NASS 29th Annual Meeting Proceedings Wednesday, November 12, 2014 7:30 – 8:30 a.m. Best Papers d Surgery 1. Outcomes of Operative and Nonoperative Treatment for Adult Spinal Deformity (ASD): A Prospective, Multicenter Matched and Unmatched Cohort Assessment with Minimum Two-Year Follow-Up International Spine Study Group 1 , Justin S. Smith, MD, PhD 2 , Virginie Lafage, PhD 3 , Christopher I. Shaffrey, MD 4 , Frank J. Schwab, MD 3 , Richard A. Hostin, MD 5 , Oheneba Boachie-Adjei, MD 6 , Behrooz A. Akbarnia, MD 7 , Eric O. Klineberg, MD 8 , Munish C. Gupta, MD 9 , Themistocles S. Protopsaltis, MD 3 , Justin K. Scheer, BS 10 , Kai-Ming G. Fu, MD, PhD 11 , Gregory M. Mundis, Jr., MD 7 , Khaled M. Kebaish, MD 12 , Breton Line 13 , Han Jo Kim, MD 6 , Vedat Deviren, MD 14 , Robert A. Hart, MD 15 , Douglas C. Burton, MD 16 , Shay Bess, MD 17 , Christopher P. Ames, MD 14 ; 1 Brighton, CO, US; 2 University of Virginia Health System, Charlottesville, VA, US; 3 New York University Langone Medical Center Hospital for Joint Diseases, New York, NY, US; 4 University of Virginia Department of Neurosurgery, Charlottesville, VA, US; 5 Southwest Scoliosis Institute, Plano, TX, US; 6 Hospital for Special Surgery, NewYork, NY, US; 7 San Diego Center for Spinal Disorders, La Jolla, CA, US; 8 University of California Davis School of Medicine, Sacramento, CA, US; 9 University of California Davis Orthopaedic Surgery, Sacramento, CA, US; 10 University of California San Diego, San Diego, CA, US; 11 Weill Cornell Medical College, New York, NY, US; 12 Baltimore, MD, US; 13 Denver, CO, US; 14 University of California San Francisco, San Francisco, CA, US; 15 Oregon Health and Science University, Portland, OR, US; 16 University of Kansas Medical Center, Kansas City, KS, US; 17 Rocky Mountain Scoliosis and Spine, Denver, CO, US BACKGROUND CONTEXT: Adults with spinal deformity typically present with pain and disability. PURPOSE: Our objective was to compare outcomes for operative (op) and nonoperative (nonop) treatment for ASD based on a prospective, mul- ticenter patient population. STUDY DESIGN/SETTING: Multicenter, prospective, consecutive case series with matched and unmatched cohort analyses. PATIENT SAMPLE: 689 ASD patients. OUTCOME MEASURES: Baseline (BL) and minimum 2-yr health- related quality of life (HRQL) measures including Scoliosis Research Society Questionnaire 22r (SRS-22r), Oswestry Disability Index (ODI), Short Form 36 Health Questionnaire (SF-36; Physical Component Score [PCS] and Mental Component Score [MCS]), and back and leg pain nu- meric rating scale (NRS) scores. METHODS: This is a multicenter, prospective analysis of consecutive ASD patients electing for either op or nonop care at enrollment. Inclusion criteria: age O 18 yr and ASD. Propensity scores were used to match op and nonop patients based on BL ODI, SRS-22r, maximum thoracolumbar/ lumbar Cobb angle, pelvic incidence to lumbar lordosis mismatch (PI-LL), and leg pain NRS score. RESULTS: 689 patients met criteria, including 286 op and 403 nonop, with mean ages of 53 and 55 yrs, minimum 2-yr follow-up rates of 86% and 55%, and mean follow-up of 24.7 and 24.8 months, respectively. At BL, compared with nonop, op patients had significantly worse HRQL based on ODI, SRS22, SF36, and leg and back pain NRS (p !0.001) and had worse deform- ity based on pelvic tilt, PI-LL, and C7SVA (p ! 0.002). Before reaching min 2-yr follow-up 38 nonop patients converted to op treatment and were ana- lyzed in the op group. At min 2-yr follow-up all HRQL measures assessed significantly improved for op patients (p !0.001), but none of these meas- ures improved significantly for nonop patients (p O 0.11). 97 matched op- nonop pairs were identified based on propensity scores. At last follow-up the 97 matched op patients had significant improvement in all HRQL meas- ures assessed (p !0.001), but the 97 matched nonop patients lacked signifi- cant improvement in any of the HRQL measures (p O0.20). Paired op-nonop analysis demonstrated the op patients to have significantly better HRQL scores at follow-up for all measures assessed (p ! 0.001), except SF36 MCS (p50.058). Overall minor and major complication rates for op patients were 53% and 40%, respectively. CONCLUSIONS: The present study is a large prospective, multicenter analysis of op and nonop treatment for ASD. At minimum 2-yr follow- up, both unmatched and matched analyses demonstrated significant im- provement in standardized HRQL measures for op patients. In contrast, nonop treatment appears to at best maintain presenting levels of pain and disability. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. http://dx.doi.org/10.1016/j.spinee.2014.08.015 2. Comparison of Best versus Worst Clinical Outcomes for Adult Spinal Deformity (ASD) Surgery: A Prospective, Multicenter Assessment with Minimum Two-Year Follow-Up International Spine Study Group 1 , Justin S. Smith, MD, PhD 2 , Christopher I. Shaffrey, MD 3 , Virginie Lafage, PhD 4 , Frank J. Schwab, MD 4 , Themistocles S. Protopsaltis, MD 4 , Eric O. Klineberg, MD 5 , Munish C. Gupta, MD 6 , Justin K. Scheer, BS 7 , Richard A. Hostin, MD 8 , Kai-Ming G. Fu, MD, PhD 9 , Han Jo Kim, MD 10 , Alexandra Soroceanu, MD, MPH 11 , Vedat Deviren, MD 12 , Robert A. Hart, MD 13 , Douglas C. Burton, MD 14 , Shay Bess, MD 15 , Christopher P. Ames, MD 12 ; 1 Brighton, CO, US; 2 University of Virginia Health System, Charlottesville, VA, US; 3 University of Virginia Department of Neurosurgery, Charlottesville, VA, US; 4 New York University Langone Medical Center Hospital for Joint Diseases, New York, NY, US; 5 University of California Davis School of Medicine, Sacramento, CA, US; 6 University of California Davis Orthopaedic Surgery, Sacramento, CA, US; 7 University of California San Diego, San Diego, CA, US; 8 Southwest Scoliosis Institute, Plano, TX, US; 9 Weill Cornell Medical College, New York, NY, US; 10 Hospital for Special Surgery, New York, NY, US; 11 Dalhousie University, Halifax, NS, Canada; 12 University of California San Francisco, San Francisco, CA, US; 13 Oregon Health and Science University, Portland, OR, US; 14 University of Kansas Medical Center, Kansas City, KS, US; 15 Rocky Mountain Scoliosis and Spine, Denver, CO, US BACKGROUND CONTEXT: Studies suggest that average clinical out- comes are improved with surgery for selected adult spinal deformity (ASD) patients, but these outcomes span a broad range. PURPOSE: Our objective was to compare ASD patients with best vs worst clinical outcomes to identify distinguishing factors. STUDY DESIGN/SETTING: Multicenter, prospective, consecutive case series. PATIENT SAMPLE: 227 ASD patients. OUTCOME MEASURES: Baseline and minimum 2-yr health-related quality of life (HRQL) measures including Scoliosis Research Society The Spine Journal 14 (2014) 1S–183S Refer to onsite Annual Meeting presentations and postmeeting proceedings for possible referenced figures and tables. Authors are responsible for accurately reporting disclosures and FDA device/drug status at time of abstract submission.