US5674295A
Expired / Lapsed
US
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Prosthetic spinal disc nucleus
Assignee: RayMedica LLC
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Filing: 1996-04-26
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Granted: 1997-10-07
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Expires: 2016-04-26
Abstract
Abstract An elongated, pillow shaped prosthetic spinal disc nucleus body for implantation into a human intervertebral spinal disc, made of a hydrogel core and a flexible constraining jacket surrounding the hydrogel material core that permits the hydrogel core to expand and contract. The hydrogel core has a length approximating the sagittal diameter of a nucleus of the human disc, a width less than the length, and a height less than the length or width. The hydrogel core will expand and contract in a desired fashion as it imbibes and expels fluids in response to various loads placed upon the spinal tract. The constraining jacket is porous to allow fluids to pass through to the hydrogel core, but prevents the hydrogel from escaping, thus fostering the natural physiology of the human intervertebral disc. By implanting two prosthetic spinal disc nucleus bodies side-by-side into a damaged disc of a human spine, both height and motion can be maintained.
Inventors
- 👤 Charles D. Ray
- 👤 Eugene A. Dickhudt
- 👤 Philip J. Ledoux
- 👤 Beth A. Frutiger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:59
CPC Classifications
A; A61; A61F; A61F2/00; A61F2/02; A61F2/30; A61F2/44; A61F2/441; A61F2/442; A61F2/3094; A61F2002/30001; A61F2002/30003; A61F2002/3006; A61F2002/3008; A61F2002/30108; A61F2002/3011; A61F2002/30138; A61F2002/30156; A61F2002/30199; A61F2002/30224; A61F2002/30235; A61F2002/30291; A61F2002/30316; A61F2002/30329; A61F2002/30461; A61F2002/30535; A61F2002/30579; A61F2002/30581; A61F2002/30617; A61F2/30767; A61F2/30771; A61F2002/30841; A61F2002/30878; A61F2002/444; A61F2002/448; A61F2002/4495; A61F2220/00; A61F2220/0025; A61F2220/0075; A61F2230/00; A61F2230/0002; A61F2230/0017; A61F2230/0023; A61F2230/0063; A61F2230/0069; A61F2230/0091; A61F2250/00; A61F2250/0058; A61F2250/0096; A61F2250/0097; A61F2250/0098
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
157 words
A prosthetic disc nucleus for implantation into a human spinal disc having a nucleus area defined generally in a horizontal plane by an anulus and generally in a vertical plane by two vertebral end plates, the nucleus area having a sagittal diameter and a traverse diameter, the prosthetic disc nucleus comprising: a hydrogel core having a length approximating the sagittal diameter of the nucleus area and a width less than half of the transverse diameter of the nucleus area, wherein the hydrogel core is configured such that it will consistently return to a predetermined shape following removal of a load; and a jacket surrounding the hydrogel core, wherein the jacket is configured to have a horizontal limit in the horizontal plane of the nucleus area such that the jacket directs expansion of the hydrogel core to only the vertical plane of the nucleus area after expansion of the hydrogel core reaches the horizontal limit of the jacket.
Claim 2
Dependent Claim
157 words
A prosthetic disc nucleus for implantation into a human spinal disc having a nucleus area defined generally in a horizontal plane by an anulus and generally in a vertical plane by two vertebral end plates, the nucleus area having a sagittal diameter and a traverse diameter, the prosthetic disc nucleus comprising: a hydrogel core having a length approximating the sagittal diameter of the nucleus area and a width less than half of the transverse diameter of the nucleus area, wherein the hydrogel core is configured such that it will consistently return to a predetermined shape following removal of a load; and a jacket surrounding the hydrogel core, wherein the jacket is configured to have a horizontal limit in the horizontal plane of the nucleus area such that the jacket directs expansion of the hydrogel core to only the vertical plane of the nucleus area after expansion of the hydrogel core reaches the horizontal limit of the jacket.
Claim 3
Dependent Claim
16 words
The prosthetic disc nucleus of claim 1 wherein the predetermined shape is an oval frontal cross-section.
Claim 4
Dependent Claim
31 words
The prosthetic disc nucleus of claim 1 wherein the hydrogel core is subjected to a plurality of compressive forces prior to implant to render the hydrogel core to the predetermined shape.
Claim 5
Dependent Claim
39 words
The prosthetic disc nucleus of claim 1 wherein the hydrogel core is dehydrated prior to implantation and hydrated after implantation, and further wherein the hydrogel core constrained by the jacket is configured to expand predominately in height upon hydration.
Claim 6
Dependent Claim
40 words
The prosthetic disc nucleus of claim 1 wherein the hydrogel core is dehydrated prior to implantation and hydrated after implantation, and further wherein the jacket is configured to direct the hydrogel core to expand in the vertical plane upon hydration.
Claim 7
Dependent Claim
26 words
The prosthetic disc nucleus of claim 5 wherein the jacket is substantially inelastic for directing the hydrogel core to expand in the vertical plane upon hydration.
Claim 8
Dependent Claim
20 words
The prosthetic disc nucleus of claim 1 wherein the hydrogel core has a water content of 25-65% when fully hydrated.
Claim 9
Dependent Claim
14 words
The prosthetic disc nucleus of claim 1 wherein the jacket is a woven tube.
Claim 10
Dependent Claim
35 words
The prosthetic disc nucleus of claim 1 wherein the jacket has openings which permit fluids to pass through the jacket to the hydrogel core while blocking passage of the hydrogel core out of the jacket.
Claim 11
Dependent Claim
20 words
The prosthetic disc nucleus of claim 1 wherein the jacket is made of a high molecular weight, high tenacity material.
Claim 12
Dependent Claim
25 words
The prosthetic disc nucleus of claim 1 wherein the jacket is woven tube having two ends and wherein at least one end has a closure.
Claim 13
Dependent Claim
14 words
The prosthetic disc nucleus of claim 1, further including: radiopaque material within the jacket.
Claim 14
Dependent Claim
32 words
The prosthetic disc nucleus of claim 1, further including: means for maintaining the prosthetic disc nucleus within the disc area following implant, wherein the means for maintaining is attached to the jacket.
Claim 15
Dependent Claim
125 words
A prosthetic disc nucleus for implantation into a human spinal disc having a nucleus area defined by an anulus, the nucleus area having a sagittal diameter and a transverse diameter, the prosthetic disc nucleus comprising: a hydrogel core having a cylindrical body and a frontal cross-section which is a flattened oval, wherein the flattened oval cross-section defines a major axis and a minor axis: and a jacket surrounding the hydrogel core, wherein the jacket is configured to have a horizontal limit in a plane defined by the major axis of the hydrogel core such that the jacket directs expansion of the hydrogel core to only the minor axis of the hydrogel core after expansion of the hydrogel core reaches the horizontal limit of the jacket.
Claim 16
Dependent Claim
125 words
A prosthetic disc nucleus for implantation into a human spinal disc having a nucleus area defined by an anulus, the nucleus area having a sagittal diameter and a transverse diameter, the prosthetic disc nucleus comprising: a hydrogel core having a cylindrical body and a frontal cross-section which is a flattened oval, wherein the flattened oval cross-section defines a major axis and a minor axis: and a jacket surrounding the hydrogel core, wherein the jacket is configured to have a horizontal limit in a plane defined by the major axis of the hydrogel core such that the jacket directs expansion of the hydrogel core to only the minor axis of the hydrogel core after expansion of the hydrogel core reaches the horizontal limit of the jacket.
Claim 17
Dependent Claim
27 words
The prosthetic disc nucleus of claim 14 wherein the frontal cross-section of the hydrogel core has a height which is less than a height of the anulus.
Claim 18
Dependent Claim
49 words
The prosthetic disc nucleus of claim 14 wherein the hydrogel core is in a dehydrated state prior to implantation and is in a fully hydrated state after implantation, and further wherein the fully hydrated hydrogel core constrained by the jacket is configured to provide a natural disc space height.
Claim 19
Dependent Claim
40 words
The prosthetic disc nucleus of claim 1 wherein the hydrogel core swells from the dehydrated state to the fully hydrated state, and further wherein the hydrogel core is configured to swell with enough to force to restore natural disc height.
Claim 20
Dependent Claim
161 words
A prosthetic disc nucleus for implantation into a human spinal disc having a nucleus area with a generally horizontal plane, a sagittal diameter and a transverse diameter defined by an anulus, and a generally vertical plane defined by two vertebral end plates, the prosthetic disc nucleus comprising: a hydrogel core having a length approximating the sagittal diameter of the nucleus area and a width less than half of the transverse diameter of the nucleus area, wherein the hydrogel core is dehydrated prior to implantation and hydrated after implantation and the hydrogel core is configured such that it will maintain a predetermined shape after hydration; and a jacket surrounding the hydrogel core, wherein the jacket is configured to have a horizontal limit in the horizontal plane of the nucleus area such that the jacket directs expansion of the hydrogel core to only the vertical plane of the nucleus area after expansion of the hydrogel core, reaches the horizontal limit of the jacket.
Claim 21
Dependent Claim
161 words
A prosthetic disc nucleus for implantation into a human spinal disc having a nucleus area with a generally horizontal plane, a sagittal diameter and a transverse diameter defined by an anulus, and a generally vertical plane defined by two vertebral end plates, the prosthetic disc nucleus comprising: a hydrogel core having a length approximating the sagittal diameter of the nucleus area and a width less than half of the transverse diameter of the nucleus area, wherein the hydrogel core is dehydrated prior to implantation and hydrated after implantation and the hydrogel core is configured such that it will maintain a predetermined shape after hydration; and a jacket surrounding the hydrogel core, wherein the jacket is configured to have a horizontal limit in the horizontal plane of the nucleus area such that the jacket directs expansion of the hydrogel core to only the vertical plane of the nucleus area after expansion of the hydrogel core, reaches the horizontal limit of the jacket.
Claim 22
Dependent Claim
187 words
A prosthetic disc nucleus for implantation into a human spinal disc having a nucleus area defined by an anulus, the nucleus area having a sagittal diameter and a transverse diameter, the prosthetic disc nucleus comprising: a hydrogel core having a length approximating the sagittal diameter of the nucleus area, a width less than half of the transverse diameter and a frontal cross-section which is a flattened oval having a major axis and a minor axis, wherein the hydrogel core has a water content of 25-65% when fully hydrated and is subjected to a plurality of compressive cycles prior to implantation so that the hydrogel core is configured such that it will consistently return to a predetermined shape following removal of a load; and a substantially inelastic woven tube surrounding the hydrogel core, wherein the woven tube is configured to have a horizontal limit in a plane defined by the major axis of the hydrogel core such that the jacket directs expansion of the hydrogel core to only the minor axis of the hydrogel core after expansion of the hydrogel core reaches the horizontal limit of the jacket.
Claim 23
Dependent Claim
187 words
A prosthetic disc nucleus for implantation into a human spinal disc having a nucleus area defined by an anulus, the nucleus area having a sagittal diameter and a transverse diameter, the prosthetic disc nucleus comprising: a hydrogel core having a length approximating the sagittal diameter of the nucleus area, a width less than half of the transverse diameter and a frontal cross-section which is a flattened oval having a major axis and a minor axis, wherein the hydrogel core has a water content of 25-65% when fully hydrated and is subjected to a plurality of compressive cycles prior to implantation so that the hydrogel core is configured such that it will consistently return to a predetermined shape following removal of a load; and a substantially inelastic woven tube surrounding the hydrogel core, wherein the woven tube is configured to have a horizontal limit in a plane defined by the major axis of the hydrogel core such that the jacket directs expansion of the hydrogel core to only the minor axis of the hydrogel core after expansion of the hydrogel core reaches the horizontal limit of the jacket.
Claim 24
Independent Claim
134 words
A method of manufacturing a prosthetic disc nucleus for implantation into a human disc having a nucleus area defined by an anulus, the nucleus area having a sagittal diameter and a transverse diameter, the method including: forming a cylindrical hydrogel core having a flattened oval-shaped frontal cross-section which defines a major axis and a minor axis; forming a woven jacket having a limit in a plane defined by the major axis of the hydrogel core, wherein the jacket is configured to direct expansion of the hydrogel core only to a direction defined by the minor axis once expansion of the hydrogel core reaches the limit of the jacket; inserting the hydrogel core into an open end of the woven jacket; and closing the open end of the woven jacket to surround the hydrogel core.
Claim 25
Independent Claim
134 words
A method of manufacturing a prosthetic disc nucleus for implantation into a human disc having a nucleus area defined by an anulus, the nucleus area having a sagittal diameter and a transverse diameter, the method including: forming a cylindrical hydrogel core having a flattened oval-shaped frontal cross-section which defines a major axis and a minor axis; forming a woven jacket having a limit in a plane defined by the major axis of the hydrogel core, wherein the jacket is configured to direct expansion of the hydrogel core only to a direction defined by the minor axis once expansion of the hydrogel core reaches the limit of the jacket; inserting the hydrogel core into an open end of the woven jacket; and closing the open end of the woven jacket to surround the hydrogel core.
Claim 26
Dependent Claim
19 words
The method of manufacturing of claim 20, further including: hydrating the hydrogel core after insertion into the woven jacket.
Claim 27
Dependent Claim
22 words
The method of manufacturing of claim 20, further including: subjecting the hydrogel core to a plurality of compressive loads prior to implant.
Claim 28
Dependent Claim
30 words
The method of manufacturing of claim 20 wherein the hydrogel core has a length approximating the sagittal diameter and a width which is less than half of the transverse diameter.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-10-06 | 2001-04-07 | 2001-10-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-10-06 | 2005-04-07 | 2005-10-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-10-06 | 2009-04-07 | 2009-10-07 | $7700.00 | Window Closed / Lapsed |