Ceramic-Ceramic Articulation Surface Implants

Abstract

A prosthesis for articulation (e.g., hip or joint prosthesis) is provided, which includes a pair of articulation components respectively defining a pair of articulation surfaces movably engageable with each other. In some embodiments, each of the articulation surfaces is formed from a biocompatible ceramic (e.g., doped silicon nitride ceramic) having a flexural strength greater than about 700 Mega-Pascal (MPa) and a toughness greater than about 7 Mega-Pascal root meter (MPam 0.5 ).

1 . A prosthesis for articulation, comprising:
 a first component having a first ceramic articulation surface; and   a second component having a second ceramic articulation surface for articulation with the first ceramic articulation surface,   wherein at least one of the first ceramic articulation surface and the second ceramic articulation surface comprises biocompatible doped silicon nitride ceramic having a flexural strength greater than about 700 Mega-Pascal (MPa) and a toughness greater than about 7 Mega-Pascal root meter (Mpam 0.5 ).   
     
     
         2 . The prosthesis of  claim 1  wherein the biocompatible doped silicon nitride ceramic has a toughness greater than about 9 Mega-Pascal root meter (Mpam 0.5 ). 
     
     
         3 . The prosthesis of  claim 1  wherein each of the first ceramic articulation surface and the second ceramic articulation surface comprises a biocompatible ceramic having a flexural strength greater than about 700 Mega-Pascal (MPa) and a toughness greater than about 7 Mega-Pascal root meter (Mpam 0.5 ). 
     
     
         4 . The prosthesis of  claim 1 , wherein at least a portion of the first ceramic articulation surface is generally concave. 
     
     
         5 . The prosthesis of  claim 4 , wherein at least a portion of the second ceramic articulation surface is generally convex. 
     
     
         6 . The prosthesis of  claim 1 , wherein the biocompatible doped silicon nitride ceramic comprises aluminum oxide. 
     
     
         7 . The prosthesis of  claim 1 , wherein the biocompatible doped silicon nitride ceramic comprises yttria. 
     
     
         8 . The prosthesis of  claim 1 , wherein the biocompatible doped silicon nitride ceramic comprises aluminum oxide and yttria. 
     
     
         9 . The prosthesis of  claim 1  wherein the biocompatible doped silicon nitride ceramic does not include strontium oxide. 
     
     
         10 . The prosthesis of  claim 1  wherein each of the first component and the second component consists essentially of the doped silicon nitride ceramic. 
     
     
         11 . The prosthesis of  claim 1 , wherein the prosthesis comprises a hip joint prosthesis. 
     
     
         12 . The prosthesis of  claim 1 , wherein the prosthesis comprises a knee joint prosthesis. 
     
     
         13 . The prosthesis of  claim 1 , wherein the prosthesis comprises a shoulder joint prosthesis. 
     
     
         14 . A prosthesis for articulation, comprising:
 a first component having a first ceramic articulation surface; and   a second component having a second ceramic articulation surface for articulation with the first ceramic articulation surface,   wherein at least one of the first ceramic articulation surface and the second ceramic articulation surface comprises biocompatible doped silicon nitride ceramic.   
     
     
         15 . The prosthesis of  claim 14 , wherein the biocompatible doped silicon nitride ceramic comprises aluminum oxide. 
     
     
         16 . The prosthesis of  claim 14 , wherein the biocompatible doped silicon nitride ceramic comprises yttria. 
     
     
         17 . The prosthesis of  claim 14 , wherein the biocompatible doped silicon nitride ceramic comprises aluminum oxide and yttria. 
     
     
         18 . The prosthesis of  claim 14  wherein the biocompatible doped silicon nitride ceramic does not include strontium oxide. 
     
     
         19 . The prosthesis of  claim 14  wherein each of the first component and the second component consists essentially of the doped silicon nitride ceramic. 
     
     
         20 . The prosthesis of  claim 14 , wherein at least a portion of the first ceramic articulation surface is generally concave and wherein at least a portion of the second ceramic articulation surface is generally convex.