Surgery improves pain and function better than nonoperative care for degenerative spondylolisthesis and spinal stenosis

SPORT finds patients treated nonsurgically showed only moderate improvements over time.

Patients treated surgically for degenerative spondylolisthesis and spinal stenosis experience a substantially greater improvement in pain and function at 2 years follow-up compared to patients managed nonsurgically, according to results from the on-going Spine Patient Outcomes Research Trial.

"In patients with image-confirmed degenerative spondylolisthesis and symptoms persisting for at least 12 weeks, the intention-to-treat analysis found no significant advantage for surgery over nonsurgical care, but the analysis was severely limited by treatment crossover," the study authors wrote.

"As-treated analyses showed that surgery was superior to nonsurgical treatment in relieving symptoms and improving function. This treatment effect was seen as early as at the 6-week follow-up and persisted over 2 years. The nonsurgical-treatment group showed only moderate improvement over time," the authors reported.

James N. Weinstein, DO, and colleagues at numerous centers in the United States, are conducting the Spine Patient Outcomes Research Trial (SPORT) to compare the efficacy of surgical and nonsurgical treatment of patients with confirmed diagnoses of intervertebral disk herniation, spinal stenosis and degenerative spondylolisthesis. They published their results of this arm of the trial in the New England Journal of Medicine.

Nonsurgical treatments included physical therapy, epidural steroid injections, NSAIDs and opioids.

Overall, the SPORT study enrolled 607 patients to either randomized or observational groups. The randomized group included 304 patients — 159 patients were randomly assigned to receive surgery and 145 were randomly assigned to nonsurgical management. Of the patients assigned to surgery, 57% received surgery within 1 year and 64% received surgery by 2 years, according to the study. Of patients assigned to nonsurgical management, 44% received surgery within 1 year and 49% by 2 years, according to the study.

The observational group included 303 patients. Of these, 173 initially chose to undergo surgery, and 97% of those patients received surgery within 1 year.

Among the 130 patients who initially chose nonsurgical management, 17% received surgery within 1 year and 25% received surgery by 2 years follow-up, according to the study.

"In both cohorts combined, 372 patients underwent surgery within the first 2 years and 235 received only nonsurgical treatment," the authors wrote.

In the intention-to-treat analysis of patients in the randomized group, investigators found no statistically significant effects for the primary outcomes at 2 years.

However, "As-treated effects for the combined cohorts were statistically significant in favor of surgery for all primary and secondary outcomes," the authors wrote, noting that the effects were stable at 2 years and were significant at all follow-up periods.

At 2 years, surgery showed a treatment effect of 18.1 for Short Form-36 (SF-36) bodily pain scores, an effect of 18.3 for physical function and an effect of –16.7 for the Oswestry Disability Index, according to the study.

"The as-treated treatment effects at 2 years were nearly identical in the randomized and the observational cohorts," the authors noted.

Surgery showed a treatment effect on SF-36 bodily pain scores of 17.8 for the randomized group and 18.5 for the observational group. The treatment effect on SF-36 physical function was 16.7 for the randomized group and 19.9 for the observational group. The effect on Oswestry Disability Index scores was –15.9 for the randomized group and –17.7 for the observational group, according to the study.

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