463 Cervical Vertebral Bone Quality (C-VBQ) Score Independently Predicts Distal Junctional Kyphosis (DJK) Following Posterior Cervical Fusion

INTRODUCTION: Posterior cervical fusion is the surgery of choice when fusing long segments of the cervical spine. However, due to the limited presence of this pathology, there is a paucity of data in the literature about the postoperative complication of distal junctional kyphosis (DJK). METHODS: A retrospective analysis of consecutive set of patients who underwent posterior cervical fusion at a single hospital between June 1, 2010 and May 31, 2020. Univariate analysis was completed between DJK and non-DJK groups, with multivariate regression completed for relevant clinical variables. Simple linear regression was completed to analyze correlation between the C-VBQ score and total degrees of kyphosis angle change. RESULTS: Ninety-three patients were identified, of whom 19 (20.4%) had DJK and 74 (79.6%) did not. The DJK group had a significantly greater number of patients with anemia than the non-DJK group (15.8% vs. 1.4%; P = .03). The DJK group had a significantly higher C-VBQ score than the non-DJK group (2.97 ± 0.40 vs. 2.26 ± 0.46; P < .001). A significant, positive correlation was found between the C-VBQ score and the total degrees of kyphosis angle change (r2 = 0.26, P < .001). On multivariate analysis, the C-VBQ score independently predicted DJK (OR, 1.50; 95% CI, 1.28-1.76; P < .001). CONCLUSIONS: We found that the C-VBQ score was an independent predictive factor of DJK after posterior cervical fusion.