Porous surface layers with increased surface roughness and implants incorporating the same

Abstract

Systems and methods for providing tissue-interfacing surface layers with increased roughness can be attained by providing a metallic powder to a machined or previously machined tissue-interfacing surface of a porous foam structure. The metallic powder can have sizes and characteristics such that the porous structure can have an increased roughness at the tissue-interfacing machined surface while inhibiting the occlusion of the open pores in the porous metallic foam structure.

1 .- 9 . (canceled) 
     
     
         10 . A method for increasing the surface roughness of a porous structure, comprising:
 bonding a plurality of powder particles to at least a portion of a machined tissue-interfacing outer surface of a machined porous structure having a desired shape,   wherein at least a portion of the plurality of powder particles has sufficient dimensions to increase the roughness of the machined tissue-interfacing outer surface of the machined porous structure without occluding a plurality of pores of the porous structure.   
     
     
         11 . The method of  claim 10  wherein at least a portion of the plurality of powder particles comprises asymmetric powder particles. 
     
     
         12 . The method of  claim 10  wherein the size of at least a portion of the plurality of powder particles is from about 75 micrometers to about 106 micrometers. 
     
     
         13 . The method of  claim 10  wherein said bonding step comprises
 applying a binder to the machined tissue-facing outer surface of the machined porous structure; 
 subsequently applying said plurality of powder particles by a means selected from the group consisting of dipping, spraying, sprinkling, and any combination thereof; and 
 sintering said porous structure to bond a portion of said plurality of powder to at least a portion of the machined tissue-facing outer surface of the porous structure. 
 
     
     
         14 . The method of  claim 10  wherein the porous structure comprises a metal foam structure. 
     
     
         15 . The method of  claim 10  further comprising the step of attaching the porous structure to a substrate. 
     
     
         16 . The method of  claim 15 , wherein the substrate comprises a metallic foam-coated implant selected from the group consisting of a knee implant, hip implant, a shoulder implant, a spinal implant, a tibial tray, an acetabular shell, a femoral stem, and a stem collar. 
     
     
         17 . The method of  claim 10  further comprising the step of applying one or more additional layers of said plurality of powder particles to one or more non-tissue-interfacing surfaces of the porous structure. 
     
     
         18 . The method of  claim 17 , wherein the step of applying one or more additional layers occurs after the step of bonding a powder to a machined tissue-interfacing outer surface of the machined porous structure. 
     
     
         19 . The method of  claim 17 , wherein at least one layer of the one or more additional layers comprises a plurality of fine spherical particles, wherein at least a portion of said particles has a size of less than about 45 micrometers. 
     
     
         21 . A porous structure with increased surface roughness comprising:
 a porous structure having a machined tissue-interfacing outer surface;   a plurality of powder particles bonded to at least a portion of said machined tissue-interfacing outer surface of the porous structure,   wherein at least a portion of the plurality of powder particles has sufficient dimensions to increase the roughness of the machined tissue-interfacing outer surface of the machined porous structure without occluding a plurality of pores of the porous structure.   
     
     
         22 . The structure of  claim 21  wherein at least a portion of the plurality of powder particles comprises asymmetric powder particles. 
     
     
         23 . The structure of  claim 21  wherein the size of at least a portion of the plurality of powder particles is from about 75 micrometers to about 106 micrometers. 
     
     
         24 . The structure of  claim 21  wherein the porous structure comprises a metal foam structure. 
     
     
         25 . The structure of  claim 21  further comprising a substrate attached a portion of said porous structure. 
     
     
         26 . The structure of  claim 25 , wherein the substrate is a metallic foam-coated implant selected from the group consisting of a knee implant, hip implant, a shoulder implant, a spinal implant, a tibial tray, an acetabular shell, a femoral stem, and a stem collar. 
     
     
         27 . The structure of  claim 21  further comprising one or more additional layers of said plurality of powder particles bonded to one or more non-tissue-interfacing surfaces of the porous structure. 
     
     
         28 . The structure of  claim 21 , wherein at least one layer of the one or more additional layers comprises a plurality of fine spherical particles, wherein at least a portion of said particles has a size of less than about 45 micrometers. 
     
     
         29 . The structure of  claim 21 , wherein the size of at least a portion of the plurality of powder particles is between about 10% and 30% of the pore size of the porous structure. 
     
     
         30 . The structure of  claim 21 , wherein the size of at least a portion of the plurality of powder particles is between about 30% and 70% of the pore size of the porous structure. 
     
     
         31 . The structure of  claim 21 , wherein the size of at least a portion of the plurality of powder particles is between about 40% and 60% of the pore size of the porous structure. 
     
     
         32 . The structure of  claim 21 , wherein the plurality of powder particles comprises material selected from a group consisting of titanium, titanium hydride, titanium dehydride, titanium alloy, cobalt-chrome alloy, tantalum, zirconium, zirconium alloy, and any combination thereof.