James N. Weinstein, DO, is the principal investigator for the SPORT study—an attempt to compare the treatment effects of nonsurgical and surgical (diskectomy) care for patients with lumbar intervertebral disk herniation. (Courtesy Mark Washburn/Dartmouth-Hitchcock Medical Center)


Published 3/1/2007
Mary Ann Porucznik

No easy answers on disk herniation surgery

Even before it was published, SPORT study was the subject of controversy and concern

Even before it was published, SPORT study was the subject of controversy and concern

Initial results from the Spine Patient Outcomes Research Trial (SPORT) study have garnered plenty of publicity—almost as much as speculation about those results before their publication. “So many people were worried about what the results would be and ready to argue with whatever we found,” recalled James N. Weinstein, DO, MS, the study’s primary author.

The study—an attempt to compare the treatment effects of nonsurgical and surgical (diskectomy) care for patients with lumbar intervertebral disk herniation—exemplifies the challenges researchers face in developing level I evidence-based treatment guidelines. SPORT, which was funded by the National Institutes of Health, had two components—a randomized trial and anobservational cohort. Thirteen multidisciplinary spine clinics in 11 states participated, with more than 1,200 patients who were enrolled between March 2000 and March 2003 (observational cohort) or between March 2000 and November 2004 (randomized trial).

When the results were published in the Journal of the American Medical Association (JAMA) (Nov. 22/29, 2006), the media reaction took Dr. Weinstein by surprise. “I was shocked by the amount of interest,” he said, “but they didn’t exactly get the message.”

Michael Goldberg, MD, chair of the AAOS Evidence-Based Practice Committee, agreed. “Mainstream media misinterpreted the study,” he told AAOS Now.

Which is better?
Much of the furor over the study rested on the hope—or fear—that it would settle the question of which treatment is better for patients with herniated lumbar disks. Consequently, initial reactions focused on the study design and patient selection.

“There aren’t a lot of randomized trials in orthopaedic surgery,” noted Dr. Weinstein. The researchers hoped that including both a randomized trial and an observational cohort would give them a unique opportunity to address two key issues—believability and reality. The randomized trial would theoretically ensure that the results were believable; the observational cohort would show the reality of what happened to patients who stayed in control of their treatment decisions.

But patient care decisions are never easy and rarely final, as every orthopaedist realizes. And the SPORT study was meant to be a “patient-centric study,” according to Dr. Weinstein.

“You cannot force a patient who responds well to nonoperative treatment to have surgery simply because that patient was randomized to surgical treatment,” said Alan S. Hilibrand, MD, a coauthor of the study. “Nor is it reasonable to deny patients surgical treatment if they are not improving with nonoperative treatment.”

As a result, the randomized trial portion of the study had considerable “crossover,” which confounded the results. Of the 245 patients assigned to receive surgery, only 140 actually had surgery within the first two years; of the 256 patients assigned to receive nonsurgical care, 107 eventually had surgery within the first two years. In the observational cohort, 528 patients received surgery and 191 received nonsurgical care.

Patients considered for inclusion in the study had to be at least 18 years old, diagnosed as having intervertebral disk herniation by one of the participating physicians, and have persistent symptoms (radicular pain and evidence of nerve-root irritation) despite at least six weeks of nonsurgical treatment.

When the results of the study were published, many surgeons found them confusing. Results were reported as to group randomized, so that the surgery results included the outcomes of patients randomized to surgery who didn’t get it, and the nonsurgical results included the outcomes of patients randomized to that group, even if they had surgery. This is required in an intent-to-treat analysis.

“In the editing process for publication, the as-treated analysis graphics were cut and are not included with the published study,” said Dr. Weinstein, “but the results are included in the text of the article.”

“Some surgeons were unhappy that the study results didn’t truly reflect the outcomes,” admitted Dr. Hilibrand. But in the end, there was good news for everyone—especially patients.

In all cases, at all times
According to the intent-to-treat analysis for the randomized trial, “for each measure and at each point, the treatment effect favors surgery.” The as-treated analysis showed “strong, statistically significant advantages…for surgery at all follow-up times through two years.”

In the observational cohort, “the benefit of surgery was seen as early as six weeks and was maintained for at least two years.”

At the same time, there was “substantial improvement for all primary and secondary outcomes in both [surgical and nonoperative] treatment groups” in the randomized trial, and “patients with persistent sciatica from lumbar disk herniation [in the observational cohort] improved in both operated and usual care groups.”

In both the randomized trial and the observational cohort, patients who opted for surgery generally had worse baseline symptoms and more baseline disability. They were also more likely to report that their symptoms were getting worse at enrollment.

“These two studies represent a colossal research effort and provide a fascinating snapshot of both modern patient preferences and clinical outcomes for this common clinical problem [lumbar disk herniation], wrote Eugene Carragee, MD, in a JAMA editorial that accompanied the studies.

Dr. Goldberg agreed. “They have a higher degree of rigor than most other studies, even though they are problematic. The refusal of a patient to be randomized is an ethical issue.”

Informed choice vs. informed consent
Although some media reports on the results sported headlines such as “Patients with back pain recover without surgery,” that wasn’t the real point of the study.

“They all did well,” said Dr. Weinstein. “Nobody got worse. And that’s the take-home message. So whether to have surgery or not becomes the patient’s decision, an informed choice of treatment, not just an informed consent to treatment.

“If we, as an Academy, are preaching evidence-based medicine and patient-centered care,” he continued, “studies like this ought to be standard in helping patients understand the outcomes of their treatment options. They should know that patients who didn’t have surgery didn’t get worse…they got better. They should know that patients who did have surgery didn’t have complications such as paralysis or cauda equina injuries.”

Dr. Hilibrand agreed. “Both [operative and nonoperative] groups got better. No one was seriously harmed by not having surgery; there were no significant neurological injuries. At the same time, no one who had surgery had any bad complications; the surgery [diskectomy] is safe and reliable. That’s a good thing for patients to hear.”

In effect, the studies validated the practice patterns of many orthopaedists. Patients who have severe back and leg pain will immediately benefit from surgery and that benefit will continue overall for at least two years after surgery. Patients whose pain is tolerable and who choose nonsurgical treatment—physical therapy, anti-inflammatory drugs, education/counseling, or other treatments—can also expect good results.

“In 80 percent of patients with radiating pain, nonoperative treatment will be successful,” said Dr. Hilibrand. “But when it’s not, patients need to know that surgery is a safe, effective option. This study proves that.”

The SPORT study is also examining the outcomes of surgical and nonsurgical treatments for two other conditions—spinal stenosis and spinal stenosis with degenerative spondylolisthesis. Results on the spinal stenosis study are expected to be released later this year.