Finite element analysis of the correlation between sacral slope and lumbar isthmus stresses
Objective To investigate the effects of different sacral slope(SS)with various motion states on the mechanical mechanisms in the lumbar isthmus based on finite element analysis.Methods CT data scans were conducted at the Xinjiang Military Region General Hospital on November 3,2021.The lumbosacral models of different SSs were constructed by using Mimics and 3-matic,and they were divided into SS=30° group,SS=35° group,SS=40°group,SS=45° group and SS=50° group.Solidworks was employed for intervertebral disc and cartilage reconstruction.Ansys finite element software was utilized to simulate motion states of stand,forward flexion,rearward extension,lateral bending,axial rotation,forward flexion+lateral bending,forwardflexion+axial rotation,rearward extension+lateral bending,and rearward extension+axial rotation.The analysis of averages of multiple groups were compared with One-way ANOVA.Results The range of motion for the lumbar 5-sacral 1(L5-S1)segment increased with the increment of SS:SS=50° group was higher than SS=45° group[(2.81±1.33)° vs.(2.35±1.36)°,F=101.72,P＜0.01],SS=45° group was higher than SS=40° group[(2.35±1.36)° vs.(1.86± 0.92)°,F=52.35,P＜0.01],SS=40° group was higher than SS=35° group[(1.86±0.92)° vs.(1.52±0.86)°,F=16.42,P＜0.05],and SS=35° group was higher than SS=30° group[(1.52± 0.86)° vs.(1.32±0.63)°,F=11.52,P＜0.05].All differences of the above were statistically signifi-cant.With increasing SS,The stress of isthmus exhibited a trend of initial decrease followed by an in-crease:SS=30° group was higher than SS=35° group[(11.42±2.13)MPa vs.(10.12±2.63)MPa,F=434.52,P＜0.01],SS=35° group was higher than SS=40° group[(10.12±2.63)MPa vs.(9.65±2.48)MPa,F=68.32,P＜0.01],SS=40° group was higher than SS=45° group[(9.65± 2.48)MPa vs.(9.23±1.72)MPa,F=13.92,P＜0.01],and SS=45° group was lower than SS=50° group[(9.23±1.72)MPa vs.(12.65±2.22)MPa,F=1 168.32,P＜0.01].All differences of the above were statistically significant.Conclusion Excessive or insufficient sacral slope may enhance or restrict the mobility of the L5 vertebral,leading to increased stress in the isthmus region and consequently elevating the risk of fractures in isthmus region.
Isthmic fracture of the lumbar spineSacral slopeReverse engineeringBiome-chanics
NETL
NSTL
万方数据
