骨水泥弥散类型影响椎体强化术后椎体生物力学的有限元分析OA

BACKGROUND:Studies on bone cement filling dosage in vertebral augmentation for osteoporotic vertebral compression fractures are relatively extensive,but there is limited research on the correlation between different bone cement dispersion patterns and their impact on treatment outcomes. OBJECTIVE:To analyze the influence of different bone cement dispersion types on the biomechanical properties of augmented vertebrae using the three-dimensional finite element method. METHODS:A T9-L3 vertebral model was established for T12 osteoporotic vertebral compression fracture.Percutaneous kyphoplasty was digitally simulated,and bone cement was injected into different regions of the T12 vertebral body.Based on the medial borders of bilateral pedicles and the midline of the spine,the T12 vertebra was divided into four regions(left pedicle region,left midline region,right midline region,and right pedicle region,labeled as regions 1,2,3,and 4,respectively).Group A:Bone cement was assigned to all regions 1-4;Group B:regions 2 and 3 were assigned bone cement;Group C:regions 1 and 4 were assigned bone cement;Group D:regions 1 and 2 were assigned bone cement;Group E:region 1 was assigned bone cement.The lower end of the L3 model was fixed.On the upper surface of T9,an axial stress of 150 N was applied to the vertebral model,together with a torque of 10 N·m to simulate flexion-extension and lateral bending under physiological load.On the upper surface of T9,an axial stress of 500 N was applied to the vertebral model,together with a torque of 15 N·m to simulate flexion-extension and lateral bending.The range of motion of the T12-L1 vertebra,the maximum Mises stress of the T12 vertebra,and the Mises stress of the T11-12 and T12-L1 intervertebral discs were recorded. RESULTS AND CONCLUSION:The range of motion of the T12 vertebra after surgery increased to varying degrees compared with before surgery.Group A had the smallest range of motion of the T12 vertebra,and the changes in the range of motion of the T12 vertebra during extension and left rotation in Group E were slightly lower than those in Group B.The Mises stress of the T12 vertebra decreased significantly after vertebral augmentation.The decrease in the Mises stress of the T12 vertebra during flexion,extension,left bending,and right bending was most obvious in Group B,with peak stress values of 13.840,29.450,49.504,and 50.020 MPa,respectively.The decrease in the Mises stress of the T12 vertebra during left rotation and right rotation was most obvious in Group C,with stress values of 33.661 and 33.450 MPa,respectively.After vertebral augmentation,the Mises stress of the T11-T12 intervertebral disc showed a decreasing trend during movement,while the Mises stress of the T12-L1 intervertebral disc showed an increasing trend during movement.Comprehensive data indicate that when T12 vertebral augmentation is performed with the bone cement dispersion pattern of Group B,the stress borne by the vertebra is significantly reduced.Part of the reduced Mises stress of the T11-T12 intervertebral disc is borne by the underlying T12-L1 intervertebral disc,reducing the risk of re-fracture in adjacent vertebrae.These findings indicate that uniformly dispersed bone cement in vertebral augmentation can better reduce the Mises stress borne by the vertebra,maximize postoperative vertebral stability,and reduce the risk of recurrent fracture of the injured vertebra after surgery.