Giuseppe Barbagallo, MD University of Catania, Catania, Italy International Variations in the Clinical Presentation and Management of Cervical Spondylotic Myelopathy. One Year Outcomes of the AOSpine Multi-Center Prospective Study. Giuseppe Barbagallo, MD University of Catania, Catania, Italy On Behalf of the CSM-I Site Investigators : Michael Fehlings, MD, University of Toronto, Toronto, ON, Canada; Branko Kopjar, MD, University of Washington, Seattle, WA; Ronald Bartels, MD, University Nijmegen Medical Centre, Nijmegen, Netherlands; Vincenzo Albanese, PhD, Medical University of Catania, Catania, Italy; Helton Defino, MD, University of Sao Paulo - Ribeirao Preto, Sao Paulo, Brazil; Paul Arnold, MD, University of Kansas, Kansas City; Qiang Zhou, MD, Southwestern Hospital, ChongQing, China; Mehmet Zileli, MD, Ege University, Izmir, Turkey; Gamaliel Tan, MD, Tan Tock Seng Hospital, Singapore, Singapore; Osmar Moraes, MD, Hospital Santa Marcelina, Sao Paulo, Brazil; Shashank Kale, MD, All India Institute of Medical Sciences, New Dehli India; Ciaran Bolger, MD, Beaumont Hospital, Dublin, Ireland; Manuel Alvarado, MD, Hospital San Juan de Dios, Caracas, Venezuela; Massimo Scerrati, MD, Medical University of Ancona, Ancona, Italy

Background Cervical spondylotic myelopathy (CSM) is the commonest cause of spinal cord impairment. There is a lack of evidence regarding the long term outcomes of surgical treatment for CSM. We report on the one year outcomes of a large prospective multicenter study to evaluate the impact of surgery on outcomes of CSM.

Patients 379 patients with clinically confirmed CSM and imaging evidence of cord compression (MRI or CT-myelogram) were enrolled in the prospective cohort study. Patients underwent anterior surgery (discectomy/corpectomy and instrumented fusion) or posterior surgery (laminectomy and fusion or laminoplasty) based on the judgment of the operating surgeon.

Subjects accounting 379 subjects were enrolled at 13 sites around the world. One year follow-up data are currently available for 193 subjects. Outcomes evaluations modified Japanese Orthopaedic Assessment scale (mJOA), Nurick Score, Neck Disability Index (NDI), Short Form-36v2, and an assessment of treatment complications.

Primary Investigators and Regions City Primary Investigator North America Toronto Dr. M. Fehlings Kansas City Dr. P. Arnold Asia / Pacific ChongQing Dr. Q. Zhou New Dehli Dr. S. Kale Singapore Dr. G. Tan Latin America Ribeirao Preto Dr. H. Defino Sao Paulo Dr. O. Moraes Caracas Dr. M. Alvarado Europe Nijmegen Dr. R. Bartels Izmir Dr. M. Zileli Dublin Dr. C. Bolger Catania Dr. G. Barbagallo Ancona Dr. M. Scerrati 125 121 81 52

Demographics Variable Anterior (N=224) Posterior (N=144) Circumferential (N=9) P-value Age 54.0±12.1 59.8±12.2 55.5±9.2 <.01 Male Gender 55.3% 73.5% 44.44% mJOA 12.9±2.1 11.9±2.9 12±2.8 Nurick 4.1±1.1 4.6±1.4 4.8±1.3 NDI 38.5±20.3 38.4±21.9 34.9±24.8 .84 SF36 V2 PCS 35.6±8.6 34.4±8.8 34.1±8.6 .30 SF36 V2 MCS 38.7±9.7 39.1±10.3 37.7±7.4 .91 Levels 2.95±.9 4.7±.9 3.9±0.9

12 months outcomes (N=193) Variable Baseline 12 Months P value mJOA 12.5±2.9 15.1±2.7 <.01 Nurick 4.3±1.2 2.9±1.5 NDI 38.2±20.9 26.7±19.1 SF36 PCS 35.1±8.6 43.2±10.1 SF36 MCS 38.8±9.9 45.2±10.6

12 months outcomes (N=193) - mJOA

Regional Differences in Demographics Variable North America (N =113) Latin America (N =43) Europe (N =123) Asia pacific (N =57) P value Age 59.7±11.6 54.6±10.2 57.4±12.1 50.5±13.2 <.001 Male Gender 57.0% 71.1% 59.3% 70.3% Surgery Anterior 56.7% 23.1% 72% 67.5% Posterior 39.2% 76.9% 24.8% 32.5% Circumferential 4.1% 0% 3.2% Number of levels 4.2±1.3 4.1±1.1 3.2±1.0 3.3±1.2 Regional Differences in Baseline Variables Variable North America Latin America Europe Asia Pacific P Value MJOA 12.2±2.3 12.4±3.5 13.1±2.9 12.3±3.2 n.s. NDI 37.6±21.7 39.1±20.6 37±20.7 41.9±20.3 Nurick 4.2±1.0 4.4±1.6 4.2±1.2 4.6±1.4 PCS 35.3±9.8 35.4±8.8 34.8±7.8 35.0±8.2 MCS 39.2±10.4 41.8±11.2 37.9±8.8 37.8±9.4

Regional Differences in Outcomes Variable North America Latin America Europe Asia Pacific P value mJOA 2.76(0.29) 2.07(0.38) 1.30(0.28) 2.92(0.39) 0.0006 NDI 7.21(2.42) 10.24(3.20) 8.23(2.28) 12.42(4.31) 0.7345 Nurick 1.56(0.17) 0.62(0.23) 1.18(0.16) 1.45(0.23) 0.0087 PCS 6.06(1.22) 10.53(1.52) 4.58(1.12) 12.35(1.55) 0.0002 MCS 5.04(1.30) 8.91(1.63) 3.17(1.19) 9.77(1.66) 0.0036 *Values in table show changes in outcome between baseline and 12 months adjusted for baseline predictors. Numbers in parenthesis are standard error.

Discussion Surgical treatment for CSM results in sustained improvement in generic and disease HRQOL The amount of improvement varied across the regions. Subjects from Asia & Pacific and Latin America had larger improvements in outcome than those from North America and Europe. The impact of differences in age (much younger in Asia/Pacific) and socio-cultural perceptions of disability and impairment likely play a role in these observations

Acknowledgements Study is funded by AOSpine International, a non-for-profit organization for excellence in spine.