Prediction of Treatment Resistance in Conservative Treatment of Osteoporotic Vertebral Fractures Using Lateral Plain Dynamic Loading Radiographs

Purpose: To elucidate the association between computed tomography (CT)/magnetic resonance imaging (MRI) and radiographic findings of fractured vertebral body instability in patients with osteoporotic vertebral fractures and to clarify whether resistance to conservative treatment can be evaluated on the basis of dynamic loading radiography.Methods: Seventy-eight patients aged ≥ 65 years who underwent conservative treatment for osteoporotic single vertebral fractures of the thoracolumbar junction were divided into the conservative treatment-resistant group (18 patients) and control group (60 patients). We evaluated the accuracy of the prediction of resistance to conservative treatment on the basis of the CT/MRI findings and the difference in compression rates between standing and supine positions at the time of the first visit. The differences in compression rates (%) were compared between the two groups. In addition, a receiver operating characteristics (ROC) curve was drawn to evaluate the accuracy of the prediction of resistance to conservative treatment.Results: In patients without (47 cases) and with CT findings (31 cases), the mean differences in compression rates (%) was 8.9% and 19.1%, respectively (p=0.0029). The mean differences in compression rates (%) of patients without (60 cases) and with MRI findings (18 cases) was 9.7% and 24.0%, respectively (p=0.0043). The mean differences in compression rates (%) in the conservative treatment-resistant group was 26.3%, while that in the control group was 9.0 (p=0.0066). In addition, according to the ROC curve of the difference in compression rate was 0.93 (95% confidence interval: 0.87–1), and when a 20% difference in compression rate was considered as the threshold value.Conclusion: Dynamic loading radiography is useful for the evaluation of resistance to conservative treatment in patients with osteoporotic vertebral fractures, and that a compression rate difference of ≥ 20% predicts resistance to conservative treatment.