Back

The Tough Task of Finding and Treating Infection in a Joint Replacement

Infection in a joint after a joint replacement is a major problem. Doctors try to make sure the joint is bacteria-free before putting in an implant. This isn't always possible. Sometimes the test results are a false negative, meaning the test says there's no infection when there really is one.

Joint infection is one of two reasons why joint implants fail most often. (The most common reason is loosening of the implant from causes other than infection.) Preventing infection is important. In this study, doctors from the Infectious Diseases section of the Mayo Clinic review joint infections after a joint replacement. They present how often infections occur and what causes them. Some risk factors for implant infection are known. These include delayed wound healing, rheumatoid arthritis, diabetes, and cancer.

Once an infection starts, the bacteria firmly attaches to the implant. It produces small units called polymers. Polymers that mix with the bacteria form a layer of cells called a biofilm. The bacteria survives in this biofilm untouched by the body's immune system. This makes it difficult to treat the infection. Sometimes the infected implant has to be removed. The joint is treated for the infection. Then a new implant is used to replace the infected one.

It's also difficult to tell when a patient has a joint infection. The authors of this report review each step in the diagnosis to help doctors. Ways to kill the bacteria are also reviewed. The authors hope the future will bring better, more accurate testing to find bacteria that are causing joint infection. Also, effective treatments to dislodge and kill the bacteria need to be found.

References: Andrej Trampuz, MD, et al. Molecular and Antibiofilm Approaches to Prosthetic Joint Infection. In Clinical Orthopaedics and Related Research. September 2003. Vol. 414. Pp. 69-88.

Back