Finite element modelling of hybrid stabilization systems for the human lumbar spine

Abstract

Intersomatic fusion is a very popular treatment for spinal diseases associated with intervertebral disc degeneration. The effects of three different hybrid stabilization systems on both range of motion and intradiscal pressure were investigated, as there is no consensus in the literature about the efficiency of these systems. Finite element simulations were designed to predict the variations of range of motion and intradiscal pressure from intact to implanted situations. After hybrid stabilization system implantation, L4-L5 level did not lose its motion completely, while L5-S1 had no mobility as a consequence of disc removal and fusion process. BalanC hybrid stabilization system represented higher mobility at the index level, reduced intradiscal pressure of adjacent level, but caused to increment in range of motion by 20% under axial rotation. Higher tendency by 93% to the failure was also detected under axial rotation. Dynesys hybrid stabilization system represented more restricted motion than BalanC, and negligible effects to the adjacent level. B-DYN hybrid stabilization system was the most rigid one among all three systems. It reduced intradiscal pressure and range of motion at the adjacent level except from motion under axial rotation being increased by 13%. Fracture risk of B-DYN and Dynesys Transition Optima components was low when compared with BalanC. Mobility of the adjacent level around axial direction should be taken into account in case of implantation with BalanC and B-DYN systems, as well as on the development of new designs. Having these findings in mind, it is clear that hybrid systems need to be further tested, both clinically and numerically, before being considered for common use.

Biomechanical finite element analysis of vertebral column resection and posterior unilateral vertebral resection and reconstruction osteotomy

“…Fusion fixation reduces thoracolumbar motion, as shown in previous studies [ 15 , 19 ]. Lu and Lu found that the short-segment fusion fixed model decreased by 52–94% compared with the intact model [ 20 ].…”

“…Finite element analysis reconstructs the shape of the spine using computer simulation. It then directly interprets spinal biomechanics changes caused by internal fixation by loading its material parameters and loading conditions and guiding the surgical plan [ 15 ]. Finite element analysis can be repeatedly applied, saving medical resources while safely and efficiently simulating complicated surgical procedures.…”

Treatment of Old Vertebral Compression Fracture With Kyphosis by Different Reconstruction Methods: a Finite Element Analysis

“…Fusion xation reduces thoracolumbar motion, as shown in previous studies [15,19]. Lu and Lu found that the short-segment fusion xed model decreased by 52-94% compared with the intact model [20].…”

“…Finite element analysis reconstructs the shape of the spine using computer simulation, and then directly interprets changes of spinal biomechanics caused by internal xation by loading its material parameters and loading conditions, and then guiding the clinical surgical plan [15]. Finite element analysis can be repeatedly applied, saving medical resources, while safely and e ciently simulating some di cult surgical procedures.…”

Computational Challenges in Tissue Engineering for the Spine

“…In fact, FE modelling has already led to relevant conclusions and supported many preclinical studies, namely in what concerns to IVD behaviour or implant development [8,[37][38][39][40]. Additionally, it has also motivated the development of new computational tools (imaging reconstruction methods, FE solvers or even kinematics simulators) that have later led to wider achievements in biomechanics and tissue engineering [41][42][43][44][45][46][47].…”