JOA - 2026-06-01 - Journal Article; Comparative Study
Comparison of Cutibacterium avidum Versus acnes in Periprosthetic Hip Infections: A Matched Cohort Analysis.
Mitterer JA, Kinsky MR, Frank BJH, Aichmair A, Dominkus M, Hofstaetter JG
Topics
Key Takeaway
C. avidum caused true PJI in 83.3% of Cutibacterium-positive rTHA cases versus 56.4% for C. acnes, and was strongly associated with the direct anterior approach (58.3% vs. 17.7%, P<0.01) and higher BMI.
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Summary
This study compared clinical presentation, risk factors, and outcomes of C. avidum versus C. acnes in culture-positive rTHA using 2018 ICM PJI criteria across 636 revisions at a single center from 2011–2021. C. avidum was more frequently associated with true PJI (83.3% vs. 56.4%), the direct anterior approach (58.3% vs. 17.7%), higher BMI, and higher ASA scores, while demonstrating increased antibiotic resistance. C. acnes-positive PJIs exhibited higher early septic failure rates despite being more commonly classified as unexpected positive intraoperative cultures.
Key Limitation
Single-center retrospective design with only 24 C. avidum cases limits generalizability and statistical power for resistance and failure rate comparisons.
Original Abstract
BACKGROUND
The precise role of Cutibacterium in periprosthetic joint infections (PJIs) and unexpected positive intraoperative cultures in presumed aseptic revision total hip arthroplasty (rTHA) remains unclear. Moreover, little is known about whether there are differences in prevalence, clinical outcomes, and microbiological characteristics between Cutibacterium avidum (C. avidum) and C. acnes. This study aimed to evaluate outcomes and related factors in C. avidum and C. acnes-positive rTHA cases.
METHODS
We analyzed 636 culture-positive rTHA of 564 patients (men: women = 253:311, mean age: 67 years [range, 37 to 88]) with a minimum follow-up of 40 months (range, 40 to 164) between 2011 and 2021 from a single center. Cases positive for C. avidum or C. acnes were evaluated for clinical presentation, risk factors, monomicrobial and polymicrobial detections, and antibiotic resistance patterns. The PJI cases were classified according to the International Consensus Meeting 2018 criteria. A 1:3 propensity score matching was used to compare outcomes between pathogens.
RESULTS
Cutibacteria were detected in 120 of 636 (18.9%) rTHA, including C. avidum in 24 of 120 and C. acnes in 96 of 120 cases. Polymicrobial infections occurred in 40 of 120 (33.3%) cases, mainly co-occurring with gram-positive pathogens. True-septic PJIs were more frequent in C. avidum (83.3%, P < 0.01), whereas C. acnes was more evenly distributed between PJI (56.4%) and unexpected positive intraoperative culture (43.6%). Cutibacterium avidum was strongly associated with the direct anterior approach (58.3 versus 17.7%, P < 0.01), higher body mass index, and American society of anesthesiologists scores (P < 0.01). Early septic failure rates were higher in C. acnes-positive PJIs, whereas increased antibiotic resistances were observed for C. avidum.
CONCLUSIONS
We found clinically relevant differences between C. avidum and C. acnes positive rTHA. Cutibacterium avidum was more prone to cause PJI in obese patients who underwent primary direct anterior approach. The higher early septic failure in C. acnes-positive PJI cases underlines their role as a clinically important pathogen in periprosthetic hip joint infections.