A retrospective comparison of bone culture techniques.

Background: The gold standard test for diagnosing osteomyelitis is bone biopsy, and IDSA 2023 guidelines recommend obtaining a "bone culture" for microbiological analysis in the setting of osteomyelitis. However, there is no consensus on the optimal method by which to obtain this bone sample.

Purpose: The purpose of this study was to retrospectively compare two intraoperative methods to obtain bone cultures: bone tissue cultures and bone swab cultures.

Study design: A retrospective review was performed on one-hundred three patients who underwent 126 surgical procedures for concern of osteomyelitis in the lower extremity.

Methods: Intraoperatively, a bone swab culture and a bone tissue culture were obtained following debridement or amputation from the same operative site and submitted for microbiological analysis.

Results: Bone swab cultures yielded positive results in 40.5 % (51/126) of procedures, while bone tissue cultures were positive in 32 % (40/126)(p = 0.027). Complete agreement between both methods occurred in 80 % (101/126) cases. In cases of disagreement, bone swab cultures resulted positive more than bone tissue cultures (p = 0.028).

Conclusion: These findings suggest that the bone swab is more sensitive overall, and surgeons may even consider the use of both bone tissue and swabs for culture.