Microbiological cultures of allografts of the femoral head just before transplantation

Abstract

Allografts of bone from the femoral head are often used in orthopaedic procedures. Although the donated heads are thoroughly tested microscopically before release by the bone bank, some surgeons take additional cultures in the operating theatre before implantation. There is no consensus about the need to take these cultures. We retrospectively assessed the clinical significance of the implantation of positive-cultured bone allografts. The contamination rate at retrieval of the allografts was 6.4% in our bone bank. Intra-operative cultures were taken from 426 femoral head allografts before implantation; 48 (11.3%) had a positive culture. The most frequently encountered micro-organism was coagulase-negative staphylococcus. Deep infection occurred in two of the 48 patients (4.2%). In only one was it likely that the same micro-organism caused the contamination and the subsequent infection. In our study, the rate of infection in patients receiving positive-cultured allografts at implantation was not higher than the overall rate of infection in allograft surgery suggesting that the positive cultures at implantation probably represent contamination and that the taking of additional cultures is not useful.

Intraoperative culture positive allograft bone and subsequent postoperative infections: a retrospective review

“…2 The rate of positive intraoperative bone allograft culture in our series was 4.3%, consistent with rates reported in other centres. 7,9,10,12,15 Furthermore, subse quent postoperative infection following a positive intraop erative positive allograft culture was rare, occurring in 2 of 37 (5%) patients in our series. Importantly, during our 4year study period, no postoperative infection could be linked to a positive allograft bone culture.…”

“…7,20 Several studies have examined complications of allograft bone, including infec tion, both for the donor 13,[21][22][23] and recipient. 1,2,4,6,7,9,12,15,20,24,25 Several studies examining the link between allograft bone and postoperative infection have cited various results, some attributing postoperative infection to allograft bone 2,6 and others to infection rates inherent with these often more complex procedures. 2,7,9,10,20 Postoperative infections in these cases are devastating complications and can be diffi cult to manage.…”

“…Previous studies are small, singlecentre reviews, most of which concluded that cases of postopera tive infection could not be clearly linked with positive intraoperative allograft bone cultures at initial sur gery. 7,9,10,15,20,27 In a retrospective study by Van de Pol and colleagues, 9 48 of 426 patients receiving allograft bone were found to have positive intraoperative cultures. Three of these patients went on to experience significant postoper ative infections; however, only 1 patient was found to have the same organism isolated from the original allograft cul ture.…”

“…Three of these patients went on to experience significant postoper ative infections; however, only 1 patient was found to have the same organism isolated from the original allograft cul ture. 9 The authors concluded that positive intraoperative allograft cultures represented contamination that was unlikely to cause subsequent postoperative infection and that intraoperative bone allograft cultures were unnecessary. …”

“…The average positive intraoperative allograft bone culture rate reported in the literature ranges from 1.4% to 12%. 4,7,9,[11][12][13] Although some studies comment that cases of positive cul ture taken at the time of implantation went on to develop wound infections, 2,6 most studies suggest that these posi tive cultures do not correlate with postoperative infections and that the organisms isolated in the postoperative infec tion are only rarely the same as those isolated in the intra operative allograft culture. 9,10,12,14,15 It is difficult to apply these results to all populations, as national policies for handling allograft bone differ.…”