A comprehensive MRI-based evaluation of bone mineral density by endplate bone quality score in patients with ossification of the posterior longitudinal ligament

Abstract

The MRI-derived cervical endplate bone quality (EBQ) score has emerged as a novel indicator in predicting postoperative implant subsidence. However, limited systematic investigations have been conducted to evaluate the EBQ score profiles among patients with cervical ossification of the posterior longitudinal ligament (OPLL). EBQ scores at each endplate were calculated. Propensity score matching (PSM) was performed to balance the clinical baseline characteristics between the two groups, and Wilcoxon’s rank-sum test was used to compare matched groups. Paired t-tests were used to compare EBQ scores between OPLL and other types of degenerative cervical myelopathy (DCM) patients, between genders, and superior and inferior endplates among different segments, and multiple linear regression analysis was used to identify associated factors. Both before and after PSM, OPLL patients had significantly lower individual, segmental, and adjacent intervertebral EBQ scores than other types of DCM patients. Females showed higher EBQ scores than males at most levels. At all intervertebral levels, the EBQ scores of the cephalad endplate yielded higher EBQ scores relative to caudal endplates. EBQ scores displayed a gradual descending trend from the cephalad C2/3 segment to the caudal C7/T1 segment, with the C3 vertebral body possessing the highest segmental EBQ score. Yet, the segmental EBQ scores did not follow the same trend, as the C3 vertebra had the highest score, followed by C6, C4, C5, C7, and T1. Multiple linear regression analysis showed that older age and reduced lumbar aBMD were the two most robust, consistent independent predictors of elevated EBQ scores. This study systematically characterized cervical EBQ in OPLL patients. Key findings include lower EBQ in OPLL vs. other types of DCM, gender-related disparities, superior-inferior endplate differences, and specific segmental EBQ trends. Accordingly, MRI-based EBQ assessment should serve as an essential adjunct to systemic bone mineral density screening via DEXA in the preoperative workup of OPLL. This combined strategy enables more precise evaluation of the implant–bone interface, thereby optimizing surgical decision-making and perioperative risk stratification.