477 posters, 14 topics, 2,065 authors, 1,055 institutions

The Joint EBJIS-MSIS 2026 Conference

17 - 19 September, 2026 | Porto, Portugal

EP310

Isolation of Multiple Positive Cultures at Resection Arthroplasty is a Predictor of Failure Following Reimplantation

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Poster Presenter

Collin Braithwaite

Authors

Collin Braithwaite, Michael L. Moore, Saad Tarabichi, David Deckey, Bryan Springer, Cody Wyles, Henry Clarke, Mark Spangehl, Joshua Bingham

Affiliations

Mayo Clinic, Mayo Clinic Department of Orthopaedic Surgery, Phoenix, United States, Mayo Clinic Department of Orthopaedic Surgery, Jacksonville, United States, Mayo Clinic Department of Orthopaedic Surgery, Rochester, United States

Part of Topic

Prosthetic Joint Infections

Background

Periprosthetic joint infection (PJI) is a major complication following total knee arthroplasty. Although organism type is an established risk factor for failure, the impact of the number of positive cultures on outcomes after two-stage exchange has not been examined.

Multiple concordant cultures may reflect a greater infectious burden and could provide prognostic information at the time of resection arthroplasty.

Purpose: To determine the prognostic utility of multiple positive cultures at resection as a predictor of failure following reimplantation.

Methods

Retrospective multicenter study of 437 patients with chronic knee PJI treated with two-stage exchange arthroplasty and ≥1 year follow-up following reimplantation.

PJI was defined using the 2013 Musculoskeletal Infection Society (MSIS) criteria.

Culture-negative PJI patients were excluded (n=138), leaving 299 patients for analysis.

Treatment failure was defined as any reoperation for infection or PJI-related mortality.

Multivariate regression controlled for risk factors for failure after two-stage exchange and evaluated whether ≥2 positive cultures at resection predicted failure compared with a single positive culture.

Results

299 patients were included; mean follow-up was 6.2 ± 2.6 years.

48 patients (16.1%) experienced treatment failure.

Patients who failed were more likely to have ≥2 positive cultures at resection (95.8% vs. 75.3%, p=0.001).

≥2 positive cultures was the only identified risk factor for failure in both univariate and multivariate regression analysis.

Conclusion

The presence of ≥2 positive cultures at resection arthroplasty was a poor prognostic indicator following reimplantation.

Patients with ≥2 positive cultures had a greater than 8-fold increased risk of treatment failure after two-stage exchange.

The number of positive cultures at resection may provide useful prognostic information when assessing risk and counseling patients before reimplantation.