Bacterial and Hematological Findings in Infected Total Hip Arthroplasties in Norway Assessment of 278 Revisions Due to Infection in the Norwegian Arthroplasty Register

Our aim was to assess the bacterial findings in infected total hip arthroplasties (THAs) in Norway. We also wanted to investigate the relationship between causal bacteria and hematological findings. Revisions reported to the Norwegian Arthroplasty Register (NAR) due to infection after total hip arthroplasty during the period 1993 through September 2007 were identified. One single observer visited ten representative hospitals where clinical history, preoperative blood samples and the bacterial findings of intraoperative samples were collected. Bacterial growth in two or more samples was found in 278 revisions, and thus included. The following bacteria were identified: Coagulase-negative staphylococci (CoNS) (41%), Staphylococcus aureus (S. aureus) (19%), streptococci (11%), polymicrobial infections (10%), enterococci (9%), Gram-negative bacteria (6%) and others (4%). CoNS were the most common bacteria throughout the period but in the acute postoperative infections (< 3 weeks) S. aureus was the most frequent bacterial finding. We found no change in the distribution of the bacterial groups over time. S. aureus appears correlated with a higher C-reactive protein value (CRP) (mean 140 (95% Confidence interval (CI): 101-180)) than CoNS (mean 42 (CI: 31-53)). S. aureus also correlated with a higher erythrocyte sedimentation rate value (ESR) (mean 67 (CI: 55-79)) than CoNS (mean 47 (CI: 39-54)).