Establishment Of Entity And Numerical Models And Risk Prediction Of Osteoporotic Vertebral Fractures In Postmenopausal Women

Objective:The entity mechanical model of fragile compression fracture of lumbar vertebrae under physiological pressure was established by using finite element analysis as a bridge.The mechanism of osteoporotic vertebral fracture analyzed by changing parameters to simulate the stress of osteoporotic patients.To predict the risk of osteoporotic vertebral fracture in postmenopausal women,to provide objective and reliable bone strength parameters for clinical intervention to prevent the occurrence of brittle fracture in patients with low vertebral bone mass,and to provide accurate guidance for the prevention and treatment of osteoporotic fracture in real patients.Materials and methods:Postmenopausal women were selected with fresh specimens of thoracic 11 and 12,lumbar 1,2 and 3,and muscle and ligament tissues were removed to make entity specimens.The vertebral bone mineral density was measured by dual-energy X-ray absorptiometry,and the morphology of the vertebral body was measured.The height and volume of the vertebral body were measured.The mechanical test specimens of thoracic 11,12,lumbar 1,2 and 3 vertebrae were prepared.Ultrafine CT scan was used to measure cortical bone thickness,cancellous bone trabecular number,spatial conformation and density,and to evaluate its quality.The entity model of vertebral compression fracture under physiological pressure was established to detect the load changes of vertebral brittle fracture with different T values when thoracic 11,12,lumbar 1,2 and 3 vertebral specimens were compressed by 30%.Ultrafine CT scanning was performed on the specimens after fracture to measure the microfracture of cortical bone in the endplate,the fracture of cancellous bone trabeculae and the change of conformation in space.The postmenopausal female volunteers with osteoporosis were randomly selected,excluding those with fractures and hormone use,for thoracolumbar CT examination.The CT images obtained from the scan were imported into the Mimics software,and the three-dimensional images of the thoracic 11,12,lumbar 1,2 and 3 vertebral bodies were selected to establish a three-dimensional digital model.After the 3d digital model is meshed by Hypermesh software,the finite element model is obtained by importing the Mimics software for assignment.The ultrafine CT data of the entity vertebral model were analyzed,and the finite element model of the entity model of osteoporotic fracture was made in the same way.The finite element model was imported into Abaqus software for finite element analysis.Comparing the finite element analysis data with the biomechanical analysis results of the solid model,the consistent results prove that the 3d digital model of osteoporotic fracture is accurate.The finite element model of osteoporosis-induced vertebral fracture in postmenopausal women was imported into the Abaqus software for finite element analysis.Data processing was performed to determine the stress concentration site and the peak displacement site,which is the site where fractures are likely to occur.The mechanism of osteoporotic vertebral fracture was analyzed.Conclusion:The reliability of the finite element model is good,and the establishment of a digital model can predict the risk of vertebral fracture in postmenopausal women with osteoporotic fracture.It is feasible for normal people to simulate the stress of osteoporotic patients by changing the parameters,and the results obtained are basically consistent with the changes of real osteoporotic patients,so as to provide a digital reference for further research on the biomechanics of osteoporotic vertebral bodies.From the perspective of finite element analysis,the establishment and analysis of 3d digital vertebral model of osteoporotic fracture in postmenopausal women can provide accurate guidance for the prevention and treatment of osteoporotic fracture in real patients.The finite element method can be used to simulate the process of vertebral body morphologic change under different stress conditions,especially the change rule of internal stress.