[A validated finite element model of the human spine--description of the model and initial application].
OBJECTIVE
To generate a finite-element model of the human cervical spine and evaluate the first application of the model to the analysis of new c-spine implants.


METHODS
CT-data were used to generate a three-dimensional, anisotrophic, linear model of the human C4-C7 motion segments using the software ANSYS 5.4. As a next step, anterior cervical fusion and plate fixation using mono- and bicortical screws was simulated in the model. Loading of the finite-element models was simulated using pure moments of +/- 2.5 Nm in flexion/extension, axial left/right rotation, and left/right lateral bending. The range of motion was calculated. The results were compared to the results of an in vitro study using human cadaveric c-spine segments C4-C7, with the same implants and moments on both the intact and surgically treated specimens.


RESULTS
The results obtained by the finite-element model were always within one standard deviation of the results of the in vitro study.


CONCLUSIONS
Keeping in mind the simplifications of such a mathematical model, it may be used for a first analysis of the shape of new c-spine implants or to predict the initial stability of a new device.
Pitzen
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Neurochirurgische Klinik, Universitätskliniken des Saarlandes, 66421 Homburg/Saar. pitzen@handshake.de
Matthis
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D
Steudel
W I
WI
D000328:Adult; D016880:Anisotropy; D001863:Bone Screws; D002574:Cervical Vertebrae / Q000502:physiology / Q000601:surgery*; D003198:Computer Simulation; D005260:Female; D020342:Finite Element Analysis; D006801:Humans; D021621:Imaging, Three-Dimensional; D016014:Linear Models; D016059:Range of Motion, Articular / Q000502:physiology; D012016:Reference Values; D012984:Software; D013123:Spinal Fusion; D014057:Tomography, X-Ray Computed; D016474:Weight-Bearing / Q000502:physiology