garthunk

http://www.ncbi.nlm.nih.gov/pubmed/23827294

it says nothing about security. other studies have showed roughly a 50/50 rate of detection. greatly depends on a large number of factors, such as surrounding tissue density, sepcific makeup and composition of alloys used in the implant, location of the implant, etc. etc. etc.

i've had hardware in my left hip, femur, and ankle since i was 13, and rarely set off security scanners. however, there was a FYE store in a mall i used to go to as a teenager that would ALWAYS go off when i passed through, incoming or outgoing. it happened so consistently (and i bought so many CDs) that the employees got to know me by sight and would be ready to deactivate the alarm as soon as it went off. once it twice it only had time to make a half-hearted blip before the employees killed it.

variance in detector ability dependent upon one model vs. another. or could have scanning ability degrade over time if the scanners are old. or could be other EM interference, or simply different scanning tech used.

must stand-alone scanners (security gates and the like) use Pulse Interference (PI) where most wand-types use BFO (Beat Frequency Oscillation). just different methods of accomplishing the same task. this link explains it nicely.

http://www.ncbi.nlm.nih.gov/pubmed/23827294