[Development, terminology, principles, and controversies in minimally invasive knee arthroplasty].

Minimally invasive total knee arthroplasty is a logical and further improvement of the good results achieved with minimally invasive unicondylar knee arthroplasty. The terminology for minimally invasive surgery (MIS) is confusing and comparison of different techniques is therefore difficult. A simple separation between less invasive and minimally invasive techniques will be presented. Besides the approach, minimally invasive surgical principles are very important. MIS in total knee arthroplasty is discussed very controversially at the moment. The preliminary results of these new techniques are very promising. Up to now there is much more feeling then knowing. Important questions (risk-benefit analysis, which technique for which patient and surgeon, education and cost-effectiveness) must be addressed by the proponents of this MIS technique. Step by step learning of these new techniques (evolution instead of revolution) in specific education centres is strongly recommended. Ultimately, patients and surgeons will have to decide whether these new techniques will only be a modern trend or represent the future.