222. Clinical Outcomes of Prosthetic Knee Joint Infection in a United States Tertiary Health Care Center
Session: Poster Abstract Session: Clinical: Bone and Joint Infection
Thursday, October 5, 2017
Room: Poster Hall CD
Posters
  • PJI Publication 2.pdf (856.1 kB)
  • Background: The 2013 IDSA prosthetic joint infection (PJI) guidelines identified some research gaps, some of which include what factors may predict PJI outcome. We therefore conducted a retrospective single-center study with the goal of addressing some of these gaps.

    Objectives:

    1. Describe the incidence, pathogens, role of inflammatory markers and treatment outcomes of knee PJI.

    2. Identify correlations between joint aspiration (JA) and intraoperative (IO) cultures.

     

    Methods:

    We retrospectively analyzed all adult knee PJI that were diagnosed and managed at our institution between 1/1/2005 and 12/31/2015.

    Statistical analysis was done using the paired t-test, Fisher exact and McNemar chi-square tests as applicable.

    Results:

    46 subjects met the inclusion criteria and were analyzed. See table below.

    Clinical and Demographic Information of PJI subjects (n=46).

    Parameter

    Value (%)

     Age (yrs)

    Range

    Median

    Mean

    ......................................................

    27- 84

    60

    58.8

    Sex

    Female

    ......................................................

    28 (61)

    Symptom onset

    < 3 wks.

    > 3 wks.

    No Data

    ......................................................

    15 (33)

    28 (61)

    3 (6)

    Implant Duration

    Early (< 3mo.)

    Delayed (3- 24 mo.)

    Late (> 24 mo.)

    ......................................................

    10 (22)

    15 (33)

    21 (45)

    Positive Culture

    JA

    IO

    ......................................................

    17 (37)

    29 (63)

    Surgical Rx

    2-stage

    Debridement & Retention

    Removal without replacement

    ......................................................

    15 (33)

    18 (39)

    13 (28)

    Outcome

    Cure

    Failure with relapse

    Failure with progression

    Indeterminate

    Death

    ......................................................

    26 (57)

    5 (11)

    6 (13)

    6 (13)

    3 (6)

    The incidence rate of PJI for the study period was 5.4%.

    Staph. aureus was the commonest pathogen accounting for 11(65%) JA and 13(40%) of IO cultures. Low virulence organisms [Staph. epidermidis n=8 (25%) and Corynebacterium spp. n =1 (3%)] were only recovered from IO cultures. Gram negative bacilli accounted for 5(30%) JA and 7(28%)IO cultures.

    JA correlates well with IO cultures using paired sample correlations (t-test); (Correlation 0.61, P= 0.027).

    97% of subjects had elevated ESR while 96% had elevated CRP.

    Concerning outcome, there was no statistically significant difference between groups based on implant duration (P=0.98), symptom onset (P=0.23), pathogen type (P=0.83) and treatment options (P=0.39).

    Conclusion:

    1. JA culture is a good predictor of IO culture in knee PJI.

    2. Yield of low virulence organisms from JA culture is poor.

    3. Elevated ESR and CRP can support diagnosis of knee PJI.

    4. Implant duration, pathogen type, duration of symptoms and treatment type do not appear to affect outcome.

    Folusakin Ayoade, MD and John Todd, MD, Infectious Diseases, Louisiana State University Health Science Center, Shreveport, LA

    Disclosures:

    F. Ayoade, None

    J. Todd, None

    Findings in the abstracts are embargoed until 12:01 a.m. PDT, Wednesday Oct. 4th with the exception of research findings presented at the IDWeek press conferences.