Methods for manufacturing implants having integration surfaces

Abstract

A method of producing an interbody spinal implant. The method includes the steps of obtaining a blank having a top surface, bottom surface, opposing lateral sides, and opposing anterior and posterior portions, and applying a subtractive process (e.g., masked acid etching) to the top surface, the bottom surface, or both surfaces of the blank to form a roughened surface topography. Subsequently, the blank is machined to form the interbody spinal implant, which includes 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 where the top surface, the bottom surface, or both surfaces of the interbody spinal implant have the roughened surface topography produced by the subtractive process. This simplified method produces more accurate and repeatable implants with fewer process steps and defects, reducing process time and costs.

1 . A method of producing an interbody spinal implant, the method comprising:
 obtaining a blank having a top surface, a bottom surface, opposing lateral sides, and opposing anterior and posterior portions;   applying a subtractive process to at least a portion of at least one of the top surface and the bottom surface of the blank to form a roughened surface topography; and   subsequently, machining the blank to form an interbody spinal implant including 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 (a) extending from the top surface to the bottom surface of the body, (b) having a size and shape predetermined to maximize the surface area of the top surface and the bottom surface available proximate the anterior and posterior portions while maximizing both radiographic visualization and access to the substantially hollow center, and (c) defining a transverse rim, wherein at least one of the top surface and the bottom surface of the interbody spinal implant has the roughened surface topography.   
     
     
         2 . The method of  claim 1  further comprising applying a maskant to at least a portion of at least one surface of the blank before applying the subtractive process. 
     
     
         3 . The method of  claim 2 , wherein the maskant is applied via sputtering, deposition, or evaporation. 
     
     
         4 . The method of  claim 2 , wherein the maskant is applied to at least one of the top surface and the bottom surface of the blank in a regular repeating pattern. 
     
     
         5 . The method of  claim 1 , wherein the roughened surface topography is oriented in opposition to the biologic forces on the interbody spinal implant and to an insertion direction. 
     
     
         6 . The method of  claim 1 , wherein the roughened surface topography promotes bone growth, fusion, and healing responses. 
     
     
         7 . The method of  claim 1 , wherein the roughened surface topography comprises a roughness average amplitude, Ra, of about 1-200. 
     
     
         8 . The method of  claim 1 , where the subtractive process comprises at least one of macro processing and micro processing. 
     
     
         9 . The method of  claim 8 , wherein the macro processing includes heavy mechanical or chemical bulk removal and the micro processing includes mechanical or chemical removal. 
     
     
         10 . The method of  claim 1 , wherein the subtractive process comprises acid etching. 
     
     
         11 . The method of  claim 1 , wherein the interbody spinal implant is machined using milling, turning, or both. 
     
     
         12 . The method of  claim 1  further comprising machining the blank to have at least one of a lordosis angle, a convex surface, and a tail before applying the subtractive process. 
     
     
         13 . The method of  claim 1  further comprising cutting the blank to implant width before machining the blank to form the interbody spinal implant. 
     
     
         14 . The method of  claim 1  further comprising subjecting at least one surface of the interbody spinal implant, once formed, to nano processing. 
     
     
         15 . The method of  claim 14 , wherein the nano processing includes mild chemical etching, laser or other directed energy material removal, abrasion, blasting, or tumbling. 
     
     
         16 . The method of  claim 1 , wherein the blank comprises titanium or a titanium alloy. 
     
     
         17 . The method of  claim 1 , wherein the blank comprises a fixture handle after applying the subtractive process to the blank, and the fixture handle is removed after the interbody spinal implant is formed. 
     
     
         18 . A method of producing a composite interbody spinal implant, the method comprising:
 obtaining a blank having a top surface, a bottom surface, opposing lateral sides, and opposing anterior and posterior portions;   applying a subtractive process to at least a portion of the top surface of the blank to form a roughened surface topography;   subsequently, machining the blank to form an integration plate having a top surface including an integration surface with the roughened surface topography, 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   combining at least one integration plate with a body to form a composite interbody spinal implant, the 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 extending from the top surface to the bottom surface of the body, and the single vertical aperture of the at least one integration plate is aligned with the single vertical aperture of the body.   
     
     
         19 . The method of  claim 18 , wherein the integration plate comprises titanium or a titanium alloy and the body comprises a non-metal. 
     
     
         20 . A method of producing an interbody spinal implant, the method comprising:
 machining a blank including a top surface, a bottom surface, opposing lateral sides, and opposing anterior and posterior portions to have a lordosis angle;   sputtering a maskant on at least a portion of at least one of the top surface and the bottom surface of the blank to provide a masked portion covered by the maskant and an unmasked portion not covered by the maskant;   acid etching at least a portion of the unmasked portion on at least one of the top surface and the bottom surface of the blank to form a roughened surface topography; and   subsequently, machining the blank to form an interbody spinal implant including 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 (a) extending from the top surface to the bottom surface of the body, (b) having a size and shape predetermined to maximize the surface area of the top surface and the bottom surface available proximate the anterior and posterior portions while maximizing both radiographic visualization and access to the substantially hollow center, and (c) defining a transverse rim, wherein at least one of the top surface and the bottom surface of the interbody spinal implant has the roughened surface topography.