Wireless tags provide details of orthopedic implants

Lee Berger

Researchers at the University of Pittsburgh have developed Ortho-tag, a system designed to identify orthopedic implants and their surrounding environment in the body through use of a wireless tag and touch probe. The Ortho-tag, which integrates radiofrequency identification technology developed at the University of Pittsburgh, uses human tissue instead of air as a conduit for radio waves.

“Ortho-tag is bringing ‘smart tag’ technology to the specialty of orthopedics. This technology will enable orthopedic surgeons and health care providers to obtain important information regarding the identification of implanted hip, knee, spine and other implanted medical devices in patients and, with the incorporated Ortho-tag biosensors, obtain information about the tissue environment in which the device is implanted,” Lee Berger, MD, orthopedic surgeon and inventor of the tagged implant, told Orthopedics Today.

The Ortho-tag and its patented touch probe system have been developed and tested in the laboratory at the University of Pittsburgh School of Bioengineering RFID Center of Excellence under the direction of Marlin H. Mickle, PhD, MSEE. Berger, Mickle and the University of Pittsburgh RFID Center for Excellence have combined their intellectual property and together developed the Ortho-tag System for implanted medical devices. Ortho-tag, Inc. was incorporated in April and now has optioned the rights to the technology.

Attached, not built in

Ortho-tag is affixed to an orthopedic implant prior to packaging and sterilization or intraoperatively at the time of surgery by the surgeon. The attached Ortho-tag is scanned via near field transcutaneous technology with a patented touch probe to obtain real time information about the implant and associated biosensors. Ortho-tag is applying for FDA approval of the system, Berger said.

“Ortho-tags are attached — not built-in — to medical implants. This enables the tag to be applied and universally easily accepted by all orthopedic manufacturers without any change in design or manufacture of their products,” Berger said. “I envision that orthopedic surgeons will offer patients the optional choice of having their implant provided with the Ortho-tag system.”

Berger said that patients want to know more about medical devices that are implanted in their bodies and want the security of knowing that there may be a way of possibly detecting infection or other problem in a non-invasive way.

“Ortho-tag is working to create integrated biosensors that can act as an early warning system of a change in the tissue environment around an implant and this may be beneficial to health care providers to improve patient diagnosis and treatment,” he said.

Orthopedic surgeons would upload information about the patient, implant and procedure performed to the Ortho-tag interoperatively or postoperatively. Once implanted, biosensors interacting with the Ortho-tag would gauge the environment around the implant, such as the chemical balance and temperature of surrounding tissue, and the presence of harmful organisms. The information would then be read by a handheld probe and displayed on a computer using software for secure data collection. The interactive data system, Berger said, includes the Ortho-tag Total Hip and Knee Registry, which has programmed templates for the surgeon to complete by using the Ortho-tag Touch Probe scanner to enter the implant and patient information into the registry postoperatively and during follow-up visits.

“The Ortho-tag implant information and registry information is programmed directly into the Ortho-tag so it is always with the patient, and this will ensure better and more accurate data collection, validation and improve outcome studies at a lower cost than anticipated for a paper- or computer-based national total joint registry,” he said.

Security

Berger said that patient confidentiality is protected by the touch probe, which is more secure than wireless RFID readers because it must physically touch the patient’s skin in the vicinity of the implanted orthopedic prosthesis for transcorporal transmission of the signal to send and receive information to the Ortho-tag and biosensors. This eliminates the possibility of “hacking” into the information programmed into the Ortho-tag, he said.

“The patients themselves decide whether or not they want to be touched by the touch probe as that is the only way to obtain information from the Ortho-tag on the implant,” he said.

Once data is collected, it is protected by a password-encrypted security system as commonly used in electrical medical records as per Health Insurance Portability and Accountability Act regulations.

Next steps

Berger said the next step is to work with orthopedic surgeons and manufacturers to bring the Ortho-tag system to the orthopedic community. For patients with existing orthopedic implants, the Ortho-tag card to provide patients and surgeons interactive access to the Ortho-tag registry system will be available by the end of the year.

“We will work with orthopedic surgeons and hospitals in offering this technology to their patients in FDA-approved clinical studies,” he said. “We will also work closely with the FDA to obtain approval of Ortho-tag products.”

He said that he believes that the Ortho-tag will not significantly add to the price of the implant and may ultimately save manufacturers time and money. The technology could also be useful in the case of a recall as defective implants are typically recalled by serial number.

“This technology will help to create a new type of information highway for implanted medical devices that will enable major advancements in health care,” Berger said. – by Kristine Houck, MA, ELS

Reference:

• www.pitt.edu

• Lee Berger, MD, can be reached at Orthopaedic Associates, 15-01 Broadway, Suite 20, Fair Lawn, NJ 07410; 201-794-6008; email: leebergermd@aol.com.
• Disclosure: Berger is chairman of Ortho-Tag Inc.