Preoperative assessment of spinal bone quality using Hounsfield unit values and vertebral bone quality scores in patients with rheumatoid arthritis: a retrospective propensity-matched study.

PURPOSE

This study aims to evaluate the feasibility and accuracy of Hounsfield unit (HU) values and vertebral bone quality (VBQ) scores for assessing bone quality in patients with rheumatoid arthritis (RA), specifically in the spine, and to compare these methods with the traditional dual-energy X-ray absorptiometry (DXA) T-score.

METHODS

A retrospective analysis was conducted on patients who underwent DXA, lumbar CT, and MRI from January 2018 to December 2023. HU values were measured on CT, while VBQ scores, Pfirrmann grading (PFG), and endplate erosion grading (EEG) were assessed on MRI. Propensity score matching compared T-scores, HU values, and VBQ scores between RA and non-RA patients. In the RA group, multiple linear regression analysis was performed to identify independent predictors of L1-L4 T-scores.

RESULTS

The RA group had higher VBQ scores, PFG, and EEG, but lower HU values. In the control group, HU values, VBQ, and T-scores exhibited comparable diagnostic performance for osteoporosis. However, in the RA group, the diagnostic accuracy of the L1-L4 T-score was significantly lower than that of HU values and VBQ. Correlation analysis showed a weaker relationship between L1-L4 T-scores and HU or VBQ scores in the RA group. Multiple linear regression analysis identified PFG (β = 0.328, P < 0.001) and EEG (β = 0.276, P < 0.001) as independent predictors of L1-L4 T-scores in the RA group, whereas HU values and VBQ were not influenced by these factors.

CONCLUSION

The lumbar T-score may not accurately reflect spinal bone quality in patients with RA. HU values and VBQ can serve as effective complementary tools for assessing bone quality alongside DXA, as they are unaffected by spinal degeneration or EE.