” Even patients who are drug-seeking have real back pain. Some patients who inject drugs have infections that are the cause of this pain. There is no single laboratory test or examination finding that will rule out vertebral osteomyelitis or discitis.
4. “The patient in bay 3 status post motor vehicle collision looks familiar. Oh yes, I just saw him for low back pain.” The medications prescribed for back pain can cause sedation; especially muscle relaxants in combination with opioids. Be sure to remind patients that they should not drive or perform dangerous tasks while using them.
5. “While I was waiting for the patient to be discharged, he had a tonic-clonic seizure.” Know the side effects of the medications that you prescribe. Tramadol can decrease the seizure threshold and should not be used in patients who are at risk for seizure. Risk Management Pitfalls For Low Back Pain
6. “The patient told me he has had back pain and urinated on himself. I was very concerned and transferred him for emergency MRI. The MRI was normal, and I don’t understand why.” Overflow incontinence and urinary retention are worrisome findings and do require emergent evaluation. However, sometimes patients just cannot make it to the bathroom because of back pain and physical limitations. Determining the cause of incontinence and assessing for postvoid residuals will improve imaging utilization.
7. “The patient was just seen by the pain management specialist and had an epidural steroid injection yesterday. He is here again with back pain, and he cannot walk. He seems weak in his legs, but that’s just pain.” Patients who are status postprocedure are at increased risk for developing complications that include epidural hematoma and spinal infection. These patients need imaging if they have new neurologic findings.
8. “This patient has new paraspinal back pain and atrial fibrillation and is on warfarin. He has a hematocrit of 25, down 10 points, and is guaiac negative. His international normalized ratio is 4.8. His neurologic examination is unrevealing. I am going to send him home.” Be more vigilant in patients with other medical problems who are on medications that cause bleeding. This patient could return to the ED after a syncopal episode and have a retroperitoneal hemorrhage.
9. “I just saw a 36-weeks’ pregnant female with paraspinal/flank pain and mild nausea. I evaluated her baby with bedside ultrasound, and things seemed normal. I planned to discharge her, but then I found she had a fever of 38.3°C.” While back pain and sciatica are common in pregnancy, you should consider other causes in your differential. This patient could also have a urinary tract infection.
10. “I should have thought of other causes of urinary retention in this 67-year-old male patient before placing the catheter and sending him home for urology follow-up.” Advanced age is a red flag sign; instead of benign prostatic hyperplasia with back pain, he could have had prostate cancer with spinal metastasis and cauda equina syndrome.

Tables and Figures

References

Evidence-based medicine requires a critical appraisal of the literature based upon study methodology and number of subjects. Not all references are equally robust. The findings of a large, prospective, randomized, and blinded trial should carry more weight than a case report.

To help the reader judge the strength of each reference, pertinent information about the study will be included in bold type following the reference, where available. In addition, the most informative references cited in this paper, as determined by the authors, are noted by an asterisk (*) next to the number of the reference.

1. Andersson GB. Epidemiological features of chronic low-back pain. Lancet. 1999;354(9178):581-585. (Review)
2. Unknown. The Edwin Smith Surgical Papyrus. 1600 BC.
3. * Chou R, Qaseem A, Snow V, et al. Diagnosis and treatment of low back pain: a joint clinical practice guideline from the American College of Physicians and the American Pain Society. Ann Intern Med. 2007;147(7):478-491. (Clinical practice guideline)
4. NICE. National Institute for Health and Clinical Excellence - low back pain (CG88). 2009. (Clinical practice guideline)
5. Perez FA, Jarvik JG. Evidence-based imaging and effective utilization: lessons in neuroradiology. Neuroimaging Clin N Am. 2012;22(3):467-476. (Review)
6. Cantrill SV, Brown MD, Carlisle RJ, et al. Clinical policy: critical issues in the prescribing of opioids for adult patients in the emergency department. Ann Emerg Med. 2012;60(4):499- 525. (Clinical policy)
7. Deyo RA MS, Martin BI. Back pain prevalence and visit rates estimates from U.S. national surveys, 2002. Spine (Phila Pa 1976). 2006;31(23):2724-2727. (Survey review)
8. Hart LG, Deyo RA, Cherkin DC. Physician office visits for low back pain. Spine (Phila Pa 1976). 1995;20:11. (Review of data from National Ambulatory Medical Care Survey, 1980- 1990)
9. Cunningham LS, Kelsey KJ. Epidemiology of musculoskeletal imparments and associated disability. Am J Public Health. 1984;74(6):574-579. (Review)
10. Luo X PR, Sun SX, Liu GG, et al. Estimates and patterns of direct care expenditures among individuals with back pain in the United States. Spine (Phila Pa 1976). 2004;29:79-86.
11. Frymoyer JW, Cats-Baril WL. An overview of the incidences and costs of low back pain. Orthop Clin North Am. 1991;22(2):263-271.
12. van Tulder MW, Assendelft WJ, Koes BW, et al. Spinal radiographic findings and nonspecific low back pain. A systematic review of observational studies. Spine (Phila Pa 1976). 1997;22(4):427-434. (Systematic review)
13. Vroomen PC, deKrom MC, Knottnerus JA. Diagnostic value of history and physical examination in patients suspected of sciatica due to disc herniation: a systematic review. J Neurol 1999;246:899-906. (Systematic review)
14. Pincus T, Burton AK, Vogel S, et al. A systematic review of psychological factors as predictors of chronicity/disability in prospective cohorts of low back pain. Spine (Phila Pa 1976). 2002;27(5):E109-120. (Systematic review)
15. Polatin PB, Cox B, Gatchel RJ, et al. A prospective study of Waddell signs in patients with chronic low back pain. When they may not be predictive. Spine (Phila Pa 1976). 1997;22(14):1618-1621. (Prospective observational study; 50 patients)
16. Blom A, Taylor A, Whitehouse S, et al. A new sign of inappropriate lower back pain. Ann R Coll Surg Engl. 2002;84(5):342-343. (Observational study; 94 patients)
17. Apeldoorn AT, Bosselaar H, Blom-Luberti T, et al. The reliability of nonorganic sign-testing and the Waddell score in patients with chronic low back pain. Spine (Phila Pa 1976). 2008;33(7):821-826. (Observational cohort study)
18. Deyo RA. Cascade effects of medical technology. Annu Rev Public Health. 2002;23:23-44.
19. Verrilli D, Welch HG. The impact of diagnostic testing on therapeutic interventions. JAMA. 1996;275(15):1189-1191. (Analysis of Medicare data, 1987-1993; approximately 30 million elderly patients in each year)
20. Pengel LH, Herbert RD, Maher CG, et al. Acute low back pain: systematic review of its prognosis. BMJ. 2003;327(7410):323. (Systematic review)
21. Chou R, Fu R, Carrino JA, et al. Imaging strategies for low-back pain: systematic review and meta-analysis. Lancet. 2009;373(9662):463-472. (Meta-analysis)
22. Boden SD, Davis DO, Dina TS, et al. Abnormal magneticresonance scans of the lumbar spine in asymptomatic subjects. A prospective investigation. J Bone Joint Surg Am. 1990;72(3):403-408. (Prospective observational cohort)
23. * el Barzouhi A, Vleggeert-Lankamp CLAM, Lycklama à Nijeholt GJ, et al. Magnetic Resonance Imaging in Follow-up Assessment of Sciatica. New Engl J Med. 2013;368(11):999- 1007. (Randomized controlled trial; 283 patients)
24. * Nachemson A. The lumbar spine: an orthopedic chalenge. Spine (Phila Pa 1976). 1976;1:59-71. (Review)
25. Chou R, Qaseem A, Owens DK, et al. Diagnostic imaging for low back pain: advice for high-value health care from the American College of Physicians. Ann Intern Med. 2011;154(3):181-189. (Practice guideline)
26. Loblaw DA, Perry J, Chambers A, et al. Systematic review of the diagnosis and management of malignant extradural spinal cord compression: the Cancer Care Ontario Practice Guidelines Initiative’s Neuro-Oncology Disease Site Group. J Clin Oncol. 2005;23(9):2028-2037. (Systematic review)
27. Todd NV. Cauda equina syndrome: the timing of surgery probably does influence outcome. Br J Neurosurg. 2005;19(4):301-306. (Meta-analysis)
28. Tayal VS, Graf CD, Gibbs MA. Prospective study of accuracy and outcome of emergency ultrasound for abdominal aortic aneurysm over two years. Acad Emerg Med. 2003;10(867-71). (Prospective observational study; 125 patients)
29. Carey TS, Mielenz TJ. Measuring outcomes in back care. Spine (Phila Pa 1976). 2007;32:S9-S14. (Review)
30. Cohen J. Statistical Power Analysis for the Behavioral Sciences. 2nd ed. Hillsdale, NJ: Lawrence Erlbaum Associates; 1988. (Textbook)
31. Jordan K, Dunn KM, Lewis M, et al. A minimal clinically important difference was derived for the Roland-Morris Disability Questionnaire for low back pain. J Clin Epidemiol. 2006;59(1):45-52. (Survey)
32. Fairbank JC, Pynsent PB. The Oswestry Disability Index. Spine (Phila Pa 1976). 2000;25(22):2940-2952. (Review)
33. * Chou R, Huffman LH, American Pain Society, et al. Medications for acute and chronic low back pain: a review of the evidence for an American Pain Society/American College of Physicians clinical practice guideline. Ann Intern Med. 2007;147(7):505-514. (Systematic review and meta-analysis)
34. van Tulder M, Becker A, Bekkering T, COST B13 Working Group on Guidelines for the Management of Acute Low Back Pain in Primary Care, et al. Chapter 3. European guidelines for the management of acute nonspecific low back pain in primary care. Eur Spine J. 2006;15 Suppl 2:S169-191. (Practice guideline)
35. Milgrom C FA, Lev B, Wiener M, Floman Y. Overexertional lumbar and thoracic back pain among recruits: a prospective study of risk factors and treatment regimens. J Spinal Disord. 1993(6):187-193. (Prospective study; 395 infantry recruits)
36. * Schnitzer TJ, Ferraro A, Hunsche E, et al. A comprehensive review of clinical trials on the efficacy and safety of drugs for the treatment of low back pain. J Pain Symptom Manage. 2004. 28(1):72-95. (Systematic review)
37. van Tulder MW, Scholten RJ, Koes BW, et al. Nonsteroidal anti-inflammatory drugs for low back pain: a systematic review within the framework of the Cochrane Collaboration Back Review Group. Spine (Phila Pa 1976). 2000;25:2501-2513. (Systematic review)
38. Roelofs PD, Deyo RA, Koes BW, et al. Non-steroidal antiinflammatory drugs for low back pain: an updated Cochrane review. Spine (Phila Pa 1976). 2008;33(16):1766-1774. (Systematic review)
39. van Tulder M TT, Furlan A, Solway S, Bouter L. Cochrane Back Review Group. Muscle relaxants for nonspecific low back pain: a systematic review within the framework of the Cochrane Collaboration. Spine (Phila Pa 1976). 2003;28:1978- 1992. (Systematic review)
40. Berry H, Hutchinson DR. A multicentre placebo-controlled study in general practice to evaluate the efficacy and safety of tizanidine in acute low-back pain. J Int Med Res. 1988;16(2):75-82. (Double-blind randomized controlled trial; 112 patients)
41. Fryda-Kaurimsky Z, Muller-Fassbinder H. Tizanidine in the treatment of acute paravertebral spasms: a controlled trial comparine tizanidine with diazepam. J Int Med Res. 1981;9:501-505. (Double-blind randomized controlled trial; 20 patients)
42. Eyssette M, Rohmer F, Serratrice G, et al. Multi-centre, double-blind trial of a novel antispastic agent, tizanidine, in spasticity associated with multiple sclerosis. Curr Med Res Opin. 1988;10(10):699-708. (Double-blind randomized controlled trial; 100 patients)
43. Gimbel J, Linn R, Hale M, et al. Lidocaine patch treatment in patients with low back pain: results of an open-label, nonrandomized pilot study. Am J Ther.12(4):311-319. (Prospective open label trial; 129 patients)
44. Galer BS, Gammaitoni AR, Oleka N, et al. Use of the lidocaine patch 5% in reducing intensity of various pain qualities reported by patients with low-back pain. Curr Med Res Opin. 2004;20 Suppl 2:5S5-S12. (Propective open label trial; 71 patients)
45. Derry S, Moore AR, Rabbie R. Topical NSAIDs for chronic musculoskeletal pain in adults. Cochrane Database Syst Rev. 2012 Sep 12;9:CD007400. (Cochrane systematic review)
46. McCleane GJ. Does gabapentin have an analgesic effect on background movement and referred pain? A randomized double-blind placebo controlled study. The Pain Clinic. 2001;13(2):103-107. (Double-blind randomized controlled trial; 80 patients)
47. Salerno SM, Browning R, Jackson JL. The effect of antidepressant treatment on chronic back pain: a meta-analysis. Arch Intern Med. 2002;162:19-24. (Meta-analysis)
48. Urquhart DM, Hoving JL, Assendelft WW, et al. Antidepressants for non-specific low back pain. Cochrane Database Syst Rev. 2008 Jan 23;(1):CD001703. (Cochrane systematic review)
49. Skljarevski V, Desaiah D, Liu-Seifert H, et al. Efficacy and safety of duloxetine in patients with chronic low back pain. Spine (Phila Pa 1976). 2010;35(13):E578-585. (Double-blind randomized controlled trial; 236 patients)
50. Hale ME, Dvergsten C, Gimbel J. Efficacy and safety of oxymorphone extended release in chronic low back pain: results of a randomized, double-blind, placebo- and activecontrolled phase III study. J Pain. 2005;6(1):21-28. (Doubleblind randomized controlled trial; 213 patients)
51. Wiesel SW, Cuckler JM, Deluca F, et al. Acute low-back pain. An objective analysis of conservative therapy. Spine (Phila Pa 1976). 1980;5(4):324-330. (Review)
52. Deshpande A, Furlan AD, Mailis-Gagnon A, et al. Opioids for chronic low-back pain. Cochrane Database Syst Rev. 2007 Jul 18;(3):CD004959. (Cochrane systematic review)
53. Schnitzer TJ, Gray WL, Paster RZ, et al. Efficacy of tramadol in treatment of chronic low back pain. J Rheumatol. 2000;27(3):772-778. (Placebo-controlled double-blind randomized trial; 380 patients)
54. Porsman O, Friis H. Prolapsed lumbar disc treated with intramuscularly administered dexamethasonephosphate. A prospectively planned double blind controlled clinical trial of 52 patients. Scand J Rheumatol. 1979;8(3):142-144. (Doubleblind randomized controlled trial; 52 patients)
55. Haimovic IC, Beresford HR. Dexamethasone is not superior to placebo for treating lumbosacral radicular pain. Neurology. 1986; 36(12):1593-1594. (Prospective double-blind study; 33 patients)
56. Cherkin DC, Deyo RA, Wheeler K, et al. Physician views about treating low back pain. The results of a national survey. Spine (Phila Pa 1976). 1995;20(1):1-9. (Survey; 2897 physicians)
57. Brox JI, Storheim K, Grotle M, et al. Systematic review of back schools, brief education, and fear-avoidance training for chronic low back pain. Spine J. 2008;8(6):948-958. (Systematic review)
58. van Middelkoop M, Rubenstein SM, Kuijpers T, et al. A systematic review on the effectiveness of physical and rehabilitation interventions for chronic nonspecific low back pain. Eur Spine J. 2011;20(1):19-39. (Systematic review)
59. Hagen KB, Hilde G, Jamtvedt G, et al. The Cochrane review of bed rest for acute low back pain and sciatica. Spine (Phila Pa 1976). 2000;25(22):2932–2939. (Systematic review)
60. Malmivaara A, Hakkinen U, Aro T, et al. The treatment of acute low back pain—bed rest, exercises, or ordinary activity? New Engl J Med. 1995;332(6):351-355. (Randomized controlled trial; 186 patients)
61. Dahm KT, Brurberg KG, Jamtvedt G, et al. Advice to rest in bed versus advice to stay active for acute low-back pain and sciatica. Cochrane Database Syst Rev. 2010 Jun 16;(6):CD007612. (Cochrane systematic review)
62. Engers AJ, Jellema P, Wensing M, et al. Individual patient education for low back pain. Cochrane Database Syst Rev. 2008 Jan 23;(1):CD004057. (Cochrane systematic review)
63. Heymans MW, van Tulder MW, Esmail R, et al. Back schools for non-specific low-back pain. Cochrane Database Syst Rev. 2004 Oct 18;(4):CD000261. (Cochrane systematic review)
64. Foster NE, Thomas E, Bishop A, et al. Distinctiveness of psychological obstacles to recovery in low back pain patients in primary care. Pain. 2010;148(3):398-406. (Prospective cohort study; 1591 patients)
65. Ostelo RW, van Tulder MW, Vlaeyen JW, et al. Behavioural treatment for chronic low-back pain. Cochrane Database Syst Rev. 2005 Jan 25;(1):CD002014. (Cochrane systematic review)
66. Hayden JA, van Tulder MW, Malmivaara A, et al. Exercise therapy for treatment of non-specific low back pain. Cochrane Database Syst Rev. 2005 Jul 20;(3):CD000335. (Cochrane systematic review)
67. Choi BK, Verbeek JH, Tam WW, et al. Exercises for prevention of recurrences of low-back pain. Cochrane Database Syst Rev. 2010 Jan 20;(1):CD006555. (Cochrane systematic review)
68. Furlan AD, Imamura M, Dryden T, et al. Massage for low-back pain. Cochrane Database Syst Rev. 2008 Oct 8;(4):CD001929. (Cochrane systematic review)
69. Preyde M. Effectiveness of massage therapy for subacute low-back pain: a randomized controlled trial. CMAJ. 2000;162(13):1815-1820. (Randomized controlled trial; 98 patients)
70. Clarke J, van Tulder M, Blomberg S, et al. Traction for lowback pain with or without sciatica: an updated systematic review within the framework of the Cochrane Collaboration. Spine (Phila Pa 1976). 2006 31(14):1591-1599 (Systematic review)
71. Nadler SF, Steiner DJ, Erasala GN, et al. Continuous low-level heatwrap therapy for treating acute nonspecific low back pain. Arch Phys Med Rehabil. 2003;84(3):329-334. (Prospective randomized parallel single-blind placebo-controlled multicenter clinical trial; 219 patients)
72. French SD, Cameron M, Walker BF, et al. Superficial heat or cold for low back pain. Cochrane Database Syst Rev. 2006 Jan 25;(1):CD004750. (Cochrane systematic review)
73. Deyo RA, Walsh NE, Martin DC, et al. A controlled trial of transcutaneous electrical nerve stimulation (TENS) and exercise for chronic low back pain. N Engl J Med. 1990;322(23):1627-1634. (Randomized controlled trial; 145 patients)
74. Khadilkar A, Odebiyi OD, Brosseau L, et al. Transcutaneous electrical nerve stimulation (TENS) versus placebo for chronic low-back pain. Cochrane Database Syst Rev. 2008 Oct 8;(4):CD003008. (Cochrane systematic review)
75. Furlan AD, van Tulder MW, Cherkin D, et al. Acupuncture and dry-needling for low back pain. Cochrane Database Syst Rev. 2005 Jan 25;(1):CD001351. (Cochrane systematic review)
76. Meng CF, Wang D, Ngeow J, et al. Acupuncture for chronic low back pain in older patients: a randomized, controlled trial. Rheumatology. 2003;42(12):1508-1517. (Randomized controlled trial; 55 patients)
77. Hurwitz EL MH, Harber P, Kominslei GF, Berhin TR, Yu F, et al. A randomized trial of chiropractic and medical care for patients with low back pain. Spine (Phila Pa 1976). 2006;31(6):611-621. (Randomized controlled trial; 681 patients)
78. UK BEAM Trial Team. United Kingdom back pain exercise and manipulation (UK BEAM) randomised trial: cost effectiveness of physical treatments for back pain in primary care. BMJ. 2004;329(7479):1381. (Stochastic cost utility analysis alongside pragmatic randomized trial)
79. Rubinstein SM, van Middelkoop M, Assendelft WJ, et al. Spinal manipulative therapy for chronic low-back pain. Cochrane Database Syst Rev. 2011 Feb 16;(2):CD008112. (Cochrane systematic review)
80. Dagenais S, Yelland MJ, Del Mar C, et al. Prolotherapy injections for chronic low-back pain. Cochrane Database Syst Rev. 2007 Apr 18;(2):CD004059. (Cochrane systematic review)
81. * Chou R, Atlas SJ, Stanos SP, et al. Nonsurgical interventional therapies for low back pain: a review of the evidence for an American Pain Society clinical practice guideline. Spine (Phila Pa 1976). 2009;34(10):1078-1093. (Systematic review)
82. Staal BJ, de Bie R, de Vet CWH, et al. Injection therapy for subacute and chronic low-back pain. Cochrane Database Syst Rev. 2008 July 16(3):CD001824. (Cochrane systematic review)
83. Hirsch C, Ingelmark BE, Miller M. The anatomical basis for low back pain. Studies on the presence of sensory nerve endings in ligamentous, capsular and intervertebral disc structures in the human lumbar spine. Acta Orthop Scand. 1963;33:1-17.
84. Mooney V Robertson J. The facet syndrome. Clin Orthop Relat Res. 1976;115:149-156. (Review)
85. Carette S, Marcoux S, Truchon R, et al. A controlled trial of corticosteroid injections into facet joints for chronic low back pain. N Engl J Med. 1991;325(14):1002-1007. (Placebocontrolled randomized trial; 95 patients)
86. Jackson RP, Jacobs RR, Montesano PX. 1988 Volvo award in clinical sciences. Facet joint injection in low-back pain. A prospective statistical study. Spine (Phila Pa 1976). 1988;13(9):966- 971. (Prospective cohort; 454 patients)
87. Carette S, Leclaire R, Marcoux S, et al. Epidural corticosteroid injections for sciatica due to herniated nucleus pulposus. N Engl J Med. 1997;336(23):1634-1640. (Double-blind randomized controlled trial; 158 patients)
88. Bush K, Hillier S. A controlled study of caudal epidural injections of triamcinolone plus procaine for the management of intractable sciatica. Spine (Phila Pa 1976). 1991;16(5):572-575. (Double-blind placebo-controlled randomized trial; 23 patients)
89. Riew KD, Yin Y, Gilula L, et al. The effect of nerve-root injections on the need for operative treatment of lumbar radicular pain. A prospective, randomized, controlled, double-blind study. J Bone Joint Surg Am. 2000;82-A(11):1589-1593. (Randomized controlled trial; 55 patients)
90. Nelemans PJ, deBie RA, deVet HC, et al. Injection therapy for subacute and chronic benign low back pain. Spine (Phila Pa 1976). 2001;26(5):501-515. (Systematic review)
91. Vroomen PC, de Krom MC, Slofstra PD, et al. Conservative treatment of sciatica: a systematic review. J Spinal Disord. 2000;13(6):463-469. (Meta-analysis)
92. Luijsterburg PA, Verhagen AP, Ostelo RW, et al. Effectiveness of conservative treatments for the lumbosacral radicular syndrome: a systematic review. Eur Spine J. 2007;16(7):881-899. (Meta-analysis)
93. Kumar K, Taylor RS, Jacques L, et al. Spinal cord stimulation versus conventional medical management for neuropathic pain: a multicentre randomised controlled trial in patients with failed back surgery syndrome. Pain. 2007;132(1-2):179- 188. (Randomized controlled trial; 100 patients)
94. Frey ME, Manchikanti L, Benyamin RM, et al. Spinal cord stimulation for patients with failed back surgery syndrome: a systematic review. Pain Physician. 2009;12(2):379-397. (Systematic review)
95. Mailis-Gagnon A, Furlan AD, Sandoval JA, et al. Spinal cord stimulation for chronic pain. Cochrane Database Syst Rev. 2004;(3):CD003783. (Cochrane systematic review)
96. Buchbinder R, Osborne RH, Ebeling PR, et al. A randomized trial of vertebroplasty for painful osteoporotic vertebral fractures. N Engl J Med. 2009;361(6):557-568. (Double-blind randomized controlled trial; 78 patients)
97. Kallmes DF, Comstock BA, Heagerty PJ, et al. A randomized trial of vertebroplasty for osteoporotic spinal fractures. N Engl J Med. 2009;361:569-579. (Randomized intervention versus sham; 131 patients)
98. Weinstein JN, Lurie JD, Olson PR, et al. United States trends and regional variations in lumbar spine surgery: 1992-2003. Spine (Phila Pa 1976). 2006;31(23):2707-2714. (Repeated crosssectional analysis)
99. Gibson JN, Waddell G. Surgical interventions for lumbar disc prolapse: updated Cochrane Review. Spine (Phila Pa 1976). 2007;32(16):1735-1747. (Systematic review)
100. * Chou R, Baisden J, Carragee EJ, et al. Surgery for low back pain: a review of the evidence for an American Pain Society Clinical Practice Guideline. Spine (Phila Pa 1976). 2009;34(10):1094-1109. (Systematic review)
101. Brox JI, Sorensen R, Friis A, et al. Randomized clinical trial of lumbar instrumented fusion and cognitive intervention and exercises in patients with chronic low back pain and disc degeneration. Spine. 28(17):1913-1921. (Single-blind randomized controlled trial; 64 patients)
102. Fritzell P, Hagg O, Wessberg P, et al. 2001 Volvo Award Winner in Clinical Studies: lumbar fusion versus nonsurgical treatment for chronic low back pain: a multicenter randomized controlled trial from the Swedish Lumbar Spine Study Group. Spine. 26(23):2521-2532. (Randomized controlled trial; 294 patients)
103. Peul WC, van Houwelingen HC, van den Hout WB, et al. Surgery versus prolonged conservative treatment for sciatica. N Engl J Med. 2007;356(22):2245-2256. (Randomized controlled trial; 283 patients)
104. * Weinstein JN, Tosteson TD, Lurie JD, et al. Surgical vs nonoperative treatment for lumbar disk herniation: the Spine Patient Outcomes Research Trial (SPORT): a randomized trial. JAMA. 2006;296(20):2441-2450. (Randomized controlled trial; 501 patients)
105. Atlas SJ, Deyo RA, Keller RB, et al. The Maine Lumbar Spine Study, Part II. 1-year outcomes of surgical and nonsurgical management of sciatica. Spine. 1996;21(15):1777-1786. (Prospective cohort study; 507 patients)
106. Atlas SJ, Keller RB, Wu YA, et al. Long-term outcomes of surgical and nonsurgical management of lumbar spinal stenosis: 8 to 10 year results from the Maine lumbar spine study. Spine. 2005;30(8):936-943. (Prospective observation cohort study; 148 patients)
107. Weinstein JN, Tosteson TD, Lurie JD, et al. Surgical versus nonsurgical therapy for lumbar spinal stenosis. New Engl J Med. 2008;358(8):794-810. (Randomized cohort; 289 patients; observational cohort; 365 patients)
108. * Weinstein JN, Lurie JD, Tosteson TD, et al. Surgical compared with nonoperative treatment for lumbar degenerative spondylolisthesis. four-year results in the Spine Patient Outcomes Research Trial (SPORT) randomized and observational cohorts. J Bone Joint Surg Am. 2009;91(6):1295-1304. (Prospective randomized cohort; 304 patients)
109. Feldman DS, Straight JJ, Badra MI, et al. Evaluation of an algorithmic approach to pediatric back pain. J Pediatr Orthop. 2006;26(3):353-357. (Observational cohort study; 87 patients)
110. Kim HJ, Green DW. Spondylolysis in the adolescent athlete. Curr Opin Pediatr. 2011;23(1):68-72. (Review)
111. Williams CM, Latimer J, Maher CG, et al. PACE--the first placebo controlled trial of paracetamol for acute low back pain: design of a randomised controlled trial. BMC Musculoskelet Disord. 2010;11:169. (Placebo-controlled randomized controlled trial; 1650 patients)
112. Hughes SP, Freemont AJ, Hukins DW, et al. The pathogenesis of degeneration of the intervertebral disc and emerging therapies in the management of back pain. J Bone Joint Surg Br. 2012;94(10):1298-1304. (Review)
113. Substance Abuse and Mental Health Services Administration. Results from the 2005 National Survey on Drug Use and Health: national findings. Rockville, MD. US Dept of Health and Human Services. Available at: http://www.samhsa.gov/data/nsduh/2k5nsduh/tabs/TOC.htm. Accessed February 15, 2013. (Government report)