Abstract
Aim
Periprosthetic joint infection (PJI) is a major complication of prosthetic implantation and needs a combined surgical and antimicrobial treatment. One-stage revision results usually in similar cure rate than two-stage (around 85–92%), but antibiotic therapy duration is not well established. The aim of study was to evaluate the efficacy of a short six-weeks antibiotic course in hip and knee PJIs after one-stage replacement arthroplasty (RA).
Method
This was a retrospective, observational study conducted at Orthopaedic Department of Cochin Hospital, Paris, between 1stJanuary 2010 and 31 December 2015. Inclusion criteria were: age>18 years; clinical/microbiological diagnosis of PJI; one-stage RA; 6-weeks course of antibiotics; follow-up of at least one year. PJIs were classified depending on the delay of infection from implantation as: early(<3 months), delayed(3–24 months), late(>24 months). Pearson's-χ2 and t-tests were used to compare categorical and continuous variables.
Results
Fifty patients with PJIs treated with one-stage hip/knee replacement arthroplasty (HRA/KRA) were included, 42 HRA, 8KRA. Median age was 69.3 years (IQR 24.5–97.4), 31 were males. Comorbidities included tumours(18%), polyarthritis(12%), chronic kidney disease (CKD), HIV infection. ASA score was ≥3 in 15(30%) cases. PJIs occurred after a mean of 36 months:9 early, 9 delayed, 32 late. Bone biopsy and synovial fluid cultures were positive for methicillin-susceptible coagulase-negative Staphylococci (MSCNS) in 19(65%) cases, methicillin-resistant CNS (MRCNS) in 5(17%), methicillin-susceptible S. aureus (MSSA) in 5(17%), P. acnes in 20(40%), Enterobacteriacae in 6(12%), Streptococcus spp. in 4(8%), E. faecium and Listeria spp.(2%). Twelve PJIs (24%) were polymicrobial. Intravenous antibiotics were administered for 11 days (IQR 4–45). Daptomycin was used in 22(44%) cases. Forty-six 46(92%) patients were switched to oral antibiotics: fluoroquinolones in 25(54%) cases, clindamycin in 19(41%), beta-lactams in 17(37%), rifampicin in 12(26%). One patient died due to a carcinoma, while others reached at least one year evaluation (IQR 12–60). Overall, the remission rate was 90%(HRA=90%, KRA=88%).
Failures included 4 relapses and one reinfection: HRA in 80%, ASA score ≥3 in 40%. Infections recurred after 6 months (IQR 4–12); bacteria involved were: MSCNS(n=2), MSSA, P. acnes and ESBL-producing K. pneumoniae. Univariate analysis, performed for demographical and PJI parameters, showed no differences between success and failures, except for radiotherapy, HIV infection and CKD associated to worst prognosis (p=0.05, OR=10.7; remission rate=50%). The lowest rate of failures was observed with rifampicin use, but it was not significant(p=0.14).
Conclusions
six-weeks course of antibiotics in knee and hip PJIs treated with one stage revision, seems sufficient with a satisfactory remission rate.
