Prioritization of realignment associated with superior clinical outcomes for surgical cervical deformity patients.

ABSTRACT

BACKGROUND: To optimize quality of life in patients with cervical deformity (CD), there may be alignment targets to be prioritized. OBJECTIVE: To prioritize the cervical parameter targets for alignment. METHODS: Included CD patients (C2-C7 Cobb >10°°, C2-C7 lordosis [CL] >10°°, cSVA > 4 cm, or chin-brow vertical angle >25°°) with full baseline (BL) and 1-year (1Y) radiographic parameters and Neck Disability Index (NDI) scores; patients with cervical (C) or cervicothoracic (CT) Primary Driver Ames type. Patients with BL Ames classified as low CD for both parameters of cSVA (<4 cm) and T1 slope minus CL (TS-CL) (<15°°) were excluded. Patients assessed Meeting Minimal Clinically Important Difference (MCID) for NDI (<-15 ΔNDI). Ratios of correction were found for regional parameters categorized by Primary Ames Driver (C or CT). Decision tree analysis assessed cut-offs for differences associated with meeting NDI MCID at 1Y. RESULTS: Seventy-seven CD patients (62.1 years, 64%F, 28.8 kg/m2). 41.6% met MCID for NDI. A backward linear regression model including radiographic differences as predictors from BL to 1Y for meeting MCID for NDI demonstrated an R 2= 0.820 (P = 0.032) included TS-CL, cSVA, MGS, C2SS, C2-T3 angle, C2-T3 sagittal vertical axis (SVA), CL. By primary Ames driver, 67.5% of patients were C, and 32.5% CT. Ratios of change in predictors for MCID NDI patients for C and CT were not significant between the two groups (P > 0.050). Decision tree analysis determined cut-offs for radiographic change, prioritizing in the following order ≥42.5° C2-T3 angle, >35.4° CL, <-31.76° C2 slope, <-11.57 mm cSVA, <-2.16° MGS, >-30.8 mm C2-T3 SVA, and ≤-33.6° TS-CL. CONCLUSIONS: Certain ratios of correction of cervical parameters contribute to improving neck disability. Prioritizing these radiographic alignment parameters may help optimize patient-reported outcomes for patients undergoing CD surgery.