Friday, May 6, 2011
Another Take on Adult Scoliosis Complications
Last week on The Spine Blog, we discussed Dr. Sansur’s review of the SRS morbidity and mortality database for adult scoliosis, which reported a seemingly low complication rate of 13.4%. This week we review a similar article from Dr. Smith, also a co-author on the SRS paper, which reports complication rates stratified by age, ranging from 17% for those aged 25-44 to 71% for those aged 65-85. These results are obviously more in line with prior studies and demonstrate that different definitions and methods of capturing complications lead to different complication rates. Interestingly, the SRS study reported no differences in complication rates for those over and under 60, which is in stark contrast to this study from the Spinal Deformity Study Group. What makes this study unique is that rather than just reporting a higher complication rate for elderly patients, it also looked at the “benefit” side of the equation to determine if elderly patients improve following surgery to a similar degree as younger patients. Somewhat surprisingly, the elderly group actually showed the greatest degree of improvement on the ODI and leg pain numeric rating scale. A portion of this large degree of improvement can likely be attributed to the elderly patients starting with the worst ODI and leg pain scores, giving them more room for improvement. However, their follow-up scores were essentially indistinguishable from the younger patients, demonstrating convincingly that the elderly benefit from scoliosis surgery. This study leaves us with the question of whether or not the potential benefits are worth the substantial risks.
To answer that question, a high quality prospective observational study controlling for baseline differences or an RCT comparing surgical to non-operative treatment for scoliosis in the elderly would be necessary. Given the heterogeneity of pathology and treatment in adult scoliosis, it is unclear if such a study will ever be performed. The current study provides tremendously important data that can be used to counsel elderly patients considering scoliosis surgery. They can be given hard data about the high complication rate as well as the significant improvement they can expect from surgery and allowed to make an informed decision. While this study does have some limitations, including a high loss to follow-up (over 50% at 2 years), it is likely the best data we currently have to counsel elderly scoliosis patients considering surgery. As mentioned, we won’t be able to answer the question of whether or not the benefits outweigh the risks until a prospective study comparing surgery to non-operative treatment is performed. Dr. Smith and the Spine Deformity Study Group did report the results of a retrospective review of their database comparing surgery to non-operative treatment for adult scoliosis and demonstrated a greater degree of improvement in back and leg pain for the surgically treated group. However, the two groups were likely quite different, and the analyses did not control for all of the potential confounders. Even if a prospective trial is performed, it will only yield answers for the “average” patient, and we never actually see the “average” patient in clinic. Such are the challenges of applying trial data to individual patients, and there will likely always be room for clinical judgment in addition to scientific data in the counseling of patients considering scoliosis surgery. Hopefully spine surgeons who treat adult scoliosis surgery will be able to use this study to educate their elderly scoliosis patients so that they can make an informed treatment decision in line with their values.
Please read Dr. Smith’s article and accompanying commentary. Will this article affect how you treat elderly scoliosis patients? Let us know by leaving a comment on The Spine Blog.
Adam Pearson, MD, MS