Infections after surgery can be severe and decrease the chances of a successful outcome. They also cause longer recovery time and costs more in medical costs due to extra doctor visits and treatments. Between one and 23 percent of people who have total knee replacements, or arthroplasties, end up with deep infections. For people who have revision surgeries, the rate is even higher, up to 6 percent higher and these infections even more difficult to treat.
The authors of this article wanted to evaluate the effectiveness of cement that was impregnated with the antibiotic vancomycin to correct the arthroplasty to see if it would prevent these infections from occurring in the first place.
Researchers looked at 179 patients who had 183 revision total knee arthroplasties between them. The majority of the patients had osteoarthritis of the knee, which made the original replacements necessary. All revisions were the first time they were done. The patients were divided into two groups: Group 1 was made up of 91 knees that received the usual cement, without antibiotics, didn’t use cement at all, or used a hybrid approach. Group 2 was made up of 93 knees that did receive the vancomycin-cement, didn’t use cement at all, or used the hybrid approach. Four patients in the study had both knees to be revised, so in each, one knee fell into group 1 and the other into group 2. All patients were given intravenous antibiotics before the surgery and some intravenous followed by oral antibiotics for several days after surgery. The average age of the patients was 70 years for group 1 and 71 years for group 2. The youngest patient was 49 years and the oldest 90 years. The most commons reason for the need for surgery was loosening of the hardware and/or wear and tear on the prosthesis.
The patients were examined and evaluated at three weeks after surgery, eight weeks, and six months. After that, the patients were seen every six months for an average follow-up period of about 89 months. The findings showed that although there were no infections in group 2, the group with the antibiotic cement, there were six deep infections and one superficial infection in group 1. Of the six, two were acute infections just after surgery and four were later, called late chronic. Overall, however, the average hospital stay period was about 13 days, ranging from nine to 17.
In discussing the study, the authors point out that while they don’t feel the vancomycin-impregnated cement can prevent infection alone, it is a good tool to be used with antibiotics before and after the surgery. They also point out that although they followed the patients for more than five years, they can’t tell if the effectiveness of the cement carries on and they would need further long-term studies for this.
The authors recommend that vancomycin-impregnated cement be used when doing a revision knee arthroplasty when the operating room lacks the necessary clean-air measures. They do note that further studies are necessary.