Limited evidence supports withholding antimicrobials for a minimum of two weeks prior to obtaining intra-articular culture to establish the diagnosis of PJI.

Rationale
One moderate strength study found that subjects who received antibiotics within two weeks of obtaining an intra-articular culture were at increased risk of false negative culture results (Trampuz et al. 2007). One low quality study failed to find a statistical difference in the risk for false negative culture results between those subjects who did and those who did not receive antibiotics within two weeks of acquiring intra-articular cultures specimens (Shahi et al. 2016).

POSSIBLE HARMS OF IMPLEMENTATION
There may be scenarios where withholding antibiotic treatment may not be appropriate, such as in the case of sepsis. In the case of a hemodynamically stable patient, there are no known associated risks or harms with this recommendation. However, it is recommended that patients remain closely monitored to ensure no worsening of their clinical status during the antibiotic free period.

FUTURE RESEARCH
Periprosthetic joint infection can be caused by a myriad of microorganisms. Whether this recommendation applies to all microorganism-types as well as all antibiotic-types is unknown. Future research is needed to better understand the effect of varying antimicrobial agents on differing organisms and to define the ideal “antibiotic-free” time prior to specimen collection for cultures in patients with suspected PJI.
  1. Shahi,A., Parvizi,J., Kazarian,G.S., Higuera,C., Frangiamore,S., Bingham,J., Beauchamp,C., Valle,C.D., Deirmengian,C. The Alpha-defensin Test for Periprosthetic Joint Infections Is Not Affected by Prior Antibiotic Administration. Clin.Orthop.Relat.Res. 2016/7; 7: 1610-1615
  2. Trampuz,A., Hanssen,A.D., Osmon,D.R., Mandrekar,J., Steckelberg,J.M., Patel,R. Synovial fluid leukocyte count and differential for the diagnosis of prosthetic knee infection. Am.J.Med. 2004/10/15; 8: 556-562