Biomechanical analysis of the intervertebral disc implant using the finite element method

Dysfunctions of the vertebral column belong to a group of civilisation diseases and they affect approximately 80% of population. The underlying cause is modern (sedentary) lifestyle, low locomotive activity of people and frequent motor vehicle and sports accidents. Despite civilisation’s progress, no injury prophylactics or prevention of dysfunctions of the vertebral column have been introduced. The key element influencing function of the vertebral column is the intervertebral disc. It enables multidimensional movements and constitutes a basic connective element between the joints of the vertebral column. It also enables performing basic daily activities. Acting as a “damper”, it cushions vibrations and transmits loads between the vertebrae. One of the diseases affecting the intervertebral disc is discopathy. This is the most common degenerative disease, which can be treated by both conservative and surgical treatment. After removal of the damaged disc, it can be replaced by an adequate implant, which will assume its function. The implant will be expected to restore the vertebral column motor function, as well as to eliminate the pain resulting from compression of the spine caused by the damaged disc. This paper presents a biomechanical analysis using the finite element method for the L2-L3 vertebrae system with natural intervertebral disc, and the L2-L3 – implant of the intervertebral disc system. Two cases of the system vertebrae-implant were analysed which differed in the placement of the artificial disc in the intervertebral space. Within the conducted analysis, the state of displacement, strain and stress of reduced analysed systems and their individual elements was determined. A comparative analysis of the results and calculations was performed, also conclusions and observations were formulated, constituting a starting point for building more advanced calculation models and further analyses of such implants.