Yes, metal implants such as artificial hips, knees, or spinal rods can and often do set off airport security scanners, particularly the traditional walk-through metal detectors. However, the high-fidelity Millimeter Wave Scanners (the "circular" machines where you put your hands up) are designed to detect items on the surface of the skin, so they may not "alarm" for an internal implant, though the agent may see an anomaly on the screen. It is a common myth that you need a "medical card" to prove you have an implant; while you can carry one, TSA officers do not require it and will not accept it as a replacement for screening. If you set off the alarm, you will simply be moved to a secondary screening area for a pat-down and potentially a wand scan. Modern implants are often made of titanium or other non-ferrous materials that are less likely to trigger older detectors, but as of 2026, you should always expect a brief additional screening. Informing the officer beforehand that you have an internal medical device is the best way to ensure a professional and efficient process.