Abstracts for CSRS 2012

Abstracts for CSRS 2012s for CSRS 2012 THE IMPACT OF POSITIVE REGIONAL SAGITTAL ALIGNMENT ON OUTCOMES IN POSTERIOR CERVICAL FUSION SURGERY Tang, J.A., Scheer, J.K., Smith, J.S., Deviren, V., Bess, S., Hart, R.A., Lafage, V., Shaffrey, C.I., Schwab, F., Ames, C.P., and the ISSG Department of Neurological Surgery, University of California, San Francisco, San Francisco, USA; School of Medicine, University of California, San Diego, School of Medicine, San Diego, USA; Department of Orthopedic Surgery, University of California, San Francisco, San Francisco, USA; Rocky Mountain Scoliosis and Spine Center, Denver, USA; Department of Orthopaedic Surgery, Oregon Health and Science University, Portland, USA; Department of Orthopaedic Surgery, NYU Hospital for Joint Diseases, New York, USA; Department of Neurosurgery, University of Virginia Health System, Charlottesville, USA Introduction: Positive spinal sagittal malalignment has repeatedly shown to correlate with pain and disability in thoracolumbar fusion. This study evaluated the relationship between cervical sagittal alignment and postoperative outcomes for patients receiving multilevel cervical fusion. Methods: From 2006-2010, 113 patients received multi-level cervical fusion for cervical stenosis, myelopathy, and kyphosis. Radiographic measurements at intermediate follow-up included: (1) C1-C2 lordosis, (2) C2-C7 lordosis, (3) C2-C7 sagittal vertical axis (C2-C7 SVA), (4) Center of gravity of head SVA (CGH-C7 SVA), and (5) C1-C7 SVA. Health related quality of life measures (HRQOL) included neck disability index (NDI), visual analog pain scale (VAS), and SF-36 physical component (PCS) scores. Pearson product-moment correlation coefficients were calculated between pairs of radiographic measures and HRQOL scores. Improvement in NDI scores following surgery were evaluated by categorizing scores into standard intervals: no disability(0-4), mild(5-14), moderate(15-24), severe(35-34), and complete([34). Results: 80 % of patients experienced an improvement of NDI scores or remained the same compared to preop. PCS scores improved by 22.0 ± 37.5 %. Both C2-C7 SVA and CGH-C7 SVA negatively correlated with PCS (r = –0.43, p \ 0.001 and r = –0.36, p = 0.005, respectively). C2-C7 SVA positively correlated with NDI scores (r = 0.20, p = 0.036). C1-C2 lordosis constituted 76.0 ± 15.8 % of total cervical lordosis (sum of C1-C2 and C2-C7 lordosis). C2-C7 SVA positively correlated with C1-C2 lordosis (r = 0.33, p = 0.0003). For significant correlations between C2-C7 SVA and NDI scores, regression models predicted a threshold C2-C7 SVA value of approximately 40 mm, beyond which correlations were most significant. Conclusion: Positive cervical sagittal malalignment, measured by C2-C7 SVA, negatively affects HRQOL scores following multi-level cervical fusion at intermediate follow-up. This is the first study to examine the impact that regional SVA in the cervical spine has upon HRQOL following multi-level cervical fusion. Our findings demonstrate that, similar to the thoracolumbar spine, the severity of disability increases with positive sagittal malalignment following surgical reconstruction. ADJACENT SEGMENT DEGENERATION FOLLOWING PRODISC-C TOTAL DISC REPLACEMENT AND ANTERIOR CERVICAL DISCECTOMY AND FUSION–DOES SURGEON BIAS EFFECT RADIOGRAPHIC