Cutting device for revision arthroplasty

Abstract

A cutting device is provided that includes a pair of cutting blades joined at a pivot point. The cutting blades are driven by an actuator to cause the cutting blades to pivot about the pivot point. The cutting device is configured to remove material underneath a surface of an implant installed on a bone during a revision arthroplasty procedure. The cutting device may travel along a length of the bone just underneath the surface of the implant to remove material and free the implant from the bone. A method for removing material underneath a surface of an implant installed on the bone is also provided. A system for removing material underneath the surface of an implant installed on the bone with the cutting device is also provided.

1 . A cutting device comprising:
 a pair of cutting blades;   a pivot point at which said pair of cutting blades are joined; and   a flexible sheath, wherein at least a portion of the pair of cutting blades extend from said flexible sheath.   
     
     
         2 . The cutting device of  claim 1 , further comprising a cam in mechanical communication with said pair of cutting blades. 
     
     
         3 . The cutting device of  claim 2 , further comprising a clip to retain said cam intermediate between said pair of cutting blades and below said pivot point. 
     
     
         4 . The cutting device of  claim 3 , wherein said clip is spring biased against rotation of said cam. 
     
     
         5 . The cutting device of  claim 2 , wherein said cam is coupled to a drive shaft. 
     
     
         6 . The cutting device of  claim 5 , wherein said clip has an opening through which said drive shaft passes. 
     
     
         7 . The cutting device of  claim 2 , wherein said cam is intermediate between said pair of cutting blades and said spring bias bounds said pair of cutting blades. 
     
     
         8 . The cutting device of  claim 1 , wherein said pair of cutting blades has a thickness of from 1 to 5 millimeters and a width of from 3 to 7 millimeters. 
     
     
         9 . The cutting device of  claim 1  wherein the cutting blades and flexible sheath flex to permit said pair of cutting blades and said flexible sheath to follow a surface of an implant installed in or on a bone. 
     
     
         10 . The cutting device of  claim 1  further comprising cutting teeth at a distal end of said pair of cutting blades, wherein the cutting teeth are angled to grab material. 
     
     
         11 . A method for removing material underneath a surface of an implant installed on the bone comprising:
 driving the cutting blades of  claim 1  to pivot about the pivot point; and   translating the cutting device along a length of the bone to remove material underneath the surface of the implant installed on the bone.   
     
     
         12 . The method of  claim 11  further comprising removing the implant from the bone. 
     
     
         13 . The method of  claim 11  wherein said translating is along a curved path. 
     
     
         14 . The method of  claim 11 , wherein the bone is a femur. 
     
     
         15 . The method of  claim 11 , wherein the bone is a tibia 
     
     
         16 . The method of  claim 15 , wherein the material removed is bone or bone cement. 
     
     
         17 . A system for removing material from a target bone comprising:
 the cutting device of  claim 1 ; and   an actuator for driving the cutting blades.   
     
     
         18 . The system of claim  19  further comprising a surgical robot controlling the cutting device of  claim 1 .