A retrospective comparison of bone culture techniques.

Abstract

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. The purpose of this study was to retrospectively compare two intraoperative methods to obtain bone cultures: bone tissue cultures and bone swab cultures. A retrospective review was performed on one-hundred three patients who underwent 126 surgical procedures for concern of osteomyelitis in the lower extremity. 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. 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). 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.