Purpose: To describe the number of prosthetic joint infections (PJIs) with late documentation and to identify associated factors. Methods: Bacterial PJIs with surgical management between November 2015 and November 2019 in a French center were analyzed. Results of short (72 h) and late culture (at 14 days) were analyzed. Results: A total of 160 PJIs were reported with 215 bacteria. Twenty-nine patients had late documentation (18.1%). The bacteria most involved were coagulase-negative staphylococci and Cutibacterium spp. (60%). In multivariate analysis, late chronic PJI (odds ratio = 2.47) and antibiotic therapy before surgery (odds ratio = 3.13) were associated with late-documented infection. Conclusion: A better knowledge of the factors associated with late-documented infections is essential in order to simplify antibiotic treatment at the appropriate time.
Keywords: Cutibacterium; coagulase-negative staphylococci; empirical antibiotherapy; late culture; prosthetic joint infection.
Prosthetic joint infections (PJIs) are rare and occur in around 1% of cases. They are often complex and require multidisciplinary management. The identification of bacteria and the implementation of an effective intravenous antibiotic therapy as soon as the surgery is performed are important points in PJI management. Some bacteria take longer to be cultivated, which is why samples are cultured for at least 14 days after surgery. As soon as the bacteria have been identified, the antibiotic therapy can be taken orally to allow the patient to be discharged early from hospital. The aim of this study was to investigate the factors associated with a positive late culture (day 14 after surgery) compared with an early culture (day 3). We showed that patients who had received antibiotic therapy within 1 month before surgery and patients with chronic PJI (i.e., more than 1 year after surgery) were at greater risk of having long-culture-positive specimens. We also showed that late samples were more often positive for two types of bacteria (Cutibacterium acnes and coagulase-negative staphylococci). In practice, when early samples are positive, oral antibiotics are given rapidly, except for patients who have had prior antibiotic therapy or who have a chronic infection for whom other samples may be positive late (14 days). Moreover, in patients with negative early culture, oral antibiotic therapy active against Cutibacterium acnes and coagulase-negative staphylococci (the two main bacteria in late culture) could be prescribed, waiting for the result of late culture.