311. Low Rate of Microbiologic Relapse in Two Stage Exchange for Knee Prosthetic Joint Infections
Session: Poster Abstract Session: Bone and Joint Infections
Thursday, October 4, 2018
Room: S Poster Hall
Posters
  • Final - Microrelapse.pdf (329.9 kB)
  • Background: Prosthetic joint infection (PJI) is a grave complication of total knee arthroplasty (TKA). Historically, two-stage arthroplasty exchange has been considered to be the definitive approach to eradicating infection and preserving joint function. However, patients are increasingly presenting with higher rates of comorbidities traditionally associated with poorer orthopedic surgical outcome, including advanced age, obesity and diabetes. We investigated whether two-stage exchange remains effective for TKA PJI in this population, and evaluated the microbiology of repeat infections.

    Methods: A retrospective cohort of TKA PJI treated with two-stage exchange was identified by query of hospital coding records from 2009 to 2014, with subsequent chart review. The primary endpoint was defined as prosthesis retention for 2 years from reimplantation. Microbiologic relapse was defined as a recurrence of a previously treated organism. Descriptive statistics were completed using the Fisher’s exact test for categorical variables and the Mann-Whitney U test for continuous variables.

    Results: 159 patients who underwent 2-stage exchange for a TKA PJI meeting Musculoskeletal Infection Society International Consensus criteria were identified. The average age was 66 years, and 37% were female. 141 underwent reimplantation; 24 of these (17%) had recurrent infection. Of the 24 patients who developed infection after reimplantation, only 4 relapsed with the same microbe; the other 20 (83%) were diagnosed with new, microbiologically distinct organisms. 3 of these 4 recurrences were due to Staphylococcus aureus infection. The likelihood of microbiologic relapse was low among reimplanted patients (3%). In univariate analysis, no associations were found between outcome and age, comorbidities, or BMI.

    Conclusion: Two-stage exchange arthroplasty for TKA infection is associated with a very low rate of microbiologic relapse. However, those patients able to undergo reimplantation remain at risk of subsequent infections with new microbes. It remains important to continue to modify risk factors in patients who have undergone a two-stage exchange for PJI.

    Michael Henry, MD1, Celeste Russell, MPH1, Allina Nocon, PhD2, Geoffrey Westrich, MD2, Barry Brause, MD3 and Andy Miller, MD4, (1)Hospital for Special Surgery, New York, NY, NY, (2)Complex Joint Reconstruction Center, Hospital for Special Surgery, New York, NY, (3)Hosp. for Special Surgery, New York, NY, (4)Infectious Disease, Weill Cornell Medical College, New York, NY

    Disclosures:

    M. Henry, None

    C. Russell, None

    A. Nocon, None

    G. Westrich, None

    B. Brause, None

    A. Miller, None

    Findings in the abstracts are embargoed until 12:01 a.m. PDT, Wednesday Oct. 3rd with the exception of research findings presented at the IDWeek press conferences.