Researcher Dr. Edward Rodriguez of Beth Israel Deaconess Medical Center in Boston used 129 volunteers with a total of 149 implants to test a borrowed detector set both on normal and sensitive and found all total hips and 90 percent of knee replacements were caught on the normal setting, the Chicago Sun-Times reported Tuesday.
None of the screws, wires or nails was caught used in some surgical repairs, while 14 percent of steel plates triggered the alarm, the study published in the Journal of Bone and Joint Surgery said.
Chicago residents Charlie Holzner, 80, and his wife Anne Marie, 79, travel often and constantly set off metal detectors with his artificial hip and her artificial knee. Holzner told the newspaper he finds it annoying, but also reassuring.
"But if I went through and it didn't go off, it would scare me," Charles said. "I have enough metal in my hip to make two or three guns."