Maintaining proper mechanics tha

Abstract

A prosthetic hip joint comprising: (a) a femoral component including a femoral head; and, (b) an acetabular component including an acetabular cup and an acetabular cup insert, the acetabular cup insert sized to receive the femoral head, where the femoral head is sized to have a spherical center that matches a spherical center of a patient's native femoral head, where the acetabular cup is sized to have a cavity with a spherical center that matches a spherical center of a cavity of a patient's native acetabulum and, where the femoral head center of the femoral component is concentric with the center of the cavity of the acetabular cup.

What is claimed is: 
     
         1 . An acetabular component of a prosthetic hip joint comprising:
 an acetabular cup adapted to be mounted to a native acetabulum;   a first acetabular cup insert to be mounted to the acetabular cup and repositionable with respect to the acetabular cup; and,   a second acetabular cup insert to be mounted to the first acetabular cup insert and repositionable with respect to the first acetabular cup insert, the first acetabular cup insert interposing the second acetabular cup insert and the acetabular cup.   
     
     
         2 . The acetabular component of  claim 1 , wherein:
 the acetabular cup includes a circumferential groove on an interior surface thereof;   the first acetabular cup includes a projection that is received within the circumferential groove; and,   the projection is repositionable with respect to the circumferential groove.   
     
     
         3 . The acetabular component of  claim 1 , wherein:
 the first acetabular cup insert includes a circumferential groove on an exterior surface thereof;   the acetabular cup includes a projection on an interior surface thereof; and,   the circumferential groove is repositionable with respect to the projection.   
     
     
         4 . The acetabular component of  claim 1 , wherein:
 the first acetabular cup insert includes a circumferential groove on an interior surface thereof;   the second acetabular cup includes a projection that is received within the circumferential groove; and,   the projection is repositionable with respect to the circumferential groove.   
     
     
         5 . The acetabular component of  claim 1 , wherein:
 the second acetabular cup insert includes a circumferential groove on an exterior surface thereof;   the first acetabular cup insert includes a projection on an interior surface thereof; and,   the circumferential groove is repositionable with respect to the projection.   
     
     
         6 . The acetabular component of  claim 1 , wherein:
 the first acetabular cup insert is slidably repositionable with respect to the acetabular cup within a first plane;   the first acetabular cup insert is slidably repositionable with respect to the second acetabular cup insert within a second plane; and,   the first plane is generally perpendicular with respect to the second plane.   
     
     
         7 . The acetabular component of  claim 1 , wherein:
 the first acetabular cup insert is rotationally repositionable with respect to the acetabular cup; and,   the first acetabular cup insert is slidably repositionable with respect to the second acetabular cup insert.   
     
     
         8 . The acetabular component of  claim 1 , wherein:
 the first acetabular cup insert is slidably repositionable with respect to the acetabular cup; and,   the first acetabular cup insert is rotationally repositionable with respect to the second acetabular cup insert.   
     
     
         9 . A method of assembling a mobile bearing acetabular component of a prosthetic hip joint, the method comprising:
 mounting a first acetabular cup insert to an acetabular cup, where mounting the first acetabular cup insert to the acetabular cup includes repositioning the first acetabular cup insert with respect to the acetabular cup without disengaging the first acetabular cup insert from the acetabular cup; and,   mounting a second acetabular cup insert to the first acetabular cup insert, where mounting the second acetabular cup insert to the first acetabular cup includes repositioning the second acetabular cup insert with respect to the first acetabular cup insert without disengaging the second acetabular cup insert from the first acetabular cup insert.   
     
     
         10 . The method of  claim 9 , wherein:
 repositioning the first acetabular cup insert with respect to the acetabular cup includes sliding the first acetabular cup insert against the acetabular cup; and,   repositioning the second acetabular cup insert with respect to the first acetabular cup insert includes sliding the second acetabular cup insert against the first acetabular cup insert.   
     
     
         11 . The method of  claim 9 , wherein:
 repositioning the first acetabular cup insert with respect to the acetabular cup includes rotating the first acetabular cup insert against the acetabular cup; and,   repositioning the second acetabular cup insert with respect to the first acetabular cup insert includes sliding the second acetabular cup insert against the first acetabular cup insert.   
     
     
         12 . The method of  claim 9 , wherein:
 repositioning the first acetabular cup insert with respect to the acetabular cup includes sliding the first acetabular cup insert against the acetabular cup; and,   repositioning the second acetabular cup insert with respect to the first acetabular cup insert includes rotating the second acetabular cup insert against the first acetabular cup insert.   
     
     
         13 . An acetabular component of a prosthetic hip joint comprising:
 an acetabular cup adapted to be mounted to a native acetabulum; and,   a first acetabular cup insert to be mounted to the acetabular cup and repositionable with respect to the acetabular cup, the first acetabular cup insert is concurrently repositionable deeper into an interior of the acetabular cup and repositionable outside of an outline of the acetabular cup.   
     
     
         14 . The acetabular component of  claim 13 , wherein:
 the acetabular cup includes a circumferential groove on an interior surface thereof;   the first acetabular cup includes a projection that is received within the circumferential groove; and,   the projection is repositionable with respect to the circumferential groove.   
     
     
         15 . The acetabular component of  claim 13 , wherein:
 the first acetabular cup insert includes a circumferential groove on an exterior surface thereof;   the acetabular cup includes a projection on an interior surface thereof; and,   the circumferential groove is repositionable with respect to the projection.   
     
     
         16 . A method of assembling a mobile bearing acetabular component of a prosthetic hip joint, the method comprising mounting a first acetabular cup insert to an acetabular cup, where mounting the first acetabular cup insert to the acetabular cup includes concurrently repositioning the first acetabular cup insert deeper into an interior of the acetabular cup and repositioning the first acetabular cup insert outside of an outline of the acetabular cup. 
     
     
         17 . The method of  claim 16 , wherein repositioning the first acetabular cup insert with respect to the acetabular cup includes sliding the first acetabular cup insert against the acetabular cup.