Paper #12 Exercise Tolerance in Growing Rod “Graduates” - New Respiratory Functional Outcome Measure

Abstracts / Spine Deformity 3 (2015) 612e629 sagittal plane a perfect fitting to the spine profile. Mean interval between two lengthening procedures was 10 months (8 to 24 months). Results: At last follow-up, mean curve correction was 57%. A total of 9 unplanned surgeries were performed for 9 complications in 6 patients (18%): 6 rod breakage and 3 cases of infection that were healed with debridement and antibiotics. No anchor failure was observed. A proximal junctional kyphosis was observed in 8 cases (24%) without clinical symptoms. No autofusion nor fibrosis was noticed at the non instrumented levels of the curve when arthrodesis was performed in the 20 patients. 13 patients (40%) with residual curve less than 30 were observed and didn’t required arthrodesis at the end of treatment. Conclusion: The single rod technique was found to be safe and effective to maintain curve correction until skeletal maturity. The complication rate was low thanks to respect of the fundamentals biomechanics rules: rod verticality, perfect sagittal contouring and mini invasive approach. Definitive arthrodesis was avoided in 40% of the patients. Author disclosures: L. Miladi: None. T. Odent: None. N. Khouri: None. C. Glorion: None. Paper #12 Exercise Tolerance in Growing Rod ‘‘Graduates’’ - New Respiratory Functional Outcome Measure Charles E. Johnston, MD, Kelly A. Jeans, MS, Dong-phuong Tran, MS, Anna McClung, RN Introduction: Pulmonary functional outcome for EOS patients who have undergone extensive treatment is thought to be relatively limited with regard to physical activity. PFTs are used in this population as a primary outcome measure of respiratory capacity but are highly dependent on effort, thus subjective. We wished to evaluate exercise O2 consumption as a new outcome measure to better characterize respiratory capacity. Methods: This IRB approved study tested EOS patients who had completed growing-rod treatment with at least 1 year since most recent surgery. They underwent oxygen consumption (VO2) testing while walking at self-selected speed overground (OG) and then during submaximal graded exercise test on a treadmill (TM). Maximal VO2 was measured in patients who were able to reach 85% age predicted heart rate (HR) maximum (85%) . Statistical analysis (student t-Tests) compared EOS patients to 20 control subjects (mean age 13). Results: 11 patients (4 congenital, 3 idiopathic,2 syndromic, 2 N-m), mean age 12.6 yr, completed OG testing. Mean %pred FVC548.4% for these subjects, who chose to walk at the same speed as controls, but at a higher VO2 Cost (0.28ml/kg/m vs 0.22ml/kg/m; p5.0001), and at a higher HR (132 vs 117, p5.021). TM testing showed 9/11 patients able to complete the protocol to 85%. EOS subjects consumed less VO2 during final stage test (28.2ml/min vs controls 34.2ml/min; p5.035), with a higher respiratory rate (50 vs 37,p5.005), lower tidal volume (.8 vs 1.5L, p5.001) and minute volume 36.2 vs 51.2 L/min, p!.003) than controls. EOS patients had lower predicted VO2 max (37.8ml/min) compared to controls (44.6ml/min, n.s.). Conclusion: While PFT data suggests worrisome pulmonary compromise in EOS ‘‘graduates’’ (!50% pred), this study shows that these children are able to keep up with their peers while walking around their communities. They also have the capacity to exercise, albeit with definite respiratory limitation. Author disclosures: C.E. Johnston: None. K.A. Jeans: None. D. Tran: None. A. McClung: None. Paper #13 Radiographic, Pulmonary, and Clinical Outcomes with Halo Gravity Traction Lauren LaMont, MD, Brandon Ramo, MD, Dong-Phuong Tran, MS, Chan-Hee Jo, PhD, Sarah Offley, MD, Heather Caine, BS, Kaitlyn Brown, BS, Wendy Wittenbrook, MA, RD, CSP, LD, Charles Johnston, MD

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Introduction: Halo gravity traction (HGT) has been proven to be a safe and effective intervention to improve spinal deformity prior to corrective instrumentation of the spine. Severe spinal deformity has been correlated with poor pulmonary; improved thoracic height afforded by HGT has the theoretical potential to improve pulmonary function prior to spinal deformity surgery. This study aims to (1) report on a large series of patients undergoing HGT, (2) demonstrate the correlation between thoracic height achieved and pulmonary function, and (3) evaluate the efficacy of nutritional assessment and intervention while in HGT for these often malnourished or nutritionally compromised patients. Methods: A single center retrospective chart review identified 107 patients who underwent HGT for severe spinal deformity from 2007- 2013 with >2 years follow-up. Major and minor coronal and sagittal Cobb angles; coronal balance; T1-T12 ht; and T1-S1 ht were collected pre HGT, during HGT, immediate postop, and 2 years postop. Pulmonary function tests (PFTs) recorded Forced Vital Capacity (FVC) and Forced Expiratory Volume in 1 second (FEV1). Nutritional interventions such as formal nutrition consult while admitted for HGT, resulting nutritional supplementation, or interventions were recorded. Results: HGT was used on average 11.5 (1.0-68.3) weeks with mean traction wt of 13.6kg (4.0-35.0) or 49.5% (16.1-107.1) of body wt. Mean coronal major Cobb angle improved by 49% from pre-op to post op, 35% improvement in sagittal plane, 23% in thoracic ht and 24% inT1-S1 height. 67 patients had PFTs pre-HGT, 17 had PFTs performed at all three data points longitudinally, comparisons were made between longitudinal data points. Significant correlations were found between improvement in thoracic ht and improvement in PFTs although not for all parameters. While there was a trend for wt gain in traction, no significant changes occurred nor did we find any significant correlations with wt gain and nutrition consult, intervention, or supplementation. Conclusion: We found a significant correlation between improvement in PFTs and thoracic height gained (graph), the first time this correlation has been shown with HGT. When stratified by BMI, there was no significant weight gain over time points, regardless of nutritional intervention. Future studies assessing non-radiographic benefits of HGT such as nutritional support and pulmonary function improvement, will benefit prospectively from assessment of patients’ pulmonary and nutritional status. Author disclosures: L. LaMont: None. B. Ramo: None. D. Tran: None. C. Jo: None. S. Offley: None. H. Caine: None. K. Brown: None. W. Wittenbrook: None. C. Johnston: None. Paper #14 The Radiographic and Clinical Impact of Preoperative Halo-Gravity Traction in the Treatment of Early-Onset Spinal Deformity Lawrence G. Lenke, MD, Patrick A. Sugrue, MD, Keith H. Bridwell, MD, Michael P. Kelly, MD, Scott J. Luhmann, MD, Brenda A. Sides, MA, Steven Bokshan, MS, David B. Bumpass, MD, Isaac O. Karkari, MD, Jeffrey L. Gum, MD Objective: To determine the radiographic and clinical impact of preoperative halo-gravity traction (HGTx) on patients < 10 years of age with early-onset spinal deformity, we performed a retrospective cohort study. Methods: Patients < 10 years of age who underwent placement of a growing construct or definitive instrumentation/fusion and were treated with preoperative HGTx were assessed using pre- and post-traction radiographs and clinical record review. A separate cohort were identified who had a growing rod construct inserted without preop HGTx and matched 1:1 with a similar group who had preop HGTx (15 pts per group). Results: 44 pts (24M, 20F) were included. The average age at time of halo placement was 6.4 years (range, 2.6 - 10.4) and the average duration of traction was 2 months (range, 1 wk - 6.5 mo.) with an average maximum traction weight of 19.3 lbs. (range, 11-32 lbs.; maximum weight on average was 55% of patient’s body weight). HGTx resulted in improvements in proximal thoracic Cobb (41.8 vs. 35.0 ; P!0.001), main thoracic Cobb (83.3 vs. 63.8 ; P!0.0001), thoracolumbar/lumbar Cobb