Data from the Swiss National Arthroplasty Registry SIRIS suggest that unicompartmental knee arthroplasty is associated with a lower risk of periprosthetic joint infection than total knee arthroplasty.
Options
Description
Open access funding provided by University of Basel.
BORIS DOI
Publisher DOI
PubMed ID
41779036
Description
Introduction
Periprosthetic joint infection (PJI) remains a severe complication in arthroplasty. Unicompartmental knee arthroplasty (UKA) may have lower PJI rates than total knee arthroplasty (TKA) because of smaller implants and less extensive surgical exposure. However, PJI treatment after UKA is challenging due to restricted debridement and limited options for local antibiotic delivery. This study compared the revision rate for PJI and the failure rate of implant-retaining revision for PJI between UKA and TKA in the Swiss national joint registry (SIRIS).Methods
A retrospective analysis was conducted using SIRIS data from 2012 to 2024, examining the first revision after primary UKA or TKA and the re-revision rate after debridement with isolated inlay exchange for PJI. Both analyses assessed revisions for any cause and specifically for PJI. Kaplan-Meier survival curves and hazard ratios (HR) were calculated.Results
Among 35’286 primary UKA and 188’952 primary TKA, 149 and 1’546 were revised for PJI, respectively. Revision rates for any cause were higher for UKA than TKA (HR 1.29, p < 0.001), whereas PJI-related revisions were about half as frequent (HR 0.53, p < 0.001). Following implant-retaining revision for PJI, repeat revision rates increased more rapidly for UKA than TKA, reaching 34.8% and 32.1%, respectively (HR 1.56, p = 0.099). The statistical precision for UKA was limited by small numbers.Conclusions
In SIRIS, the revision rate for PJI after primary UKA was about half that after primary TKA, while the revision rate for any cause was higher. These findings support the hypothesis that smaller implants and less extensive surgery may be associated with lower infection risk. Despite limited debridement options, implant-retaining revision for PJI after UKA was as successful as after TKA. Nonetheless, failure rates for such procedures remain high in Switzerland, at roughly one-third.Supplementary Information
The online version contains supplementary material available at 10.1007/s00402-025-06156-5.
Periprosthetic joint infection (PJI) remains a severe complication in arthroplasty. Unicompartmental knee arthroplasty (UKA) may have lower PJI rates than total knee arthroplasty (TKA) because of smaller implants and less extensive surgical exposure. However, PJI treatment after UKA is challenging due to restricted debridement and limited options for local antibiotic delivery. This study compared the revision rate for PJI and the failure rate of implant-retaining revision for PJI between UKA and TKA in the Swiss national joint registry (SIRIS).Methods
A retrospective analysis was conducted using SIRIS data from 2012 to 2024, examining the first revision after primary UKA or TKA and the re-revision rate after debridement with isolated inlay exchange for PJI. Both analyses assessed revisions for any cause and specifically for PJI. Kaplan-Meier survival curves and hazard ratios (HR) were calculated.Results
Among 35’286 primary UKA and 188’952 primary TKA, 149 and 1’546 were revised for PJI, respectively. Revision rates for any cause were higher for UKA than TKA (HR 1.29, p < 0.001), whereas PJI-related revisions were about half as frequent (HR 0.53, p < 0.001). Following implant-retaining revision for PJI, repeat revision rates increased more rapidly for UKA than TKA, reaching 34.8% and 32.1%, respectively (HR 1.56, p = 0.099). The statistical precision for UKA was limited by small numbers.Conclusions
In SIRIS, the revision rate for PJI after primary UKA was about half that after primary TKA, while the revision rate for any cause was higher. These findings support the hypothesis that smaller implants and less extensive surgery may be associated with lower infection risk. Despite limited debridement options, implant-retaining revision for PJI after UKA was as successful as after TKA. Nonetheless, failure rates for such procedures remain high in Switzerland, at roughly one-third.Supplementary Information
The online version contains supplementary material available at 10.1007/s00402-025-06156-5.
Date of Publication
2026-03-04
Publication Type
Article
Subject(s)
Keyword(s)
Arthroplasty
•
DAIR
•
Implant retention
•
Joint registry
•
Knee
•
PJI
•
Periprosthetic joint infection
•
SIRIS
•
Unicompartmental
Language(s)
en
Contributor(s)
Additional Credits
Series
Archives of Orthopaedic and Trauma Surgery
Publisher
Springer
ISSN
1434-3916
0936-8051
Access(Rights)
open.access