Operative management of symptomatic adult spinal deformity may provide best outcomes

Nonoperative treatments for patients with adult spinal deformity may not provide durable health outcomes improvements, according to study results.

BOSTON — Adults with symptomatic spinal deformity can opt for either an operative or nonoperative course of treatment. Researchers, however, recently found that available surgical procedures may provide patients with better outcomes for adult spinal deformity than nonoperative treatment.

Justin S. Smith, MD, PhD, said, “If we look at the entire nonoperative group as a whole, we can see at 2-year follow up they did not clinically significantly improve with regard to any of the outcomes measures used in this study. In contrast, the operative group improved significantly for all of the outcomes measured in this study.”

Justin S. Smith

Smith presented results of a prospective, multicenter patient population study at the Congress of Neurological Surgeons Annual Meeting, which was conducted to analyze the results of surgery compared to nonoperative treatment for patients with adult spinal deformity (ASD).

To operate or not

For the study, investigators in the International Spine Study Group (ISSG) analyzed results for 689 consecutive patients over the age of 18 with ASD who had a minimum 2-year follow up and opted for either surgery or nonoperative treatment. There were 286 patients in the operative group (mean age of 53 years) and 403 patients in the nonoperative group (mean age of 55 years).

The investigators performed both unmatched and propensity-matched analyses to compare minimum 2-year outcomes for operative and nonoperative treatment approaches for symptomatic ASD. Propensity matching of operative and nonoperative pairs was performed using baseline Oswestry Disability Index (ODI) scores, Scoliosis Research Society (SRS) Questionnaire 22r scores, SF-36 questionnaire results, including the Physical Component Scores (PCS) and Mental Component Scores (MCS), as well as back and leg pain numeric rating scale (NRS) scores. The propensity matching was also based on the severity of spinal deformity at presentation, using the maximum thoracolumbar/lumbar Cobb angle and pelvic incidence to lumbar lordosis mismatch (PI-LL), according to Smith.

The mean length of follow-up was 24.7 months and 24.8 months for the operative and nonoperative groups, respectively.

At baseline, the operative group of patients had significantly worse measurements than the nonoperative group of patients, Smith said. Compared with nonoperative patients, operative patients had significantly worse health-related quality of life (HRQOL) based on ODI, SRS22, SF-36, and leg and back pain NRS and had worse deformity based on pelvic tilt, PI-LL mismatch, and C7 sagittal vertical axis.

Better outcomes with operations

At a minimum 2-year follow-up, Smith said all of the HRQOL measures that the investigators assessed significantly improved for operative patients, but none of the measures demonstrated clinically significant improvement for nonoperative patients over the same time interval based on the unmatched analyses. With regard to the propensity matched analyses, at the last follow-up, the 97 matched operative patients had significant improvement in all HRQOL measures assessed, but the 97 matched nonoperative patients lacked clinically significant improvement in any of the HRQOL measures, he said.

Smith said that for the propensity matched operative/nonoperative pairs, the only measurement in which the operative group did not have a significantly better outcome was the SF-36 MCS, but even for this measure the operative group had a non-significant trend toward better scores than the nonoperative patients. In addition, baseline back pain NRS score was not used to generate the matched pairs and it was found that matched operative patients started out with significantly worse back pain compared with matched nonoperative patients. But, by 2-year follow-up, these operative patients had significantly less back pain compared with the matched nonoperative patients.

Overall, minor and major complication rates for operative patients were 53% and 40%, which is comparable to previous reports, he said.

“In summary, patients in this study who elected for nonoperative treatment tended to be less affected at presentation. They had less deformity, less pain, and less disability than those who elected for surgery. Based on this series, operative treatment for adult spinal deformity provided significant improvement in health-related quality of life. In contrast, nonoperative treatment appeared to, at best, maintain presenting levels of pain and disability over 2-year follow up. Thirdly, prospective studies are needed to assess the cost effectiveness of these treatments and these studies are currently underway through the ISSG,” Smith said. – by Robert Linnehan

Reference:

Smith JS. Paper #117. Presented at: Congress of Neurological Surgeons Annual Meeting; Oct. 18-22, 2014; Boston.

For more information:

Justin S. Smith, MD, PhD, can be reached at the University of Virginia School of Medicine, 1215 Lee St., Charlottesville, VA 22903; email: slb2jd@virginia.edu.

Disclosure: Smith receives royalties and honorarium for teaching from and is a consultant to Biomet. He is a consultant to and receives honorarium for teaching from Nuvasive. He receives honorarium for teaching from Globus. He is a consultant to Cerapedics. He receives honorarium for teaching and research funding from DePuy Synthes. He receives fellowship support from NREF. He receives fellowship and research support from AOSpine.