Treatment strategies for late acute prosthetic joint infections should be individualized according to patients’ age, presence of comorbidities, clinical presentation, and microorganism etiology, according to a study recently published in the Journal of Infection.
Prosthetic joint infections are subdivided into early postsurgical, chronic, and late acute infections. These subdivisions aid in identifying patients in whom the infected prosthesis can be debrided and retained (in the case of acute infections) vs patients for whom the infected prosthesis should be removed (chronic infections). Debridement, antibiotics, and implant retention (DAIR) is the recommended treatment for all acute prosthetic joint infections. However, because of the low incidence of late acute prosthetic joint infections, clinical data and specific treatment recommendations for this subgroup are limited and not well described.
Several previous studies indicate that late acute prosthetic joint infections have a higher failure rate compared with early acute postsurgical infections, particularly when the infection is caused by Staphylococcus aureus. Therefore, this international multicenter retrospective observational study described the clinical outcome and risk factors for failure in late acute prosthetic joint infections treated with DAIR.
Individuals (n=340) from 27 different centers diagnosed with late acute prosthetic joint infections between 2005 and 2015 were retrospectively evaluated. Late acute prosthetic joint infection was defined as the development of acute symptoms (present for ≤3 weeks) occurring ≥3 months after arthroplasty. Failure was defined as the need for implant removal, infection-related death, need for suppressive antibiotic therapy, and/or relapse or reinfection during follow-up.
From the total cohort, 72.6% had prosthetic joint infection of the knee. Coagulase-negative staphylococci were isolated in 8.8% of cases, including 24 monomicrobial infections. Early failure occurred in 53.5% of failed cases, and late failure occurred in 46.5% of failed cases and was mostly the result of relapse of infection with the same microorganism during follow-up (63.3%), followed by reinfection with another microorganism (11.2%). In 50% of cases, a source of prosthetic joint infection was identified: skin infection (36.5%), dental procedure (10.6%), recent surgery (14.1%), or other (38.8%). A preceding skin infection was described in 25.2% of S aureus and in 22.7% of streptococcal infections. In gram-negative prosthetic joint infections, recent surgery or a source other than skin infection was marked in 42% of cases.
Late acute prosthetic joint infections treated with surgical debridement and implant retention have a high failure rate, especially when caused by S aureus. The overall failure rate was 45% and failure was dominated by S aureus prosthetic joint infections (54.7%). Preoperative risk factors for failure are fracture as indication for the prosthesis (odds ration [OR] 5.4), rheumatoid arthritis (OR 5.1), age >80 years (OR 2.6), male gender (OR 2.0), chronic obstructive pulmonary disease (OR 2.9), and C-reactive protein level >150 mg/L at baseline (OR 2.0). Alternatively, the exchange of mobile components during DAIR was the most potent predictor for treatment success (OR 0.35).
Overall, the study authors concluded that, “[L]ate acute prosthetic joint infections treated with DAIR have a high failure rate, especially when caused by S aureus and without the exchange of mobile components. Treatment strategies should be tailored and optimized to improve the outcome.”
Wouthuyzen-Bakker M, Sebillotte, Lomas J, et al. Clinical outcome and risk factors for failure in late acute prosthetic joint infections treated with debridement and implant retention. [published online August 6, 2018] J Infect. doi:10.1016/j.jinf.2018.07.014