A SPINAL FIXATION DEVICE FOR IN-VIVO LOAD MEASUREMENT

An instrumented spinal fixation device has been developed that allows in vivo measurement of the forces and moments acting on the implant. T he telemetry is inductively powered, hermetically sealed by electron b eam welding and is active only during the measurements. The instrument ed fixateur interne is similar in size to the original Dick internal f ixator implant and has the strength of the original implant. Laborator y tests with paired implants mounted in plastic vertebrae show that sm all changes in the position of the implants have a strong influence on the distribution of the loads on the implants.