Flexibility of the coronal lumbosacral region of congenital scoliosis: a three-dimensional finite element analysis / 中国组织工程研究

ABSTRACT

BACKGROUND: In the patients with congenital scoliosis, the spinal motor units exhibit developmental disorders and poor range of motion. It has been found that the compensation ability of coronal lumbosacral region (L4-S1) is associated with the occurrence of non-compensable trunk migration postoperatively.OBJECTIVE: To establish the three-dimensional finite element models of coronal lumbosacral region of normal and patients with congenital scoliosis and to compare the strain, displacement, stress and stiffness under different loading conditions among models.METHODS: One normal subject and two congenital scoliosis patients with different coronal lumbosacral region flexibility were selected, DICOM image datawere obtained by spiral CT scanning at the lumbosacral region, and then imported into MIMICS software, and a three-dimensional model was established according to the gray values of each tissue on CT,followed by simplified by GEOMAGIC, and finally imported into ABAQUS foftware to conduct a mechanic analysis under different loading conditions.RESULTS AND CONCLUSION: (1) Under different lateral forces, in the three models, the maximum stress mainly distributed on the frontal region of L4 cortical bone, and maximum displacement concentrated on L5. (2) There was no significant change in the stress distribution in the two scoliosis models, but the compensable model showed larger displacement change, and its stiffness was significantly less than that of the non-compensable model, indicating that the compensable model is easy to deform. (3) These findings suggest that three-dimensional finite element model is helpful to perform a biomechanical analysis for coronal lumbosacral region of congenital scoliosis, among which, a compensable model exhibits large displacement, suggesting a good flexibility.