Surgery and Low Back Pain

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Authors and Disclosures

Author

P. Vega, MD

Associate Professor; Residency Director, Department of Family Medicine, University of California, IrvineDisclosure: P. Vega, MD, has disclosed no relevant financial relationships.

From Medscape Family Medicine > Best Evidence Review

Surgery and Low Back Pain -- Is the Choice Clear?

P. Vega, MD

Posted: 02/25/2011

Best Evidence Review February, 2011More research suggests that surgery for low back pain is overused

Best Evidence Reference

Brox JI, Nygaard OP, Holm I, Keller A, Ingebrigsten T, Reikeras O. Four-year follow-up of surgical versus non-surgical therapy for chronic low back pain. Ann Rheum Dis. 2010;69:1643-1648.

This study was selected from Medscape Best Evidence, which uses the McMaster Online Rating of Evidence System. Of a possible top score of 7, this study ranked 6 for newsworthiness and 6 for relevance by clinicians who used this system.

Abstract

Background

Low back pain is a very common condition, accounting for 2.3% of physician visits in the United States.[1] The total cost of low back pain exceeds $100 billion per year in the United States alone.[2] Two-thirds of these costs are related to lost wages and decreased productivity at work. A small minority of patients with severe back pain account for a significant majority of the total socioeconomic cost of back pain. Thus, it is not surprising that surgical treatment for low back pain has grown more widespread over the past 20 years. The analysis of long-term data discussed in this review suggests that surgery is not superior to a short, intensive cognitive and exercise intervention among patients with common low back pain. This research suggests that surgical treatment for chronic low back pain may be overused.

In an analysis of 2 national surveys performed in the United States in 2002, 26.4% of respondents reported a history of back pain lasting at least 1 day during the previous 3 months.[1] The prevalence of back pain was inversely related to educational attainment and income, and the rate of back pain appeared stable compared with estimates from the previous decade.

The practice dictum states that low back pain nearly always resolves spontaneously. This may be true, but important caveats are needed. One study found that although the majority of patients discontinue seeking medical care for their low back pain, nearly 80% of these patients continued to experience some pain or disability at 1 year following their initial clinic visit for low back pain.[3] In a more recent study of 973 primary care patients with less than 2 weeks of low back pain, the rates of returning to work were approximately 50% at 14 days and 83% at 3 months.[4] However, these statistics belied the median recovery times for disability (31 days) and pain (58 days). Only 72% of participants reported complete recovery at 12 months.

The fact that many patients have lingering symptoms, in combination with the introduction and promotion of new surgical techniques and equipment, has led to an explosive increase in the use of surgery for low back pain. The estimated number of lumbar fusion procedures increased by an estimated 134% between 1993 and 2003; other estimates have suggested a more than 200% increase in the number of these procedures during a similar time frame.[5,6]

But does surgery afford better outcomes to patients with chronic low back pain? Several studies have examined this issue. A previous large trial of surgery for lumbar spondylolisthesis and spinal stenosis demonstrated that surgery did not improve pain or disability compared with usual care on intent-to-treat analysis.[7,8] However, significant crossover between the surgery and usual care groups occurred in this research, and as-treated analyses found that surgery improved pain, function, and disability at 2 years compared with usual care.

This research was important and provocative, but not necessarily definitive. Moreover, it did not compare surgery with an active intervention. Previously, the authors of the current study reported on outcomes at 1 and 2 years in a comparison of lumbar fusion with a program of cognitive intervention and prescribed exercises among patients with chronic low back pain.[9,10] They found that outcomes were similar in the surgical and nonsurgical groups. However, given the chronic nature of low back pain among many patients, it remained unclear if their results would continue to remain the same in the very long term. The current study addresses this issue with a report from their patient cohort at 4 years.

Current Trial

The study was conducted at 4 university hospitals in Norway. The limitations on study enrollment ensured that patients with more significant symptoms and findings were not included in the protocol. All participants had low back pain for at least 1 year, moderate disability, and evidence of disk degeneration at L4-L5 or L5-S1; those with symptomatic spinal stenosis were excluded from study participation. Similarly, patients with disk herniation or lateral recess stenosis plus signs of radiculopathy were excluded, as were those with generalized disk degeneration, ongoing serious somatic or psychiatric disease, or " reluctance " (term not defined) to undergo one of the study treatments.

Participants were randomized to receive instrumented transpedicular fusion or nonsurgical therapy. The nonsurgical therapy was very intensive and included initial education, support, and physical training sessions that lasted an average of 25 hours per week over 3 weeks. There were 4-7 participants assigned to this training at a time, and they stayed in a hotel for patients during the 3 weeks. Specialists in physical medicine and rehabilitation guided the program, and participants also met with a peer who had previously completed the nonsurgical program. At the end of the 3 weeks, participants were prescribed a home exercise program.

The primary study outcome was the Oswestry disability index, which measures both pain and disability. Researchers also followed participants' ratings of treatment effectiveness, quality of life, and effects of the interventions on medication use and time missed from work. The current study focuses on these results measured at 4 years after randomization, and results were adjusted to account for sex, age, previous surgery for disk herniation, and baseline pain and disability scores.

Of 234 eligible patients, 124 were enrolled in the trials. Baseline data were similar for the 2 groups. The mean age of participants was 42 years, and 72% were women. The average duration of low back pain was 9 years, and the mean severity of back pain was 64 on a scale of 0 to 100, with 100 being the most severe pain. Both treatment groups professed stronger beliefs in surgical vs non-surgical treatment of chronic low back pain at baseline.

In the surgical group, the rates of undergoing surgery were 88% at 1 year and 91% at 4 years. The respective rates of surgery in the nonsurgical group were 5% and 24%. Study follow-up was excellent, with rates of 92% and 86% in the surgical and nonsurgical groups at 4 years.

Beyond comparing surgical and nonsurgical treatment for chronic low back pain, the study also gives some insight into the use of healthcare and other resources by these patients. Only a slight majority of patients saw a physician for back pain in the year before study follow-up at year 4. Less than one fourth received physical therapy. However, the rate of repeat surgery after the initial study surgery was 25% over 4 years. This high repeat surgery rate was recorded despite the fact that no major adverse events related to surgery occurred through year 1 of the study.

Participants who received surgery were more than twice as likely to receive a disability pension, regardless of their randomized group. However, it would be wrong to infer that surgery itself promoted a higher rate of disability. These patients had surgery in response to more severe symptoms, and were therefore more likely to receive a disability pension in the first place. Moreover, applications for disability pension from patients who had received surgery could have received more favorable reviews.

There were no differences between randomized groups in the outcomes of pain and disability in either intent-to-treat or as-treated analyses at 4 years. The mean Oswestry disability index score declined in both groups from an approximate mean of 44 at baseline to 28 at 4 years.

Among secondary outcomes, the only difference between treatment groups was a reduction in fear and avoidance of physical activity, favoring the nonsurgical group. Measurements of general function improved by approximately 40% in both groups, and life satisfaction also improved. The number of participants returning to work improved with both treatments to a similar degree, and the proportions of participants rating their treatment as successful at 1 year were 61% and 65% in the surgical and nonsurgical cohorts, respectively. Use of pain medication was higher among participants who received surgery, but any difference between treatment groups was not significant on intent-to-treat analysis.

Discussion

The current study jives with a previous systematic review of surgical vs nonsurgical care for chronic low back pain.[11] The review found methodologic problems with each of the 5 trials included in the analysis, including a high degree of treatment crossover among randomized groups and a limited power to detect important differences between treatments. Overall, the review concluded that surgery may be superior to unstructured usual care for chronic low back pain, but it may not provide improvement over a back care program, such as the one featured in the current study. A more recent review reached the same conclusion, noting that fewer than half of patients with nonradicular low back pain with common degenerative changes experience optimal outcomes after fusion.[12] However, patients with specific anatomic changes, such as spinal stenosis, or symptoms, such as radiculopathy with a herniated disk, appear to have better results with surgery compared with conservative treatment.

The current study is eye-opening in that it suggests that an invasive and high-cost procedure does not afford better outcomes compared with a conservative treatment approach to low back pain. Moreover, it demonstrates similar outcomes for these interventions over several domains, including patient symptoms, quality of life, and the use of healthcare resources.

A legitimate question exists as to whether a sample size of 124 adults is sufficient to adequately test the study's hypotheses. Examining the data in both the intention-to-treat and as-treated analyses does not yield a strong trend toward significance for either surgical or nonsurgical treatment, however, so the concept of underpowering in the current study is less credible. The study was limited by treatment crossover, although the degree of crossover was less than that observed in previous trials. The researchers account for the phenomenon of treatment crossover with their as-treated analysis of study outcomes. Finally, there was no placebo or " usual treatment " group. Adding such a feature to the study protocol would have been reasonable and could have further established the legitimacy of the study’s conclusions.

Conclusion

What can physicians apply from this study and those that have preceded it? First, these data should give doctors pause when recommending lumbar fusion surgery without compelling indications, particularly when strong back rehabilitation programs are available.

But the issue of an adequate rehabilitation program for back pain presents another quandary for the clinician: how much is enough? The current intervention amounts to intensive training, essentially as an inpatient, over 3 weeks in very small groups. It may be easy to understand how such a program could have a positive effect, but it is much more difficult to imagine how this program could be used more broadly to help the millions of adults with low back pain.

Another remarkable feature of this rehabilitation program is that it did not feature prominent follow-up for therapy. Apparently, the lessons learned during the intensive training period helped patients over years. Further research might focus on certain elements of this training used in routine clinical practice and how a more gradual implementation and simple reinforcement over time improve patient outcomes.

Clinical Pearls

More than one fourth of Americans have experienced significant back pain in the past 3 months, and the total cost of low back pain exceeds $100 billion per year in the United States alone;

Surgical treatment of low back pain has become more prevalent;

In the current study, an intensive, brief program of cognitive and exercise treatment produced similar outcomes as surgical treatment of chronic low back pain;

The current study is in accord with previous systematic reviews of treatment for low back pain without significant anatomic changes (such as spinal stenosis) or symptoms (such as radiculopathy); and

Further research could highlight how to use elements of the intensive back rehabilitation program in everyday practice.

References

Deyo RA, Mirza SK, BI. Back pain prevalence and visit rates: estimates from U.S. national surveys, 2002. Spine. 2006;31:2724-2727. Abstract

Katz JN. Lumbar disc disorders and low-back pain: socioeconomic factors and consequences. J Bone Joint Surg Am. 2006;88: 21-24. Abstract

Croft PR, Macfarlane GJ, Papageorgiou AC, E, Silman AJ. Outcome of low back pain in general practice: a prospective study. BMJ. 1998;316:1356-1359. Abstract

Henschke N, Maher CG, Refshauge KM, et al. Prognosis in patients with recent onset low back pain in Australian primary care: inception cohort study. BMJ. 2008;337:a171.

Deyo RA, Gray DT, Kreuter W, Mirza S, BI. United States trends in lumbar fusion surgery for degenerative conditions. Spine. 2005;30:1441-1445. Abstract

Cowan JA Jr, Dimick JB, Wainess R, Upchurch GR Jr, Chandler WF, La Marca F. Changes in the utilization of spinal fusion in the United States. Neurosurgery. 2006;59:15-20. Abstract

Weinstein JN, Lurie JD, Tosteson TD, et al. Surgical versus nonsurgical treatment for lumbar degenerative spondylolisthesis. N Engl J Med. 2007;356:2257-2270. Abstract

Weinstein JN, Tosteson TD, Lurie JD, et al. Surgical versus nonsurgical therapy for lumbar spinal stenosis. N Engl J Med. 2008;358:794-810. Abstract

Brox JI, S?ensen 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. 2003;28:1913-1921. Abstract

Brox JI, Reikeras O, Nygaard O, et al. Lumbar instrumented fusion compared with cognitive intervention and exercises in patients with chronic back pain after previous surgery for disc herniation: a prospective randomized controlled study. Pain. 2006;122:145-155. Abstract

Mirsa SK, Deyo RA. Systematic review of randomized trials comparing lumbar fusion surgery to nonoperative care for treatment of chronic back pain. Spine. 2007;32:816-823. Abstract

Chou R, Baisden J, Carragee EJ, Resnick DK, Shaffer WO, Loeser JD. Surgery for low back pain: a review of the evidence for an American Pain Society Clinical Practice Guideline. Spine. 2009;34:1094-1099. Abstract

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