Micro-organisms and risk factors associated with prosthetic joint infection following primary total knee replacement-our experience in Pakistan.

PURPOSE: To identify potential risk factors and micro-organisms associated with prosthetic joint infection following primary total knee replacement surgery.

HYPOTHESIS OF STUDY: Our hypothesis is that body mass index (BMI), operative time, type of surgery, and order of surgery especially in bilateral simultaneous cases have a major impact on prosthetic joint infection (PJI).

METHODOLOGY: We identified 4269 patients who underwent for primary knee replacement surgery between 2008 and 2018. We recorded patient demographics, comorbidities, order of surgery, type of surgery, causative micro-organism, and their antibiotic susceptibility. Multivariable logistic regression analysis was built to identify risk factors that are associated with prosthetic joint infection following primary total knee replacement.

RESULTS

Forty-eight patients developed prosthetic joint infection. The factors that are found to be associated with prosthetic joint infection are BMI, operative time, type of surgery, order of surgery, diabetes, and rheumatoid arthritis. Methicillin-resistant Staphylococcus aureus (MRSA) was the major underlying pathogen seen in majority of cases.

CONCLUSION

Despite low incidence of prosthetic joint infection following primary total knee replacement, there are patients at higher risk that would benefit by addressing modifying risk factors significantly associated with prosthetic joint infection.