Comparison of Best Versus Worst Clinical Outcomes for Adult Cervical Deformity Surgery. Issue 3 (May 2019) - Smith, Justin S.
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.