Is There a Positive or Negative Correlation Between Cervical Vertebral Bone Quality and Intervertebral Disc Degeneration by Pfirrmann Grading

Objective: Cervical degeneration involves many pathophysiological changes. Vertebral bone loss, sclerotic hyperplasia of the vertebral body and intervertebral disc degeneration (IDD) are most common degenerative factors. However, whether there is a correlation between changes in vertebral bone mass and IDD remains unclear. In this study, based on magnetic resonance imaging (MRI), Pfirrmann method was used to grade cervical disc degeneration, and vertebral bone quality (VBQ) was measured. The correlation between VBQ and IDD was analyzed, and its potential mechanism was discussed as well.

Methods: From June 2019 to June 2023, clinical data of patients undergoing surgical treatment for cervical degenerative disc diseases (CDDD) in our department were retrospectively analyzed. Preoperative MRI was collected, the degree of IDD was assessed by Pfirrmann grading, and VBQ was measured by T1-weighted image of MRI. With VBQ score = 3.08 as the threshold, Spearman correlation analysis was used to quantified the correlation between IDD grade and VBQ, and multiple ordered Logistic regression analysis was used to evaluate the effect of VBQ on IDD grade.

Results: The preoperative MRI data of 94 patients (male, 42; female, 52) with CDDD were collected. Spearman correlation analysis: When VBQ score ≤ 3.08, the IDD grade was negatively correlated with VBQ (p < 0.05, r = -0.153). When VBQ score > 3.08, the IDD grade was positively correlated with VBQ (p < 0.05, r = 0.306). Multiple ordered Logistic regression analysis: When VBQ score ≤ 3.08, the effect of VBQ on IDD was negatively correlated (p < 0.05, β = -0.597). When VBQ score > 3.08, the effect of VBQ on IDD was positively correlated (p < 0.05, β = 0.986).

Conclusions: Either excessive increased or decreased VBQ in the cervical spine may accelerate the progression of IDD. The reason may be that both abnormal interference from the VBQ may imbalance the cervical spinal biomechanics and compromise the absorption of nutrients in the disc, thus accelerating the IDD. Therefore, cervical VBQ may have a bidirectional effect on IDD.