Outcome of Total Hip and Total Knee Revision Arthroplasty With Minor Infection Criteria: A Retrospective Matched-Pair Analysis

Although diagnostic modalities for the detection of periprosthetic joint infection have improved, some infectious revision cases may still be diagnosed as aseptic complications.

We raised the question whether patients with positive Musculoskeletal Infection Society minor infection criteria differ in their outcome parameters (revision-free survival, revision rate) when compared to patients with “true” aseptic complications. Additionally, we asked whether the indication for revision surgery (eg, loosening) might have an influence on possible outcome discrepancies.

A retrospective matched-pair analysis was performed with 98 patients who had undergone revision surgery after total joint arthroplasty. Forty-nine patients showed less than 3 positive minor criteria (PMC), whereas 49 patients without any PMC were compared regarding re-revision rate and revision-free survival. Reasons for revisions were categorized according to loosening, liner wear, implant failure, and soft-tissue complication.

In the group of patients with PMC, 30.6% (n = 15) had to undergo re-revision compared to 6.12% (n = 3) in the true aseptic complication control group. The long-term implant survival in the PMC group was 69.4% (95% confidence interval [CI], 47-69 months) and in the aseptic control group was 93.9% (95% CI, 82-94 months; P = .001). In patients with PMC and loosening of the implant, the long-term survival was 55.2% (95% CI survival time, 28.9-53.2 months) whereas in patients without PMC and loosening, the overall survival was 96.2% (95% CI survival time, 83.5-96 months; P = .001).

Our findings suggest that in the presence of prosthetic loosening, even a single positive minor criterion may have a negative impact on the outcome after total hip arthroplasty and total knee arthroplasty revision surgeries.