General Session: Innovative Technologies I - Hall F

Presented by: B. Khechen

Author(s):

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

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

Abstract

Introduction: Minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) has exhibited favorable outcomes in the treatment of degenerative lumbar disease. However, similar to other fusion procedures, the risk of pseudarthrosis remains a predominant concern. Few studies have analyzed risk factors predisposing patients to pseudarthrosis following MIS TLIF. Accordingly, the objective of this study is to determine the demographic, diagnostic, and procedural risk factors associated with pseudarthrosis following single level MIS TLIF.

Methods: A prospectively maintained surgical database of patients who underwent primary, single level MIS TLIF by a single surgeon from 2005-2016 was reviewed. Patients were excluded if they received less than 6-months clinical follow-up. Rates of pseudarthrosis at final follow up were calculated. 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 pseudarthrosis. 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: A total of 439 patients were included in the analysis; of these, 12 demonstrated pseudarthrosis at 6-month follow-up. Upon bivariate analysis, females (5.81% vs. 0.75%; p=0.008), smokers (7.37% vs. 1.17%; p=0.003), and patients with Charlson Comorbidity Index (CCI) ≥ 2 (5.63% vs 1.35%; p=0.018) were at increased risk for pseudarthrosis. No other risk factors for pseudarthrosis were noted on bivariate analysis. Final multivariate analysis was not able to be performed due to a small number of cases of pseudarthrosis.

Conclusion: The rate of pseudarthrosis reported in the current study is similar to that reported in the literature. The results of the current study suggest that gender, smoking status, and increased comorbidity burden may serve as risk factors for pseudarthrosis following MIS TLIF. Consequently, patients exhibiting these risk factors may require further counseling on expectations for outcomes following MIS TLIF.

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