LAUSR

BACKGROUND Knowledge concerning the curvature of the vertebrae through the transverse section is of clinical significance. However, relevant reports are scarce. This study investigated the features based on the cross-sections of lumbar vertebral endplates to provide information for clinical practice. METHODS Computed tomography images of 78 subjects were retrospectively reviewed. The geometric morphometrics was performed and the curvature of the vertebral endplates was calculated by the self-written MATLAB algorithm. The principal component analysis, the canonical variate analysis, the discriminant function analysis and the Mann-Whitney U test were performed. Statistical significance was set at P<0.05. RESULTS No gender difference was found. In contrast, morphologic difference was found between the superior and inferior lumbar vertebral endplates and between different segments. More specifically, the shape of the endplates gradually changes from the renal shape at superior L1 to the shell-like shape at inferior L5. The mean curvature values of the lateral anterior border were all around 0.60 cm-1 while the mean curvature values of the lateral posterior borders range from 0.66 cm-1 to 1.09 cm-1 from L1 to L5. From L1 to L3, the mean and maximum curvature of the lateral posterior superior vertebral endplates decrease. The trend could also be found on the lateral posterior border of the inferior endplates from L1 to L3. CONCLUSIONS The current study described morphologic variations and curvature of the lumbar vertebral endplates, which have not been reported previously. The different curvature distribution could provide important information for surgeons and manufacturers.