[Metal detectors for security checks mostly insensitive for metal implants]

To determine whether metal implants may cause problems at security checks (e.g. at airports).

Amsterdam, Schiphol.

Fifty operated scoliosis patients chosen at random were asked by questionnaire whether they had ever been checked with a metal detector at an airport and whether the detector had reacted to the implant. In addition, several types of implants were tested with two types of detectors in collaboration with the airport State Police.

Forty-six questionnaires were returned. Twenty-two respondents stated having been checked with a metal detector gate at least once. In three cases the detector had sounded. During the Schiphol trial it was found that the metal detector gate did not react to various types of osteosynthesis material nor to a Harrington rod.

Metal detectors may be expected as a rule not to react to medical implants. This is due among other things to the relative insensitivity of metal detectors to the alloy used in the implant and to their being adjusted to react only to metal in quantities above a certain minimum.