LEBANON, New Hampshire—Data from the Spine Patient Outcomes Research Trial (SPORT) reported in two articles in the November 22 Journal of the American Medical Association provide no definitive answer whether diskectomy is better than nonoperative management for treating lumber disk herniation; however, findings do show that no great risk is attached to delaying surgery.^1,2

SPORT design had both randomized and observational cohorts

Led by James N. Weinstein, DO, MSc, of Dartmouth-Hitchcock Medical School, in Hanover, New Hampshire, SPORT enrolled patients from 13 multidisciplinary spine clinics in 11 US states. All patients were candidates for surgery, with imaging-confirmed lumbar intervertebral disk herniation and radiculopathy of at least 6 weeks' duration.

Correctly anticipating that a large number of patients who met the study eligibility criteria would decline randomization, Dr. Weinstein and colleagues conducted a two-part analysis. The first was of patients who were randomized either to diskectomy (n = 232) or to individualized nonoperative treatment (n = 240), which included physical therapy, education/counseling with home exercise instruction, and nonsteroidal anti-inflammatory drugs, if tolerated.1 The second was an observational study of the 743 patients who declined randomization, of whom 528 had surgery and 191 had usual nonoperative care.2 Primary outcomes were changes from baseline for the Medical Outcomes Study 36-item Short-Form Health Survey (SF-36) pain and function scales and the modified Oswestry Disability Index (ODI), which were measured at 6 weeks, 3 months, 6 months, and 1 and 2 years from enrollment.

RCT complication: patients crossing over in both directions

Data interpretation for the randomized study was complicated by the fact that half the patients randomized to surgery had not yet had this elective surgery at the 3-month point of first follow-up, and nearly one-third never had surgery. Furthermore, of those randomized to nonoperative treatment, 45% actually had surgery.

The authors comment, "Because of the large numbers of patients who crossed over in both directions, conclusions about the superiority or equivalence of the treatments are not warranted based on the intent-to-treat analysis."

The intent-to-treat analysis (perhaps unsurprisingly) showed that patients in both the surgery and the nonoperative groups "improved substantially over a 2-year period." There were nonsignificant diffferences in favor of surgery for all periods.

The investigators note that those randomized to surgery but more likely to have opted for nonoperative care "were older, had higher incomes, were more likely to have an upper lumbar disk herniation, less likely to have a positive straight leg-raising test result, had less pain, better physical function, less disability on the ODI, and were more likely to rate their symptoms as getting better at enrollment than the other surgery patients."

Conversely, those randomized to nonoperative care who opted for diskectomy instead "tended to have lower incomes, worse baseline symptoms, more baseline disability on the ODI, and were more likely to rate their symptoms as getting worse at enrollment than other patients receiving nonoperative treatment."

Observational cohort data suggest surgery benefit, but with caveats

Data from the observational study of the 743 patients who had declined randomization add a further suggestion of benefit from surgery versus nonoperative treatment, but the researchers warn that "nonrandomized comparisons of self-reported outcomes are subject to potential confounding and must be interpreted cautiously." 

As in the randomized cohort, both the operated and the usual care groups in the observational cohort improved on measures of pain, physical function, and disability during the 2 years of study. Those who had surgery reported significantly greater improvements at each time point, although the differences had narrowed somewhat at 2 years.

"Patient perception that the problem was getting worse at enrollment was a more striking factor predicting participation in the observational cohort as well as in initially choosing surgery. This preference for surgery seemed to be an important factor for those declining randomization," the authors write.

David R. Flum, MD, MPH, in an accompanying editorial notes that in some cases much of the effect of surgery "is related to the hopes, expectations, and beliefs of the patient."³ Dr. Flum, of the University of Washington, in Seattle, points to the study by Moseley et al of knee osteoarthritis treated with arthroscopic surgery versus sham arthroscopy, in which patients in both groups had comparable pain scores and functional scores at 2 years.⁴

Reassuring safety data for nonoperative management

In a second editorial, Eugene Carragee, MD, of Stanford University Medical Center, in California, wrote that since so many SPORT patients improved without diskectomy, "these findings suggest that in most cases there is no clear reason to advocate strongly for surgery apart from patient preference. For the patient with emotional, family, and economic resources to handle mild or moderate sciatica, surgery may have little to offer."⁵

Dr. Carragee added, "Furthermore, the SPORT data clearly show that the risk of serious problems (neurologic deterioration, cauda equina syndrome, or progression of spinal instability) when receiving nonoperative care is extremely small. The fear of many patients and surgeons that not removing a large disk herniation will likely have catastrophic neurologic consequences is simply not borne out."

CIAOMed editorial board member Stefan Lohmander, MD, PhD, commented, "It is very challenging to do these sorts of randomized, controlled surgical trials. The long-term (2 years and longer) outcome difference between surgery or rehab is modest, at best. Patient expectations and lack of patient and surgeon equipoise confound interpretation of the results. We really need a randomized, controlled trial comparing sham surgery and real surgery, and in my personal view the ethics issues can be dealt with appropriately, considering today's 'minimal impact' spine surgery." Dr. Lohmander is professor and senior consultant in the department of orthopaedics at Lund University Hospital, in Lund, Sweden.


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References

1. 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. Flum DR. Interpreting surgical with subjective outcomes. Avoiding UnSPORTsmanlike conduct (editorial). JAMA. 2006;296:2483-2485.
4. MOseley JB, O'Malley K, Petersen NJ, et al. A controlled trial of arthroscopic surgery for osteoarthritis of the knee. N Engl J Med. 2002;347:81-88.
5. Carragee E. Surgical treatment of lumbar disk disorders (editorial). JAMA. 2006;296:2485-2487.