Self-centering, anti-seizing acetabular liner

Abstract

A liner adapted for insertion into an acetabular shell for use in hip arthroplasty. The liner includes a concave inner surface adapted to engage a femoral head. The liner also includes an outer surface adapted to engage the acetabular shell and a rim that extends between the inner surface and the outer surface. The outer surface includes a locking section extending from the rim, a composite-curved section extending from the locking section at a first transition point, and a dome section extending from the composite-curved section, wherein at the first transition point, the composite-curved section is tangential to the locking section.

1 . A liner adapted for insertion into an acetabular shell for use in hip arthroplasty, the liner comprising:
 a concave inner surface adapted to engage a femoral head;   an outer surface adapted to engage the acetabular shell; and   a rim extending between the inner surface and the outer surface, wherein the outer surface includes a locking section extending from the rim, a composite-curved section extending from the locking section at a first transition point, and a dome section extending from the composite-curved section, wherein at the first transition point, the composite-curved section is tangential to the locking section.   
     
     
         2 . The liner of  claim 1 , wherein the composite-curved section includes a radial portion and a tangential portion. 
     
     
         3 . The liner of  claim 2 , wherein the radial portion extends from the locking section at the first transition point. 
     
     
         4 . The liner of  claim 2 , wherein the tangential portion is a straight line. 
     
     
         5 . The liner of  claim 4 , wherein the tangential portion extends from the radial portion at a second transition point. 
     
     
         6 . The liner of  claim 5 , wherein the tangential portion is tangential to the radial portion at the second transition point. 
     
     
         7 . The liner of  claim 2 , wherein the dome section extends from the tangential portion at a third transition point. 
     
     
         8 . The liner of  claim 7 , wherein the tangential portion is tangential to the dome section at the third transition point. 
     
     
         9 . The liner of  claim 1 , wherein the dome section extends from the composite-curved section at a transition point and the composite-curved section is tangential to the dome section at the transition point. 
     
     
         10 - 15 . (canceled) 
     
     
         16 . A liner for use in arthroplasty, the liner comprising an inner surface and an outer surface, the inner surface being generally concave, the outer surface adapted to engage an acetabular shell, the outer surface including a locking section and a composite-curved section, wherein the composite-curved section extends tangentially from the locking section. 
     
     
         17 . The liner of  claim 16 , wherein the outer surface further includes a dome section, the dome section extending tangentially from the composite-curved section. 
     
     
         18 . The liner of  claim 17 , wherein the composite-curved section includes a radial portion and the dome section extends tangentially from the radial portion. 
     
     
         19 . The liner of  claim 16 , wherein the composite-curved section includes a radial portion having a radius and a tangential portion.
 The liner of  claim 16  further comprising a rim between the inner and outer surfaces.