Variable prosthesis

Abstract

The present teachings are directed to a shoulder prosthesis having an adjustable radial offset and/or angular inclination provided by relative rotation of an adapter interdisposed between a stem and a head. In one example, a prosthesis has a stem having a first longitudinal axis. The prosthesis can also include an adaptor including a first taper. The first taper can have a first taper axis. The prosthesis can include a head supported by the adaptor. The head can be selectively oriented and then coupled to the first taper and the combination can be selectively orientated and the coupled to the stem.

1 . (canceled) 
     
     
         2 . A method of implanting a prosthesis system in a patient, comprising:
 determining an anteversion angle of a natural bone relative to a pelvis of the patient;   selecting an adapter having an adapter center axis and an adapter offset connection, wherein the adapter offset connection has an adapter connection center axis;   selecting a head having a head center axis and an offset head connection, wherein the offset head connection has a head connection center axis;   selecting a distance offset between the adapter connection center axis and the head connection center axis based on the determined anteversion angle; and   rotating the selected adapter relative to the selected head to achieve the selected distance offset between the adapter connection center axis and the head connection center axis.   
     
     
         3 . The method of  claim 2 , wherein selecting the distance offset includes selecting a radial distance offset between the adapter connection center axis and the head connection center axis. 
     
     
         4 . The method of  claim 2 , wherein the prosthesis comprises a femoral prosthesis, the natural bone comprises a natural femur, and the selected head comprises a selected femoral head. 
     
     
         5 . The method of  claim 2 , wherein the adapter offset connection includes a female locking taper. 
     
     
         6 . The method of  claim 4 , further comprising:
 providing the adapter connection center axis substantially through a center of the adapter offset connection.   
     
     
         7 . The method of  claim 2 , wherein rotating the selected adapter relative to the selected head to achieve the selected distance offset between the adapter connection center axis and the head connection center axis includes forming the selected distance offset at or between a maximum offset and a substantially zero offset. 
     
     
         8 . The method of  claim 7 , wherein selecting the head includes selecting a head member having a curved articulating surface configured to articulate relative to the pelvis when replacing at least a portion of the natural bone. 
     
     
         9 . The method of  claim 8 , wherein selecting the head further includes selecting the head member to include a substantially planar surface opposed to the curved articulating surface and configured to interconnect with a stem, wherein the stem is configured to be implanted into the natural bone. 
     
     
         10 . The method of  claim 7 , wherein the maximum offset is defined as positioning the adapter connection center axis away from the head center axis a maximum distance. 
     
     
         11 . The method of  claim 7 , wherein the substantially zero offset is defined as generally aligning the adapter connection center axis and the head center axis. 
     
     
         12 . A method of implanting a femoral prosthesis system in a patient, comprising:
 selecting a femoral head having a head center axis, an offset head connection, and a curved articulating surface, wherein the offset head connection has a head connection center axis that is displaced a distance from the head center axis, wherein the curved articulating surface is configured to articulate within at least one of a an acetabular prosthesis or an acetabulum in a pelvis of the patient,   selecting an adapter having an adapter center axis and an adapter offset connection, wherein the adapter offset connection has an adapter connection center axis that is displaced a distance from the adapter center axis;   selecting a distance offset between the adapter connection center axis and the head connection center axis based on a determined anteversion angle of a femur relative to the pelvis of the patient; and   rotating the selected adapter relative to the selected femoral head to achieve the selected distance offset between the adapter connection center axis and the head connection center axis.   
     
     
         13 . The method of  claim 12 , wherein the selected distance offset is a radial distance offset between the adapter connection center axis and the head connection center axis. 
     
     
         14 . The method of  claim 12 , further comprising measuring a position of the femur relative to the acetabulum in the pelvis to determine the anteversion angle. 
     
     
         15 . The method of  claim 14 , further comprising:
 obtaining access to a hip joint between the femur and the pelvis;   resecting a natural femoral head of the femur; and   implanting the selected femoral head to replace the resected femoral head.   
     
     
         16 . The method of  claim 15 , wherein the selected distance offset is at or between a maximum offset and a minimum offset;
 wherein the maximum offset is a maximum displacement of the adapter connection center axis and the head center axis; and   wherein the minimum offset is a substantial alignment of the adapter connection center axis and the head center axis.   
     
     
         17 . The method of  claim 16 , further comprising:
 implanting a femoral stem into the femur;   connecting the selected adapter to the femoral stem; and   connecting the selected femoral head to the selected adapter.   
     
     
         18 . The method of  claim 17 , wherein connecting the selected femoral head to the selected adapter includes:
 fixing the selected femoral head to the selected adapter, wherein fixing the selected femoral head to the selected adapter occurs after rotating the selected femoral head to the selected adapter to achieve the selected distance offset.   
     
     
         19 . A method of implanting a prosthesis system in a patient, comprising:
 selecting an adapter having an adapter center axis and an adapter offset connection, wherein the adapter offset connection has an adapter connection center axis;   selecting a femoral head having a head center axis and an offset head connection, wherein the offset head connection has a head connection center axis;   selecting a distance offset between the adapter connection center axis and the head connection center axis based on an anteversion angle of a natural femur relative to a pelvis of the patient; and   rotating the selected adapter relative to the selected femoral head to achieve the selected distance offset between the adapter connection center axis and the head connection center axis.   
     
     
         20 . The method of  claim 19 , wherein selecting the distance offset includes selecting a radial distance offset between the adapter connection center axis and the head connection center axis. 
     
     
         21 . The method of  claim 19 , further comprising:
 providing the adapter connection center axis substantially through a center of the adapter offset connection.