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(Left to right) Kenneth M.C. Cheung, MD; Tsz Ping Lam, MD; Justin S. Smith, MD, PhD; and SRS President David W. Polly Jr, MD.
Courtesy of the SRS

AAOS Now

Published 12/1/2016
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Paul D. Sponseller, MD

International Teams Are Making Advances in Scoliosis Research

SRS annual meeting provides forum for innovations
With more than 1,500 attendees, the 51st annual meeting & course of the Scoliosis Research Society (SRS) was an opportunity to learn about the newest developments in both pediatric and adult deformity. The 3-day meeting, held in the Soviet-era Congress Centre in Prague, Czech Republic, included more than 130 podium presentations by researchers from all parts of the globe.

The wide-ranging presentations not only explored the etiology of spinal deformity, but also examined the need for risk stratification and investigated both the safety and outcomes of surgery.

Osteopenia and AIS
The Russell A. Hibbs Award for the best clinical paper was presented to Tsz Ping Lam, MD, and his team from the Chinese University of Hong Kong for their paper, "Preventing Curve Progression in Adolescent Idiopathic Scoliosis (AIS) with Calcium and Vitamin D Supplementation—A Randomised, Double-blinded, Placebo-controlled Trial." Based on previous research showing that adolescents with idiopathic scoliosis have a significant incidence of osteopenia, the researchers tested whether this has a causative role in progression of the curves.

The 2-year prospective randomized clinical trial involved three groups of girls diagnosed with AIS (Cobb angle greater than 15 degrees) and osteopenia. The control group was given a placebo while the two treatment groups received 600 mg calcium and either 400 IU or 800 IU of vitamin D3. Not only did the treatment groups gain bone density as measured by computed tomography and dual-energy X-ray absorptiometry (DEXA), they also had a lower rate of significant curve progression.

The authors speculate that the interaction between growth and the osteopenic vertebra may play a role in AIS progression. They recommend testing AIS patients for osteopenia and treating them appropriately. According to Dr. Lam, "This trial provides strong evidence of the therapeutic effect of calcium and vitamin D supplementation for improving bone health and preventing curve progression in AIS."

Although the inclusion criteria for the study applied to a limited population, the authors noted, "We believe that optimizing both vitamin D status and dietary calcium intake needs to be considered when managing AIS patients. As for the dosage, 'one formula for all' is probably not applicable. Supplementation is best individualized to supplement what the patient lacks, either in form of lifestyle modification or taking oral tablets. Once treatment starts, it may take 2 to 3 years before the therapeutic effects become clinically apparent."

Melatonin and AIS
The best basic science paper also dealt with AIS etiology, the understanding of which has progressed slowly but steadily compared to genetic science as a whole. In Japan, Masafumi Machida, MD, and his lab have previously demonstrated the development of scoliosis in melatonin-deficient bipedal mice. In their basic science Russell A. Hibbs Award-winning paper, "The Possible Pathogenesis in Adolescent Idiopathic Scoliosis Based on Experimental Model of Melatonin-deficient C57BL/6J Mice," they showed that supplementing melatonin prevented the development of scoliosis.

Iodine labeling was used to demonstrate that the location of the melatonin action was the paraventricular hypothalamus nucleus. The researchers suggest that this nucleus may be responsible for the development of scoliosis. Although human trials were not involved, findings such as this show the potential for new ways of affecting the development of scoliosis.

Data quality and risk stratification
As healthcare costs and quality become more pressing issues, spinal deformity surgeons are working to refine the quality of data available to physicians and payers. Although many different databases exist, some are more robust than others. The International Spine Study Group studied this potential flaw and presented its findings in a paper by Amit Jain, MD, and his team. "Medical Complications in 3,519 Surgically Treated Elderly Patients with Adult Spinal Deformity: Comparison of Multicenter Surgeon-Maintained vs. Medicare Claims Database" won the John H. Moe Award for best poster.

The researchers compared information in both databases on adults older than age 65 who underwent surgery for spine deformity. They found that both databases provided similar information on mortality and most major medical complications. However, the surgeon-maintained database provided much greater detail on the characteristics of the deformity and the procedure—information which would be needed to stratify risk accurately.

Other research
Answering a commonly asked question, Pawel Grabala, MD, and coauthors studied the pregnancy experience of women after surgery for AIS. They found no increased incidence of back pain during pregnancy. However, they did note an increased incidence of cesarean section in the women who had undergone fusion.

Other papers dealt with preventing complications around a fusion, such as at the proximal or distal junction where movement and fusion intersect.

The next annual meeting of the SRS will be held in Philadelphia, Sept. 6–9, 2017. For more information on the 2016 meeting, including the final program, visit www.srs.org

Paul D. Sponseller, MD, is chief of pediatric orthopaedics at the Johns Hopkins School of Medicine; he can be reached at psponse@jhmi.edu

About the SRS
The Scoliosis Research Society (SRS) is an international organization with a membership of 1,300 representing 61 countries. Of the 52 new members inducted this year, 40 percent were from outside the United States. Reflecting the interdisciplinary nature of spine surgery, neurosurgeons now account for 5 percent of the SRS membership.

The primary focus of the SRS is on providing continuing medical education for healthcare professionals and on funding and supporting research in spinal deformities. Founded in 1966, the SRS has gained recognition as the world's premier spine deformity society. For more information, visit www.srs.org