Process of fabricating composite implants having integration surfaces composed of a regular repeating pattern

Abstract

Processes of fabricating a roughened surface topography on a composite interbody spinal implant including a body having a top surface, a bottom surface, opposing lateral sides, and opposing anterior and posterior portions; a first integration plate affixed to the top surface of the body; and an optional second integration plate affixed to the bottom surface of the body. At least a portion of the first integration plate, optional second integration plate, or both has a roughened surface topography including macro features, micro features, and nano features, without sharp teeth that risk damage to bone structures, adapted to grip bone through friction, inhibit migration of the implant, and promote bone growth. The process steps may include separate and sequential macro processing, micro processing, and nano processing steps.

What is claimed is: 
     
         1 . A process of fabricating a roughened surface topography on at least one surface of a composite implant, the process comprising:
 macro processing at least one of a top surface of a first integration plate and a top surface of a second integration plate adapted to be in contact with adjacent vertebral endplates,   micro processing at least one of the top surface of the first integration plate and the top surface of the second integration plate, and   nano processing at least one of the top surface of the first integration plate and the top surface of the second integration plate,   wherein the macro processing, the micro processing, and the nano processing are separate and sequential steps.   
     
     
         2 . The process of  claim 1 , wherein the macro processing includes heavy mechanical or chemical bulk removal of at least a portion of the top surface of the first integration plate or the top surface of the second integration plate. 
     
     
         3 . The process of  claim 1 , wherein the micro processing includes mechanical or chemical removal of at least a portion of the top surface of the first integration plate or the top surface of the second integration plate. 
     
     
         4 . The process of  claim 1 , wherein the nano processing includes mild chemical etching, laser or other directed energy material removal, abrasion, blasting, or tumbling, followed by cleaning. 
     
     
         5 . The process of  claim 1 , wherein the nano processing includes acid etching with an acid selected from the group consisting of hydrochloric acid, hydroiodic acid, hydrobromic acid, hydrofluoric, perchloric acid, nitric acid, and sulfuric acid. 
     
     
         6 . The process of  claim 1 , wherein the nano processing comprises:
 preparing an acid solution comprising hydrochloric acid, water, and titanium;   applying the acid solution to at least one of the top surface of the first integration plate and the top surface of the second integration plate;   removing the acid solution by rinsing with water; and   heating and subsequently cooling each top surface to which the acid solution was applied.   
     
     
         7 . The process of  claim 6 , wherein the acid solution comprises a concentration of 25-31% hydrochloric acid. 
     
     
         8 . The process of  claim 6 , wherein the titanium is seeded in the acid solution or is present from titanium previously removed from at least one surface of the implant. 
     
     
         9 . The process of  claim 6 , wherein the acid solution is heated to a temperature of about 200-210° F. when applied. 
     
     
         10 . The process of  claim 6 , wherein the acid solution is applied to at least one of the top surface of the first integration plate and the top surface of the second integration plate for a period of time of about 15-25 minutes. 
     
     
         11 . The process of  claim 1 , wherein the nano processing includes tumble finishing. 
     
     
         12 . The process of  claim 1 , wherein at least one of the first integration plate and the second integration plate comprises titanium. 
     
     
         13 . The process of  claim 1 , wherein:
 the macro processing forms macro features having a mean spacing between about 400-2,000 microns, a maximum peak-to-valley height between about 40-500 microns, and an average amplitude between about 20-200 microns;   the micro processing forms micro features having a mean spacing between about 20-400 microns, a maximum peak-to-valley height between about 2-40 microns, and an average amplitude between about 1-20 microns; and   the nano processing forms nano features having a mean spacing between about 0.5-20 microns, a maximum peak-to-valley height between about 0.2-2 microns, and an average amplitude between about 0.01-1 microns.   
     
     
         14 . The process of  claim 1 , wherein the micro processing and the nano processing form a roughened surface topography having repeating micro features and nano features of smooth shapes oriented in opposition to the biologic forces on the implant and to the insertion direction. 
     
     
         15 . The process of  claim 14 , wherein the micro features and the nano features overlap. 
     
     
         16 . The process of  claim 1 , further comprising an initial step of providing the composite implant, wherein the composite implant has:
 (a) a body having a top surface, a bottom surface, opposing lateral sides, opposing anterior and posterior portions, a substantially hollow center, and a single vertical aperture;   (b) the body having generally rounded and blunt intersections defined along the entire lengths between the top surface and the lateral sides and the bottom surface and the lateral sides;   (c) the first integration plate affixed to the top surface of the body, the first integration plate having a top surface, a bottom surface, opposing lateral sides, opposing anterior and posterior portions, and a single vertical aperture extending from the top surface to the bottom surface of the first integration plate and aligning with the single vertical aperture of the body, defining a transverse rim with a varying thickness; and   (d) the first integration plate having at least one sharp edge between the top and the anterior portion or the posterior portion;   (e) the optional second integration plate affixed to the bottom surface of the body, the second integration plate having a top surface, a bottom surface, opposing lateral sides, opposing anterior and posterior portions, and a single vertical aperture extending from the top surface to the bottom surface of the optional second integration plate and aligning with the single vertical aperture of the body, defining a transverse rim with a varying thickness; and   (f) the optional second integration plate having at least one sharp edge between the top and the anterior portion or the posterior portion.   
     
     
         17 . The process of  claim 1 , further comprising an initial step of providing the composite implant, wherein the composite implant has:
 (a) a body having a top surface, a bottom surface, opposing lateral sides, opposing anterior and posterior portions, a substantially hollow center, and a single vertical aperture;   (b) the body having generally rounded and blunt intersections defined along the entire lengths between the top surface and the lateral sides and the bottom surface and the lateral sides;   (c) the first integration plate affixed to the top surface of the body and the second integration plate affixed to the bottom surface of the body, wherein the first integration plate and the second integration plate each have a top surface, a bottom surface, opposing lateral sides, opposing anterior and posterior portions, and a single vertical aperture extending from the top surface to the bottom surface and aligning with the single vertical aperture of the body, defining a transverse rim having a varying thickness; and   (d) at least one of the first integration plate and the second integration plate having at least one sharp edge between the top and the anterior portion or the posterior portion.   
     
     
         18 . The process of  claim 17 , wherein the body comprises a non-metal selected from the group consisting of polyetherether-ketone, hedrocel, and ultra-high molecular weight polyethylene. 
     
     
         19 . The process of  claim 17 , wherein the first integration plate and the second integration plate comprise titanium. 
     
     
         20 . The process of  claim 17 , wherein the first integration plate and the second integration plate comprise titanium and the body comprises a polymer.