Modular resurfacing prosthetic

Abstract

Femoral head modular resurfacing systems are described. The systems primarily include a head component and a stem component. The configuration of the head component and stem components allow for minimum invasiveness into the femur head region, thus conserving greater amounts of bone tissue than would be possible with conventional hip replacement systems. The systems also provide for various angles and offsets to be achieved between the systems and the femur head. The systems are useful in partial hip replacement procedures, as well as total hip replacement procedures, in which case an optional acetabular component would also be employed.

What is claimed is:  
     
         1 . A partial hip prosthesis for replacing a portion of a natural articulating surface of a hip, the prosthetic comprising: 
 an acetabular implant configured to replace only a portion of the acetabulum articulating surface, the acetabular implant having a partial concave articulating surface, said partial concave articulating surface being configured to be positioned congruent with an unmodified portion of the natural articulating surface.    
     
     
         2 . The partial hip prosthetic according to  claim 1  wherein the acetabular implant comprises a first generally flat coupling surface.  
     
     
         3 . The partial hip prosthetic according to  claim 2  further comprising a second generally flat coupling surface disposed perpendicular to the first generally flat coupling surface.  
     
     
         4 . The partial hip prosthetic according to  claim 1  further comprising a femoral implant configured to interface with the partially concave articulating surface and the unmodified portion of the natural articulating surface.  
     
     
         5 . The partial hip prosthetic according to  claim 4  wherein the femoral component defines only a portion of a convex articulating surface configured to be positioned congruent with an unmodified portion of a natural head articulating surface.  
     
     
         6 . The partial hip prosthetic according to  claim 5  wherein the femoral component defines a cup having a convex interface surface.  
     
     
         7 . The partial hip prosthetic according to  claim 6  wherein the convex interface surface defines a cup axis and wherein the femoral component comprises a coupling member defined at a predetermined distance from the cup axis.  
     
     
         8 . The partial hip prosthetic according to  claim 7  wherein the tapered member is a tapered shaft.  
     
     
         9 . The partial hip prosthetic according to  claim 1  wherein the partial concave articulating surface is positioned with respect to the unmodified portion of the natural articulating surface so as t allow articulation of the joint.  
     
     
         10 . A partial hip prosthetic for replacing a portion of a natural articulating surface of a hip, the prosthetic comprising: 
 a femoral implant configured to replace only a portion of a femoral head articulating surface, the femoral implant having a partial convex articulating surface, said partial convex articulating surface being configured to be positioned congruent with an unmodified portion of the natural femoral head articulating surface, the femoral implant further comprising a concave interface surface defining a cup axis and a coupling mechanism defined at a predetermined distance from the cup axis.    
     
     
         11 . The partial hip prosthetic according to  claim 10  further comprising an acetabular implant configured to place only a portion of an acetabular articulating surface, the acetabular implant having a partial concave articulating surface, said partial concave articulating surface configured to be positioned congruent with an unmodified portion of the natural articulating surface.  
     
     
         12 . The partial hip prosthetic according to  claim 11  wherein the acetabular implant comprises a first generally flat coupling surface.  
     
     
         13 . The partial hip prosthetic according to  claim 12  further comprising a second generally flat coupling surface deposed perpendicular to the first generally flat coupling surface.  
     
     
         14 . The partial hip prosthetic according to  claim 10  further comprising a connection member which extends outward from the concave interface surface, said connection member defining a structure which cooperates with a complimentary connection member on a stem component.  
     
     
         15 . The partial hip prosthesis according to  claim 14  wherein the complimentary connection member is a Morse taper.  
     
     
         16 . The partial hip prosthesis according to  claim 12  wherein said first surface defines at least one coupling member which is configured to be implanted into a partially resected acetabulum.  
     
     
         17 . The partial hip prosthesis according to  claim 10  wherein the partial convex articulating surface is positioned with respect to the unmodified portion of the natural articulating surface so as to allow articulation of the joint.  
     
     
         18 . A method for implanting a joint prosthesis into a joint having a first area of defective articulating tissue and a secondary of non-defective articulating tissue comprising: 
 minimally distracting a head portion from a socket portion of the joint;    removing only defective tissue from the first area of the joint articulating surface; and    implanting a prosthetic device to replace the first area, the prosthetic having an articulating surface congruent with the second area.    
     
     
         19 . The method according to  claim 18  wherein removing defective tissue is removing defective tissue from an acetabulum.  
     
     
         20 . The method according to  claim 18  wherein defective tissue is removing defective tissue from a femoral head.  
     
     
         21 . The method according to  claim 18  wherein the first and second areas are congruent surfaces.  
     
     
         22 . The method according to  claim 18  wherein the first and second areas are defined on the socket portion of the joint.