Treatment of Low Back Pain

February 2007, Vol. XXIV, No. 2

There are many treatments for low back pain (LBP). Unfortunately, there is a dearth of controlled studies on these modalities. As a result, patients with LBP are often treated based on physicians' prevailing thoughts as to what is most appropriate rather than on hard science. Two recently published studies on the treatment of LBP associated with lumbar disk herniation demonstrate that what is widely viewed as the optimal treatment is not necessarily the best.

The studies were part of the Spine Patient Outcomes Research Trial (SPORT), a multicenter research project. In the first study, patients were randomized to 2 groups: those who received surgical treatment and those who received nonsurgical therapies that included medical management, patient education, and physical therapy.¹ The second study used the same 2 treatment categories for the groups, but the patients were those who had refused randomization and had chosen which treatment group to enter.²

Herniated disks are a relatively uncommon cause of LBP. Deyo and Weinstein,³ both of whom participated in SPORT, previously reported that only 4% of adult patients who complained of LBP to primary care practitioners suffered from herniated disks. However, whereas the relationship between most other anatomic changes, including bulging but nonherniated disks and LBP, has long been questioned, it has been widely believed that herniated disks are clearly associated with LBP and the development of radicular pain. Furthermore, there has been continuing concern that failure to surgically repair the herniation could result in progressive and more severe problems, including irreversible nerve damage, which makes many physicians hesitant to take a conservative approach when treating these patients.

Diagnostic imaging in the current studies demonstrated that patients had herniated disks; the patients had suffered from both LBP and lower extremity radicular pain and had evidence of nerve root irritation on physical examination. The patients had undergone various conservative treatment modalities for at least 6 weeks but still suffered from persistent pain.

The randomized study
In the randomized study, 501 patients were assigned to either a surgical group, who received discectomies, or a nonsurgical group, who received treatments that included medical management; physical therapy; education; and a variety of other therapies such as injections, acupuncture, and transcutaneous electrical nerve stimulation. Although the surgery was standardized to an open discectomy, there was no standardization of nonsurgical treatments.

The initial intent of the study was for patients to remain in the assigned groups; however, there was a significant amount of crossover between the 2, with 60% of those assigned to the surgical group and 45% of those in the nonsurgical group eventually receiving surgery. The patients were followed up at 3-month, 6-month, 1-year, and 2-year periods.

The results of the study demonstrated that while the outcome measures showed surgery to be more beneficial, the difference between it and more conservative therapies was slight. The only measure for which there was a statistical difference between the groups was on patients' self-rated progress.

The nonrandomized study
In the second observational study in which patients had the ability to choose the type of treatment, 528 patients received surgery and 191 received other treatment. Both groups demonstrated marked improvement; however, on all but 1 of the measures, those in the surgical group had a statistically significant advantage, although the difference between the 2 groups narrowed over the 2-year period.

The only measure in which no difference was reported was work status (ie, patients were just as likely to be able to continue working or to return to work whether or not they received surgery).

Interpreting the findings
In neither of the studies were the patients who did not undergo surgery found to be at greater risk for progressive problems than those whose disk herniation was repaired.

The results of these studies indicate that the previous view that the presence of a herniated disk associated with LBP radiating into the lower extremities always warrants surgical intervention is not supported. Of all the types and causes of back pain, this is the one that has long been believed to have the clearest evidence for surgery, so it certainly raises the question of how reasonable it is for patients with LBP not related to herniated disks to have surgery, especially before they receive an adequate trial of conservative modalities.

An additional factor is that the discectomies performed in the current studies were infrequently associated with side effects or “failed back syndrome,” where there is no response to surgery or the patient's condition worsens following it. These problems appear more likely to occur when patients who have back pain in the absence of herniated disks receive more invasive surgery, such as spinal fusions.⁴

An important factor highlighted in the discussion sections of the 2 studies and in the accompanying editorials^5,6 was the possible role of a placebo effect of surgery and of patient expectations when they chose the form of treatment. Furthermore, patient circumstances may be as important to consider as physical findings. There is no need for physicians to automatically recommend surgery to patients who are able to function despite pain.

The results of these studies fit in with other findings. Staiger and associates⁷ found that for patients with back pain, agreement between the patients and their physicians regarding diagnosis, evaluation, and treatment plan was associated with greater patient satisfaction and better outcome. Carragee and colleagues⁸ reported that psychosocial factors appear to be stronger predictors than MRI findings of disability and improvement in patients with LBP.

Although it received scant discussion in either study or editorial, I believe an important factor that may have limited the benefits of conservative treatment was the lack of standardization of the nonsurgical therapies. Most patients had already undergone some therapy before entering the studies, but it was unclear how many received different treatment approaches after they did so. Further, the studies did not provide any direction regarding whether some forms of conservative therapies are better than others. This is information that we need not only for patients with herniated disks but for all patients with LBP.

Dr King is clinical professor of psychiatry at the New York University School of Medicine.

References1. 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;296:2441-2450.
2. Weinstein JN, Lurie JD, Tosteson TD, et al. Surgical vs nonoperative treatment for lumbar disk herniation: the Spine Patient Outcomes Research Trial (SPORT): observational cohort. JAMA. 2006;296:2451-2459.
3. Deyo RA, Weinstein JN. Low back pain. N Engl J Med. 2001;344:363-370.
4. Deyo RA, Nachemson A, Mirza SK. Spinal-fusion surgery-the case for restraint. N Engl J Med. 2004;350: 722-726.
5. Carragee E. Surgical treatment of lumbar disk disorders. JAMA. 2006;296:2485-2487.
6. Flum DR. Interpreting surgical trials with subjective outcomes: avoiding unSPORTsmanlike conduct. JAMA. 2006;296:2483-2485.
7. Staiger TO, Jarvik JG, Deyo RA, et al. Brief report: patient-physician agreement as a predictor of outcomes in patients with back pain. J Gen Intern Med. 2005;20:935-937.
8. Carragee EJ, Alamin TF, Miller JL, Carragee JM. Discographic, MRI and psychosocial determinants of low back pain disability and remission: a prospective study in subjects with benign persistent back pain. Spine J. 2005;5:24-35.