Wednesday, September 26, 2018 7:35 AM–9:00 AM ePosters: P95. Quantitative age-adjusted targets for ideal cervicothoracic sagittal alignment in asymptomatic adults

Abstract

BACKGROUND CONTEXT Recent research has identified increased C2-T3 angle as a risk factor for persistent sagittal malalignment following thoracolumbar surgery. Despite this, no ideal cervicothoracic alignment thresholds exist in the literature. As several studies have demonstrated a clear relationship between the normal aging spine and sagittal spinal alignment, such ideal-alignment thresholds should also account for patient age. PURPOSE This study proposes age-specific cervicothoracic alignment targets using previously published age-specific normative Neck Disability Index (NDI) values. STUDY DESIGN/SETTING Single center retrospective review. PATIENT SAMPLE A total of 223 patients with available biplanar full-body stereographic x-rays. OUTCOME MEASURES C2-T3 lordosis; Neck Disability Index score. METHODS Patients >18 years with cervical sagittal vertical axis RESULTS Overall, 223 patients (50±20years, 65% F) met inclusion criteria, presenting with a mean sagittal vertical axis (SVA) of 17.8±47.7 mm, cervical SVA 19.8±11.2 mm, T1 Slope-C2-C7 lordosis 24.7°±16.2°, and C2-T3 of 2.1°±16.5°. At baseline, increased C2-T3 angle was significantly correlated with both NDI score (r=0.266, p 75 years: 27.8. Liner regression analysis showed a significant relationship between NDI score, age, and baseline cervicothoracic alignment, as assessed by C2-T3 angle (r=0.497, p 75 years: 6.7°. CONCLUSIONS Significant relationships exist between age, neck disability, and cervicothoracic alignment, suggesting broad measurements across the cervicothoracic junction may be clinically relevant in predicting postoperative outcomes of surgical spine deformity patients. Taking into account patient age and USA-normative values of neck disability, this study offers a set of ideal age-adjusted alignment targets for C2-T3. By proposing a set of normative, age-specific cervicothoracic alignment targets, this study better facilitates individual optimization of surgical planning.