Comparison of Best Versus Worst Clinical Outcomes for Adult Cervical Deformity Surgery

Study Design: Retrospective cohort study. Objective: Factors that predict outcomes for adult cervical spine deformity (ACSD) have not been well defined. To compare ACSD patients with best versus worst outcomes. Methods: This study was based on a prospective, multicenter observational ACSD cohort. Best versus worst outcomes were compared based on Neck Disability Index (NDI), Neck Pain Numeric Rating Scale (NP-NRS), and modified Japanese Orthopaedic Association (mJOA) scores. Results: Of 111 patients, 80 (72%) had minimum 1-year follow-up. For NDI, compared with best outcome patients (n = 28), worst outcome patients (n = 32) were more likely to have had a major complication (P =.004) and to have undergone a posterior-only procedure (P =.039), had greater Charlson Comorbidity Index (P =.009), and had worse postoperative C7-S1 sagittal vertical axis (SVA; P =.027). For NP-NRS, compared with best outcome patients (n = 26), worst outcome patients (n = 18) were younger (P =.045), had worse baseline NP-NRS (P =.034), and were more likely to have had a minor complication (P =.030). For the mJOA, compared with best outcome patients (n = 16), worst outcome patients (n = 18) were more likely to have had a major complication (P =.007) and to have a better baseline mJOA (P =.030). Multivariate models for NDI included posterior-only surgery (P =.006), major complication (P =.002), and postoperative C7-S1 SVA (P =.012); models for NP-NRS included baseline NP-NRS (P =.009), age (P =.017), and posterior-only surgery (P =.038); and models for mJOA included major complication (P =.008). Conclusions: Factors distinguishing best and worst ACSD surgery outcomes included patient, surgical, and radiographic factors. These findings suggest areas that may warrant greater awareness to optimize patient counseling and outcomes.