Composite orthopedic implant having a low friction material substrate with primary frictional features and secondary frictional features

Abstract

An orthopedic implant comprising a substrate material adapted to provide the orthopedic implant. The implant has a primary friction area located on or integral with the substrate material. The primary friction area defining an engagement surface having a primary frictional feature. A secondary friction area is located on or integral with the engagement surface and defining a second frictional feature. The primary friction area and the secondary friction area defining a friction interface zone between the orthopedic implant and at least one bone. The secondary friction area increases a friction of the engagement surface and modulus of elasticity to enhance the frictional engagement between the engagement surface and the at least one bone.

What is claimed is: 
     
         1 . An orthopedic implant comprising:
 a substrate material adapted to provide the orthopedic implant;   a primary friction area located on or integral with said substrate material, said primary friction area having a primary surface having a primary frictional feature; and   a secondary friction area located on or integral with said primary surface and defining a secondary frictional feature;   said primary friction area and said secondary friction area defining a friction interface zone, said secondary friction area increasing a friction of said primary surface to enhance the frictional engagement between said primary surface and at least one bone;   wherein said primary surface defines a plurality of teeth or serrations;   wherein said secondary frictional feature defines a plurality of teeth, points or peaks located on or integral with said primary friction area.   
     
     
         2 . The orthopedic implant as recited in  claim 1  wherein said primary friction area having a primary friction surface that is at least one of machined, molded, extruded, sintered or deposited substrate. 
     
     
         3 . The orthopedic implant as recited in  claim 2  wherein said deposited substrate is a polymeric substrate. 
     
     
         4 . The orthopedic implant as recited in  claim 2  wherein said primary friction surface defines a plurality of teeth or serrations. 
     
     
         5 . The orthopedic implant as recited in  claim 4  wherein said secondary friction area that is at least one of machined, molded, extruded, sintered or deposited substrate. 
     
     
         6 . The orthopedic implant as recited in  claim 4  wherein said secondary friction area comprises at least one of a microscopically or macroscopically rough surface. 
     
     
         7 . The orthopedic implant as recited in  claim 1  wherein said secondary friction area is regular in shape. 
     
     
         8 . The orthopedic implant as recited in  claim 1  wherein said secondary friction area is irregular in shape. 
     
     
         9 . The orthopedic implant as recited in  claim 1  wherein said substrate material is made from a thermoplastic. 
     
     
         10 . The orthopedic implant as recited in  claim 9  wherein said thermoplastic is a polyetheretherketone (PEEK). 
     
     
         11 . The orthopedic implant as recited in  claim 1  wherein a modulus of elasticity of said substrate material is less than or equivalent to bone. 
     
     
         12 . The orthopedic implant as recited in  claim 11  wherein said substrate material has a low coefficient of friction with bone. 
     
     
         13 . The orthopedic implant as recited in  claim 1  wherein at least one of said primary friction area or said secondary friction area being made from a metal or metallic alloy. 
     
     
         14 . The orthopedic implant as recited in  claim 1  wherein at least one of said primary friction area or said secondary friction area having a modulus of elasticity that is the same as or greater than bone. 
     
     
         15 . The orthopedic implant as recited in  claim 11  wherein said at least one of said primary friction area or said secondary friction area having a modulus of elasticity that the same as or greater than bone. 
     
     
         16 . The orthopedic implant as recited in  claim 1  wherein at least one of said primary friction area or said secondary friction area comprising a higher coefficient of friction with bone. 
     
     
         17 . The orthopedic implant as recited in  claim 16  wherein at least one of said primary friction area or said secondary friction area having a modulus of elasticity that the same as or greater than bone. 
     
     
         18 . The orthopedic implant as recited in  claim 1  wherein said primary friction area comprising a higher coefficient of friction with bone and said secondary friction area comprising a higher coefficient of friction than said primary friction area. 
     
     
         19 . The orthopedic implant as recited in  claim 1  wherein said primary friction area having a modulus of elasticity that the same as or greater than bone and said secondary friction area having a modulus of elasticity that is the same or greater than said primary friction area. 
     
     
         20 . The orthopedic implant as recited in  claim 1  wherein said secondary frictional feature is integral with, welded to, adhered to or otherwise affixed to said primary frictional feature. 
     
     
         21 . The orthopedic implant as recited in  claim 1  wherein said secondary frictional feature is sprayed onto, melted to or applied to said primary friction area. 
     
     
         22 . The orthopedic implant as recited in  claim 21  wherein said secondary frictional feature is defined by particles that are at least one of round, not round or acicular, circular, coarse, acyclic. 
     
     
         23 . The orthopedic implant as recited in  claim 22  wherein said particles are continuous or discontinuous or discrete on at least a portion of said primary frictional feature. 
     
     
         24 . The orthopedic implant as recited in  claim 1  wherein said secondary frictional feature defines a plurality of teeth, points or peaks are located on or integral with said primary friction area. 
     
     
         25 . The orthopedic implant as recited in  claim 24  wherein said plurality of teeth, points or peaks are neither regular nor symmetrical. 
     
     
         26 . The orthopedic implant as recited in  claim 24  wherein said plurality of teeth, points or peaks are regular and symmetrical. 
     
     
         27 . The orthopedic implant as recited in  claim 1  wherein said primary frictional feature and said secondary frictional feature are made from different materials. 
     
     
         28 . The orthopedic implant as recited in  claim 1  wherein said primary frictional feature and said secondary frictional feature are made from the same materials. 
     
     
         29 . The orthopedic implant as recited in  claim 1  wherein said at least one of said primary frictional feature, said secondary frictional feature or said substrate material is made from a different material than the others. 
     
     
         30 . The orthopedic implant as recited in  claim 1  wherein said secondary frictional feature increases a coefficient of friction of said orthopedic implant and bone. 
     
     
         31 . The orthopedic implant as recited in  claim 1  wherein said orthopedic implant is a spinal implant. 
     
     
         32 . The orthopedic implant as recited in  claim 31  wherein said spinal implant is a cage. 
     
     
         33 . The orthopedic implant as recited in  claim 1  wherein said secondary frictional feature is a deposit onto said primary surface. 
     
     
         34 . The orthopedic implant as recited in  claim 33  wherein said deposit is a plasma vapor deposition deposit. 
     
     
         35 . The orthopedic implant as recited in  claim 33  wherein said primary surface defines a plurality of teeth or serrations and said deposit is applied to surfaces of one or more of said plurality of teeth or serrations. 
     
     
         36 . An orthopedic implant comprising:
 a body comprising a composite material;   a first friction area situated between the body and bone of a patient when the orthopedic implant is implanted in the patient, said first friction area comprising a plurality of teeth or serrations; and   a second friction area associated with said first friction area for directly engaging said bone;   wherein said second friction area defines a plurality of teeth, points or peaks located on or integral with said first friction area;   each of said first and second friction areas for improving a frictional engagement between said bone and said orthopedic implant.   
     
     
         37 . A method for improving a frictional interface between an implant and bone of a patient, comprising the steps of:
 processing a body to comprise a primary friction feature; and   processing said body to comprise a secondary friction feature directly located on or integral with said primary friction feature;   wherein said secondary friction feature defines a plurality of teeth, points or peaks that are located on or integral with said primary friction feature.