[Importance of computer-assisted navigation in total knee arthroplasty - results of a nationwide survey in Germany].
Total knee arthroplasty is one of the standard procedures in severe osteoarthritis of the knee. Computer-assisted navigation systems became more popular in the last decade. Navigation systems improve the component positioning and the alignment in total knee arthroplasties. The aim of this survey was to capture the actual trend in computer-assisted total knee arthroplasties in Germany and to discuss the results in comparison to the current literature. A questionnaire form was sent to 506 orthopaedic and trauma surgery departments in Germany. The first part of the survey included general questions about the department and total knee arthroplasties. The surgeons were asked about their application behaviour and their rating of computer-assisted navigation in total knee arthroplasty in the second part. Questions concerning total knee arthroplasties, unicondylar knee arthroplasties and revision total knee arthroplasties were included in the form. 194 of the departments returned the questionnaire. A total of 39 941 knee arthroplasty surgeries were performed in these departments. 35 624 of these surgeries were primary knee arthroplasties including 32 789 total knee arthroplasties and 2835 unicondylar knee arthroplasties. In addition, 4317 revision total knee arthroplasties were performed by the respondents. 60 % of the departments used a computer-assisted navigation system. In synopsis 29 % of the primary total knee arthroplasties, 4 % of the unicondylar knee arthroplasties and 7 % of the revision knee arthroplasties were performed with a computer-assisted navigation system. Minimal invasive surgery was performed in 31 % of the departments and 36 % of these surgeries were done with navigation-assistance. The "ligament-balanced" procedure was the most common used technique to determine the femur rotation in navigated total knee arthroplasties. In 75 % of navigated total knee arthroplasties cemented components were implanted. Overall 65 % of respondents approved of navigation-assisted surgeries and 77 % saw an improved precision by this technique. The number of computer-assisted navigation uses in surgeries is increasing in 34 % of the departments and decreasing in 13 %. The computer-assisted navigation in total knee arthroplasties is a frequently used technique. The most respondents support the application of navigation-assisted knee arthroplasties and indicate an improved outcome measured by the postoperative alignment. Nevertheless, long-term results are needed for a final evaluation of navigation-assisted surgery.