Surgical vs nonoperative treatment for lumbar disk herniation: the Spine Patient Outcomes Research Trial (SPORT): a randomized trial

Abstract

Context: Lumbar diskectomy is the most common surgical procedure performed for back and leg symptoms in US patients, but the efficacy of the procedure relative to nonoperative care remains controversial.

Objective: To assess the efficacy of surgery for lumbar intervertebral disk herniation.

Design, setting, and patients: The Spine Patient Outcomes Research Trial, a randomized clinical trial enrolling patients between March 2000 and November 2004 from 13 multidisciplinary spine clinics in 11 US states. Patients were 501 surgical candidates (mean age, 42 years; 42% women) with imaging-confirmed lumbar intervertebral disk herniation and persistent signs and symptoms of radiculopathy for at least 6 weeks.

Interventions: Standard open diskectomy vs nonoperative treatment individualized to the patient.

Main outcome measures: Primary outcomes were changes from baseline for the Medical Outcomes Study 36-item Short-Form Health Survey bodily pain and physical function scales and the modified Oswestry Disability Index (American Academy of Orthopaedic Surgeons MODEMS version) at 6 weeks, 3 months, 6 months, and 1 and 2 years from enrollment. Secondary outcomes included sciatica severity as measured by the Sciatica Bothersomeness Index, satisfaction with symptoms, self-reported improvement, and employment status.

Results: Adherence to assigned treatment was limited: 50% of patients assigned to surgery received surgery within 3 months of enrollment, while 30% of those assigned to nonoperative treatment received surgery in the same period. Intent-to-treat analyses demonstrated substantial improvements for all primary and secondary outcomes in both treatment groups. Between-group differences in improvements were consistently in favor of surgery for all periods but were small and not statistically significant for the primary outcomes.

Conclusions: Patients in both the surgery and the nonoperative treatment groups improved substantially over a 2-year period. 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.

Trial registration: clinicaltrials.gov Identifier: NCT00000410.

Figure 1. Flow Diagram of the SPORT Randomized Controlled Trial of Disk Herniation: Exclusion, Enrollment, Randomization, and Follow-up

SPORT indicates Spine Patient Outcomes Research Trial. *Cumulative over time. †Percentages of patients undergoing surgery at each time point were calculated using the number included in the primary analysis as denominator (n=232 for surgery; n=240 for nonoperative care).

Figure 2. Mean Scores Over Time for SF-36 Bodily Pain and Physical Function Scales and Oswestry Disability Index

Age- and sex-weighted population normative scores are plotted for Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) scales. To enhance readability, the plot symbols and error bars for the surgical group are slightly offset. Error bars indicate 95% confidence intervals.

Figure 3. Measures Over Time for Sciatica Bothersomeness Index, Employment Status, Satisfaction With Symptoms, Satisfaction With Care, and Self-rated Improvement

To enhance readability, the plot symbols and error bars for the surgical group are slightly offset. Error bars indicate 95% confidence intervals.