Is There a Difference in Treatment Outcome for Monomicrobial and Polymicrobial Periprosthetic Joint Infections? Systematic Review and Study Quality Analysis

SLR - October 2019 - Leslie Joseph

Reference: Chahla J, Cinque M, Garabano G, Gessara A, Connors KM, Aman ZS, Del Sel H. Is There a Difference in Treatment Outcome for Monomicrobial and Polymicrobial Periprosthetic Joint Infections? Systematic Review and Study Quality Analysis. Journal of Arthroscopy and Joint Surgery 6(2): 82-7, 2019.

Scientific Literature Review

Reviewed By: Leslie Joseph, DPM
Residency Program: SSM Health DePaul Hospital – St. Louis, MO

Podiatric Relevance: Total ankle arthroplasty is increasingly being utilized for osteoarthritis as well as complex ankle deformity. The concepts and principles of ankle replacement surgery are similar to that of total hip and knee replacements, therefore the complications found in these cases especially with the current lack of scientific literature on total ankle replacements should be utilized in podiatric medicine. Like any prosthetic joint procedure one of the major postoperative concerns is surgical site infection. This study performs a systematic review analyzing the functional and objective outcomes for periprosthetic joint infection (PJI) caused by a single organism versus a polymicrobial PJI. Joint infection treatments are frequently dependent on the causative organism therefore the study focuses on valuable information that could potentially allow for decreased length of stay for patient’s admitted after total joint procedures, this translates to orthopedic and podiatric physicians alike.

Methods: A systematic review was performed on outcomes of clinical studies comparing single organism and polymicrobial PJI. A review of the literature was performed on studies with a minimum evidence of III and a mean follow up of 24 months. Two reviewers used a modified Coleman methodology score to assess the quality of each study based on 10 criteria which ensured the study largely avoided chance, biases and confounding factors.

Results: A total of 134 articles were fully reviewed and a total of six level III studies were identified that explicitly reported demographics of mono and polymicrobial PJI. The six studies included 1075 patients, which consisted of 829 in mono and 246 in the polymicrobial group. The mean success rate of treatment of monomicrobial infection was 70.4 percent (range, 64.7-87.5 percent) and 58.4 percent (range, 27.8-85.7 percent) for polymicrobial infections (p=0.29). The mean survivorship for monomicrobial PJI was 69.4 percent and 58 percent for polymicrobial PJI.

Conclusions: Following treatment, the outcomes of polymicrobial PJI were consistently worse than single monomicrobial PJI, however there was no significant difference between the survival rates of both groups. Staphylococcus aureus and Coagulase Negative Staphylococci were the main pathogens reported for single organism PJI, while Enterococcus and gram negatives were reported for polymicrobial cases. The two-stage revision process with use of an antibiotic spacer resulted in better outcomes, although it was noted that infections with polymicrobial organisms which consisted of a gram negative was less successful. This identifies the importance of antibiotic selection when treating PJI, especially in cases with gram negative organisms.