Revision knee arthroplasty methods and instruments

Abstract

According to one example, a for revision knee arthroplasty is disclosed. According to this example, the method can include shaping a bone of a patient to create one or more recesses therein, selecting a stem provisional, disposing the stem provisional within the one or more recesses, and assembling in vivo the stem provisional with both a first provisional component configured to simulate a shape of one of a tibial tray implant or a femoral implant and a second provisional component configured to simulate a shape of at least one of a sleeve component, a cone component or a keel component of an implant.

1 .- 13 . (canceled) 
     
     
         14 . An assembly for a medical device comprising:
 a fastener having a thread portion and a head portion; and   a component with a bore, the bore comprising:
 a corresponding thread portion configured to couple with the thread portion of the fastener, 
 a pocket portion within the bore adjacent the corresponding thread portion, wherein the pocket is configured to be receive the fastener when the thread portion of the fastener is decoupled from the corresponding thread portion, and 
 a restriction disposed adjacent the pocket portion, wherein the restriction is configured with a diameter substantially equal to or smaller than that of the head portion so as to retain the fastener within the pocket when the thread portion of the fastener is decoupled from the corresponding thread portion. 
   
     
     
         15 . The assembly of  claim 14 , wherein the pocket portion has a diameter greater than that of the head portion. 
     
     
         16 . The assembly of  claim 14 , wherein one or more of the restriction and the head portion of the fastener have a chamfer surface configured to act as a ramp to facilitate insertion of the head portion past the restriction. 
     
     
         17 . A provisional orthopedic system for an arthroplasty procedure comprising:
 a provisional component configured to be disposed in a first recess beneath a resected surface of a bone, wherein the provisional component is configured to simulate a shape of at least one of a sleeve component, a cone component or a keel component of an implant;   a stem provisional assembly configured to be disposed in a second recess adjacent to and communicating with the first recess; and   a handle configured to engage the provisional component to the stem provisional assembly, wherein when engaged with the handle the provisional component and the stem provisional assembly are insertable into the first recess and the second recess of the bone, respectively.   
     
     
         18 . The system of  claim 17 , further comprising a second provisional component having a proximal surface and a distal surface opposing the proximal surface, one of the distal surface and the proximal surface configured to be disposed on the resected surface of the bone. 
     
     
         19 . The system of  claim 18 , wherein the stem provisional assembly is configured to be engageable in situ via a passageway through a fastener to position the second provisional component on the resected surface of the bone. 
     
     
         20 . The system of  claim 18 , wherein the provisional component, the second provisional component and the stem provisional assembly are removable from the bone together as the assembly with relative positions of each component maintained relative to one another upon removal from the bone. 
     
     
         21 . The system of  claim 18 , further comprising:
 a fastener configured to couple the provisional component, the second provisional component and the stem provisional assembly together as an assembly, wherein the fastener includes a passage to allow access to the stem provisional assembly from adjacent the second provisional component; and   a driver or plurality of drivers configured to at least one of:
 engage the fastener to thread the fastener into a threaded recess of the stem provisional assembly; and 
 pass through the passage in the fastener to engage the stem provisional assembly, wherein engagement between the driver and the stem provisional assembly rotates the stem provisional assembly in vivo and positions the first provisional component on the resected surface. 
   
     
     
         22 . The system of  claim 17 , wherein at least a portion of the handle is cannulated and is configured to receive a post that is coupled to the stem provisional assembly. 
     
     
         23 . The system of  claim 22 , further comprising a cannulated reamer configured to receive the post and a portion of the stem provisional assembly, wherein the cannulated reamer is configured to remove the bone to form the first recess. 
     
     
         24 . The system of  claim 17 , wherein the stem provisional assembly is constructed from one of a plurality of adaptors and one of a plurality of stem extensions, wherein the plurality of adaptors are configured to interchangeably couple with the plurality of stem extensions. 
     
     
         25 . The system of  claim 17 , further comprising a femoral component configured to couple with the provisional component, the femoral component having an elongated slot configured to receive a pin therein, wherein the elongated slot is configured to allow proximal-distal movement of the femoral component relative to the pin with adjustment of the stem provisional assembly in situ. 
     
     
         26 . The system of  claim 17 , wherein the handle is configured to couple with an offset broach, and wherein the offset broach has cutting surface along only a first side thereof and a second side thereof opposing the first side is configured to receive and interface with a reamer, wherein the offset broach is configured to offset the first recess relative to the second recess. 
     
     
         27 . The system of  claim 17 , wherein the handle has a cannulated shaft and includes a slap hammer that is configured to be moveable along the shaft of the handle and fixable thereto. 
     
     
         28 . The system of  claim 17 , further comprising a drill guide configured to be mountable to the stem provisional assembly and configured to pre-drill out the bone prior to broaching for the sleeve component or the cone component. 
     
     
         29 . The system of  claim 17 , further comprising a tibial cut guide assembly configured to guide a resection that forms the resected surface, wherein the tibial cut guide assembly has a boom arm and a body coupled to the boom arm by a collar, and wherein the collar includes an opening configured to allow for removal of the boom arm from the collar without a position of the body being changed relative to the bone. 
     
     
         30 . A reamer for removing bone during an orthopedic procedure comprising:
 a distal nose portion;   a proximal shaft portion; and   a cutting portion between the distal nose portion and the proximal shaft portion, the cutting portion having an enlarged diameter relative to the distal nose portion and the proximal shaft portion, the cutting portion comprising:
 a first tapered section adjacent the distal nose portion, wherein the first tapered section has an increasing diameter as measured distal-to-proximal along a longitudinal axis of the reamer; and 
 a second tapered section distal of the first tapered section and adjacent the proximal shaft portion, wherein the second tapered section has a back taper relative to the first tapered section such that the second tapered section has a decreasing diameter as measured distal-to-proximal along a longitudinal axis of the reamer. 
   
     
     
         31 . The reamer of  claim 30 , wherein the cutting portion includes a transition region between the first tapered section and the second tapered section, wherein the transition region comprises the section of the reamer having a largest diameter, and wherein the region can have a length along the longitudinal axis of the reamer of between 16 mm and 60 mm, inclusive. 
     
     
         32 . The reamer of  claim 30 , wherein the first tapered section has a length along the longitudinal axis of the reamer of between 11 mm and 24 mm and an angle of between 10 degrees and 40 degrees as measured from an outer surface of the first tapered section to the longitudinal axis. 
     
     
         33 . The reamer of  claim 32 , wherein the second tapered section has a length along the longitudinal axis of the reamer of between 20 mm and 60 mm and an angle of between 4 degrees and 16 degrees as measured from an outer surface of the second tapered section to the longitudinal axis. 
     
     
         34 . The reamer of  claim 30 , wherein the distal nose portion has a blunt tip and a length along the longitudinal axis of the reamer of between 15 mm and 70 mm as measured from the blunt tip to a beginning of the first tapered section.