Factors associated with implant failure in anterior cervical plating: retrospective analysis from a large cohort study.

Abstract

This study aims to retrospectively analyze the factors affecting implant failure in patients who underwent anterior cervical plating (ACP) following anterior cervical discectomy and fusion (ACDF). Data from 332 patients who underwent ACDF and ACP at a single center between January 2011 and January 2023 were retrospectively reviewed. Patients who underwent ACP due to trauma, tumor, or infection, as well as those with missing data or incomplete follow-up, were excluded. Demographic and surgical data, such as age, sex, body mass index, preoperative and postoperative lordosis angles, type of screw used, screw length, bone quality, smoking and the number of fixed segments, were recorded. Implant failure (screw loosening, breakage, plate seperation) and pseudoarthrosis rate were evaluated. Logistic regression and Kaplan-Meier analysis were used for analyses. Implant failure was observed in 28 of the 332 patients (8.43%). The average follow-up duration was 36.8 months. Multivariate logistic regression analysis showed that greater fixation length (OR = 2.98, p < 0.0001), lower vertebral bone density measured by HU values (OR = 0.948, p < 0.0001), smoking (OR = 2.97, p = 0.032), and lower preoperative lordosis angle (OR = 0.873, p = 0.024) were independently associated with implant failure. Age, sex, type of screw, and postoperative lordosis angle had no significant effect on implant failure. According to Kaplan-Meier analysis, most failures occurred within the first six months. This study analyzes one of the largest anterior cervical plating series in the literature. In anterior cervical plating, an increase in the number of fixed segments, reduced bone quality, smoking and a low preoperative lordosis angle are significant risk factors for implant failure. These factors should be considered in surgical planning.