According to a study published in Spine, using data from the SPORT (Spine Patient Research Outcomes Trial) study, surgical treatment for lumbar disc herniation is associated with significantly greater improvements than non-operative management at eight years. However, there was little or no degeneration in outcomes in either group.
Jon D Lurie (Department of Medicine, of Orthopaedics, and of Dartmouth Institute for Health Policy and Clinical Practice, Geisel School of Medicine at Dartmouth and Dartmouth-Hitchcock, Lebanon, USA) and others write that a previous study showed that surgery was not associated with a significant improvement in outcomes at 10 years compared with non-operative management.
However, they note: “A number of patients in the non-operative group eventually underwent surgery during that time, complicating the interpretation of the long-term results.” This new study, they comment, reviewed the eight-year results of patients who received treatment (surgery or non-operative care) for lumbar disc herniation in the SPORT study. In SPORT, there were two cohorts—randomised (in which patients eligible for surgery were randomised to receive surgery or non-operative care) and observational (in which patients chose to undergo surgery or non-operative care). Therefore, Lurie et al looked at both of these cohorts; they also performed two analyses: intention-to-treat, which compared patients assigned surgery vs. patients assigned non-operative care; and as-treated, which adjusted for the characteristics of the crossover patients. Overall, 803 patients received surgery and 392 received non-operative treatment.
At eight years, in the randomised cohort, the intention-to-treat analysis indicated that there were no significant differences between the surgery and non-operative patients in terms of the primary outcomes (bodily pain, physical function, and Oswestry Disability Index). However, in the overall cohort, the intention-to-treat analysis showed that surgery was associated with significant improvements in the secondary outcomes (sciatica bothersomeness [p=0.005], satisfaction with symptoms [p=0.013], and self-rated improvement [p=0.013]) compared with non-operative management. Furthermore, the as-treated analysis (for the combined cohort) indicated that surgery was associated with significant improvements in both the primary and secondary outcomes measures (with the exception of work status that did not differ between treatment groups). Lurie et al state: “The large effects seen in the as-treated analysis after adjustments for characteristics of the crossover patients suggests that the intention-to-treat analysis may underestimate the true effect of surgery since the mixing of treatments due to crossover can be expected to create a bias toward the null in the intention-to-treat analyses.”
Other findings showed that in both groups, there was little or no degradation of outcomes between four and eight years and 34% of patients with strong surgical indications were still in the non-operative group at eight years.