Promising results found for inexpensive antibiotic mixture for two-stage revision of infected TKA
NEW ORLEANS — Research presented at the American Academy of Orthopaedic Surgeons Annual Meeting indicates that a mixture of ceftazidime and vancomycin in cement is an effective alternative antibiotic combination for patients who undergo a two-stage revision to treat an infected total knee arthroplasty.
“This combination of cement and antibiotics for two-stage has a reasonable and typical failure rate compared with all other methods that are published in the literature, and we therefore think it is a good alternative,” David Backstein, MD, said during his presentation here. “Because it is inexpensive, it is readily available, people with renal function limitations that you do not want to use aminoglycosides; these are all good reasons in my hands to use ceftazidime.”
The researchers retrospectively reviewed 82 patients with periprosthetic knee infections who were treated with this antibiotic combination during two-stage revision procedures. The patients had a mean age of 68 years at the time of surgery, and the mean time to infection from the index arthroplasty was 45 months.
To make the antibiotic mixture, surgeons typically used three bags of powered cement and added 4 grams of vancomycin and 4 grams of ceftazidime per bag for a total of 12 grams of each. All patients had a dynamic spacer and a static spacer was also used in cases of extreme bone loss and soft tissue instability. Postoperatively, Backstein said patients underwent weight-bearing as tolerated and started range of motion when the wound looked like it could tolerate it, he said. The patients had a minimum follow-up of 1 year.
“Our first two-stage success rate was 70 out of 82 patients or 85%. A second two-stage had to be done in 12 patients; five of those were polymicrobial [and] 33% of those 12 patients ended up having their infection cured,” Backstein said. “A third two-stage was required in three out of 82 patients. All three had polymicrobial [infections] and only one of those three eventually was successfully treated.”
Risk factors for failure to irradiate infection included polymicrobial infection and irrigation and debridement prior to the initial two-stage revision, he said.— by Gina Brockenbrough
Backstein D. Paper #488. Presented at: American Academy of Orthopaedic Surgeons Annual Meeting; March 11-15, 2014; New Orleans.
Disclosure: Backstein has no relevant financial disclosures.