[In-vitro measurement of loading using an instrumented vertebral internal fixator].

Only little is known about the loads acting on internal spinal fixation devices. The forces and moments for different external loads were now measured using instrumented implants. Measurements were performed on intact cadaver spines and after a corpectomy. Additionally the influence of the mounting accuracy on the distribution of the loads in the fixators was investigated. It could be shown that the implants are not loaded symmetrically. After a corpectomy the loads on the implants are significantly higher than for an intact spine.