1. IDWeek October 2015
1546. Two-year Outcomes of Infected Total Knee Arthroplasty (TKA) Treated
With Debridement and Implant Retention: Improved Outcomes with
Arthrotomy and Liner Exchange
Part of Session: 221. Clinical Infectious Diseases: Prosthetic Joint Infections
ANDY MILLER, MD1, MICHAEL HENRY, MD1, ASHLEE REILLY, MA2, EILEEN FINERTY, FNP CIC2, BARRY BRAUSE, MD1 and GEOFFREY WESTRICH, MD1;
1Weill Cornell Medical College of Cornell University and Hospital for Special Surgery, New York, NY, 2Hospital for Special Surgery, New York, NY
Background: Prosthetic joint infection (PJI) is a grave complication of total knee arthroplasty (TKA). Tw o-stage exchange is highly successfulat curing infection, but
remains morbid and costly. Debridement, antibiotics, and implant retention (DAIR) is an appropriate strategy in some patients, but factors effecting success rates remain
unclear. We studied a large cohort w ith infected TKA treated w ith DAIR at our specialized orthopedic hospital.
Methods:A retrospective cohort of TKA PJI treated w ith DAIR over 4.3 years w as identified by query of hospital coding records. The primary endpoint w as defined as 2-
year implant failure. Clinical data from multiple databases w ere collected.
Results: 111 patients w ith 115 TKR PJI w ere identified. 61% of TKA w ere retained at 2 years. Pathogens included methicillin-sensitive and -resistant Staphylococcus
aureus (MSSA, 26%; MRSA, 3.5%), coagulase-negative staphylococci (15%), and streptococci (22%). 20% of cases w ere culture-negative, of w hich 70% had
histopathologic evidence of infection. Comorbidities included obesity (average BMI 30.1), diabetes (23%), and cardiac (17%), kidney (15%), and
rheumatologic (8.6%) disease. 31% had a history of tobacco, w ith a trend tow ards w orse outcomes in this group (RR=1.4, p=0.1).
81% of patients underw ent arthrotomy instead of arthroscopy, and 57% underw ent polyethylene liner exchange (PLE). Each w as strongly associated w ith retention
(RR=0.49, 95% CI: 0.33-0.75 and RR=0.54, 0.34-0.86 respectively).
S. aureus infections fared poorly, compared to non-S. aureus (70% vs. 28% failure rate, RR=2.6, 1.6-4.1). Among all staphylococcal infections, those treated w ith rifampin
had improved outcomes (RR=0.39, 0.19-0.79). Culture-negative cases had a 78% rate of TKA retention. There w ere no major differences betw een subgroups undergoing
debridement more or less than 1 year after TKA.
Conclusion: We present 2-year outcomes on the largest reported cohort of TKA PJI treated w ith DAIR. Arthrotomy and PLE improved outcomes. S. aureus infection w as
associated w ith poor outcomes. Rifampin improved outcomes in staphylococcal infection. No link w as seen betw een age of TKA at the time of debridement and primary
outcome. Our data may help guide evidence-based decision-making in TKR PJI.