On Emerging Technology: What to Know When Your Patient Has a Microchip in His Hand.

Radio-frequency identification (RFID) technology uses an antenna to respond to an incoming signal by sending an outgoing message. This technology has been in use for over 50 years and is common in daily activities such as tapping a credit card to a reader, swiping an ID badge to open a door, paying highway tolls, and operating keyless entry cars. This technology can be implanted, such as in the microchips used to identify domestic pets. Since 1998, RFID chips have also been implanted in humans. This practice is little studied but appears to be increasing; rice-sized implants are implanted by hobbyists and even offered by some employers for uses ranging from access to emergency medical records to entry to secured workstations. These implants are of special concern to hand surgeons because they are most commonly placed in the subcutaneous dorsal first web space. The US Food and Drug Administration first approved this technology in 2004, with stated potential risks including adverse tissue reaction, migration of the implanted transponder, compromise of information security, electrical hazards, and magnetic resonance imaging incompatibility. Here, we explain implanted RFID technology, its potential uses, and what is and is not known about its safety. We present images of a patient with an RFID chip who presented to our clinic for acute metacarpal and phalangeal fractures, to demonstrate the clinical and radiographic appearance of these chips.