In my practice patients will ask whether their orthopedic implant will cause any trouble at an airport security checkpoint. Until now I had not been able to reference any scientific studies that have evaluated which implants would trigger the airport metal detector.
An article that recently caught my attention was titled "Detection of Orthopaedic Implants in Vivo by Enhanced-Sensitivity, Walk-Through Metal Detectors" and appeared in the April, 2007 Journal of Bone and Joint Surgery. This article will be of general interest to patients in predicting whether their implant will trigger extra scrutiny at a security checkpoint. Shown on the right is an xray of a stainless steel plate and screws at the knee joint. This is likely to be detected by the Airport Metal Detector because of the large size of the blade plate and screws.
Patients with Total Hip and Total Knee replacements are commonly given credit card sized identification cards to travel with. However, in reality these cards are not acknowledged by airport screeners. If you have an orthopedic implant in your body that is likely to trigger the Airport Metal Detector allow extra time (5-15 minutes) to pass through airport security. What my patients with Knee Replacements tell me is that their implant does trigger the detector, and they are taken to the secondary screening station. There they are "wand ed" to verify the cause of the Metal Detector alarm was in fact their artificial knee and then they are cleared through the screening area. Rarely is any other type of more prolonged and time consuming screening done.
In their study the authors looked at Hip replacements, Knee replacements, spine fusion hardware, and upper and lower extremity fracture repair rods, plates and screws and wire.
Xray of Total Hip Replacement (above). This has a 100% chance of triggering the Airport Metal Detector.
The findings are summarized here. As you read the findings keep in mind that detection rates will vary because of the following facts: 1. Different brands and models of detector machines will have variable detections rates. 2. Sensitivities of metal detectors can be influenced by local magnetic interference such as fluorescent lighting or from other medical imaging devices. Repeating this study in a different location, such as your hometown airport, may show different detection rates. However in general the following observations can guide you as to the likelihood of whether your orthopedic implant will trigger an airport metal detector.
- Total Hip replacements were detected 100% of the time.
- Total Knee replacements were detected 90% of the time.
- Total Shoulder and wrist replacements were not detected.
- Plates with screws were detected approximately 25% of the time.
- Screws alone or wire alone or intramedullary rods alone were usually not detected.
- Lower extremity implants were detected 66 % of the time.
- Upper extremity implants were detected 17% of the time.
- Spine implants were detected 14% of the time.
And the type of metal matters. Cobalt chrome and titanium were likely to be detected, while stainless steel was unlikely to be detected.
Photograph of Knee Replacement implants made of cobalt chrome (above). Total Knee Replacements are detected 90% of the time by Airport Metal Detectors.
I invited readers to submit their experiences navigating through security with orthopedic implants.
