Paper #9: Growth Patterns of the Neurocentral Synchondrosis in Immature and Growing Vertebra

Abstracts / Spine Deformity 2 (2014) 498e517 for the elaboration of a spinal standard growth curve that could help health care providers better assess patients’ spinal growth. These data could eventually be used to predict spinal length at maturity or spinal height changes in pathologic conditions.

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framework for determining the difference between ribs from normal children and those with scoliosis.

Author disclosures: PT (none); LT (none); MR-B (none); MB (none); HL (grants/research support from Canadian Institutes of Health Research, Spinologics, Natural Sciences and Engineering Council of Canada, DePuy Synthes; ownership interest/shareholder in Spinologics; royalty/patent holder of Spinologics; SP (grants/research support from DePuy Synthes, EOS Imaging, Canadian Institutes of Health Research, Fonds de Recherche Quebec-Sante, Natural Sciences and Engineering Council of Canada; Consulting fees from Medtronic, DePuy Synthes, EOS Imaging, Spinologics, AO Foundation; ownership interest/shareholder with Spinologics; royalty/patent holder of Spinologics) Paper #8 Coupled Symmetry and Pattern of Rib Growth in the Growing Human Richard M. Schwend, John Schmidt, PhD, Laurel C. Blakemore, MD, Julie L. Reigrut, MS, Behrooz Akbarnia Introduction: Whereas there is substantial information on changes of the ribcage during childhood and asymmetry of the thorax in children with scoliosis, there are virtually no normative data on the growth of ribs throughout childhood and adolescence. Methods: The HamanneTodd Osteological Collection provided the bones of 32 specimens aged 1 to 18 years. A total of 6,226 individual photographs of all vertebral bodies and ribs were obtained from these specimens. Quantitative measurements were taken with image analysis software and the results of 2 of the measurements, the outer costal length (OCL) and base diameter (BD), are presented here. Results: With the exception of the ribs at T12, both the OCL and the BD showed a linear, statistically significant growth with age for all ribs, and the linear relationship between the BD and OCD correlated across all ages, which indicated that the ribs changed their dimensions in unison. The BD  OCL product indicates that the ribs grow through coupled symmetry, in which ribs in the upper and lower thorax start at the same size and grow at the same rate within the pair; ribs 1 and 12, 2 and 11, and 3 and 10. Each rib pair grows at a significantly different rate from the other pairs. Measurements of BD and OCL from a specimen with scoliosis from the collection compared with these normative values were greatly different. The principle that ribs follow a known geometric shape, called the golden spiral, is introduced. Similar to a nautilus shell, rib growth is primarily at the sternal end of the rib spiral. Conclusions: The authors believe that this is the first report of the change in length and shape of normal ribs, measured directly from the human specimens in a wide age range of children who did not have scoliosis. These data add to the understanding of normal rib growth and provide a

Author disclosures: RMS (grants/research support from K2M, Inc; consulting fees from advisory boards: Project Perfect World, Miracle Feet; chair: AAP Section on Orthopaedics); JS (grants/research support from K2M, Inc); LCB (grants/research support from K2M, Inc); JLR (grants/ research support from K2M, Inc.); BA (grants/research support from DePuy Spine (to institution); consulting fees from K Spine, Ellipse Inc, K2M; ownership interest/shareholder in K Spine, Ellipse; royalty/patent holder of DePuy Spine, K2M) Paper #9 Growth Patterns of the Neurocentral Synchondrosis in Immature and Growing Vertebra Richard M. Schwend, Laurel C. Blakemore, MD, John A. Schmidt, PhD, Behrooz Akbarnia, MD Introduction: Understanding the development, growth, and closure of the neurocentral synchondrosis (NCS) is essential for proper recognition and treatment of pediatric spinal disorders. Published information on normal growth of the NCS is limited to magnetic resonance imaging evaluation of the thoracic and lumbar spine, showing differential closure based on age and vertebral level. The intent of this study was to evaluate the growth pattern of NCS in all 3 regions of the spine in actual pediatric specimens. Methods: Measurements were taken from the cervical, thoracic, and lumbar vertebral bodies (VB) of 32 pediatric specimens, ranging from age

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Abstracts / Spine Deformity 2 (2014) 498e517

1 to 18 years (there were no 2- or 9-year-old specimens in this dataset) from the HamanneTodd Osteological Collection at the Cleveland Museum of Natural History. A total of 733 VBs were available for analysis. All available VBs from C1 to L5 were photographed in 6 orthogonal planes using high-definition photography. All images were calibrated and quantitative measurements taken from the photographs of the cranial-caudal view using Scandium Image Analysis System. For each VB, both the left and right sides of each NCS and the actual width of the pedicle (at the same level as the NCS) were measured. Dividing NCS by the pedicle width and multiplying by 100 provided the percentage of the open growth plate. Results: Age and the 3 regions of the spine were evaluated. The graph shows that in early childhood and in all 3 regions of the spine the NCS was active and open. By age 5 years, the cervical spine NCS had virtually closed; only 10% of the NCS remained open. Although it closed rapidly, the lumbar spine was still nearly 50% open at age 5 years and was closed by age 10 years. The thoracic spine was only 25% closed at age 5 years and remained open through age 17 years. There was no difference between the left and right NCS data (t test, not significant). Conclusions: These data support the theory that vertebral growth can still be ongoing in the thoracic spine when the NCS is already closed in both cervical and lumbar regions. This may coincide with adolescent peak growth velocity, the doubling of thoracic volume after age 10 years, a period for the development of idiopathic scoliosis.

Paper #10 Does Initial Cast Correction Predict Treatment Success for Infantile Scoliosis? Jaime A. Gomez, MD, Alexandra Grzywna, BS, Lawrence Karlin, MD, Patricia Miller, MS, John Emans, MD, Michael Glotzbecker, MD Purpose: Casting treatment for early-onset scoliosis results in varying amounts of curve correction. Because the reasons for patients’ differential outcomes are not fully elucidated, the aim was to examine casting outcomes and identify which factors correlate with appropriate curve control. Methods: Patients who underwent scoliosis casting for idiopathic earlyonset scoliosis between 2010 and 2013 were identified. Demographic and clinical data were collected, including Cobb angles and ribevertebra angle difference at presentation, after first casting, and at last follow-up. Univariate and multivariate regression analysis was used to identify prognostic factors associated with good outcomes. Results: The researchers identified 29 patients (13 female and 16 males), a mean age at initial casting of 2.2 years (range, 0.6e5.8) years. Mean follow-up after initial casting was 2 ( 0.9) years. Cobb angles were improved from a mean of 45 ( 9.9 ) to 17.3 ( 6.4 ) with the initial cast application demonstrating a 62.1% correction. Ribevertebra angle difference showed improvement from 26 to 13 (48% correction) after placement of initial cast. Overall, patients remained a mean of 15 months in a body cast and required an average of 6 casts (range, 2e13 casts) during the follow-up period. Multivariate analysis determined that age and change in Cobb angle after initial cast were significant predictors of most recent Cobb (p 5 .004; R2 5 29.9%). Subjects who were placed in a cast at a younger age yielded a smaller Cobb angle at follow-up compared with those who casted at an older age. For each additional year of age at placement in a cast, the most recent Cobb angle increased by 4 (p 5 .01). Also, patients with greater change in Cobb angle with initial placement in a cast yielded a smaller Cobb angle at follow-up. For each additional percent change in Cobb angle at casting, the final Cobb angle decreased by 0.41 (p 5 .005). Conclusions: Age and change in Cobb angle with initial casting were significant predictors of curve outcome at 2-year follow-up. Curve control is more likely attained the younger a child is casted, which reaffirms the importance of early treatment. Furthermore, initial cast correction, which may represent curve flexibility and/or cast quality, can predict the overall success of casting treatment, and therefore should be taken into account when considering the future of patients’ care. Author disclosures: JAG (none); AG (none); LK (none); PM (none); JE (none); MG (none) Paper #11 Effectiveness of Serial Derotational Casting for Treatment of Children With Early-Onset Scoliosis Anny Hsu, MD, Hiroko Matsumoto, PhDc, Mark Sullivan, BA, Evan Trupia, BS, Benjamin Roye, MD, MPH, David P. Roye, MD, Michael G. Vitale, MD, MPH

Author disclosures: RMS (grants/research support from K2M; advisory board of Project Perfect World, Miracle Feet; Chair of AAP Section on Orthopaedics); LCB grants/research support from K2M; consulting fees from Medtronic, Stryker; Associate Editorial Board of Spinal Deformity, Member at large, board of directors of Scoliosis Research Society); JAS (grants/research support from K2M); BA (grants/research support from DePuy Spine to institution; consulting fees from K Spine, K2M; ownership interest/shareholder in K Spine, Ellipse; royalty/patent holder for DePuy Spine, K2M)

Introduction: Early-onset scoliosis (EOS) is a challenging orthopedic disorder and can be disabling or even fatal if left untreated. Serial derotational casting has emerged as a potentially curative technique for EOS patients. The purposes of this study were to examine the effectiveness of scoliosis casting and identify factors that will affect the efficacy of casting treatment for children with EOS. Methods: The authors retrospectively reviewed 28 patients who underwent serial casting for EOS at a single institution from 2009 to 2014. Sixteen patients met inclusion criteria including a diagnosis of EOS, having undergone serial Mehta/Cotrel derotational casting, and radiographic evaluation between treatments. Patients with prior spine casting or pertinent surgical interventions were excluded. Diagnosis, time in cast, and number of casts were recorded. Cobb angles were calculated. Results: Sixteen patients met the inclusion criteria (13 idiopathic, 1 congenital/structural, and 2 syndromic). Mean age at initial casting was 2.4 years, with mean major curvature of 50.3 . Patients had an average of 4.4 derotational