Fig. 3

Data measurement schematic of the thoracic vertebrae. a Axial view of the thoracic data measurement schematic showing lines PVWCD and VBSD. PVWCD represents the depth of the concave posterior vertebral wall; VBSD represents the mid-sagittal diameter of the nonfractured vertebral body. b Sagittal view of the thoracic data measurement schematic shows lines L1 and L2. L1 corresponds to the true projection line of the posterior wall of the thoracic vertebra, while L2 corresponds to the posterior border of the vertebral body on the lateral C-arm X-ray view