OTA 2005 Posters
Scientific Poster #53 Basic Science
Are Orthopaedic Implants Detectable by Airport Metal Detectors?
Purpose: This study reports the effect of patient body mass index (BMI) and implant type, size, location, number, and material on detection by a certified Tranportation Safety Authority and Federal Aviation Administration airport arch and wand metal detectors that had been in use at a major metropolitan airport.
Methods: Over a 1-month period, 96 trauma clinic patients who were ambulatory with a wide variety of orthopaedic implants consented and enrolled in the study to test if their implants were detectable by an airport-quality arch detector and wand. Arch detector sensitivity was set at comparable levels used at airports in the United States. Patients had height, weight, implant type, size, and location recorded. They then passed through an airport arch metal detector and the area where the implant was located was wanded with a handheld metal detector. A positive detection by the arch device was indicated by an alarm and detection by the wand with an audible beep.
Results: All prostheses (10/10) were detected. Subjects with no implants other than 4 or fewer screws were never detected by the arch (0/7). For the remaining 78 subjects, the two best predictors of detection by the arch were having plates of length >10 holes and having titanium nails (P<0.001 for each predictor, Wald's test for effects in a logistic model). None of the three stainless steel nails were detected. Nearly all implants were detected by the handheld wand.
Conclusions: Prostheses, large plates (length >10 holes), and titanium nails were the best predictors of detection by the arch. These three factors accounted for 42 of the 43 detections by the arch. BMI was not shown to affect detectability of orthopaedic implants.