In patients with a total knee arthroplasty (TKA) periprosthetic joint infection who have undergone debridement, antibiotic therapy, and implant retention (DAIR), the addition of extended treatment with oral antibiotics appears to be safe and efficacious, according to a study published in Clinical Infectious Diseases.1

Although TKA periprosthetic joint infection can be managed with DAIR, the success rate has been variable, with failure rates ranging from 26% to 84%.2,3 One solution to decrease the failure rate associated with DAIR includes the use of oral antibiotics for an extended period after the initial course of intravenous antibiotic therapy. As such, researchers performed a multicenter, observational study to assess the treatment failure rate between patients who received only primary therapy (≤6 weeks of antibiotics) and those who received primary therapy and additional oral antibiotics (>6 weeks). They also evaluated types of adverse events associated with extended antibiotic use and the optimal time period to discontinue antibiotic use.    

A total of 108 patients (44% women) diagnosed with TKA periprosthetic joint infection between 2005 and 2015 at any University of Pittsburgh Medical Center institution were included in the study. The mean age was 67.5 years and the median duration of follow up was 2.3 years.

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Of the 108 patients, 57 received only primary therapy and 51 received antibiotics for >6 weeks. The most common antibiotics used in the primary treatment period were vancomycin, rifampin (which was never used as monotherapy), cefazolin, and ceftriaxone. Cephalexin, trimethoprim-sulfamethoxazole, and doxycycline were used in the extended time period.

Overall, patients who received an extended course of oral antibiotics had a significantly higher survival probability (68.5%) compared with those who received only primary therapy (39.4%) following their DAIR procedure (hazard ratio 2.47; P =.009). Multivariable analysis demonstrated extended antibiotics independently predicted treatment success controlling for other variables.

The benefit of continued therapy, however, was finite. Researchers observed that there was no difference in failure rates between an extended course of oral antibiotics less or more than 12 months (P =.23).

The most common side effect was gastrointestinal related, however, the rate of Clostridioides difficile (formerly Clostridium difficile) was very rare, occurring in only 1 patient. Moreover, the rate of adverse events for patients who received antibiotics for ≤6 weeks was not different from the rate for patients who received antibiotics for >6 weeks during their treatment course (P =.59).

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Researchers stressed that both infectious disease and orthopedic input is important in managing periprosthetic joint infection. They noted that while further studies are needed to reinforce the findings of this study, the extended course of oral antibiotic use for one year following DAIR appears to be safe and efficacious and optimizes antibiotic stewardship.


  1. Shah NB, Hersh BL, Kreger AM, et al. Benefits and adverse events associated with extended antibiotic use in total knee arthroplasty periprosthetic joint infection [published online April 4, 2019]. Clin Infect Dis. doi:10.1093/cid/ciz261
  2. Swenson RD, Butterfield JA, Irwin TJ, Zurlo JJ, Davis CM III. Preoperative anemia is associated with failure of open debridement polyethylene exchange in acute and acute hematogenous prosthetic joint infection. J Arthroplasty. 2018;33(6):1855-1860.
  3. Bradbury T, Fehring TK, Taunton M, et al. The fate of acute methicillin-resistant Staphylococcus aureus periprosthetic knee infections treated by open debridement and retention of components. J Arthroplasty. 2009;24(6 Suppl):101-104.