Factors affecting risk of recurrence with periprosthetic infection in shoulder arthroplasty

Abstract

BackgroundThe goal of treating periprosthetic infection, beside its eradication, is to avoid recurrence. The purpose of this study was to evaluate the impacts of increasing Infection Severity (IS) score (based on the 2018 International Committee on Orthopedic Infection Consensus statement), single-stage revision and the pathogenicity of the infective organism have on the risks of infection recurrence. MethodsA database of 790 revisions performed by a single surgeon from 2004-2020 was reviewed for patients with minimum 2-year follow-up and at least 1 positive culture and/or pathology result from that revision surgery. One hundred fifty-seven cases performed in 144 patients met inclusion criteria. Cases were then categorized by infection probability (IS score) according to the 2018 consensus statement. Forty-six of 157 (29%) cases were classified as definite/probable, 25/157 (16%) were classified as possibly infected, and 86/157 (55%) were classified as unlikely to be infected. Additionally, patients were grouped by single-stage surgery, and pathogenicity of infective organism. ResultsA recurrence in this study was classified as any patient requiring revision surgery that grew the same organism. The 86 cases in the unlikely group had a recurrence rate of 2.3%. The 25 cases in the possibly infected group had a recurrence rate of 12%. The 46 cases in the definite/probable group had a recurrence rate of 17.4%. Patients in the definite/probable group had a higher rate of recurrence than the possible and unlikely groups (p=0.009). The IS score was higher in the recurrence group than the non-recurrence group (7.5±4.3 vs 3.9±3.4; p<0.001). Overall, one-stage revision had a 5.0% recurrence rate, but of the 34 patients with an infection classification of definite/probable who underwent a one-stage revision, the recurrence rate was 5.9%. Highly virulent methicillin-resistant Staphylococcus aureus (MRSA) also had a recurrence rate of 30.8% compared to 4.0% and 5.9% in C. acnes and Coagulase-negative staphylococci, respectively (p=0.005). ConclusionRecurrent infection after treating a periprosthetic infection is associated with increasing severity scores as defined in 2018 consensus statement and more aggressive microorganisms. However, a single-stage surgery, even in patients with a higher IS score, did not impart a significant increased risk of recurrence.