Proposed empiric antibiotic therapy for prosthetic joint infections: an analysis of the Prosthetic Joint Infection in Australia and New Zealand, Observational ( PIANO) cohort

Modern Microbiological Methods to Detect Biofilm Formation in Orthopedy and Suggestions for Antibiotic Therapy, with Particular Emphasis on Prosthetic Joint Infection (PJI)

Biofilm formation is a serious problem that relatively often causes complications in orthopedic surgery. Biofilm-forming pathogens invade implanted foreign bodies and surrounding tissues. Such a condition, if not limited at the appropriate time, often requires reoperation. This can be partially prevented by selecting an appropriate prosthesis material that prevents the development of biofilm. There are many modern techniques available to detect the formed biofilm. By applying them we can identify and visualize biofilm-forming microorganisms. The most common etiological factors associated with biofilms in orthopedics are: Staphylococcus aureus, coagulase-negative Staphylococci (CoNS), and Enterococcus spp., whereas Gram-negative bacilli and Candida spp. also deserve attention. It seems crucial, for therapeutic success, to eradicate the microorganisms able to form biofilm after the implantation of endoprostheses. Planning the effective targeted antimicrobial treatment of postoperative infections requires accurate identification of the microorganism responsible for the complications of the procedure. The modern microbiological testing techniques described in this article show the diagnostic options that can be followed to enable the implementation of effective treatment.

Success of Debridement, Antibiotics, and Implant Retention in Prosthetic Joint Infection Following Primary Total Knee Arthroplasty: Results from a Prospective Multicenter Study of 189 Cases

BACKGROUND

This study aimed to identify the success rate of debridement, antibiotics, and implant retention (DAIR) for prosthetic joint infection (PJI) in a large prospective cohort of patients undergoing total knee arthroplasty (TKA). The ability for different PJI classification systems to predict success was assessed.

METHODS

Prospective data recorded in the Prosthetic Joint Infection in Australia and New Zealand Observational (PIANO) study was analyzed. 189 newly diagnosed knee PJIs were managed with DAIR between July 2014 and December 2017. Patients were prospectively followed up for 2 years. A strict definition of success was used, requiring the patient being alive with documented absence of infection, no ongoing antibiotics and the index prosthesis in place. Success was compared against the Coventry (early PJI = ≤1 month), International Consensus Meeting (early = ≤90 days), Auckland (early = <1 year), and Tsukayama (early = ≤1 month, hematogenous = >1 month with <7 days symptoms, chronic = >1 month with >7 days symptoms) classifications.

RESULTS

DAIR success was 45% (85/189) and was highest in early PJIs defined according to the Coventry (adjusted odds ratio [aOdds Ratio (OR)] = 3.9, P=0.01), the ICM (aOR = 3.1, p=0.01), and the Auckland classifications (aOR = 2.6, P=0.01). Success was lower in both hematogenous (aOR = 0.4, P=0.03) and chronic infections (aOR = 0.1, P=0.003).

CONCLUSION

Time since primary TKA is an important predictor of DAIR success. Success was highest in infections occurring <1 month of the primary TKA and progressively decreased as time since the primary TKA increased.

Differing Microorganism Profile in Early and Late Prosthetic Joint Infections Following Primary Total Knee Arthroplasty - Implications for Empiric Antibiotic Treatment

BACKGROUND

Prosthetic joint infection (PJI) is the leading cause of revision following total knee arthroplasty (TKA). Prior to microorganism identification, the choice of the correct empiric antibiotics is critical to treatment success. This study aims to 1) compare the microorganism and resistance profile in early and late PJIs; 2) recommend appropriate empiric antibiotics.

METHODS

A multicentre retrospective review was performed over a 15-year period. First episode PJIs were classified by both the Tsukayama Classification and Auckland Classification. For each PJI case, the causative organism and antibiotic sensitivity were recorded.

RESULTS

Of eligible patients, 232 culture-positive PJI cases were included. Using either classification system, early PJIs (<4 weeks or <1 year since primary) were significantly more likely to be resistant and polymicrobial. The predominant organisms were coagulase-negative Staphylococci in early PJIs while Staphylococcus aureus was the most common in late PJIs. The distribution of gram-negative cases was higher in early Class-A than late Class-C PJIs (25% versus 6%, P = .004). Vancomycin provided significantly superior coverage when compared to Flucloxacillin for early infections, and addition of a gram-negative agent achieved coverage over 90% using both classification systems.

CONCLUSION

Based on the microbiological pattern in Tsukayama criteria, Vancomycin with the consideration of Gram-negative agent should be considered for Class-A infections given the high proportion of resistant and polymicrobial cases. For Class-C infections, Cephazolin or Flucloxacillin is likely sufficient. We recommend antibiotics to be withheld in Class-B infections until cultures and sensitivities are known.

Epidemiology and antibiotic resistance of prosthetic joint infections according to time of occurrence, a 10-year study

OBJECTIVES

To describe the microorganisms responsible for prosthetic joint infections (PJIs) and their antimicrobial susceptibilities, and to propose appropriate empirical antimicrobial treatments (EATs) according to time of occurrence METHODS: : This 10-year retrospective study presents the bacterial etiology of 282 consecutive PJIs in a French hospital according to time of occurrence (adapted from Zimmerli's classification: early, <3 months; delayed, 3-12 months; late acute, >12 months with hematogenous seeding or contiguous spread; late chronic, >12 months without hematogenous seeding). The expected efficacy of various EATs was analyzed for each PJI.

RESULTS

Staphylococci were the most commonly found bacteria (S. aureus (44.3%), coagulase-negative staphylococci (25.2%) with 15.2% and 49.3% methicillin resistance respectively), followed by Gram-negative bacilli (GNB) (17.7%) and streptococci (14.9%). The distribution of species varied between categories, but antibiotics targeting GNBs were required in all categories. Imipenem-vancomycin was the most effective combination (99.3%) but should be reserved for patients with suspected resistant GNB. Cefotaxime-vancomycin was less effective in early/delayed and late PJIs (91.1% and 86.1% respectively), due to resistant GNB and polymicrobial infections. Piperacillin/tazobactam-vancomycin appeared to be appropriate in all situations (>96% efficacy).

CONCLUSION

Proposing universal recommendations remains challenging, but a good understanding of the local epidemiology is important for optimizing EATs.