[Is the prediction of initial stability of cervical spinal osteo-synthesis possible using a finite element model?]

The study is dealing with a three segmental (C4-C7) finite element model of the intact human cervical spine. Additionally, anterior cervical fusion and plating (ACFP) with Caspar-plate and bicortical screws in C5/6 was simulated. The models were loaded using pure moments of 2.5 Nm in flexion-extension, axial rotation and lateral bending. The range of motion in C5/6 was calculated and compared to the results of a biomechanical in vitro study, that used six cadaveric human spinal segments C4-C7 for analysing range of motion C5/6 in the intact state and following ACFP. The predictions of the finite element models were always within one standard deviation of the results of the in vitro study. Thus, the current model could be used for first analysis on new C-spine implants. However, the results should be interpreted as a trend and the limitations of these models should be kept in mind.