BIOMECHANICAL VALIDATION OF TOPOGRAPHIC PATTERNS OF NEW VERTEBRAL COMPRESSION FRACTURES AFTER VERTEBROPLASTY USING

Abstract

Despite the high clinical effectiveness of percutaneous vertebroplasty, the occurrence of new osteoporotic vertebral compression fractures after the procedure remains a significant clinical problem. One of the key mechanisms of recurrent fractures is believed to be the redistribution of mechanical loads within the spine caused by changes in geometry and stiffness after vertebral collapse and cement augmentation. Finite element analysis (FEA) is an appropriate tool for quantitative assessment of these biomechanical processes. The purpose. To provide biomechanical validation of topographic patterns of new vertebral fractures by analyzing the stress-strain state of a multisegment spinal model. Methods. Three-dimensional finite element models of the ThV–LV s pine w ere d eveloped, t aking i nto a ccount o steoporotic bone properties, including an intact model and models with compression fractures at different vertebral levels. Additional models simulated post-vertebroplasty conditions with local replacement of cancellous bone by bone cement. Results. The simulations demonstrated that vertebral compression fractures lead to significant redistribution of stresses in adjacent and distant spinal segments, with the location of high-stress zones depending on the level of the primary fracture. Vertebroplasty reduced stress in the treated vertebra but did not eliminate elevated stresses in other spinal segments, where biomechanical conditions favorable for subsequent fractures persisted. Conclusion. These findings confirm that the level of the primary fracture determines the spatial pattern of load redistribution in the spine and may explain the topographic features of new fractures after vertebroplasty. Finite element analysis is an effective method for investigating mechanisms of cascade fractures and for supporting preventive strategies in patients with osteoporosis.