Pre-operative methicillin-resistant Staphylococcus aureus colonization increases the risk of 90-day medical and 2-year implant-related complications following primary total shoulder arthroplasty: a propensity-matched analysis.

BACKGROUND

Pre-operative methicillin-resistant Staphylococcus aureus (MRSA) colonization has been associated with increased risk of post-operative infection and medical complications in lower-extremity arthroplasty; however, its impact on outcomes following total shoulder arthroplasty (TSA) remains poorly understood. This study aims to evaluate the association between MRSA colonization and early medical as well as mid-term implant-related complications after primary TSA.

METHODS

The TriNetX US Research Network was queried to identify primary TSA patients. Propensity score matching (1:1) was performed using demographic characteristics and relevant comorbidities. Ninety-day medical complications, including readmission, emergency department utilization, venous thromboembolism, pneumonia, urinary tract infection, stroke, sepsis, respiratory failure, and cardiac events, were assessed. Two-year implant-related outcomes included periprosthetic joint infection, aseptic loosening, dislocation, periprosthetic fracture, revision TSA, and all-cause mortality. Risk ratios (RRs) with 95% confidence intervals (CIs) were generated for all comparative analyses.

RESULTS

Overall, 122,665 patients met eligibility criteria. Matching resulted in 2 well-balanced cohorts of 1,781 patients each. At two years, MRSA colonization was associated with significantly higher rates of periprosthetic joint infection (RR, 6.64; 95% CI, 3.53-12.47), aseptic loosening (RR, 1.63; 95% CI, 1.08-2.47), revision surgery (RR 1.75; 95% CI, 1.22-2.52), dislocation (RR, 1.76; 95% CI, 1.08-2.86), and mortality (RR, 1.90; 95% CI, 1.55-2.33). Ninety-day medical complications were also significantly higher among MRSA-colonized patients, with higher rates of readmission, emergency department utilization, venous thromboembolism, pulmonary embolism, pneumonia, urinary tract infection, stroke, sepsis, and respiratory failure (all P < .01). Cardiac events occurred at similar rates between cohorts (P = .390).

CONCLUSION

Pre-operative MRSA colonization was associated with substantially higher risks of both 90-day medical and 2-year implant-related complications following TSA. These findings highlight the importance of routine MRSA screening, consideration of decolonization protocols, and heightened perioperative vigilance in this high-risk population.