MINIMALLY INVASIVE TOTAL KNEE ARTHROPLASTY, NEW INSTRUMENTS AND TECHNIQUES

Introduction Minimally invasive total knee arthroplasty has gained interest among total joint surgeons across the USA. It remains, however, somewhat unclear how to define minimally invasive. Small incisions may be a focal point of the surgery, but unless one is performing “limited incision surgery”, the skin does not define minimalness. The techniques and instrumentation for performing a minimally invasive total knee arthroplasty are presented. Methods The principles of a minimally invasive total knee arthroplasty procedure include: a small incision, a vastus-medialis split, mobilization of the patella without eversion, and the use of modified instruments that have been designed for use with standard implants. The implantation instruments are downsized versions of a standard system and are easily applied to the routine arthroplasty patient. Results The mid-vastus split appears to protect the quadriceps’ function and promote early recovery relative to the more traditional para-patellar arthrotomy. By avoiding patellar eversion altogether or only everting for a limited period, in extension, at the end of the case, elongation of the quadriceps fibers is avoided. These two measures appear protective and may promote early muscle recruitment during the post-operative recovery phase. The miniaturization of the familiar easier. Early review of post-operative radiographs has not revealed detriment to implant positioning. Conclusions While only developmental, this technique appears amenable to navigation systems that may further the minimalization by avoiding violation of the femoral and tibial canals. Minimally invasive total knee arthroplasty needs to be defined as a concept and as to what role it should play in a surgeon’s armamentarium. While in its infancy as a technique, the new instruments and refined surgical approach appear to allow rapid rehabilitation and patient satisfaction without sacrificing positioning or outcome. In relation to the conduct of this study, one or more of the authors has received, or is likely to receive direct material benefits.