Guidelines
Prosthetic Joint Infections (PJIs)

Prosthetic Joint Infections (PJIs)

Microbiology

Risk Stratification

PJI is present when 1 major criteria exist or 4 out of 6 minor criteria exist

Major Criteria:

  • 2 positive periprosthetic cultures with phenotypically identical organisms
  • A sinus tract communicating with the joint

Minor Criteria:

  • Elevated CRP and ESR
  • Elevated synovial fluid WBC count or ++ change on leukocyte esterase test strip
  • Elevated synovial fluid PMN%
  • Presence of purulence in the affected joint
  • Positive histologic analysis of periprosthetic tissue
  • A single positive culture
  • Early onset = 1-3 month after surgery 
  • Delayed onset = 1-2 years after surgery 
  • Late onset = >2 year after surgery

Clinical Considerations

Contiguous disease WITHOUT vascular insufficiency

Diagnosis of PJI may be established in the setting of: 

  • Two or more periprosthetic cultures with phenotypically identical organisms (a combination of preoperative synovial fluid aspiration culture and intraoperative tissue culture or ≥2 intraoperative tissue cultures)
  • Growth of a virulent microorganism (e.g. S. aureus) in a single specimen of a tissue biopsy or synovial fluid
  • In patients with a sinus tract: drainage (collected by aspiration) should be sent for culture
    • Swabs from the sinus tract should not be sent given discordance with deep cultures
    • Cultures of a superficial wound or sinus tract are often positive because of microbial colonization from the surrounding skin and should therefore be avoided
  • In patients with fever or other systemic manifestations of infection: blood cultures (two sets) should be obtained
  • If the prosthesis is removed: the implant or its components can be cultured in enrichment broth
    • However, the risk of contamination during specimen processing is high
  • Cultures of periprosthetic tissue provide the most reliable means of detecting a pathogen
  • At least three to six intraoperative tissue specimens should be sampled for culture
  • Cultures are more likely to be negative if insufficient tissue was sent or if only swabs were collected
  • Culture yields are more likely to be diminished and negative if antibiotics were administered prior to culture collection
  • Negative cultures can be attributed to slow growing and difficult to detect variants of staphylococci, or fastidious pathogens that includes Coxiella Burnetii, Brucellosis, Bartonellosis, Abiotrophia defectiva, Granulicatella adiacens, Mycoplasma, Mycobacteria, and Fungi
  • Cultures may be negative due to prolonged transport time to the microbiology laboratory
  • Swab cultures have a low sensitivity and should be avoided
  • To detect cases of low-grade infection, antimicrobial therapy should be discontinued at least two weeks before tissue specimens are obtained
  • If revision surgery is planned, perioperative prophylaxis should not be administered until after tissue specimens have been collected for culture

More Information

Osmon DR, Berbari EF, Berendt AR, Lew D, Zimmerli W, Steckelberg JM, Rao N, Hanssen A, Wilson WR; Infectious Diseases Society of America. Diagnosis and management of prosthetic joint infection: clinical practice guidelines by the Infectious Diseases Society of America. Clin Infect Dis. 2013 Jan;56(1):e1-e25. doi: 10.1093/cid/cis803. Epub 2012 Dec 6. PMID: 23223583.