Corrosion Called Cause of Joint Failure

More than seven million Americans are living with an artificial hip or knee joint and the number is increasing, according to a report published online by Newswire. Because the recipients of those joints are living longer and maintaining active lifestyles, they are creating the need for long-lasting joint replacements. Newswire reports that in 2011 doctors performed an additional 50, 600 revision procedures to replace previously implanted artificial hips.

Robin Pourzal, Ph.D., a research scientist in the Department of Orthopedic Surgery at Rush University Medical Center, notes that total hip replacements now last between 15 and 25 years. However, if a reaction occurs, the implant life time can be less than five years. He said, “If we know why and when the implants fail, the implant can be adjusted before surgically implanting, and surgeons can plan in advance for how and when an implant may fail.”

Pourzal notes that the reasons for revision surgery are varied and include problems such as infection, instability and a loosening of the prostheses. He believes that a poorly understood cause of implant failure is the corrosion or wear that takes place on implant surfaces.

Implant failure, he says, “occurs due to adverse reactions in surrounding tissue to the minute debris that results from corrosion and/or implant debris wearing off a non-corrosive joint.” In addition, he adds that there are adverse local tissue reactions, which often are not examined in detail.

“Currently, there isn’t much research data published on this topic, because typically corrosion is not documented as a cause for revision, ” Pourzal said. However he does believe that awareness of corrosion as a major contributor to joint failure has been increasing over the last few years.