A Finite Element Analysis Of Biomechanics Of The Middle Segment After Cross-segmental Vertebral Augmentation

BackgroundOsteoporotic vertebral compression fracture (OVCF) is the most common complication in elderly patients with osteoporosis. Percutaneous vertebroplasty (PVP) and percutaneous kyphoplasty (PKP) are the primary treatments of OVCF in elderly patients. We often intensify the cross-segment vertebras to treat multiple segmental OVCFs. There is few studies about how it affects the middle vertebral body and whether to intensify the middle segment.ObjectiveWith the finite element analysis, this study aims to investigate the biomechanical influence of the cross-segment vertebral augmentation on the middle non-augmented segment, explore whether to intensify the middle vertebrae and discuss the treatment of multiple segmental OVCFs.MethodsT12-L2segment data are obtained from computed tomography (CT) scans of an elder female with multiple segmental OVCFs. A three-dimensional finite element model of thoracolumbar spine (T12-L2) is built in the Mimics and the ABAQUS software. Observe the biomechanical changes of L1before and after the augmentation of T12and L2.ResultsBased on the patient’s CT data, we have established the3-dimensional finite element model of multiple segmental OVCFs, including3types. Type A:No vertebral augmentation; Type B:cross-segment vertebral augmentation; Type C:All (T12-L2) Vertebral augmentation. With the axial pressure of0.3MPa, the L1vertebra endplate can be found with uneven stress distribution before and after the augmentation of the cross-segment. With the increase of the axial pressure, maximum Von Mises stress increases linearly. The maximum compressive stress of L1slightly decreases compared with the preoperative after the cross-segment augmentation. The maximum compressive stress will also decreases slightly after its self-augmentation.Conclusions1. Using the finite element method, the study establishes a3D finite element model section of multiple segmental OVCFs.2. The stress of the middle vertebra did not change significantly when the corss-segment vertebral bodies were intensified.3. When the middle segment is intensified, its stress did not change significantly.4. When we intensify the cross-segment vertebras to treat multiple segmental OVCFs, the middle segment does not require augmentation unless it is the responsible vertebra.