# Clinical outcomes after revision knee arthroplasty due to periprosthetic joint infection: A single‐centre study of 359 knees at a high‐volume centre with a minimum of one year follow‐up

## TL;DR

This study examines the outcomes of different surgical treatments for knee infections after joint replacement, finding that one-stage revision has the lowest risk of failure.

## Contribution

The study provides real-world evidence comparing the effectiveness of various surgical approaches for treating knee joint infections.

## Key findings

- One-stage revision had the lowest reoperation risk at 15% compared to two-stage at 28%.
- Higher ASA scores were linked to increased risk of death.
- Failure rates favored one-stage revision over two-stage for all infection types.

## Abstract

Decisions on the treatment of periprosthetic joint infection (PJI) are typically guided by established algorithms. However, as these algorithms often lack substantial supporting evidence, this study aimed to evaluate 1‐year survival rates and compare different surgical approaches.

In this single‐centre retrospective cohort study, all revisions of the knee due to PJI with at least 1 year of follow‐up performed between January 2008 and September 2021 were identified. In total, 141 debridement, antibiotics, and implant retentions (DAIRs), 98 one‐stage, and 120 two‐stage revisions were performed. Infections were classified as early, acute hematogenous, or chronic infections. Survival was calculated using the Kaplan–Meier method and the cumulative incidence function. Predictors of outcomes were examined with Fine‐Gray regression and Cox proportional hazards regression, and subdistribution hazard ratios (sdHR) and adjusted hazard ratios (aHR) with 95% confidence intervals (CIs) were calculated.

At 1‐year follow‐up, 23% (CI 19%–27%) of patients had undergone a reoperation, and 4% (CI 2%–6%) had died. The risk of reoperation was largest after two‐stage revision (28%, CI 20%–36%) and smallest after one‐stage revision (15%, CI 9%–23%). For every infection type, the failure rates at one‐year follow‐up favoured one‐stage revision over two‐stage revision. Higher ASA‐scores increased the risk of death (aHR 1.7, CI 1.1–2.5 per one‐unit increase).

The risk of failure after one‐year follow‐up is high after revision for periprosthetic joint infection. The lowest risk was observed after one‐stage revision; however, this may partly reflect patient selection, as one‐stage revision may not be suitable for all patients.

Level III, retrospective comparative study.