Optimal Culture Incubation Time in Orthopedic Device-Associated Infections: a Retrospective Analysis of Prolonged 14-Day Incubation

Abstract

Accurate diagnosis of orthopedic device-associated infections can be challenging. Culture of tissue biopsy specimens is often considered the gold standard; however, there is currently no consensus on the ideal incubation time for specimens. The aim of our study was to assess the yield of a 14-day incubation protocol for tissue biopsy specimens from revision surgery (joint replacements and internal fixation devices) in a general orthopedic and trauma surgery setting. Medical records were reviewed retrospectively in order to identify cases of infection according to predefined diagnostic criteria. From August 2009 to March 2012, 499 tissue biopsy specimens were sampled from 117 cases. In 70 cases (59.8%), at least one sample showed microbiological growth. Among them, 58 cases (82.9%) were considered infections and 12 cases (17.1%) were classified as contaminations. The median time to positivity in the cases of infection was 1 day (range, 1 to 10 days), compared to 6 days (range, 1 to 11 days) in the cases of contamination (P < 0.001). Fifty-six (96.6%) of the infection cases were diagnosed within 7 days of incubation. In conclusion, the results of our study show that the incubation of tissue biopsy specimens beyond 7 days is not productive in a general orthopedic and trauma surgery setting. Prolonged 14-day incubation might be of interest in particular situations, however, in which the prevalence of slow-growing microorganisms and anaerobes is higher.

Optimal Length of Cultivation Time for Isolation of Propionibacterium acnes in Suspected Bone and Joint Infections Is More than 7 Days

“…Since recent studies recommended a prolonged cultivation time of up to 14 days for bone and joint infections (17,18), the diagnosis of P. acnes infections has become more frequently documented (19). In view of the high costs of a long incubation period, a recent study suggested that 7 days of incubation should be sufficient for accurately diagnosing orthopedic implant-associated infections (20). In this study, 96.6% of the infections were detected within 7 days.…”

“…However, reducing the cultivation time to 7 days as proposed by previous studies (20,23) would have resulted in missing diagnosis in 15 patients (21.4%), suggesting that in patients with a high prevalence of P. acnes infections, a prolonged cultivation is crucial for detecting infections. This supports the results of a study, including fewer P. acnes infections (37 cases), …”

Meta-Analysis of Sonication Fluid Samples from Prosthetic Components for Diagnosis of Infection after Total Joint Arthroplasty

“…Butler-Wu et al suggested that for all periprosthetic specimens, minimal aerobic and anaerobic culture incubation periods of 13 days are highly recommended (29). However, Esteban et al and Schwotzer et al reported that compared with a 7-day incubation period, a 14-day incubation period does not add more positive results for sonicated orthopedic implants (28,33). In this meta-analysis, six studies were cultured anaerobically for 7 days and five studies were cultured anaerobically for 14 days.…”

“…The duration of incubation is still controversial (28). Five-or 7-day incubations have often been reported (9,13,15,17).…”

“…Low-virulence microorganisms that adhere to foreign material are replicated slowly. They are characteristically in a dormant starved state and thus need longer culture incubation times (28,32). Portillo et al compared the time to culture tissue and sonication fluid in PJI and aseptic failure (31).…”