Problem: Deep infection after hip- or knee-replacement is a severe complication that may lead to implant removal or arthrodesis.

Aim: In our hospital intraoperativ subcoutanues culture samples were taken before wound closure. We wanted to know if positive cultures are of any predicitive value in relation to early or late periprosthetic infection. If so, is there a consequence in treatment ? Also costs were analysed.

Material and methods: In 2002 we performed 167 primary hip and knee replacements. We retrospectivaly analysed the outcome of 159 cases over a follow-up period of up to 28 month.

Results: In 96.8% of the cases a culture sample was taken. Of these 5.8% showed germ growth. In only 4 cases positive cultures were followed by a change in treatment, either antibiotics or revision. Of nine patients with revision surgery only one had a positive culture. Four cases showed germ growth during revision surgery after sterile cultures during implantation. Most often different bacterias were found in primary and revision surgery. In 1.25% deep periprosthetic infection occured. One required second stage knee-replacement, one case ended in resection arthroplasty.

Conclusion: Intraoperative culture sample is of no predictive value in primary joint replacement. There is no correlation between positiv cultures and indication for revision surgery. However costs for culture analysis and antibiotics are low compared to the increase of expense caused by periprosthetic infections.