Do We Need New Implant Designs

The basic principles of minimally invasive total knee arthroplasty (MIS-TKA) emphasize changes in surgical technique and instrumentation to maximize exposure through a limited incision. These include smaller incisions, modified surgical techniques including no patella eversion [1], no frank joint dislocation, quadriceps-sparing, and also down-sized instrumentation. Many of these ideas have been adapted from the experience with unicompartmental knee replacement. Modifications such as not resurfacing the patella, careful incision placement, and instrumentation-design changes have all helped unicompartmental arthroplasty trend towards minimally invasive and these changes have carried over to MIS-TKA. Furthermore, exact incision planning and placement is paramount to facilitate proper component orientation and fixation through the smallest incision possible. Unicompartmental knee arthroplasty has specific component designs that can accommodate the smaller incisions and reduced exposures.