gms | German Medical Science

Objectives: Differentiating periprosthetic joint infections (PJI) from aseptic failure is challenging in total joint arthroplasty. Various criteria for PJI diagnosis have been established. To date, there is no consensus about the most accurate criteria. The current study aims to compare the most common diagnostic criteria for hip and knee PJI.

Methods: 256 total hip and knee arthroplasties that underwent revision surgery between 2017 and 2022 were retrospectively classified as PJI or non PJI according to the following definitions: 2011 Musculoskeletal Infections Society (MSIS), 2013 Infectious Disease Society of America (IDSA), 2018 International Consensus Meeting on Periprosthetic Joint Infections (ICM), 2021 European Bone and Joint Infections Society (EBJIS), and ProImplant Foundation. Accuracy, Sensitivity, Specificity, and predictive values were calculated with reference to 1) microbiological cultures, 2) MSIS criteria, 3) the surgeon’s diagnosis. Results were compared between hip- and knee arthroplasties using Fisher’s Exact test or Chi-square test, outcomes were compared between two criteria using Pearson correlation.

Results and conclusion: PJI was diagnosed in 47.7% of cases applying MSIS criteria, 49.2% for IDSA criteria, 55.5% for ICM criteria, 62.1% for EBJIS criteria, 67.2% for ProImplant criteria, and 55.1% according to the surgeon. ProImplant criteria showed lowest accuracy compared to microbiological cultures and a rate of 35.5% culture negative infections. ICM criteria showed best concordance with the surgeon's diagnosis. Both EBJIS and ProImplant criteria showed a high sensitivity but low specificity (79.1% and 68.7%, respectively) when using the surgeon’s intraoperative judgement as reference. Results for hip and knee arthroplasties were similar.

The current study showed that the diagnosis of PJI is highly dependent on the applied diagnostic criteria. EBJIS- and ProImplant criteria classified more cases as PJI compared to other diagnostic criteria. Care should be taken to avoid overdiagnosis and overtreatment, especially if low synovial leucocyte thresholds are applied as definite signs of PJI.