This article is more than 5 years old. Information may no longer be current.
MRSA septic TKA revisions yield typical post-revision outcomes
Click Here to Manage Email Alerts
NEW ORLEANS — Joint replacement surgeons should expect some technical difficulties associated with revising a total knee arthroplasty for septic methicillin-resistant Staphylococcus aureus, according to results of a recent study.
But the good news from the findings that Richard L. McGough, MD, of Pittsburgh, presented at the 2010 Annual Meeting of the American Academy of Orthopaedic Surgeons, here, was that when patients endure the aggressive treatment needed to treat this complication, they can expect to achieve motion and outcomes similar to those attained by patients whose TKAs revised for other reasons.
"We really feel that MRSA sepsis doesn’t necessarily preclude a good functional outcome if the patient is able to keep with the treatment,” McGough said.
Assessment at 2 years
For the study, which McGough described as both retrospective and prospective, investigators included 101 patients (103 knees) who received a mobile bearing-style total knee arthroplasty (TKA) primary prosthesis at a single institution between 2003 and 2006. They performed a chart review of all the knees, nine of which were infected with methicillin-resistant S. aureus (MRSA).
At the 2 year follow up from revision investigators assessed the available patients (49 knees; six with MRSA) based on their WOMAC score, activities of daily living score (ADLS), SF-36 and Knee Society Score (KSS) results.
McGough and colleagues then grouped the revised knees according to whether they were MRSA positive or MRSA negative and added a third group: knees revised for aseptic loosening (ASL). These three groups were the same demographically, McGough said.
Operative time
Investigators found the main technical challenge in the MRSA positive group was a longer average operative time of 166 minutes compared to 149 minutes in the non-MRSA group and 121 minutes in the ASL group, which was a statistically significant difference.
“All of the outcomes were essentially negative,” meaning there were no differences in the groups’ WOMAC, KSS, ADLS or SF-36, McGough noted.
The 6-month postoperative range of motion was also not significantly different between the three groups; however McGough said some decreased range of motion was detected in the MRSA group at 2 years postoperatively.
“Our results overall compared favorably to the existing literature with a similar percent of treatment failures. We had similar functional outcomes in non-MRSA infected vs. infected knees as in the literature, despite the small sample size,” he said.
The study was the senior project of first author Dann J. Laudermilch, MSIV.
- Reference:
Laudermilch DJ, Fedorka CJ, Klatt BA, et al. Revision total knee arthroplasty outcome after methicillin-resistant Staphylococcus aureus infections. Paper #604. Presented at the 2010 Annual Meeting of the American Academy of Orthopaedic Surgeons. March 9-13, 2010. New Orleans.
McGough received research/institutional support from DePuy, A Johnson & Johnson Company.
