How Many Samples and How Many Culture Media To Diagnose a Prosthetic Joint Infection: a Clinical and Microbiological Prospective Multicenter Study

Abstract

h Although numerous perioperative samples and culture media are required to diagnose prosthetic joint infection (PJI), their exact number and types have not yet been definitely determined with a high level of proof. We conducted a prospective multicenter study to determine the minimal number of samples and culture media required for accurate diagnosis of PJI. Over a 2-year period, consecutive patients with clinical signs suggesting PJI were included, with five perioperative samples per patient. The bacteriological and PJI diagnosis criteria were assessed using a random selection of two, three, or four samples and compared with those obtained using the recommended five samples (references guidelines). The results obtained with two or three culture media were then compared with those obtained with five culture media for both criteria. The times-to-positivity of the different culture media were calculated. PJI was confirmed in 215/264 suspected cases, with a bacteriological criterion in 192 (89%). The PJI was monomicrobial (85%) or polymicrobial (15%). Percentages of agreement of 98.1% and 99.7%, respectively, for the bacteriological criterion and confirmed PJI diagnosis were obtained when four perioperative samples were considered. The highest percentages of agreement were obtained with the association of three culture media, a blood culture bottle, a chocolate agar plate, and Schaedler broth, incubated for 5, 7, and 14 days, respectively. This new procedure leads to significant cost saving. Our prospective multicenter study showed that four samples seeded on three culture media are sufficient for diagnosing PJI. There is still no standard definition of prosthetic joint infection (PJI). Although numerous perioperative samples are needed to diagnose PJI, their optimal number is not yet definitively known. In 1998, Atkins et al., using a mathematical model, demonstrated that five or six perioperative samples, with a cutoff of three or more culture-positive samples, are needed to diagnose PJI with high sensitivity and specificity (1). Recent guidelines still recommend that about five samples should be cultured for optimal diagnosis of PJI (2, 3). Since each tissue specimen is cultured on four to five culture media, a total of 20 to 25 culture media have to be analyzed per patient. The optimal duration of incubation for periprosthetic cultures was extended to 13 or 14 days, especially for Propionibacterium acnes recovery (4, 5). The implementation of 14-day culture incubation in combination with the use of multiple solid and liquid aerobic and anaerobic culture media makes the daily monitoring of PJI by the laboratory very complex, costly, and time-consuming. Moreover, the number of cases of PJI will continue to increase in the coming decades. Forecasts predict that by 2030, the demand for total hip and knee arthroplasties will grow to 4 million in the United States (6). A major economic effect is that device-associated costs are significantly higher than native bone and joint infections, as recently reported (7). Thi...

Optimal Periprosthetic Tissue Specimen Number for Diagnosis of Prosthetic Joint Infection

“…Results of this study are similar to those of the recently published study by Bémer et al (12) assessing the number of perioperative specimens, including periprosthetic tissue, bone, and joint fluid samples, required for the accurate diagnosis of PJI. This prospective cohort study involved 215 patients with confirmed PJI according to modified IDSA criteria (3,12).…”

“…Also at variance is that Schaedler broth was used for anaerobic culture and that patients without PJI were not included. In addition, the microbiological criteria used by Bémer et al and in our study differed; in our study, a culture result was considered positive only if the same microorganism was isolated in two or more specimens with no reference to organism type or virulence (4,12).…”

“…This prospective cohort study involved 215 patients with confirmed PJI according to modified IDSA criteria (3,12). The microbiological criterion for infection was the isolation of a "strict pathogen" in one or more cultures or the isolation of a "skin commensal" in two or more cultures (12). The authors assessed agreement between microbiological and PJI diagnostic criteria for each stratum of specimen numbers, performing 1,000 iterations of a random sample to obtain the average agreement rate.…”

“…This prospective cohort study involved 215 patients with confirmed PJI according to modified IDSA criteria (3,12). The microbiological criterion for infection was the isolation of a "strict pathogen" in one or more cultures or the isolation of a "skin commensal" in two or more cultures (12).…”

Periprostetik enfeksiyonlar: mikrobiyoloji, antibiyotik uygulamaları

“…Ameliyat sırasında kültür örneği alınırken, en az üç adet olması-na özen gösterilmelidir; hatta en az 5-6 örnek alınma-sını telkin eden çalışma sonuçları da vardır. [17] Son yıllarda, total protez enfeksiyonlarının tanısında immünofloresan mikroskopi ve PCR (polimeraz zincir reaksiyonu) gibi moleküler yöntemlerin kullanılmasıyla ilgili araştırmalar yapılmaktadır. [18,19] Yakın zamanda, Amerikan Enfeksiyon Derneği'nin yıllık toplantısında bildirilen bir çalışmada, PCR'nin kültüre bir üstünlüğü olmadığı bildirilmiştir.…”