Extended antibiotics reduced PJI in high-risk patients after TJA

High-risk patients who received extended antibiotics after total joint arthroplasty experienced a significant reduction in risk of periprosthetic joint infection, according to published and recently presented results.

“Extended oral antibiotic prophylaxis may be a simple, safe and cost-effective measure to counteract poor host factors, which can be difficult to modify or optimize in order to reduce [periprosthetic joint infection] PJI rates at 1-year postoperatively,” investigatorMichael M. Kheir, MD,of the department of orthopedic surgery at Indiana University School of Medicine, toldOrthopedics Today.

Extended antibiotics for infection

Kheir and his colleagues retrospectively reviewed and compared 3,855 patients who underwent either primary total hip or knee arthroplasty between 2011 and 2019 at a suburban academic hospital with modern perioperative and infection prevention protocols. Patients were defined as high risk for PJI if they had a BMI of 35 kg/m²or higher, diabetes mellitus, positiveStaphylococcus aureusnasal colonization, chronic kidney disease, were an active smoker or had an autoimmune disorder.

“We categorized [patients] into one of three groups,” Kheir said in his presentation at the American Association of Hip and Knee Surgeons Annual Meeting, which received the AAHKS Clinical Research Award. “Group A is low risk for PJI and were not given extended antibiotics. Group B are high risk for PJI, also not given antibiotics, and group C is the group we were most interested in, as patients at high risk for PJI but received extended oral antibiotics.”

Patients in group C had a significantly lower infection rate compared with patients in group B, according to Kheir, who said patients in group C also had a lower infection rate compared with patients in group A, although this rate did not reach statistical significance.

“Based on these infection rates, we determined the number needed to treat was 57 patients with extended oral antibiotics to prevent one PJI in this high-risk group,” he said.

Safety, cost-effectiveness

According to Kheir, sub-stratification by joint type and log regression analysis revealed patients who underwent THA who were high risk but did not receive extended antibiotics were 3.4 times more likely to develop PJI compared with patients who did receive extended antibiotics. Researchers found a similar effect among male patients who underwent TKA, and women had a significantly lower 1-year infection rate vs. men, he said.

“Lastly, there are no known cases of[Clostridioides difficile]C. difficilecaused by our protocol,” Kheir said during his presentation. “We identified six possible antibiotic-related complications, all of which resolved acutely with no long-term effects.”

In an interview withOrthopedics Today, Kheir said the number of patients needed to treat to prevent PJI may also lead to cost savings in the long-term.

“When we looked at the average manufacturer pricing for our antibiotic of choice, cefadroxil costs about $1.40 for a 1-week supply,” Kheir said. “That means for 57 patients with a 1-week supply, it would cost an average around $80, which is, as we know, magnitudes lower than the cost of treating a single PJI, which in the literature we can see costing anywhere up to $100,000 or more in certain cases.”

Reference:

Kheir MM, et al. Extended oral antibiotics prevent PJI in high-risk cases: 3,855 patients with 1-year follow-up. Presented at: American Association of Hip and Knee Surgeons Annual Meeting; Nov. 5-8, 2020; Dallas (hybrid meeting).

Kheir MM, et al.J Arthroplasty. 2021;doi:10.1016/j.arth.2021.01.051.

For more information:

Michael M. Kheir, MD,can be reached at 340 West 10th St., Fairbanks Hall, Suite 6200, Indianapolis, IN 46202; email:mikemkheir@gmail.com.