Minimally Invasive Surgery for Unicondylar Knee Arthroplasty: The Extramedullary Technique

Abstract

MIS unicondylar knee arthroplasty was introduced in the mid-1990s by Repicci and Eberle.1 The procedure was essentially a freehand technique that used limited instrumentation. Over the years there have been modifications in the surgical instruments in order to perform the procedure accurately and reproducibly through a limited incision. The Miller Galante Unicondylar prosthesis (Zimmer, Warsaw, IN) introduced intramedullary instrumentation and most recently extramedullary instrumentation.2 The smaller modified instruments clearly help in bone preparation and component position. Reliable instrumentation and surgical technique produce clinical results that are comparable with a conventional procedure.3 Reproducible and predictable placement of the components is based on sound surgical principles.4 Improved instrumentation allows the surgeon to operate through a minimally invasive arthrotomy, without everting the patella, and permits more accurate bone resection. It is the refinements in instrumentation that have contributed to successful clinical results.