Composite joint arthroplasty systems and methods

Abstract

A prosthesis may have an articulating component formed via casting and a 3D printed bone anchoring component with a joint-facing side and a bone-facing side. The bone-facing side may have a bone engagement surface with a porous structure with pores selected to facilitate in-growth of the bone into the pores. The bone facing side may further have a surface layer of Titanium Dioxide nanotubes. The joint-facing side may be secured to the articulating component by melting Titanium nanoparticles at a temperature below the melting temperatures of the major constituents of the articulating component and/or the bone anchoring component, such as Cobalt, Chromium, and/or Titanium, so as to avoid significantly modifying the crystalline structures of the articulating component and/or the bone anchoring component. The melting temperature of the Titanium nanoparticles may be about 500° C.

What is claimed is: 
     
         1 . A prosthesis for replacing an articular surface on bone, the prosthesis comprising:
 an articulating component formed via casting, the articulating component comprising:
 an articulating component joint-facing side comprising an articular surface; and 
 an articulating component bone-facing side comprising a bone-facing shape; and 
   a bone anchoring component having a 3D printed structure, the bone anchoring component comprising:
 a bone anchoring component joint-facing side comprising a joint-facing shape that is complementary to the bone-facing shape, wherein the bone anchoring component joint-facing side is secured to the articulating component bone-facing side; and 
 a bone anchoring component bone-facing side comprising a bone engagement surface having a porous structure with pores selected to facilitate in-growth of the bone into the pores. 
   
     
     
         2 . The prosthesis of  claim 1 , wherein:
 the bone anchoring component is formed of DMLS Titanium; and   the 3D printed structure comprises a porous structure.   
     
     
         3 . The prosthesis of  claim 2 , wherein the porous structure has a lower porosity on the bone anchoring component joint-facing side than on the bone anchoring component bone-facing side. 
     
     
         4 . The prosthesis of  claim 1 , wherein the bone anchoring component joint-facing side comprises a surface layer of Titanium Dioxide nanotubes formed via anodization. 
     
     
         5 . The prosthesis of  claim 4 , wherein the Titanium Dioxide nanotubes comprise an anatase structure. 
     
     
         6 . The prosthesis of  claim 1 , wherein:
 the articulating component is formed of an alloy of Cobalt Chromium comprising one or more crystalline structures established by a casting process used to form the articulating component; and   the bone anchoring component joint-facing side is secured to the articulating component bone-facing side via a bonding process occurring at a bonding temperature far below melting temperatures of Cobalt and Chromium, such the crystalline structures are not significantly modified by the bonding process.   
     
     
         7 . The prosthesis of  claim 6 , wherein:
 the bonding process occurs at a bonding temperature, at the bone anchoring component joint-facing side and the articulating component bone-facing side, of about 500° C.; and   the prosthesis further comprises a bonding zone, between the bone anchoring component joint-facing side and the articulating component bone-facing side, formed of melted and re-solidified Titanium nanoparticles.   
     
     
         8 . The prosthesis of  claim 6 , wherein:
 the bonding process occurs via laser welding a perimeter and/or seams of the bone anchoring component joint-facing side and the articulating component bone-facing side together; and   the prosthesis further comprises a bonding zone at the perimeter and/or seams, formed of melted and re-solidified Titanium, Cobalt, and/or Chromium nanoparticles.   
     
     
         9 . A method for manufacturing a prosthesis for replacing an articular surface on a bone, the method comprising:
 casting an articulating component comprising:
 an articulating component joint-facing side comprising an articular surface; and 
 an articulating component bone-facing side comprising a bone-facing shape; and 
   3D printing a bone anchoring component comprising:
 a bone anchoring component joint-facing side comprising a joint-facing shape that is complementary to the bone-facing shape; and 
 a bone anchoring component bone-facing side comprising a bone engagement surface having a porous structure with pores selected to facilitate in-growth of the bone into the pores; and 
   securing the bone anchoring component joint-facing side to the articulating component bone-facing side.   
     
     
         10 . The method of  claim 9 , wherein 3D printing the bone anchoring component comprises direct metal laser sintering Titanium to form a porous structure. 
     
     
         11 . The method of  claim 9 , wherein forming the porous structure comprises providing lower porosity on the bone anchoring component joint-facing side than on the bone anchoring component bone-facing side. 
     
     
         12 . The method of  claim 9 , further comprising anodizing the bone anchoring component to form a surface layer of Titanium Dioxide nanotubes on the bone anchoring component joint-facing side. 
     
     
         13 . The method of  claim 12 , further comprising heating the bone anchoring component to a temperature sufficient to change at least a portion of the surface layer of Titanium Dioxide nanotubes to anatase. 
     
     
         14 . The method of  claim 9 , wherein:
 casting articulating component comprises casting the articulating component from an alloy of Cobalt Chromium to establish one or more crystalline structures of the alloy of Cobalt Chromium; and   securing the bone anchoring component joint-facing side to the articulating component bone-facing side comprises heating at least part of the bone anchoring component and at least part of the articulating component to a bonding temperature far below melting temperatures of Cobalt and Chromium, so as to avoid significantly modifying the crystalline structures.   
     
     
         15 . The method of  claim 14 , wherein heating at least part of the bone anchoring component and part of the articulating component to the bonding temperature comprises laser welding a perimeter and/or seams of the bone anchoring component joint-facing side and the articulating component bone-facing side together. 
     
     
         16 . The method of  claim 14 , further comprising, prior to heating at least part of the bone anchoring component and part of the articulating component to the bonding temperature, applying a paste to one or both of the bone anchoring component joint-facing side and the articulating component bone-facing side, the paste comprising Titanium nanoparticles and a gelatin and/or a glycerin. 
     
     
         17 . The method of  claim 16 , further comprising, after applying the paste on one or both of the bone anchoring component joint-facing side and the articulating component bone-facing side, and prior to heating at least the bone anchoring component joint-facing side and the articulating component bone-facing side to the bonding temperature:
 assembling the articulating component and the bone anchoring component such that the paste is sandwiched between the bone anchoring component joint-facing side and the articulating component bone-facing side; and   pressing the bone anchoring component joint-facing side and the articulating component bone-facing side together.   
     
     
         18 . The method of  claim 17 , wherein heating at least the bone anchoring component joint-facing side and the articulating component bone-facing side to the bonding temperature comprises, with the bone anchoring component joint-facing side and the articulating component bone-facing side pressed together, heating at least the bone anchoring component joint-facing side and the articulating component bone-facing side to about 500° C. to debind the gelatin and/or glycerin and melt the Titanium nanoparticles. 
     
     
         19 . A method for manufacturing a prosthesis for replacing an articular surface on a bone, the method comprising:
 casting metals comprising at least Cobalt and Chromium to form an articulating component comprising:
 an articulating component joint-facing side comprising an articular surface; and 
 an articulating component bone-facing side comprising a bone-facing shape; and 
   direct metal laser sintering Titanium to form a bone anchoring component comprising:
 a bone anchoring component joint-facing side comprising a joint-facing shape that is complementary to the bone-facing shape; and 
 a bone anchoring component bone-facing side comprising a bone engagement surface having a porous structure with pores selected to facilitate in-growth of the bone into the pores; 
   applying a paste containing Titanium nanoparticles to at least one of the bone anchoring component joint-facing side and the articulating component bone-facing side;   assembling the articulating component and the bone anchoring component such that the paste is sandwiched between the bone anchoring component joint-facing side and the articulating component bone-facing side; and   heating the paste to a bonding temperature sufficient to commence melting of the Titanium nanoparticles to secure the bone anchoring component joint-facing side to the articulating component bone-facing side.   
     
     
         20 . The method of  claim 19 , further comprising:
 anodizing the bone anchoring component to form a surface layer of Titanium Dioxide nanotubes on the bone anchoring component joint-facing side; and   after assembling the articulating component and the bone anchoring component, pressing the articulating component and the bone anchoring component together;   wherein:
 the paste further comprises a gelatin and/or a glycerin; and 
 heating the paste to the bonding temperature comprises, with the articulating component and the bone anchoring component pressed together, heating at least the bone anchoring component joint-facing side and the articulating component to about 500° C. to debind the gelatin and/or glycerin, melt the Titanium nanoparticles, and changing at least a portion of the surface layer of Titanium Dioxide nanotubes to anatase.