Dr. Rihn and his coauthors are to be congratulated on their excellent publication titled “The Influence of Obesity on the Outcome of Treatment of Lumbar Disc Herniation. Analysis of the Spine Patient Outcomes Research Trial (SPORT).” This study represents a retrospective analysis of prospectively collected data from the Spine Patient Outcomes Research Trial (SPORT), focusing on patients with radiculopathy due to lumbar disc herniation and specifically on the influence of obesity on complication rates, reoperation rates, and patient-reported outcomes.
Although the original SPORT study was a randomized clinical trial, for this study, the authors have utilized an as-treated analysis, eliminating the design benefit of randomization. In addition, this is a retrospective analysis of data that were not initially collected with the intent to evaluate the effect of obesity on outcomes. Finally, several potential confounding variables, including sex, education and income levels, compensation claims, and medical comorbidities, differed at baseline between obese patients and nonobese patients.
Recognizing these limitations, the current study nonetheless represents the highest-level medical evidence yet presented, analyzing the effect of obesity in patients managed operatively and nonoperatively for lumbar disc herniation. Importantly, although obese patients did not share the same clinical benefit that nonobese patients did from either operative or nonoperative interventions, both groups showed significant improvements in clinical outcomes with operative treatment compared with nonoperative treatment for this condition. Other important conclusions were that complication and reoperation rates were similar between the two groups, despite the finding that operative times and length of hospitalization were slightly longer for obese patients.
Perhaps the most important aspect of this publication is its demonstration of the remarkable value returned on the financial investment and work effort in the SPORT study1-4. A brief PubMed search reveals that the total number of peer-reviewed publications derived from the SPORT database is approaching forty. Although the primary clinical reports of patient outcomes with lumbar disc herniation2, lumbar spinal stenosis3, and degenerative spondylolisthesis4 in themselves represent a landmark achievement, continuing subanalyses of the SPORT database have provided high-quality evidence, furthering our understanding of specific variables of importance in managing these patients. Indeed, the accomplishments of the SPORT investigators serve as a unique demonstration of the importance and impact of high-quality orthopaedic research. The current study represents the latest installment in this ongoing enterprise, and as such is a welcome addition to the orthopaedic literature.