Board Review: Prosthetic Joint Infections

Which of the following is NOT a diagnostic criterion for the definition of PJI according to the IDSA guidelines (2013)?

A 47 yo otherwise healthy avid runner presents to your office with a painful red R knee 2 weeks after undergoing a R TKA. He had seen his orthopedic surgeon 2d prior and underwent an xray which noted intact hardware, routine bloodwork noting a ESR of 105 and a CRP of 15. Aspiration of synovial fluid returned with 8,095 WBC with 87% PMNs. Right as you are about to evaluate the patient, you receive a call from the orthopedic surgeon that the synovial culture is now + for S aureus. After discussing the case with the orthopedic surgeon, what should you recommend to the patient be the next course of action?

A 63 yo Indian F with a PMH of diabetes, hypertension and OA s/p L THA in 2019 was sent to you for evaluation after repeated appointments with her orthopedic surgeon for ongoing pain in her L hip for the last 6 months. She has had repeated evaluations for this, including a negative plain film, blood work with a ESR of 52, a CRP of 5 and an IL-6 level of 12. She also has had synovial aspirations done with no cell counts performed but with negative routine bacterial cultures done x 2; negative crystal analysis, alpha defensin (ELISA) of 59.6 mg/L (ULN 5.2 mg/L) and a CRP of 17. What do you recommend as the next course of action?

Intraoperatively, the patient in question #3 had a frozen section sent for histopathology, which noted >10 PMNs/hpf. The surgeon opts to perform a single stage procedure while in the OR. Pre-operative and 1 intraoperative cultures ultimately returned + for M tuberculosis. What do you recommend to the surgeon and to the patient?