[Biomechanical analysis of artificial intervertebral disc in a 3-dimensional finite-element model].
OBJECTIVE
To evaluate the mechanical properties of artificial lumbar intervertebral disc by finite-element (FE) analysis, to predict the mechanical influence of loading on the prosthesis after placement, especially after the long-term employment,and to offer the mechanical basis and technological means for the design optimization.


METHODS
A 3-dimensional solid model was built according to the geometry of the prosthesis; finite-element analysis was applied to determine the effect of the implanted artificial disc prosthesis on the biomechanical behavior; and the data of its mechanical responses were calculated in 3 compression modes which simulated its different load conditions in vivo. Simulations were conducted in a new specially designed manner, preferably simulated load conditions in vivo.


RESULTS
A finite-element model was established by generating mesh out of the prosthesis geometry. The analysis was conducted in employing models of the disc prosthesis under 3 types of emulational realism loading conditions, obtaining the distributing characteristics and data of displacement-stress-strain-energy in the structure, which are difficult to measure exactly by conventional methods.


CONCLUSIONS
Implanted loading strongly influences prosthesis in its internal distribution of displacement-stress-strain-energy in the structure, suggesting that the disc prosthesis allows correctly reproducing a profitable motion and cushion at the implanted level. Predictive wear may occur in special parts according to the designed prosthesis mechanical structure. When implanting an artificial disc, proper size should be taken in choosing disc and the higher core could provide better mechanical characteristics. The Results may assist in optimizing artificial lumbar disc replacement primarily from a biomechanical point of view.
Ge
Lei
L
Department of Spinal Surgery, Xiangya Hospital, Central South University, Changsha 410008, China.
Li
Kang-hua
KH
D001696:Biomechanical Phenomena; D003198:Computer Simulation; D020342:Finite Element Analysis; D006801:Humans; D007403:Intervertebral Disc; D007405:Intervertebral Disc Displacement / Q000209:etiology / Q000473:pathology / Q000503:physiopathology*; D008159:Lumbar Vertebrae / Q000502:physiology; D008954:Models, Biological; D019736:Prostheses and Implants; D013314:Stress, Mechanical; D016474:Weight-Bearing / Q000502:physiology