SAT0026 Is radiographic examination sufficient for detection of non traumatic spinal fractures in ankylosig spondylitis: comparison of radiographic and mri findings

Abstract

Background Objectives To compare plain radiographic and MRI findings in evaluation of non traumatic spinal fractures in patients with ankylosing spondylitis (AS), and to find correlation between spinal fractures and disease activity, age of patients, and disease duration. Methods 21 males and 2 females with AS, mean aged 49.8, were studied. Lateral radiographs and MRI examinations of lumbar, thoracic and cervical spine were performed in all patients. To detect vertebral body fractures with radiographs, the anterior, posterior and central heights of each vertebral body were measured. The ratio of each height to that of the two adjacent vertebrae, the ratio of the anterior height to the posterior height and of the central height to the posterior height were calculated. The subjects were considered to have fracture if any of these ratios was less than 0,85 for lumbar spine and less than 0,8 for thoracic and cervical spine. We assessed also the following indexes of disease activity: BASFI, BASDAI, BASG-t, BASG-6, BSMI. Results Total 25 fractures were found with the radiographic method: 7 fractures in lumbar spine, 15 in thoracic and 3 in cervical. The MRI examinations revealed total 51 fractures: 24 fractures in lumbar spine, 18 in thoracic and 9 in cervical. Out of 25 fractures detected by X-ray examination, MRI confirmed the site of fracture only in 10 (40%). Age of patients and disease duration correlated positively with total number of fractures, number of fractures in lumbar spine and number of fractures in thoracic detected by MRI. There was no such correlation for fractures detected by X-ray. Assessing indexes of disease activity we found positive correlation between BASFI, BASDAI, BASMI and total number of fractures and number of fractures in lumbar spine detected by MRI. Conclusion The significant difference between radiographic and MRI findings in detecting of vertebral fractures was found. The results suggest that plain X-rays cannot be considered as a sufficient method for detection vertebral fractures in patients with AS. MRI should be considered as the method of choice in revealing spinal fractures in AS patients. Disease activity may contribute in developing of non – traumatic spinal fractures in this group of patients.