Radiation-free spinometry adds to the predictive power of historical height loss in clinical vertebral fracture assessment

UNLABELLED: After introducing radiation-free spinometry as a diagnostic tool to predict prevalent vertebral fractures, its validity and comparison with established tools such as historical height loss (HHL) was missing. This study shows that radiation-free spinometry is valid and its application adds predictive power to the ability of HHL to assess presence of vertebral fractures.

INTRODUCTION: Recently, radiation-free spinometry was introduced to identify patients with vertebral fractures (VFs). The goals of this study were to validate previous findings and to test the predictive accuracy of radiation-free spinometry compared to the assessment of historical height loss (HHL).

METHODS: We analyzed 304 patients [258 (85%) females (age range, 42-90 years) and 46 males (50-84 years)], including 108 patients with VFs. We performed receiver operator characteristic and net reclassification improvement (NRI) analyses to quantify the predictive power and the added predictive ability of radiation-free spinometry and HHL for VFs.

RESULTS: The estimated odds ratios in the thoracic and the lumbar spine showed no significant differences compared to the previously published, except for the effect of thoracic kyphosis in region "Th12 + L4-5." Radiation-free spinometry and HHL were both moderately accurate to raise suspicion for VFs. According to the NRI, which is defined as the net sum of the predicted risk increase in individuals who have VFs and the predicted net risk decrease for those who have not, we found significant improvements in all regions of interest when HHL and radiation-free spinometry were used in combination (area under the curve (AUC) 0.729-0.788).

CONCLUSION: Our results based on a new data set suggest validity of the prognostic score published previously. In addition, although our findings did not confirm our initial hypothesis that radiation-free spinometry alone performs superior to the assessment of HHL to predict VFs, we showed that radiation-free spinometry still adds predictive power to the ability of HHL to discriminate patients with VFs.