Prevention of infection after knee arthroplasty.

Scientific background: Man-made joints (joint endoprostheses), including knee endoprostheses, are used in some irreversible diseases of the human joints. The implantation of joint endoprostheses (arthroplasty) is associated with an increased risk for infection. To prevent infections, different interventions without and with the use of antibiotics (hygiene procedures and antibiotic prophylaxis) are used. The benefits of these interventions are not clear yet.

Research questions: The presented report addresses the questions regarding the medical effectiveness, the cost-effectiveness as well as the ethical, social and legal aspects related to the use of interventions to prevent infections after knee arthroplasty.

Methods: A systematic literature search is conducted in the medical electronic databases MEDLINE, EMBASE, SciSearch etc. in June 2009 and has been completed by a hand search. The analysis includes publications which describe and/or evaluate clinical data from randomized controlled trials (RCT), systematic reviews of RCT, registers of endoprostheses or databases concerning interventions to prevent infections after knee arthroplasty. The conducted literature search also aims to identify health-economic studies and publications dealing explicitly with ethical, social or legal aspects in the use of interventions to prevent infections after knee arthroplasty. The synthesis of information from different publications has been performed qualitatively.

Results: The systematic literature search yields 1,030 hits. Based on the predefined inclusion and exclusion criteria a total of ten publications is included in the analysis. The presented report does not find evidence of the effectiveness of different hygiene interventions with a high evidence level. Most of the unspecific interventions are recommended on the basis of results from non-RCT, from studies for other clinical indications and/or for clinically not relevant endpoints, as well as on the basis of expert opinions. The evidence of the effectiveness of intravenous prophylaxis with antibiotics in knee arthroplasty on a high level of evidence is also missing. The recommendations use evidence on the intravenous antibiotic prophylaxis transferred from RCT in hip arthroplasty to the arthroplasty of all joints including knee replacement. Moreover, no evidence is found for differences in the effectiveness between various antibiotics in knee arthroplasty. The presented report finds strong hints for the effectiveness of antibiotics in cement in addition to the intravenous prophylaxis; however, evidence of the effectiveness may be accepted only for operating rooms without clean-air measures.

Discussion: The conclusiveness of the results from non-RCT and from studies for clinically non-relevant endpoints is relatively low. The determined evidence from studies for other clinical indications may be generally transferred to knee replacement operations.

Conclusions: No proposal to change the recommendations of the Robert Koch Institute with respect to hygiene interventions and intravenous antibiotic prophylaxis can be made from the presented analysis. Also, no recommendations on the selection of certain antibiotic can be derived from the analysed data. The use of antibiotics in cement in addition to the intravenous prophylaxis may be generally recommended. The cost-effectiveness of different interventions to prevent infections in knee arthroplasty remains unclear. There are no signs for concern regarding any ethical, social and/or legal consequences in the use of interventions to prevent infections in knee arthroplasty.