Cutibacterium acnes Prosthetic Joint Infections: Is Rifampicin-Combination Therapy Beneficial?

Area of Science:

• Orthopedics
• Infectious Diseases
• Pharmacology

Background:

• Optimal antibiotic treatment for Cutibacterium acnes prosthetic joint infections (Ca-PJIs) remains unclear.
• In vitro studies suggest rifampicin is effective against biofilm-associated C. acnes, but clinical evidence is lacking.
• Previous clinical studies have not confirmed rifampicin-combination therapy's superiority over monotherapy.

Purpose of the Study:

• To analyze the outcomes of patients with chronic monomicrobial Ca-PJI treated with or without rifampicin.
• To compare the 2-year reinfection-free probability in patients undergoing exchange arthroplasty for Ca-PJI.

Main Methods:

• Prospective cohort study of 70 patients with chronic monomicrobial Ca-PJI undergoing exchange arthroplasty.
• Patients were divided into two groups: rifampicin-combination therapy (n=37) and monotherapy without rifampicin (n=33).
• Primary endpoint was the 2-year Kaplan-Meier-estimated reinfection-free probability.

Main Results:

• The 2-year reinfection-free rate was high in both groups (89.2% with rifampicin vs. 93.8% without rifampicin; p=0.524).
• No patients experienced relapse of Ca-PJI.
• Six patients developed new-pathogen PJIs.

Conclusions:

• Rifampicin-combination therapy does not appear to offer a benefit for patients undergoing exchange arthroplasty for chronic Ca-PJIs.
• The study suggests that standard monotherapy may be sufficient for treating these infections.