In silico investigations of surgical interventions in the thoracolumbar and lumbopelvic region
Turbucz Máté
Clinical Medicine
Dr. Reusz György
MOM Kulturális Központ Simándy József terem
2024-09-18 08:30:00
Physiology and Pathology of the Musculoskeletal System
Dr. Szőke György
Dr.Éltes Péter, Dr.Lazáry Áron
Dr. Fabio Galbusera
Dr. Hangody László Rudolf
Dr. Szendrői Miklós
Dr. Hangody György Márk
Dr. Manó Sándor
In Part I, three healthy FE models were developed and validated. Regarding bone modelling approaches, this section introduced two types of bone modelling strategies: a patient-specific approach for the lumbar spine and a literature-based technique for the thoracolumbar spine. The FE model of the healthy pelvis was developed using both strategies and was validated with bony tissues as rigid bodies. Based on the results of the validation processes, all three FE models are suitable for further biomechanical analysis, as they agree with available in vitro, in vivo and in silico data from the literature.
In Part II, the validated thoracolumbar spine FE model was utilized to investigate the biomechanical effect of one rigid and two types of SFTs on developing PJK. For the analysis, a modified multidirectional hybrid test protocol was used. First, a pure bending moment of 5 Nm was applied to measure the IVR angles. Second, the rigid technique’s displacement from the first loading step was applied to the instrumented FE models to compare the pedicle screw stress values in the UIV. The FE analysis has shown that the SFTs increase the mobility at the upper instrumented segment and, therefore, provide a more gradual transition in motion between the instrumented and cranial non-instrumented spine segments. In addition, SFTs decrease the screw loads at the UIV level and hence could help reduce the risk for PJK.
In Part III, the validated pelvis FE model was used to evaluate and compare the biomechanical efficacy of six ISS fixation techniques for treating unilateral Denis Type II sacral fractures using literature-based (LBM) and QCT-based bone material properties (PSM) in FE models. The results demonstrated that all investigated techniques demonstrated clinically sufficient stability, with TISS12 being superior from a biomechanical standpoint. Both LBM and PSM models indicated a consistent trend in ranking the fixation techniques based on stability.
In Part IV, the lumbar part of the literature-based thoracolumbar spine and the pelvis FE model were combined to evaluate and compare the biomechanical characteristics of four LPRTs while considering the effect of LPDR. Based on the findings, LPDR significantly improved both lumbopelvic stability and implant safety in all reconstruction techniques after total sacrectomy. However, all four investigated LPRTs demonstrated suitability for lumbopelvic reconstruction, with the ICR technique exhibiting the highest lumbopelvic stiffness.
