Lightning Podiums: Cervical Degenerative - Room 802A

Presented by: B. Khechen


B. Khechen(1), B. Haws(1), A. Narain(1), F. Hijji(1), J. Guntin(1), K. Cardinal(1), N. Shoshana(1), K. Singh(1)

(1) Rush University Medical Center, Orthopaedic Surgery, Chicago, IL, United States


Introduction: The minimum clinically importance difference (MCID) represents a threshold for improvements in patient-reported outcomes (PROs) that patients deem important following spine surgery. Previous studies have analyzed risk factors for decreased PRO improvement based on absolute score differences. However, no study has comprehensively examined potential risk factors for failure to achieve MCID after anterior cervical discectomy and fusion procedures. Therefore, the objective of the current study is to determine risk factors for failure to reach MCID for Neck Disability Index (NDI), Visual Analogue Scale (VAS) neck pain, and VAS arm pain in patients undergoing 1- or 2-level ACDF procedures.

Methods: A prospectively maintained surgical database of patients who underwent primary, 1- or 2-level ACDF from 2005-2016 was reviewed. Patients with incomplete preoperative PRO data or less than 6-months clinical follow up were excluded from this study. Rates of overall MCID achievement for NDI, VAS neck pain, and VAS arm pain at final clinical follow up were calculated based on published MCID values. Patients were then categorized into different demographic and procedural categories. Bivariate testing via Poisson regression with robust error variance was used to test for association of demographic and procedural characteristics with failure to reach MCID for each PRO measured. The final multivariate model including all demographic and procedural categories as controls was created using backward, stepwise regression until only those variables with p< 0.05 remained.

Results: After exclusion of patients with incomplete PRO survey data, 78, 78, and 73 patients were included in the analysis for VAS neck, VAS arm, and NDI, respectively. Rates of MCID achievement for VAS neck, VAS arm, and NDI were 52.56%, 35.90%, and 73.97%, respectively. Upon bivariate analysis, patients with Charlson Comorbidity Index (CCI) ≥ 2 were less likely to achieve MCID for NDI than patients with CCI < 2 (61.54% vs. 80.85%, p=0.047). No other risk factors for failure to reach MCID for VAS neck or VAS arm were found upon bivariate analysis. Upon multivariate analysis, CCI ≥ 2 (RR 0.14, p=0.036) and American Society of Anesthesiologists (ASA) Score > 2 (RR 0.69, p=0.017) were associated with failure to reach MCID for NDI.

Conclusion: The results of this study suggest that the majority of patients do not reach MCID for arm pain. Additionally, higher comorbidity burden as evidenced by higher CCI and ASA scores may be negative predictive factors for the achievement of MCID in neck disability following ACDF.

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