Implantable metallic medical articles having microporous surface structure

Abstract

A process for creating surface microporosity on a titanium (or other metal) medical device includes creating a surface oxide layer on the device; placing the device, which is connected to a negative terminal of an electrical power supply, into a calcium chloride bath; connecting the positive terminal of the power supply to an anode immersed in or containing calcium chloride thereby forming an electrolytic cell; passing current through the cell; removing the device from the bath; and cooling and rinsing the device to remove any surface salt. If necessary, the device is etched to remove metal oxide which may have formed during the cooling process. The resulting device has a microporous surface structure. Alternatively, only a designated surface portion of a medical device is made microporous, either by applying a non-oxidizing mask, removing a portion of the oxide layer, or subtracting a portion of a microporous surface.

1 . A medical device, comprising: 
 a metal structure at least a portion of which has a microporous surface structure, said microporous surface structure formed by the process of oxidizing a surface of said medical device, and reducing said oxide layer to form a microporosity in said surface, wherein said structure at least partly defines one of 
 (i) a bone implant,  
 (ii) a bone replacement,  
 (iii) a structural device which expands and reinforces arterial, vascular, or other body structures,  
 (iv) a wire embolization coil,  
 (v) an enclosure for a pacemakers, a defibrillator, or an implantable infusion pump,  
 (vi) a pacing lead,  
 (vii) a wire suture or ligature,  
 (viii) a surgical staple,  
 (ix) a filter to catch thrombi and emboli, and  
 (x) an orthodontic implant or appliance.  
   
     
     
         2 . A medical device according to  claim 1 , wherein: 
 said metal is one of titanium and a titanium alloy.    
     
     
         3 . A medical device according to  claim 1 , wherein: 
 said reducing includes electrolyzing said medical device in a bath of molten calcium chloride for a period of time.    
     
     
         4 . A medical device according to  claim 1 , wherein: 
 said microporous surface structure includes a plurality of non-linear tunnel-like micropores.    
     
     
         5 . A medical device according to  claim 4 , wherein: 
 at least one of said micropores extends into and beneath said surface of said device, turns under said surface and interconnects with another of said at least one of said micropores.    
     
     
         6 . A medical device, comprising: 
 a metal structure at least a portion of which has a microporous surface structure including a plurality of non-linear tunnel-like micropores, wherein said structure at least partly defines one of 
 (i) a bone implant,  
 (ii) a bone replacement,  
 (iii) a structural device which expands and reinforces arterial, vascular, or other body structures,  
 (iv) a wire embolization coil,  
 (v) an enclosure for a pacemakers, a defibrillator, or an implantable infusion pump,  
 (vi) a pacing lead,  
 (vii) a wire suture or ligature,  
 (viii) a surgical staple,  
 (ix) a filter to catch thrombi and emboli, and  
 (x) an orthodontic implant or appliance.  
   
     
     
         7 . A medical device according to  claim 6 , wherein: 
 at least one of said micropores extends into and beneath said surface of said device, turns under said surface and interconnects with another of said at least one of said micropores.    
     
     
         8 . A medical device according to  claim 6 , wherein: 
 said metal is one of titanium and a titanium alloy.    
     
     
         9 . A medical device, comprising: 
 a metal structure at least a portion of which has a microporous surface structure including a plurality of micropores extending in a non-line-of-sight manner into said structure, wherein said structure at least partly defines one of 
 (i) a bone implant,  
 (ii) a bone replacement,  
 (iii) a structural device which expands and reinforces arterial, vascular, or other body structures,  
 (iv) a wire embolization coil,  
 (v) an enclosure for a pacemakers, a defibrillator, or an implantable infusion pump,  
 (vi) a pacing lead,  
 (vii) a wire suture or ligature,  
 (viii) a surgical staple,  
 (ix) a filter to catch thrombi and emboli, and  
 (x) an orthodontic implant or appliance.  
   
     
     
         10 . In a metal medical device, the improvement being: 
 a surface of said metal medical device treated by a process comprising, 
 a) oxidizing a surface of said medical device; and  
 b) reduction of at least a portion of said surface such that a microporosity is provided on said surface of said medical device, wherein said medical device is one of 
 (i) a bone implant,  
 (ii) a bone replacement,  
 (iii) a structural device which expands and reinforces arterial, vascular, or other body structures,  
 (iv) a wire embolization coil,  
 (v) an enclosure for a pacemakers, a defibrillator, or an implantable infusion pump,  
 (vi) a pacing lead,  
 (vii) a wire suture or ligature,  
 (viii) a surgical staple,  
 (ix) a filter to catch thrombi and emboli, and  
 (x) an orthodontic implant or appliance.  
 
   
     
     
         11 . The improvement of  claim 10 , wherein: 
 said metal is one of titanium and titanium alloy.    
     
     
         12 . The improvement of  claim 10 , wherein: 
 said microporosity includes a plurality of non-linear tunnel-like micropores.    
     
     
         13 . The improvement of  claim 12 , wherein: 
 at least one of said micropores extends into and beneath said surface of said device, turns under said surface and interconnects with another of said at least one of said micropores.    
     
     
         14 . In a metal medical device, the improvement being: 
 a surface of said metal medical device having a microporous surface structure including a plurality of non-linear tunnel-like micropores.    
     
     
         15 . The improvement of  claim 14 , wherein: 
 at least one of said micropores extends into and beneath said surface of said device, turns under said surface and interconnects with another of said at least one of said micropores.    
     
     
         16 . The improvement of  claim 14 , wherein: 
 said medical device is one of 
 (i) a bone implant,  
 (ii) a bone replacement,  
 (iii) a structural device which expands and reinforces arterial, vascular, or other body structures,  
 (iv) a wire embolization coil,  
 (v) an enclosure for a pacemakers, a defibrillator, or an implantable infusion pump,  
 (vi) a pacing lead,  
 (vii) a wire suture or ligature,  
 (viii) a surgical staple,  
 (ix) a filter to catch thrombi and emboli, and  
 (x) an orthodontic implant or appliance.  
   
     
     
         17 . The improvement of  claim 14 , wherein: 
 said metal is one of titanium and titanium alloy.    
     
     
         18 . In a metal medical device, the improvement being: 
 a surface of said metal medical device having a microporous surface structure including a plurality of micropores which extend into the surface in a non-line-of-sight manner.