Trabecular Bone Score May Predict Future Vertebral Fracture in Axial Spondyloarthritis

New data published in Rheumatology found that patients with axial spondyloarthritis (axSpA) with vertebral fractures had a lower trabecular bone score compared with patients without vertebral fractures. These findings suggest that trabecular bone scores may be predictive of future vertebral fractures in patients with axSpA.

Investigators recruited 255 patients who met the criteria for the imaging group of the Assessment of Spondyloarthritis International Society. At the time of enrollment, patients underwent lateral radiographs of the thoracic and lumbar spine and were assessed for trabecular bone scores, bone mineral density (BMD), and osteoporosis risk factors. Researchers also collected demographic and disease-related data, including the use of tumor necrosis factor (TNF) inhibitors and the presence of syndesmophytes.

Investigators identified vertebral fractures in 11% of participants in the study cohort. The mean trabecular bone score was 1.30 and 1.39 in patients with and without vertebral fractures, respectively (P <.001). Across the cohort, low trabecular bone scores were more frequent in patients with vertebral fractures compared with those without (P =.003). In patients with vertebral fractures, 28.6% met the trabecular bone score high (score <1.23) fracture risk and 21.4% met the intermediate (1.23-1.30) fracture risk compared with 8.8% and 10.1%, respectively, in patients without vertebral fractures (P =.001).

The mean BMD at the femoral neck was lower in patients with vertebral fractures compared with patients without a vertebral fracture (P =.027), although no between-group BMD differences were observed in the lumbar spine or total hip. Per BMD data, osteoporosis and osteopenia were more frequent in patients with vertebral fractures, although the numbers were not statistically significant. Compared with BMD, trabecular bone scores had a better discriminatory value at the total hip for prediction of vertebral fractures (P =.034). Researchers identified age ≥50 years (OR, 6.9; 95% CI, 2.0-24.4), TNF inhibitor treatment (OR, 2.4; 95% CI, 1.0-5.5), the presence of syndesmophytes (OR, 5.5; 95% CI, 2.2-13.5), and trabecular bone scores <1.23 (OR, 5.3; 95% CI, 2.0-14.1) as predictors of prevalent vertebral fractures.

Investigators noted that longer prospective longitudinal studies are necessary to confirm the strength of trabecular bone scores in predicting vertebral fractures. The study excluded spinal process fractures or pseudarthrosis, which may also limit the generalizability of findings. However, these data indicate that trabecular bone scores may be useful to clinicians in assessing vertebral fracture risk in patients with axSpA.

Reference

Kang KY, Kim IJ, Park SH, Yeon SH. Associations between trabecular bone score and vertebral fractures in patients with axial spondyloarthritis [published online March 9, 2018]. Rheumatology. doi10.1093/rheumatology/key027