Authors: Kurd M, Ghanem E, Purtill J, Parvizi J, Rothman Institute, Pensylvania PA
Title: Two-Stage Exchange Arthroplasty-The Challenges of Treating Infections Caused by Resistant Organisms
Purpose: The purpose of our study was to determine patient related factors predisposing them to MRSA and MRSE infections and to test our hypothesis that patients with resistant organism infections have suboptimal outcomes.
Methods: 130 patients underwent two-stage exchange arthroplasty for infected TKA between 1998 and 2005 at our institution. 102 were successfully reimplanted. A successful outcome was defined as resolution of the infection. Patients were followed-up after reimplantation on a regular basis in the clinic for a minimum of two years.
Results: Methicillin sensitive Staphylococcus aureus (MSSA) was the most commonly cultured organism at the time of initial resection (18 patients) followed by MRSA (15), MRSE (15), negative cultures (15) and methicillin sensitive Staphylococcus epidermidis (MSSE) (13). Stepwise logistic regression analysis demonstrated that age (p = 0.009), BMI (p = 0.002), history of thyroid disease (p = 0.03) and post-operative wound class of 2, 3 or 4 (p = 0.002) were significant predictors of susceptibility to resistant organism infection. Reinfection after component reimplantation occurred in 26 of the 96 (27%) patients. Regression analysis measuring variables associated with failed two-stage resection arthroplasty identified a significant association with methicillin resistant organism infections (p = 0.01).
Discuassion and Conclusion: Management of PJI, especially those caused by resistant organism, continues to pose a challenge. It appears that infection with resistant organism does adversely affect the outcome of two-stage exchange arthroplasty. The orthopedic community needs to develop strategies that mimizes infection by methicillin resistant organisms, or is able to deliver a better care when this circumstance arises.
