As the population ages, total knee arthroplasty (TKA) and total hip arthroplasty (THA) are being performed more often. Concerningly, data from 2001 to 2009 point to a rise in the incidence of yearly PJI from 1.99% to 2.18% for THA and from 2.05% to 2.18% for TKA. Minimizing the risk for infection and optimizing the treatment course of IV antibiotics when a PJI occurs are essential. However, achieving these goals is not straightforward. There is discrepancy between the United States and European clinical guidelines on the length of treatment needed for IV antibiotics for PJI, with the American standard of care requiring 2 to 6 weeks of pathogen-specific IV antibiotic therapy and the European guidelines recommending shorter IV antibiotic courses.

To help address this issue, researchers conducted a systematic review and meta-analysis (SR/MA) to determine if the success rate of short-duration IV antibiotics is noninferior to long-duration IV antibiotics for the treatment of PJI. The investigators searched the Cochrane Library, PubMed/Medline, Scopus, Google, Google Scholar, references from recent meta-analyses, and clinicaltrials.gov.

Studies were included in the SR/MA if they involved human subjects, were comparative studies, reported on short (<4 weeks) versus long (>4 weeks) duration of IV antibiotics for PJI associated with TKA or THA, and if the articles discussed efficacy and success rate outcomes, postoperative complications, or safety measures.

The SR/MA included nine articles that involved 1,051 patients (521 who had had THA and 530 who had undergone TKA). These trials were eight cohort studies and one randomized, controlled noninferiority study. The quality of the included cohort studies ranged from good (three studies), fair (three studies), to poor (two studies). The mean age of the study patients was from 61 to 77 years, and the mean follow-up period lasted from 12 to 75 months.

The authors included the Musculoskeletal Infection Society’s (MSIS) definition of successful infection management and guidelines for reporting of outcomes after surgical treatment of PJI to standardize research outcome definitions and to provide information on the initial treatment. Correlations were made between a successful outcome based on the infecting organism, the onset of infection post surgery (early was defined as <3 months, delayed was defined as 3-12 months, and late was defined as >12 months), duration of infection, length of hospitalization, and mortality. Measured outcomes differed across studies but the authors aligned the success rate definition outcomes and information from the MSIS tool.

The investigators found that there was no statistically significant difference between the short- and long-duration treatment groups (odds ratio [OR], 1.65; 95% CI, 0.78-3.46). However, the study demonstrated moderate to high heterogeneity in the overall success rate. Two studies were considered outliers because of large disparities in the number of patients in the short- and long-duration treatment groups. Excluding these two studies, the homogeneity of the comparisons resulted in a statistically significant difference in favor of the short-duration IV treatment group (OR 2.45; 95% CI, 1.21-4.96).

As a result of the small numbers of studies involved, the authors did not include other outcomes such as hospital length of stay or mortality in the SR/MA.

Although limited in generalizability due to the paucity of information, this paper provides pharmacists with preliminary evidence of the potential benefit associated with short-course IV antibiotic therapy for PJI. However, large, well-performed, randomized, controlled trials are needed before changes to clinical practice are made.

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