Just Do It!

Commentary The original cohort of patients included in the Spine Patient Outcomes Research Trial (SPORT) represents the largest group that will likely ever be assembled in order to definitively answer questions regarding the efficacy of surgery for intervertebral disc herniation, degenerative spondylolisthesis, and spinal stenosis. Certainly, multiple limitations of the SPORT study have been identified, but the data remain the best available to evaluate these conditions. The present study by Rihn et al. represents the largest prospective study comparing patients with degenerative spondylolisthesis and spinal stenosis treated operatively and nonoperatively, looking specifically at patients at least eighty years of age. This elderly population represents a large subset of patients with these two conditions for whom there is little evidence regarding optimal treatment. Every spine surgeon moves forward with trepidation in treating such elderly patients because of the medical comorbidities facing this population. The results of this study demonstrate that this demographic group benefits from surgery similarly to a younger population; this information is useful in counseling patients and indicating operative treatment. In their article, Rihn et al. perform a subgroup analysis of the original SPORT cohort of patients and compare patient-reported measures at baseline and at follow-up time points up to four years. Specifically, the authors evaluated and compared patients younger than eighty and at least eighty years of age in an “as-treated” analysis to assess the clinical outcomes of operative and nonoperative treatment for spinal stenosis and stenosis with degenerative spondylolisthesis. The rationale behind performing an as-treated analysis was the high rate of crossover between the nonoperative and operative groups in the original studies, which has been discussed previously1,2. As expected, the authors found a greater prevalence of comorbidities in the older group. They also found greater prevalences of multilevel stenosis, severe stenosis, and asymmetric motor weakness in the older cohort. Despite this, compared with the younger cohort, the patients who were at least eighty years old had similar treatment effects for all primary and secondary outcomes with the exception of a smaller improvement in SF-36 (Short Form-36) bodily pain and a lower percentage of self-rated major improvement. The rates of intraoperative and postoperative complications, reoperation, and postoperative mortality were not higher than those in the younger cohort. In addition, within the cohort of patients who were at least eighty years old, those treated operatively had significantly greater improvement over baseline in all primary and secondary outcome measures compared with those treated nonoperatively. As discussed in the article, there is an increasing elderly population in the United States who suffer from the effects of lumbar spinal stenosis and spondylolisthesis, although little is known about the safety and effectiveness of operative treatment in patients over eighty years of age. With changing reimbursement rates, it will be important to determine the most economical and efficacious treatment for this cohort. This study is important, as it is the largest prospective study, drawing on the best data possible, to compare patients at least eighty years of age who were treated operatively and nonoperatively for these conditions. As the authors discuss, one of the weaknesses of the study involved the proportion of patients who underwent instrumented (as opposed to noninstrumented) arthrodesis, which was higher in the younger group (53%) than in the older group (32%). Had these proportions been comparable, a higher complication rate could have resulted in the older group, particularly given the greater prevalences of comorbidities, severe stenosis, and motor weakness seen in this age group. In addition, the original trial was not powered to detect differences between age groups. Thus, the present study may be underpowered to detect differences between the patients who were at least eighty years of age and those who were younger, although this should not affect the intragroup analysis. In the end, this study uses the best available data to demonstrate the short and long-term clinical benefits of surgical treatment of degenerative spondylolisthesis and spinal stenosis in patients of all ages, including those at least eighty years of age, and shows no substantially increased complication rate in the latter group. As the authors state, however, further investigation will be needed regarding whether surgery in this elderly population is cost-effective.