Orthopedic Fixation Screw With Bioresorbable Layer

Abstract

An orthopedic screw is used in a fixation device for treating fractures. The device has a body with holes to accept the bone screws. The bone screws have a layer of bioresorbable material on a surface portion of the head of the screw contiguous with the shaft. Engagement between the bone screws and the body is initially through the bioresorbable material, which engagement rigidly fixes the relative angular orientation between the bone screws and the body when the device is applied to a bone. As the bioresrobable material is resorbed the angular relation between the bone screws and the body is no longer rigidly fixed, thereby effecting a transformation from rigid osteosysthesis to flexible osteosynthesis to allow micromotion between the bone fragments which promotes healing.

What is claimed is: 
     
         1 . A method of treating a bone fracture in a living organism having a plurality of bone fragments, said method comprising:
 attaching a body to at least two of said bone fragments using a plurality of fasteners joining said body to said fragments;   fixing an angular orientation of at least one of said fasteners in relation to said body using a bioresorbable material positioned between said fastener and said body, said bioresorbable material contacting said one fastener and said body and preventing relative rotation therebetween;   allowing said bioresorbable material to be resorbed by said living organism, thereby allowing relative rotation between said one fastener and said body.