Bone preserving intraoperative downsizing system for orthopaedic implants

Abstract

An orthopedic implant system includes a set of provisional orthopedic implants having different implant sizes, in which each provisional implant facilitates an intraoperative selection of the next-smallest implant size without removing the provisional implant from the bone. All of the implant sizes share a common sagittal configuration of distal and anterior bone contacting surfaces, but have variable sagittal configurations only in the posterior bone contacting surfaces. Thus, where a relatively larger femoral provisional component is mounted to a femur, changing to a smaller provisional component (i.e., 'downsizing') can be accomplished by recutting only two of five original femoral cuts. Cut slots provided in each provisional implant are sized and positioned to correspond to the posterior bone contacting surface geometry of the next-smallest provisional implant size. Thus, the cut slots in a mounted, relatively larger implant can be used to further resect posterior femoral surfaces to accept the next smallest implant component size.