Under tissue conditions degradable material and a method for its manufacturing

Abstract

This invention relates to a material that degrades after implantation into a patient's tissue, and resorbs into the patient's body, which material is manufactured of polymer, copolymer or polymer alloy. The material has a non-crystalline, i.e., amorphous structure and is molecularly oriented and reinforced by mechanical deformation. Further, the material can be formed into surgical devices, such as screws and pins, for implantation into a patient.

What is claimed is:  
     
         1 . A material that resorbs after implantation into a patient's tissue comprising a resorbable, thermoplastic polymer, copolymer or polymer alloy, said material having an amorphous region that is mechanically modified to provide a molecularly oriented, reinforced structure.  
     
     
         2 . The material as set forth in  claim 1 , wherein the amorphous region of the material is mechanically modified uni-axially, by drawing.  
     
     
         3 . The material as set forth in  claim 1 , wherein the amorphous region of the material is mechanically modified bi-axially, by drawing.  
     
     
         4 . The material as set forth in  claim 1 , wherein the amorphous region of the material is mechanically modified by rolling, compression shear transformation, combined with drawing or performed separately.  
     
     
         5 . A surgical implant formed from the material of  claim 1 , said implant having a longitudinal axis, wherein the molecular orientation of the amorphous region is parallel with said longitudinal axis.  
     
     
         6 . A surgical implant manufactured from the material of  claim 1 , said implant having a shear strength greater than 60 MPa.  
     
     
         7 . A surgical implant manufactured from the material of  claim 1 , said implant having a bending strength greater than 130 MPa.  
     
     
         8 . The material as set forth in  claim 1 , wherein said material is poly-L/DL-lactide.  
     
     
         9 . A method for manufacturing the material of  claim 1 , comprising the steps of: 
 selecting a starting composition from a group of resorbable, thermoplastic polymers, copolymers polymer alloys having an amorphous region, and    mechanically modifying the starting composition to molecularly orient and reinforce the amorphous region, yielding the molecularly oriented, reinforced material of  claim 1 .    
     
     
         10 . The method as set forth in  claim 9 , further comprising the step of: 
 forming the material into a surgical implant having a longitudinal axis, wherein the molecular orientation of the material is substantially parallel to the longitudinal axis of the implant.    
     
     
         11 . The method as set forth in  claim 9 , wherein said starting composition is mechanically modified uni-axially or bi-axially.  
     
     
         12 . The method as set forth in  claim 9 , further comprising the step of: 
 forming the material into a surgical implant having a longitudinal axis, wherein the molecular orientation of the material is substantially twisted, threaded or spiral in relation to the longitudinal axis of the implant.    
     
     
         13 . A surgical implant formed from the material of  claim 1 , said implant having a longitudinal axis, wherein the molecular orientation of the amorphous region is twisted, threaded or spiral in relation to said longitudinal axis of the implant.  
     
     
         14 . The material as set forth in  claim 1 , wherein said material is an amorphous copolymer of lactide and glycolide.  
     
     
         15 . The material of  claim 14 , wherein said material is formed into a rod, screw, pin, hook, nail, plate, bolt, suture anchor, foils, wire, tube, stent or spiral for use as a resorbable, surgical implant in a patient.  
     
     
         16 . The material of  claim 8 , wherein said material is formed into a rod, screw, pin, hook, nail, plate, bolt, suture anchor, foils, wire, tube, stent or spiral for use as a resorbable, surgical implant in a patient.