INFLUENCE OF CLAMPING RIGIDITY ON THE LOA D DISTRIBUTION BETWEEN PAIRED INTERNAL SPINAL FIXATION DEVICES

Paired internal spinal fixation devices are not necessarily loaded sym metrically when the vertebrae are unable to support one another direct ly. A finite element model has been developed to predict the influence of clamping rigidity on the load distribution. If the stiffness of on e clamping element is significantly reduced, the corresponding implant will bear only about 30 percent of the outer bending moment. The theo retical results were confirmed experimentally with sensor-loaded inter nal spinal fixation devices.