Efficacy of intraoperative cultures obtained during revision total hip arthroplasty

The purpose of this study was to determine the incidence of positive intraoperative cultures, correlate the findings of the permanent histopathology with the results of culture, and determine the natural history and predictive value of the positive intraoperative culture in a consecutive series of 138 revision total hip arthroplasties. The incidence of positive cultures was 30% (42 hips). Of these 42 hips, only 1 ultimately developed sepsis, requiring a second surgical procedure. After a mean follow-up period of 48 months, the remaining 41 culture-positive hips show no evidence of sepsis and are considered clinical successes. The histologic appearance of the infected case was characterized by polymorphonuclear leukocyte infiltration suggestive of acute inflammation. The remaining hips demonstrated findings of chronic inflammation consistent with a diagnosis of aseptic loosening. With the development of sepsis as an endpoint, the positive predictive value of a positive intraoperative culture is 2.4%. The results demonstrate that intraoperative cultures are an unreliable predictor of sepsis and that permanent histologic sectioning is a more useful tool in determining sepsis at the time of revision surgery.