The Presence of Preoperative Cervical Deformity in Adult Spinal Deformity Patients is a Strong Predictor of Inferior Outcomes and Failure to Reach MCID at 2-Year Follow-Up: Analysis of 235 Patients

Abstract

Introduction A high prevalence of cervical deformity (CD) has been identified among adult spinal deformity (ASD) patients undergoing surgical treatment. The clinical impact of this is uncertain. This study aims to quantify the difference in patient-reported outcomes among ASD patients based on presence of CD before treatment. Material and Methods Retrospective review of a multicenter prospective database of surgical ASD patients with 2-year follow-up. CD was defined as: C2C7 SVA > 4 cm, cervical kyphosis (CK) C2C7angle > 0. Univariate testing was performed using t-tests, or tests of proportion. Multivariate models determined impact of preoperative CD on health-related quality of life (HRQL) scores (SF-36, ODI, and SRS) and obtaining minimally clinically important difference (MCID) at 2 years. Results A total of 235 patients met the criteria, of which 65 with preoperative C2C7 SVA > 4 cm, 57 with CK. Patients with and without CD saw improvements in 2-year HRQL scores ( p < 0.001). Overall, patients with preoperative CD had inferior postoperative HRQL and were less likely to achieve MCID for HRQL at 2-years. Those with preoperative SVA > 4 cm had worse ODI, PCS, SRS activity, appearance, pain, and total, and were less likely to meet MCID for ODI, PCS, SRS activity, and pain scores (odds ratio 0.39 for ODI CI 0.19:0.81 p < 0.05), (0.34 for PCS CI 0.16:0.72 p < 0.05), (0.29 CI 0.14:0.62 p < 0.05 SRS activity) (0.41 CI 0.20:0.86 p < 0.05 SRS pain). Similarly, patients with CK had inferior 2-year HRQL scores. Patients without any CD were four times more likely to reach 2-year SRS activity MCID (OR 0.40 CI 0.19:0.86 p < 0.05). Conclusion Despite experiencing significant improvements in HRQL scores, preoperative CD in ASD patients is a strong predictor of inferior outcomes and failure to reach MCID at 2-year follow-up. This information will help surgeons educate patients at risk for inferior outcomes and direct future research to improve patient outcomes.