Effect of antibiotic prophylaxis before revision for periprosthetic joint infection on positive rate of intraoperative specimen culture / 中华创伤骨科杂志

ABSTRACT

Objective:To investigate whether the prophylactic use of a dose of sensitive antibiotics before revision for periprosthetic joint infection (PJI) may affect the positive rate of intraoperative specimen culture.Methods:This prospective study recruited the patients who underwent revision due to PJI from July 1, 2017 to February 1, 2019 at Department of Orthopaedics, The First Affiliated Hospital to Fujian Medical University. After use of antibiotics was stopped in all patients for 2 weeks before operation, synovial fluid was extracted for culture to confirm pathogenic bacteria and drug sensitivity and some/all of the prostheses were removed during operation. According to their sequence number of admission, the patients were randomly divided into group A and group B. Samples were taken in group A after a dose of sensitive antibiotics was administered 30 to 60 minutes before revision while a dose of sensitive antibiotics was given in group B after all samples were taken. Intra-operatively, synovial fluid, tissue grinding fluid (TGF) and ultrasonic prosthesis lysate (UPL) were taken for aerobic and anaerobic culture. According to whether there was a positive culture of at least one microbiological specimen, the preoperative and intraoperative culture results were analyzed and compared between the 2 groups.Results:A total of 32 PJI patients were included in this study due to positive culture of synovial fluid before operation, with 16 cases in group A and 16 in group B. The most common infection bacteria were staphylococci (59.3%, 19/32). There was no significant difference in age, gender, mode of operation, Tsukayama classification, prosthesis removal, preoperative ESR, CRP, synovial fluid white blood cell count (SF-WBC) or polymorphonuclear cell percentage (PMN) between the 2 groups. The positive rates of synovial fluid, tissue, TGF and UPL were 81.3% (13/16), 62.5% (10/16), 93.8% (15/16) and 93.8% (15/16) for group A, and 87.5% (14/16), 68.8% (11/16), 93.8% (15/16) and 100.0% (16/16) for group B, showing insignificant differences between the 2 groups ( P>0.05). The positive rates of TGF and UPL culture showed no significant difference between them in group A or in group B ( P>0.05), but they were significantly higher than those of traditional tissue culture ( P<0.05). Conclusions:As prophylactic use of antibiotics before PJI revision may not affect the positive rate of intraoperative specimen culture, it is not necessary to postpone use of prophylactic antibiotics before PJI revision. Furthermore, as positive rates of TGF and UPL culture are similar but significantly higher than those of traditional tissue culture, tissue grinding can be used to improve the positive rate of tissue culture.