Wedging of vertebral bodies at the thoracolumbar junction in asymptomatic healthy subjects on magnetic resonance imaging

Purpose: Wedging of the vertebral body on radiological examination is a valuable indicator of a vertebral compression fracture, although it can also be observed in subjects with no history of trauma. The purpose of this study was to elucidate the normative value of vertebral wedging at the thoracolumbar junction in asymptomatic healthy subjects for differential diagnosis of vertebral compression fractures using MRI. Methods: A total of 115 subjects without back pain at the time of the examination and without history of spinal trauma was included (68 males, 47 females, mean age 49.5 years). They underwent MRI of the thoracic and lumbar spine, and the ratio of anterior vertical height to posterior vertical height of the vertebral body (APR) was determined from T10 to L2 on T2 weighted sagittal images. Results: APR was 0.92 ± 0.08 at T10, 0.92 ± 0.08 at T11, 0.90 ± 0.06 at T12, 0.89 ± 0.06 at L1, and 0.90 ± 0.07 at L2, indicating that vertebral bodies at the thoracolumbar junction appear wedge-shaped rather than rectangular. Males, thinner subjects, smokers, and subjects with abnormalities of the endplates such as a Schmorl nodule had a significantly smaller APR than females, fatter subjects, non-smokers, and those without endplate abnormalities. Conclusion: The normative values of APR obtained in the present study can represent a valuable reference in the diagnosis of vertebral compression fracture to help prevent confusion with physiological vertebral wedging.