US Patent 6866667 Patellar milling clamp

A patellar milling clamp is provided with a depth control for limiting and controlling the milling depth of a grater rotated against a bone secured in the milling clamp. A stop ring is provided on a shaft of the milling tool. The shaft is slidable in a guide bushing of the milling clamp, and a rotatable cap on the guide bushing is selectively engaged in notches in the guide bushing to provide an abutment surface at selectively different elevations. Further advancement of the tool is prevented when the stop ring abuts the abutment surface of the cap. The depth of milling is precisely controlled regardless of the original thickness of the patellar bone being milled.