Fixation of orthopaedic devices

Abstract

An orthopaedic implant includes a bone screw having a surface with a plurality of threads extending from the surface and a plurality of holes formed through the surface and located between the threads. The bone screw defines an inner chamber that is in communication with the holes. A fixation material is placed in the inner chamber and configured to chemoattract tissue surrounding the bone screw following implantation to fill in at least some of the holes.

What is claimed is: 
     
         1 . An orthopaedic implant, comprising:
 a bone screw having a surface with a plurality of threads extending from the surface and a plurality of holes formed through the surface and located between the threads, the bone screw defining an inner chamber that is in communication with the holes; and   a fixation material placed in the inner chamber and configured to chemoattract tissue surrounding the bone screw following implantation to fill in at least some of the holes.   
     
     
         2 . The orthopaedic implant of  claim 1 , wherein the bone screw defines a wall thickness in a range of 1 mm to 1.5 mm. 
     
     
         3 . The orthopaedic implant of  claim 1 , wherein the holes are located axially in valleys between the threads and go through to a centerline of the bone screw. 
     
     
         4 . The orthopaedic implant of  claim 1 , wherein the holes are placed along a full length of the bone screw. 
     
     
         5 . The orthopaedic implant of  claim 1 , wherein the holes are concentrated near a distal end of the bone screw. 
     
     
         6 . A method of forming an orthopaedic implant, the method comprising:
 adhering a fixation material to a screw blank; and   cutting a plurality of threads into the screw blank and the adhered fixation material to form a completed orthopaedic implant.   
     
     
         7 . The method of  claim 6 , wherein each of the threads are composed of half fixation material and half material of the screw blank. 
     
     
         8 . The method of  claim 6 , wherein the fixation material is porous and comprises at least one titanium, cobalt chrome, stainless steel, polyether ether ketone, polylactic acid, polyglycolic acid, or polyethylene. 
     
     
         9 . The method of  claim 6 , wherein the fixation material has pores that include at least one biologically active substance. 
     
     
         10 . The method of  claim 6 , wherein adhering the fixation material to the screw blank comprises filling elongated pockets formed in the screw blank with the fixation material. 
     
     
         11 . The method of  claim 6 , wherein adhering the fixation material to the screw blank comprises bonding the fixation material to the screw blank.