Tibial augments for use with knee joint prostheses, method of implanting the tibial augment, and associated tools

Abstract

A tibial augment for use with a knee joint prosthesis, composed of annular members of different stock sizes, each size being configured to fit within a cavity formed in a human tibia. The augment may include a stepped distal surface. A provisional (temporary) tibial augment used to ensure a proper fit for the permanent augment is also provided. The provisional may include grooves configured to cooperate with a set of ribs on a tong-like holder used for removing the provisional from the cavity. A pusher for use implanting the tibial augment is also provided. In addition, a system for creating a cavity in a human tibia is also described. The system preferably includes a guide with a slot therein and a set of osteotomes that are inserted to within different portions of the slot. Methods for using the tools and/or implanting the prosthetic devices discussed above are also described.

1 . (canceled) 
     
     
         2 . A tibial implant system, comprising:
 a tibial component of a knee joint prosthesis, the tibial component positionable in a proximal portion of a human tibia and comprising a tibial plate and a tibial stem component, the tibial stem component contacting the tibial plate and extending from the tibial plate to a distal-most end of the tibial stem component;   a first shaped annular member constructed separately from the tibial plate and the tibial stem component, the first shaped annular member connected to the tibial stem component for augmenting the tibial component in the proximal portion of the human tibia; and   a second shaped annular member constructed separately from the tibial plate and the tibial stem component, the second shaped annular member connected to the tibial stem component for augmenting the tibial component in the proximal portion of the human tibia;   wherein the first shaped annular member and the second shaped annular member are of different sizes and each have a height extending between a proximal end and a distal end of the respective shaped annular member, wherein said first shaped annular member and said second shaped annular member each consist essentially of a porous metal material for facilitating bony ingrowth into and throughout said first shaped annular member and said second shaped annular member for restoring bone in the proximal portion of the human tibia when the first shaped annular member and the second shaped annular member are implanted in the proximal portion of the human tibia, and wherein said first shaped annular member and said second shaped annular member each provide a passageway extending entirely through the respective shaped annular member, and   wherein the first shaped annular member and the second shaped annular member being connected to the tibial stem component includes the first shaped annular member and the second shaped annular member being in a stacked arrangement in a proximal-distal direction with the tibial stem component extending through the passageways of the respective shaped annular members such that the distal-most end of the tibial stem component protrudes from the stacked arrangement of the first shaped annular member and the second shaped annular member to allow the distal-most end of the tibial stem component to contact bone in the human tibia upon implantation in the human tibia.   
     
     
         3 . The tibial implant system of  claim 2 , wherein the first shaped annular member and the second shaped annular member each include a tapered outer surface that tapers in a direction toward the distal end of the respective shaped annular member. 
     
     
         4 . The tibial implant system of  claim 2 , wherein at least one of said first shaped annular member and said second shaped annular member includes a tantalum-based porous material. 
     
     
         5 . The tibial implant system of  claim 2 , wherein a majority of at least one of the first shaped annular member and the second shaped annular member is of a uniform wall thickness. 
     
     
         6 . The tibial implant system of  claim 2 , wherein said stacked arrangement creates extensions of outer lateral, medial, posterior, and anterior surfaces of said first shaped annular member and said second shaped annular member. 
     
     
         7 . The tibial implant system of  claim 2 , wherein the height of at least one of said first shaped annular member and said second shaped annular member is at least 15 mm but no more than 30 mm extending between the proximal end and the distal end of the respective annular member. 
     
     
         8 . A tibial implant system, comprising:
 a tibial component of a knee joint prosthesis, the tibial component positionable in a proximal portion of a human tibia and comprising a tibial plate and a tibial stem component, the tibial stem component contacting the tibial plate and extending from the tibial plate to a distal-most end of the tibial stem component;   a first shaped annular member constructed separately from the tibial plate and the tibial stem component, the first shaped annular member connected to the tibial stem component for augmenting the tibial component in the proximal portion of the human tibia; and   a second shaped annular member constructed separately from the tibial plate and the tibial stem component, the second shaped annular member connected to the tibial stem component for augmenting the tibial component in the proximal portion of the human tibia;   wherein the first shaped annular member and the second shaped annular member each have a height extending between a proximal end and a distal end of the respective shaped annular member, said first shaped annular member and said second shaped annular member each being formed with a porous metal material for facilitating bony ingrowth into said first shaped annular member and said second shaped annular member, said first shaped annular member and said second shaped annular member each providing a passageway that extends entirely through the respective shaped annular member, and   wherein the first shaped annular member and the second shaped annular member being connected to the tibial stem component includes the first shaped annular member and the second shaped annular member being in a stacked arrangement in a proximal-distal direction with the tibial stem component extending through the passageways of the respective shaped annular members.   
     
     
         9 . The tibial implant system of  claim 8 , wherein the distal-most end of the tibial stem component protrudes from the stacked arrangement of the first shaped annular member and the second shaped annular member so that the distal-most end of the tibial stem component can contact bone in the human tibia upon implantation in the human tibia. 
     
     
         10 . The tibial implant system of  claim 8 , wherein at least one of said first shaped annular member and said second shaped annular member includes a stepped distal surface. 
     
     
         11 . The tibial implant system of  claim 8 , wherein at least one of said first shaped annular member and said second shaped annular member includes a tantalum-based porous material. 
     
     
         12 . The tibial implant system of  claim 8 , wherein said first shaped annular member and said second shaped annular member are of different sizes. 
     
     
         13 . The tibial implant system of  claim 8 , wherein a majority of at least one of the first shaped annular member and the second shaped annular member is of a uniform wall thickness. 
     
     
         14 . The tibial implant system of  claim 8 , wherein at least one of the first shaped annular member and the second shaped annular member has a medial-lateral width of said proximal end of the respective shaped annular member that is greater than a medial-lateral width of said distal end of the respective shaped annular member. 
     
     
         15 . The tibial implant system of  claim 8 , wherein at least one of the first shaped annular member and the second shaped annular member has an anterior-posterior width of said proximal end of the respective shaped annular member that is greater than an anterior-posterior width of said distal end of the respective shaped annular member. 
     
     
         16 . The tibial implant system of  claim 8 , wherein said respective passageway of at least one of said first shaped annular member and said second shaped annular member is tapered. 
     
     
         17 . The tibial implant system of  claim 8 , wherein said stacked arrangement creates extensions of outer lateral, medial, posterior, and anterior surfaces of said first shaped annular member and said second shaped annular member. 
     
     
         18 . The tibial implant system of  claim 8 , wherein the height of at least one of said first shaped annular member and said second shaped annular member is at least 15 mm but no more than 30 mm extending between the proximal end and the distal end of the respective annular member. 
     
     
         19 . A tibial implant system, comprising:
 a tibial component of a knee joint prosthesis, the tibial component positionable in a proximal portion of a human tibia and comprising a tibial plate and a tibial stem component, the tibial stem component contacting the tibial plate and extending from the tibial plate to a distal-most end of the tibial stem component;   a first shaped annular member constructed separately from the tibial plate and the tibial stem component, the first shaped annular member connected to the tibial stem component for augmenting the tibial component in the proximal portion of the human tibia; and   a second shaped annular member constructed separately from the tibial plate and the tibial stem component, the second shaped annular member connected to the tibial stem component for augmenting the tibial component in the proximal portion of the human tibia;   wherein the first shaped annular member and the second shaped annular member each have a height extending between a proximal end and a distal end of the respective shaped annular member, wherein the first shaped annular member and the second shaped annular member each include a tapered outer surface that tapers in a direction toward the distal end of the respective shaped annular member, said first shaped annular member and said second shaped annular member each being formed with a porous metal material for facilitating bony ingrowth into said first shaped annular member and said second shaped annular member, said first shaped annular member and said second shaped annular member each providing a passageway that extends entirely through the respective shaped annular member, and   wherein the first shaped annular member and the second shaped annular member being connected to the tibial stem component includes the first shaped annular member and the second shaped annular member being in a stacked arrangement in a proximal-distal direction with the tibial stem component extending through the passageways of the respective shaped annular members.   
     
     
         20 . The tibial implant system of  claim 19 , wherein the distal-most end of the tibial stem component protrudes from the stacked arrangement of the first shaped annular member and the second shaped annular member so that the distal-most end of the tibial stem component can contact bone in the human tibia upon implantation in the human tibia. 
     
     
         21 . The tibial implant system of  claim 19 , wherein, in the proximal-distal direction, the tapered outer surfaces of the respective shaped annular members occur where the tibial stem component extends through the passageways of the respective shaped annular members. 
     
     
         22 . The tibial implant system of  claim 19 , wherein the height of at least one of said first shaped annular member and said second shaped annular member is at least 15 mm but no more than 30 mm extending between the proximal end and the distal end of the respective annular member.