In patients with bacteremia or with a hematogenous periprosthetic joint infection (PJI), there is a low incidence of a second PJI in concomitant prosthetic implants that have no clinical signs or symptoms of infections, according to study results published in Clinical Infectious Diseases. Study results suggest that performing additional diagnostics for these joints is unnecessary.

Since patients who are diagnosed with a PJI and who have concomitant prosthetic joints in situ appear to have the highest risk for having a second PJI, using data from a large, international, multicenter observational study, researchers retrospectively analyzed patients with a hematogenous PJI who had at least 1 additional prosthetic joint in situ to see how many asymptomatic joints were diagnosed with PJI at the time of presentation and how many developed a PJI during a follow-up period of more than 1 year.

The final analysis included 91 patients with a hematogenous PJI, who had at least 1 additional prosthetic joint in situ, resulting in a total of 108 concomitant prostheses (56 knees, 44 hips, 3 shoulders, and 5 other joints). The incident PJI was most frequently caused by Staphylococcus aureus (43%), followed by streptococci (26%), and Gram-negative rods (18%). Of the 108 concomitant prosthetic joints, 13 showed signs or symptoms of infection at the time of presentation, and 10 patients were diagnosed with a second PJI.

The median time of follow-up for those with the 95 asymptomatic joints was 52 months (range, 13-130 months); only 4 developed PJIs during the follow-up period, all of which were caused by S aureus. Altogether, only 1 out of the 95 asymptomatic prosthetic joints was classified as an unrecognized PJI at the time of the first clinical presentation (1.1%). When considering only S aureus PJI, the percentage was 2.7% (1 out of 37), and 5.6% (1 out of 18) in those with documented S aureus bacteremia.


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Researchers further investigated whether the type of joint or the age of the prosthesis influenced the risk of infection. They found that the infected prosthetic joint was younger than the noninfected joints in 67% of the cases, with a median prosthesis age of 4.5 (interquartile range [IQR], 1.5-11.8) vs 6.7 (IQR, 2.8-14.3) years, respectively (P =.04). In 27 patients with both knee and hip prostheses in situ, the knee prosthesis became infected in 78% of cases, and the hip prosthesis became infected in 22% of cases. There were no cases were both joints were infected.

A key limitation of this study was that not all hematogenous PJIs had positive blood cultures at the time of clinical presentation, calling into question the hematogenous origin of infection.

Unless symptoms or signs of infection are present, in patients with bacteremia or with a hematogenous PJI, “concomitant asymptomatic prosthetic joints have a very low risk of being infected, and additional diagnostic work-up for these joints is not necessary,” researchers concluded.

Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.

Reference

Wouthuyzen-Bakker M, Sebillotte M, Arvieux C, et al; ESCMID Study Group for Implant-Associated Infections (ESGIAI). How to handle concomitant asymptomatic prosthetic joints during an episode of hematogenous PJI, a multicentre analysis [published online August 18, 2020]. Clin Infect Dis. doi: 10.1093/cid/ciaa1222