Anyone who has been to an airport in the past few years has seen that security has certainly stepped up. There is no easy trip anymore. 

If you've had a bone fracture that has required plates or screws, or hip or knee replacement, for instance, you may find yourself getting patted down or at least a visited by "the wand" on your next out-of-town trip.

More and more individuals are having orthopedic surgical procedures. Numbers are at an all-time high. Many individuals wind up with metal implants in their body. Interestingly, these implants can set off airport metal detectors. Even more interestingly, some metal implants pass through quietly, going unrecognized.

A recent study published in the April 2007 issue of the Journal of Bone and Joint Surgery looked at this very issue. Which implants will set off an airport metal detector, and which won't.

Harvard researchers used M-Scope three zone metal detectors identical to those used at airports and had 129 volunteers with a total of 149 implants walk through these detectors. Some interesting findings occurred:

• More than half of all orthopedic type implants are detected. This means that almost half go undetected.
• Every total hip replacement was detected as were 90 percent of knee replacements.
• Implants in the lower extremity were much more likely to be detected than those in the upper extremity or spine.
• Plates, screws, wires, and intramedullary nails, or rods are rarely detected.
• Implants made from titanium and cobalt-chromium are much more likely to be detected than those from stainless steel.

In the past, orthopedic surgeons would give patients a note or small card stating that that patient has a joint replacement or metallic implant, and that would suffice. While it is still a good idea to have that type of note, it certainly will not in and of itself get you on the plane.

It is probably a good idea to let the security staff know about your implant before walking through the detector, and expect some closer scrutiny. You can request that this be in private if needed.

The American Academy of Orthopedic Surgeons offers some additional information and advice on this new problem of the new world in which we live.

Do you have a good orthopedic implant airport-related story? Please share it with us. Are you concerned that not all implants are detected?