The not-so-good prognosis of streptococcal periprosthetic joint infection managed by implant retention: The results of a large multicenter study

Background. Streptococci are not an infrequent cause of periprosthetic joint infection (PJI). Management by debridement, antibiotics, and implant retention (DAIR) is thought to produce a good prognosis, but little is known about the real likelihood of success. Methods. A retrospective, observational, multicenter, international study was performed during 2003-2012. Eligible patients had a streptococcal PJI that was managed with DAIR. The primary endpoint was failure, defined as death related to infection, relapse/persistence of infection, or the need for salvage therapy. Results. Overall, 462 cases were included (median age 72 years, 50% men). The most frequent species was Streptococcus agalactiae (34%), and 52% of all cases were hematogenous. Antibiotic treatment was primarily using β-lactams, and 37% of patients received rifampin. Outcomes were evaluable in 444 patients: Failure occurred in 187 (42.1%; 95% confidence interval, 37.5%-46.7%) after a median of 62 days from debridement; patients without failure were followed up for a median of 802 days. Independent predictors (hazard ratios) of failure were rheumatoid arthritis (2.36), late post-surgical infection (2.20), and bacteremia (1.69). Independent predictors of success were exchange of removable components (0.60), early use of rifampin (0.98 per day of treatment within the first 30 days), and long treatments (≥21 days) with β-lactams, either as monotherapy (0.48) or in combination with rifampin (0.34). Conclusions. This is the largest series to our knowledge of streptococcal PJI managed by DAIR, showing a worse prognosis than previously reported. The beneficial effects of exchanging the removable components and of β-lactams are confirmed and maybe also a potential benefit from adding rifampin. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America

Challenges in periprosthetic knee-joint infection

The number of knee arthroplasty procedures is growing and projected to further increase. The risk for periprosthetic joint infection (PJI) is estimated to be low (>1%). However, considering the increasing number of total knee arthroplasty, the increasing number of patients with multiple comorbidities, and the lifelong risk for acquiring hematogenous infection, the total number of PJI will further increase. Despite existing treatment concepts for PJI of the knee, there are still questions to solve, such as type of debridement surgery in case of implant retention, the role of a spacer from a microbiological perspective, and the optimal duration of antimicrobial therapy. In this REVIEW, these questions will be analyzed according to the available literature and the experience of the authors. Moreover, we REVIEW the most recent data on infection, risk factors, and microbiology of PJI