Culture-Negative Periprosthetic Joint Infection: An Update on What to Expect

Authors/contributors
Abstract
Background: Culture-negative periprosthetic joint infection (PJI) is a challenging condition to treat. The most appropriate management of culture-negative PJI is not known, and there is immense variability in the treatment outcome of this condition. The purpose of this study was to elucidate the characteristics, outcomes, and risk factors for failure of treatment of culture-negative PJI. Methods: A retrospective review of 219 patients (138 hips and 81 knees) who had undergone surgery for the treatment of culture-negative PJI was performed utilizing a prospectively collected institutional PJI database. PJIs for which the results of culture were unavailable were excluded. An electronic query and manual review of the medical records were completed to obtain patient demographics, treatment, microbiology data, comorbidities, and other surgical characteristics. Treatment failure was assessed using the Delphi consensus criteria. Results: The prevalence of suspected culture-negative PJI was 22.0% (219 of 996), and the prevalence of culture-negative PJI as defined by the Musculoskeletal Infection Society (MSIS) was 6.4% (44 of 688). Overall, the rate of treatment success was 69.2% (110 of 159) in patients with >1 year of follow-up. Of the 49 culture-negative PJIs for which treatment failed, 26 (53.1%) subsequently had positive cultures; of those 26, 10 (38.5%) were positive for methicillin-sensitive Staphylococcus aureus. The rate of treatment success was greater (p = 0.019) for patients who had 2-stage exchange than for those who underwent irrigation and debridement. Conclusions: The present study demonstrates that culture-negative PJI is a relatively frequent finding with unacceptable rates of treatment failure. Every effort should be made to isolate the infecting organism prior to surgical intervention, including extending the incubation period for cultures, withholding antibiotics prior to obtaining culture specimens, and possibly using newly introduced molecular techniques.
Publication
JBJS Open Access
Date
2018-09-25
Notes

The study retrospectively reviewed 219 patients with culture-negative PJI between 2000 and 2014. Culture-negative infection was defined as cases where joint aspirate and/or tissue samples did not isolate an organism.

Key findings:

  1. Prevalence and Trends:

    • The prevalence of culture-negative PJI is 22.0% among 996 joints.
    • There is an observed increase in culture-negative PJI, potentially attributed to various factors like low-virulence organisms, premature antibiotic treatment, and issues with culture techniques.
  2. Treatment Outcomes:

    • The overall rate of treatment success for culture-negative PJI patients, followed for more than one year, is 69.2%.
    • The infection-free survival rates are 81.1% at 1 year, 78.1% at 2 years, and 65.3% at 5 years.
    • There is a high rate of complications, including 6 amputations and 3 PJI-related deaths.
  3. Treatment Strategies:

    • 2-stage exchange shows improved survivorship compared to irrigation and debridement.
    • Knee joint involvement and surgical management with irrigation and debridement are identified as risk factors for treatment failure.
  4. Microbiological Aspects:

    • Routine cultures have low sensitivity in identifying infecting organisms in PJI.
    • Premature antibiotic administration may compromise culture yield, but evidence is conflicting.
  5. Comparison with Other Studies:

    • The study contrasts with some prior research that suggested better outcomes for culture-negative PJI compared to culture-positive cases. This study indicates equivalent or worse outcomes for culture-negative cases.

Clinical Implications:

  1. Culture-negative PJI is associated with poor outcomes and a high rate of treatment failure.
  2. Efforts should be made to identify the infecting organism before surgical intervention to improve treatment success.
  3. Advanced diagnostic techniques, such as next-generation sequencing and sonication, are suggested to improve organism identification.

Limitations:

  1. Limitations include retrospective nature, variable inclusion criteria, and heterogeneity in sampling techniques and treatments.

Strengths:

  1. Strengths include sample size and length of follow up.

Level of evidence: Low (retrospective)

Citation
1.
Tan TL, Kheir MM, Shohat N, et al. Culture-Negative Periprosthetic Joint Infection: An Update on What to Expect. JBJS OA. 2018;3(3):e0060.