LEIDEN, The Netherlands, and LEBANON, New Hampshire—Two major studies on back surgery that appear in the May 31 New England Journal of Medicine caution that surgery does not result in better outcomes; these findings offer some reassurance to patients who are not eager to go under the knife. Wilco C. Peul, MD, et al report that standard microdiskectomy performed within 2 weeks of symptom onset provided faster relief of leg pain than conservative treatment but did not affect the probability of perceived recovery after 1 year, which was 95% in both groups.¹ James N. Weinstein, DO, et al report the degenerative spondylolisthesis data from the Spine Patient Outcomes Research Trial (SPORT), which show that laminectomy plus fusion relieved pain and improved function better than nonsurgical treatment.²

"Absent major neurologic deficits, patients with herniated disks, degenerative spondylolisthesis, or spinal stenosis do not need surgery, but the appropriate surgical procedures may provide valuable pain relief. In such situations, decisions should be made jointly by well-informed patients and their physicians," writes Richard A. Deyo, MD, MPH, in an accompanying editorial.³ Dr. Deyo is a professor in the departments of medicine and health services and codirector of the center for cost and outcomes research at the University of Washington, in Seattle.

Lumbar-disk surgery provides faster relief of sciatica pain, little difference in 1-year outcomes

Lead researcher Dr. Peul, with the department of neurosurgery at Leiden University Medical Center, in The Netherlands, randomly assigned 283 patients with severe sciatica lasting 6-to-12 weeks to early surgery (n = 141) or to conservative treatment (n = 142). Eighty-nine percent of the surgery group had microdiskectomy after a mean of 2.2 weeks following randomization. Thirty-nine percent of the conservative treatment group was offered microdiskectomy after a mean of 18.7 weeks following randomization if sciatica persisted for 6 months after randomization and sooner than 6 months if they had progressive neurologic deficits or leg pain not responsive to medication.

"There was no significant overall difference in disability scores during the first year (P = .13). Relief of leg pain was faster for patients assigned to early surgery (P <.001). Patients assigned to early surgery also reported a faster rate of perceived recovery (hazard ratio, 1.97; 95% confidence interval, 1.72 to 2.22; P <.001). In both groups, however, the probability of perceived recovery after 1 year of follow-up was 95%," Dr. Peul writes.

The investigators conclude that patients are likely to opt for surgery if they have severe, continuing leg pain, find the results of conservative management too slow, or want to shorten the time before pain is relieved. "Patients whose pain is controlled in a manner that is acceptable to them may decide to postpone surgery in the hope that it will not be needed, without reducing their chances for complete recovery at 12 months," Dr. Peul notes.

The investigators point out that the slow rate of recovery 2 weeks after surgery was likely due to the use of standard microdiskectomy techniques rather than to the microendoscopic or sequestrectomy techniques now in widespread use. They also note that patients assigned to conservative therapy were guided by research nurses experienced in pain management. "Although this additional support did not prevent surgery in 39% of patients with severe sciatica, it does not reflect usual care. This must be kept in mind when a strategy of prolonged conservative treatment is implemented for wider populations," the researchers warn.

Dr. Deyo comments, "Thus, for patients with persistent sciatica, there seems to be a reasonable choice between surgical and nonsurgical treatment, which may be influenced by aversion to surgical risks, the severity of symptoms, and willingness to wait for spontaneous healing. Since patients who underwent surgery months after entering the study did as well as those who had surgery within 2 weeks, there does not seem to be a therapeutic window that closes quickly."

Pain, function better after surgery for lumbar degenerative spondylolisthesis

Lead researcher Dr. Weinstein, with the departments of orthopaedics and community and family medicine at Dartmouth Medical School, in Lebanon, New Hampshire, reports data for patients with image-confirmed degenerative spondylolisthesis enrolled in either the randomized cohort (n = 304) or the observational cohort (n = 303) of the SPORT study. Due to 1-year crossover rates of 40% in each direction in the randomized cohort, there were no statistically significant differences for primary outcomes in intention-to-treat analysis. Primary outcome measures were the Medical Outcomes Study 36-item Short-Form General Health Survey (SF-36), bodily pain, and physical function scores, and the modified Oswestry Disability Index at 6 weeks, 3 months, 6 months, 1 year, and 2 years.

"As treated" analysis for the combined cohorts showed "a significant advantage for surgery at 3 months that increased at 1 year and diminished only slightly at 2 years," Dr. Weinstein reports. The outcome measures included 2-year treatment effects of 18.1 for bodily pain, 18.3 for physical function, and -16.7 for the Oswestry Disability Index.

"In these nonrandomized comparisons with careful control of potentially confounding baseline factors, patients with persistent neurogenic claudication from degenerative spondylolisthesis treated surgically showed substantially greater improvement in pain and function, as well as satisfaction, for 2 years," Dr. Weinstein concludes.

Dr. Deyo points out that the analysis "essentially creat[ed] a single large cohort study showing that surgery offers a significant advantage over nonsurgical therapy." He notes, however, that this approach bears the risk of overestimating the benefits of surgery due to possible differences between the treatment groups and also bears the risk of underestimating the benefits of surgery because of the many crossovers.

"In the two trials presented here, both back and leg pain were ameliorated by surgery, but leg pain resolved more quickly and fully than back pain. Thus, benefits are likely to be greatest for nerve-root-associated symptoms," Dr. Deyo concludes.

References

1. Peul WC, van Houwelingen HC, van den Hout WB, et al. Surgery versus prolonged conservative treatment for sciatica. N Engl J Med. 2007;356:2245-2256.
2. Weinstein JN, Lurie JD, Tosteson TD, et al. Surgical versus nonsurgical treatment for lumbar degenerative spondylolisthesis. N Engl J Med. 2007;356:2257-2270.
3. Deyo RA. Back surgery—who needs it? N Engl J Med 2007;356:2239-2243.