Nonoperative Treatment for Disc Herniations
Henry Ahn, M.D., FRCSC
Disc herniation causing only radiculopathy and back pain (excluding cauda equina syndrome) is an elective spinal disorder. Surgery is not mandatory. Furthermore, nonoperative therapy can result in marked improvement in pain over time. The recently published multi-centre randomized Spine Patient Outcomes Research Trial (SPORT) demonstrated that patients with persistent sciatica (>6 weeks) substantially improved with nonoperative "usual care"1. This included different combinations of education and counseling (92%), non-steroidal anti-inflammatory drugs (58%), narcotic analgesics (35%), physiotherapy (43%) and epidural steroid injections (38%) depending upon physician prescribing preferences. There was no statistical difference in outcomes between the surgical and nonoperatively treated groups for all time periods using intention-to-treat analysis.
One criticism of the study has been the use of intention-to-treat analysis in a trial where a large proportion of patients have crossed over from their initially randomized groups due to non-adherence of treatment. Specifically, 50% from the surgical group and 30% from the nonoperative group crossed into the other treatment group. In this setting, intention-to-treat may minimize or underestimate the effect of surgery. However, despite potential underestimation of the effect of surgery, nonoperative therapy provided patients with a substantial amount of improvement in pain over time.
The trial also included "as treated analysis" data to better assess the effect of surgery. However, patients who had crossed over were substantially different from their counterparts who did not cross over indicating the cross over effect was not a random phenomenon. In this situation, "as treated analysis", eliminates the benefit of randomization in balancing out known and unknown confounders. Baseline comparisons of the groups in the "as treated" analysis display significant differences, preventing firm conclusions about the benefits of surgery. In fact, comparisons done in the "as treated" analysis would be akin to comparing "apples to oranges" due to differences in patient characteristics.
Furthermore, patients were not blinded to surgical intervention. Patients undergoing surgery, especially those who cross over in a trial from nonoperative to operative groups, may have pre-existing positive expectations of the benefits of surgery that artificially elevate their outcomes through a placebo effect rather than through the benefits of the intervention itself2.
This is also true of patients who selected themselves out of the randomized trial and decided to continue on with the parallel prospective observational cohort study3. This cohort study followed patients who declined enrollment in the randomized control trial. These patients who sought out surgery, outside of the randomized control trial, may have underlying desires and beliefs regarding surgery that are substantially different from those who sought out nonoperative treatment. Again, firm conclusions cannot be drawn from the prospective SPORT observational cohort. However, even within the observational cohort, the initial benefit of surgery over nonoperative treatment, narrowed over a two year period. Furthermore, nonoperative therapy again provided substantial improvement in pain over the two year follow-up period.
In summary, patients can get substantially better with nonoperative therapy for a disc herniation causing leg radiculopathy. The current trial did not show a statistical difference. However, even if there is a statistically significant benefit of surgery over nonoperative treatment, it maybe a clinically small difference. Furthermore, not having surgery does not equate to poor outcomes for a patient.
Weinstein J.N., Tosteson T.D., Lurie J.D., et al. Surgical vs nonoperative treatment for lumbar disk herniation: the Spine Patient Outcomes Research Trial (SPORT): a randomized trial. JAMA 2006; 296(20):2441-50.
Moseley J.B., O'Malley K., Petersen N.J., et al. A controlled trial of arthroscopic surgery for osteoarthritis of the knee. N Engl J Med 2002; 347(2):81-8.
Weinstein J.N., Lurie J.D., Tosteson T.D., et al. Surgical vs nonoperative treatment for lumbar disk herniation: the Spine Patient Outcomes Research Trial (SPORT) observational cohort. 2006; 296(20):2451-9.