Encapsulated intervertebral disc prosthesis and methods of manufacture
The present invention relates generally to intervertebral disc repair devices and methods of manufacture. A method of manufacturing a dynamically responsive encapsulated intervertebral disc repair device that prevents the flow of disc material out of the disc, provides support to the anulus fibrosus, and shields the nerves of the anulus and spinal cord, is provided.
1. A method of making an intervertebral prosthesis comprising the steps of:
placing a first biocompatible encapsulating material over a heatable mold with a curved face, said first biocompatible encapsulating material sized to extend from about 0.1 mm to about 0.5 mm beyond the edges of a barrier frame;
placing the barrier frame on the first encapsulating material, said barrier frame dimensioned to span beyond the distance defined by the maximum distance between an inferior and superior endplate of a normal intervertebral disc and to extend circumferentially along the lateral and posterior surfaces of an anulus, wherein at least a portion of said barrier has a curvilinear cross-section and is comprised of nickel titanium alloy;
placing a second encapsulating material on top of the barrier frame, said second biocompatible encapsulating material designed to extend from about 0.1 mm to about 5 mm beyond the edges of the barrier frame;
placing a mold cover with a concave interior corresponding to face of the mold on top of the second encapsulating material and applying force such that the edges of the first and second encapsulating material form one or more contact points with each other around the barrier frame; and
heating the base and the cover and the frame sandwiched between the first and the second encapsulating material until the first and second encapsulating material bond to each other at said one or more contact points.
2. The method of claim 1 , wherein said placing a first biocompatible encapsulating material over a heatable mold with a curved face comprises placing a first biocompatible encapsulating material over a heatable mold with a curved face having a first axis and a second axis which are perpendicular to one another.
3. The method of claim 2 , wherein said first axis is a longitudinal axis having a first radius of curvature and said second axis is a transverse axis having a second radius of curvature.
4. The method of claim 3 , wherein said first radius of curvature has a range of about 0.2 cm to about 2.5 cm and said second radius of curvature has a range of about 3.0 cm to about 5.0 cm.
5. The method of claim 1 , wherein said curvilinear cross-section is a semi-circular cross-section.
6. The method of claim 1 , wherein said first biocompatible encapsulating material comprises ePTFE.
7. The method of claim 1 , wherein said first biocompatible encapsulating material comprises a biological material selected from the group consisting of one or more of the following: keratin, collagen, bio-engineered anulus fibrosus, and protein polymers.
8. The method of claim 1 , wherein said first biocompatible encapsulating material comprises a synthetic material selected from the group consisting of one or more of the following: polyamides, polyimides, silicones, polyurethane, natural rubber, latex, perfluoroalkoxy and fluorinated ethylene-propylene.
9. The method of claim 1 , wherein said first biocompatible encapsulating material is constructed of the same material as said second biocompatible encapsulating material.