Anterior-posterior difference of MRI-based cervical vertebral bone quality score independently predicts overloaded vertebral body wedge deformity after anterior cervical discectomy and fusion.

PURPOSE: This study aimed to develop and validate a novel MRI-based regional cervical vertebral bone quality (VBQ) scoring system for predicting overloaded vertebral body (OVB) wedge deformity following anterior cervical discectomy and fusion (ACDF) with zero-profile implants. The primary research question addressed whether anterior-posterior bone quality disparities could serve as superior predictors compared to body or endplate-specific scores.

METHODS

A retrospective analysis included 153 patients undergoing two-level ACDF between June 2016 and June 2024. Bone quality was assessed by preoperative T1-weighted MRI in seven anatomical regions: upper/lower endplates (UEBQ/LEBQ), anterior/posterior shells (ASBQ/PSBQ), and anterior/middle/posterior vertebral bodies (AVBQ/MVBQ/PVBQ). Wedge deformity was defined as ≥ 2° kyphotic change in OVB at 3-month follow-up. Multivariate logistic regression and ROC analysis evaluated predictive performance.

RESULTS

The wedge deformity group exhibited significantly higher bone quality scores in upper endplate and anteromedial regions (UEBQ, ASBQ, AVBQ, MVBQ; all p ≤ 0.043). Anterior-posterior differences (ASBQ-PSBQ and AVBQ-PVBQ) demonstrated superior predictive value (ASBQ-PSBQ: AUC = 0.811; AVBQ-PVBQ: AUC = 0.792) over mean VBQ, UEBQ and LEBQ scores (AUCs < 0.7). The model combining both differences achieved 84.5% classification accuracy.

CONCLUSION

Regional MRI-based bone quality differences between anterior and posterior structures reliably predicted OVB wedge deformity after ACDF. The findings highlight the clinical relevance of biomechanical heterogeneity in vertebral body, suggesting preoperative MRI evaluation of bone quality could guide implant selection and risk stratification.