MEMs Sensor Technology
for Orthopedic Implants

Advances in surgical techniques and materials have enabled widespread use of complete joint replacements for knees and hips. Though improving, friction surfaces in all orthopedic implants experience load-dependent wear that ultimately limits their useful lifetime. Replacement of a worn artificial joint, though possible, is generally avoided due to the need for additional surgery. Because of this, joint replacements are often delayed so that the life expectancy of the recipient and the artificial joint are approximately correlated.

Researchers at Oak Ridge National Laboratory (ORNL) and the University of Tennessee have developed a patented approach for implanting MEMs (micro-electro-mechanical systems) sensors for monitoring orthopedic implants. The invention is a technique enabling accurate measurement of direct wear and force parameters that can be incorporated into both research and clinical implants for continuous or periodic wear and load assessment. In addition, the invention can incorporate different sensor types allowing monitoring of surrounding physiological parameters including tissue encapsulation, bone condition, osteo-integration status including implant loosening, and the presence of infection. The invention is suitable for use with many different implant types including artificial knee, hip, shoulder, and elbow joints, and may find use in spinal or other applications where bone is involved.

The invention has recently been licensed to Zimmer, Inc of Warsaw, Indiana, a worldwide leader in joint replacement solutions for knee pain and hip pain. The company also provides a broad range of trauma, dental implant, and orthopedic surgical products. Founded in 1927, Zimmer is committed to providing effective techniques in hip replacement and knee replacement for orthopedic surgeons who restore mobility and relieve the pain of osteoarthritis and traumatic injuries with valuable partners in more than 80 countries.

MEMs sensor placed on orthopedic implant.

Zimmer has embarked on a 10-year plan to develop, test and introduce artificial joints and other products incorporating this patented technology.