Pfizer Hospital Products Group, Inc.

Howmedica Corp.

Stryker Technologies Corporation

Paul A Higham

Qi-Bin Bao

Jessica Dee Posey-Dowty

Casper F Stark

Nestor A Arroyo

Larry T Warfield

John H Dumbleton

Harold M Aberman

Charanpreet S Bagga

Hansen A Yuan

James J Barry

An article for use in the preparation of a hydrogel prosthetic nucleus, for an intervertebral disc, having equilibrium water contents (EWCs) of from about 30 to about 90% and compressive strengths of at least 4 meganewtons per square meter (MNm,), at their EWCs, when subjected to the same constraints as the normal nucleus, comprising one or more xerogel rods containing from zero to less than the EWC. A method for preparing a hydrogel prosthetic nucleus, for a vertebral disc, comprising one or more hydrogel rods containing from about 30 to about 90% water, and having compressive strengths of at least 1 MNmn,, at their EWCs, which comprises inserting one or more hydrophilic xerogel rods, which at their EWC will contain from about 30 to about 90% water and have compressive strengths of at least 1 MNm,, containing water in an amount from about zero to less than their EWC, into the cavity of the disc through an opening in its annulus and allowing the rod, or rods, to absorb sufficient water from the body fluids to attain their EWCs and essentially fill the intervertebral nuclear disc cavity.

Hydrogel intervertebral disc nucleus implantation method

An article for use in the preparation of a hydrogel prosthetic nucleus, for an intervertebral disc, having equilibrium water contents (EWCs) of from about 30 to about 90% and compressive strengths of at least 4 meganewtons per square meter (MNm.sup.-2), at their EWCs, when subjected to the same constraints as the normal nucleus, comprising one or more xerogel rods containing from zero to less than the EWC. A method for preparing a hydrogel prosthetic nucleus, for a vertebral disc, comprising one or more hydrogel rods containing from about 30 to about 90% water, and having compressive strengths of at least 1 MNm.sup.-2, at their EWCs, which comprises inserting one or more hydrophilic xerogel rods, which at their EWC will contain from about 30 to about 90% water and have compressive strengths of at least 1 MNm.sup.-2, containing water in an amount from about zero to less than their EWC, into the cavity of the disc through an opening in its annulus and allowing the rod, or rods, to absorb sufficient water from the body fluids to attain their EWCs and essentially fill the intervertebral nuclear disc cavity.

Hydrogel intervertebral disc nucleus

A femoral hip component for use in hip arthroplasty has a stem portion for contact with bone cement. The stem portion is formed from a biocompatible material having a surface finish of less than about four microinches. This surface is coated with a uniform layer of material selected from the group consisting of diamond-like carbon, chromium carbide, titanium nitride, titanium carbo-nitride, chromium and zirconium and a combination thereof.

Coated femoral stem prosthesis

A method and apparatus for injecting an elastic spinal implant into a cavity in a spinal disc so as to treat disc degeneration are given. The method and apparatus can be used in a variety of surgical approaches with respect to the patient. An elastic spinal nucleus prosthesis is very quickly inserted into the cavity through a small opening in the disc so that permanent deformation of the prosthesis is avoided.

Method and apparatus for injecting an elastic spinal implant

A prosthetic nucleus for a vertebral disc is made of a hydrogel material. The hydrogel prosthetic nucleus has a shape generally conforming to the natural nucleus pulposus, and it exhibits diminished lateral bulging under high compressive loads. The hydrogel has a water content of from 30% to 90% and has a compressive strength of 4 MNm.sup.-2 or greater. When the hydrogel material is dehydrated, it has a dimension of less than half of that of the hydrated hydrogel nucleus. The prosthetic nucleus may be formed of two or more pieces of hydrogel material which pieces, when combined, have a shape generally conforming to the natural nucleus. The prosthetic nucleus may have a stiff posterior periphery and/or a thickened anterior wall.

Hydrogel intervertebral disc nucleus with diminished lateral bulging

A method of modifying salts of alginic acid in situ for prevention and treatment of various intra-articular and extra-articular (spine) complications modifies the alginate in situ to an insoluble gel. This in situ modification provides a final product which can be compressed within the intra-articular space thus remaining localized. The modified material can have varied mechanical strengths and thus varied degradation times and can serve as a matrix for localizing and slowly releasing therapeutic agents. The modified material is biocompatible and biodegradable, thus requiring no reoperation for removal.

In situ modification of alginate

An implantable material for promoting bone growth has a microporous structure exhibiting an average pore size of at least 30 .ANG.. The porous biomaterial is capable of retaining macromolecules having a molecular weight of at least 15,000 and up to 500,000.

Bone growth stimulator

A bone cement is disclosed wherein the liquid component contains a therapeutic or diagnostic substance in combination with an emulsifying agent for said substance.

Bone cement for sustained release of substances

A prosthetic nucleus for implantation in the disc space after removal of a damaged or degenerated nucleus is formed from a multiplicity of hydrogel beads having a water content of at least 30%. The beads are covered by a semi-permeable membrane. The membrane has porosity less than the size of the beads to thereby retain the beads therein but permit fluids to flow in and out of the prosthetic nucleus.

Hydrogel bead intervertebral disc nucleus

A method for preventing adhesion between vital tissues includes the step of placing between the tissues a material made up of biodegradable derivatives of chitin which are soluble in aqueous solutions containing dilute acids such as acetic acid. This material has the advantage of requiring no reoperation for its removal since it would be degraded and absorbed after completing its function in vivo. These materials may be in the form of a visco-elastic fluid, a gel, a film or a membrane.

Use of derivatives of chitin soluble in aqueous solutions for preventing

A prosthetic nucleus for a vertebral disc is made of a hydrogel material. The hydrogel prosthetic nucleus has a shape generally conforming to the natural nucleus pulposus. The hydrogel has a water content of at least 30% and has a compressive strength of 4MNm.sup.-2 or greater. When the hydrogel material is dehydrated, it has a dimension of less than half of that of the hydrated hydrogel nucleus. The prosthetic nucleus may be formed of two or more pieces of hydrogel material which pieces, when combined, have a shape generally conforming to the natural nucleus.

A method for preventing adhesion utilizes a viscoelastic gel formed from xanthan gum. The gel is more viscous than blood and is soluble in aqueous solutions. The gel is placed between the tissues by a syringe. The method includes mixing the xanthan gum with either a saline solution or Tyrode's solution to form the gel.

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Ringwood, NJ, United States of America

Paul A Higham