Instruments for knee placement

Abstract

There are provided various embodiments of medical instruments to perform knee surgery. In one embodiment a finned platform for mounting a cutting block is provided. The finned platform can be used on either a femur or tibia to allow for the proper cuts when performing a knee surgery. In another embodiment, a tibial trial is shown having a fin. The fin is useful to reinforce the bone to reduce the risk of fracture during bone preparation. In another embodiment, a reamer is provided having a plurality of cutting flutes. It may be desirable to utilize a guide with the reamer to allow the reamer to cut a non-circular portion of the tibial bone. In yet another embodiment, a plurality of fixation pegs are provided on the tibial implant to allow for easy removal of such implant if a revision surgery becomes necessary.

I claim: 
     
         1 . A cutting system comprising:
 an anchor including:
 a head having an upper support surface; 
 a shaft depending from the head; and 
 a fin laterally extending from the shaft for engaging a bone segment upon insertion of the shaft and the fin into the bone segment; and 
   a cutting instrument including:
 a shaft portion including one or more cutting elements; and 
 a tip portion arranged and configured to contact the head of the anchor to removably couple the cutting instrument with the anchor so that the cutting instrument can rotatably and pivotally move relative to the anchor to enable the one or more cutting elements to engage with the bone. 
   
     
     
         2 . The cutting system of  claim 1 , wherein the upper surface of the head of the anchor includes a depression or opening extending into the upper support surface, the depression or opening arranged and configured to receive the tip portion of the cutting instrument. 
     
     
         3 . The cutting system of  claim 2 , wherein the tip portion of the cutting instrument is rounded so that the rounded tip portion of the cutting instrument is received within the depression or opening formed in the head of the anchor to removably engage the cutting instrument with the anchor so that the cutting instrument can rotatably and pivotally move relative to the anchor. 
     
     
         4 . The cutting system of  claim 1 , wherein the cutting instrument includes a depth stop. 
     
     
         5 . The cutting system of  claim 1 , further comprising a guide arranged and configured to interact with the shaft portion of the cutting instrument to guide movement of the cutting instrument within the bone. 
     
     
         6 . The cutting system of  claim 5 , wherein the guide includes a stator with a cam opening, the shaft portion of the cutting instrument arranged and configured to move along the cam opening to guide movement of the cutting instrument within the bone. 
     
     
         7 . The cutting system of  claim 1 , wherein the upper support surface of the head of the anchor includes a substantially planar surface. 
     
     
         8 . The cutting system of  claim 1 , wherein the fin is a continuous thread extending about the shaft. 
     
     
         9 . The cutting system of  claim 1 , wherein the fin includes a plurality of ribs extending about the shaft. 
     
     
         10 . The cutting system of  claim 1 , wherein the fin includes a plurality of longitudinally extending ribs extending along the shaft. 
     
     
         11 . The cutting system of  claim 1 , wherein the fin has a greater lateral surface relative to a thickness of the fin to adequately engage a relatively soft, spongy bone segment. 
     
     
         12 . The cutting system of  claim 1 , wherein the cutting instrument comprises a reamer. 
     
     
         13 . The cutting system of  claim 1 , wherein the one or more cutting elements comprise one or more cutting flutes that do not extend across the tip portion. 
     
     
         14 . The cutting system of  claim 1 , wherein the bone segment is selected from one of a distal portion of a femur adjacent a knee joint and a proximal portion of a tibia adjacent a knee joint. 
     
     
         15 . A cutting system comprising:
 an anchor including:
 a head having an upper support surface and a depression or opening extending into the upper support surface; 
 a shaft depending from the head; and 
 a fin laterally extending from the shaft for gripping a bone segment upon insertion of the shaft and fin into the bone segment; and 
   a reamer including:
 a shaft portion including one or more cutting elements; and 
 a rounded tip portion arranged and configured to be received within the depression or opening formed in the upper support surface of the head of the anchor to removably couple the shaft portion of the reamer with the anchor so that the reamer can rotatably and pivotally move relative to the anchor to enable the one or more cutting elements to engage with the bone. 
   
     
     
         16 . The cutting system of  claim 15 , wherein the reamer includes a depth stop. 
     
     
         17 . The cutting system of  claim 15 , further comprising a guide arranged and configured to interact with the shaft portion of the reamer to guide movement of the reamer within the bone. 
     
     
         18 . The cutting system of  claim 17 , wherein the guide includes a stator with a cam opening, the shaft portion of the reamer arranged and configured to move along the cam opening to guide movement of the reamer within the bone. 
     
     
         19 . The cutting system of  claim 15 , wherein the upper support surface of the head of the anchor includes a substantially planar surface. 
     
     
         20 . The cutting system of  claim 15 , wherein the one or more cutting elements comprise one or more cutting flutes that do not extend across the tip portion.