Infection a Major Reason for Revision Knee Replacement

Revision total knee replacement commonly caused by periprosthetic joint infection as revision procedure rates grow

(RxWiki News) The hope is always that surgery will be the end-of-the-line answer to a health issue, but that ideal is not always the reality. After knee replacement, a revision surgery is sometimes needed.

Researchers behind a new study explored cases of revision total knee replacement surgeries in the US.

These researchers found that infection of the replacement joint was the most common cause of revision surgery, and that rates of these revision procedures seem to be growing.

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This new study, which was led by Kevin J. Bozic, MD, MBA, of the University of California San Francisco Medical Center, aimed to explore revision knee replacement surgery — a procedure that occurs when the previous replacement knee joint implant, or prosthesis, fails.

Using data from the Nationwide Inpatient Sample, Dr. Bozic and team evaluated 301,718 revision knee replacement surgeries that took place from the end of 2005 to 2010. The researchers looked at information like reason for the revision procedure and demographic data on the patients.

The procedures were most commonly performed in people between the ages of 65 and 74, and 58 percent of the revision knee replacement surgeries occurred in women. In over 60 percent of the cases, patients' arthritis was determined to be of "moderate severity."

The most common reasons for the revision procedure were periprosthetic joint infection (an infection in the prosthetic knee joint), which occurred in 25 percent of the cases, and mechanical loosening of the prosthesis, which occurred in 18.5 percent of cases.

"In total knee replacement, the large foreign metal and plastic implants can serve as a surface for the bacteria to latch onto, inaccessible to antibiotics," explained the Hospital for Special Surgery, a center specializing in orthopedics and based in New York. "Even if the implants remain well fixed, the pain, swelling, and drainage from the infection make the revision surgery necessary."

The researchers found that revision knee replacement procedures increased during the time period of the study, from 48,260 procedures in 2006 to 67,534 in 2010. In 37 percent of the cases, all of the components had to be replaced.

"The burden of revision [total knee replacement] is growing. Elderly and female patients with a moderate number of comorbidities represent a large proportion of the revision population," wrote Dr. Bozic and team.

Further research is needed to confirm these findings, especially if instances of revision knee replacement surgeries continue to grow.

This study was presented March 12 at the American Academy of Orthopaedic Surgeons' annual meeting. Studies presented at conferences are considered preliminary until published in a peer-reviewed journal.

Review Date: 
March 13, 2014