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EP0919209A1 Expired / Lapsed EP ⏱️ 0.0 years remaining

Hydrogel intervertabral disc nucleus with diminished lateral bulging

Assignee: Howmedica Osteonics Corp
•
Filing: 1994-01-28
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Granted: —
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Expires: 2014-01-28
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Abstract

Abstract A prosthetic nucleus (10) 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 4NM -2 or greater. When the hydrogel material is dehydrated, it has a dimension of less than half ofthat of the hydrated hydrogel nucleus. The prosthetic nucleus may be formed of two or more pieces of hydrogel material (42, 44) which pieces, when combined, have a shape generally conforming to the natural nucleus. The prosthetic nucleus may have a stiff posterior periphery (24) and/or a thickened anterior wall (28).

Inventors

  • 👤 Qi-Bin Bao
  • 👤 Paul Anthony Higham

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-10-23 13:48
CPC Classifications
A; A61; A61F; A61F2/00; A61F2/02; A61F2/30; A61F2/44; A61F2/441; A61F2/442; A61F2/3094; A61F2002/30001; A61F2002/30003; A61F2002/30004; A61F2002/30014; A61F2002/30108; A61F2002/3011; A61F2002/30112; A61F2002/30133; A61F2002/30182; A61F2002/30187; A61F2002/30199; A61F2002/30224; A61F2002/3023; A61F2002/4435; A61F2002/444; A61F2002/448; A61F2230/00; A61F2230/0002; A61F2230/0004; A61F2230/0015; A61F2230/0028; A61F2230/0034; A61F2230/0063; A61F2230/0069; A61F2250/00; A61F2250/0014; A61F2250/0018; Y; Y10; Y10S; Y10S606/00; Y10S606/907; Y10S606/91

Claims Analysis

Total Claims: 5
Claim 1
Independent Claim 123 words
A prosthetic nucleus (10) for implanting into a disc space after removal of a degenerated or damaged nucleus of an intervertebral disc, said prosthetic nucleus comprising: a biologically compatible hydrogel material having, when fully hydrated, a size and shape generally conforming to a natural nucleus or to the shape of a cavity created after removal of the degenerated or damaged nucleus; a water content in the range of 30% to 90%; and a compressive strength of 4MN -2 or greater; and a prosthetic nucleus periphery a part of which exhibits diminished lateral bulging in comparison to other parts of the prosthetic nucleus periphery, characterised in that the nucleus periphery wall varies in height by at least 1 mm in the fully hydrated implant.
Claim 2
Dependent Claim 44 words
The prosthetic nucleus (10) as claimed in Claim 1 wherein the nucleus has an anterior wall (28) and a posterior wall (30) and the anterior wall (28) is at least about 1 mm thicker than the posterior wall (30) in the fully hydrated implant.
Claim 3
Dependent Claim 30 words
The prosthetic nucleus (10) as claimed in Claim 2 wherein the anterior wall (28) is at least 2 mm thicker than the posterior wall (30) in the fully hydrated implant.
Claim 4
Dependent Claim 23 words
The prosthetic nucleus (10) as claimed in Claim 2 wherein the height of the nucleus gradually increases from the posterior to anterior side.
Claim 5
Dependent Claim 61 words
The prosthetic nucleus (10) as claimed in Claim 2 formed from a first piece (42) and a second piece (44) of hydrogel material having a combined shape generally conforming to the natural nucleus, wherein at least part of the wall of the first piece is at least 1 mm thicker than at least part of the wall of the second piece.

References Cited (Backward Citations)

FR2124815A5 Cited
EP0277282A1 Cited
US4863477A Cited
EP0356112A1 Cited
EP0505634A1 Cited

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