Patent US5545229A successfully refreshed from Google Patents.
US5545229A
Expired / Lapsed
US
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Functional and biocompatible intervertebral disc spacer containing elastomeric material of varying hardness
Assignee: Rutgers Health
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Filing: 1993-07-28
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Granted: 1996-08-13
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Expires: 2013-07-28
Abstract
Abstract The construction and manufacturing technique for a functional biocompatible intervertebral disc spacer is described. This device is useful for a replacement for a degenerated disc in certain treatments of back pain and spinal disease. The disc spacer possesses mechanical properties akin to those of the normal disc and will preserve normal functions of the spinal motion segment. The device achieves the desired properties by varying the hardness of the elastomeric material in its nucleus and annulus.
Inventors
- 👤 John R. Parsons
- 👤 Casey K. Lee
- 👤 Noshir A. Langrana
- 👤 Alastair J. Clemow
- 👤 Elizabeth H. Chen
- 👤 Monica V. Hawkins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:09
CPC Classifications
A; A61; A61F; A61F2/00; A61F2/02; A61F2/30; A61F2/44; A61F2/442; A61F2/30721; A61F2/30724; A61F2/30767; A61F2002/30001; A61F2002/30003; A61F2002/30004; A61F2002/30016; A61F2002/3006; A61F2002/30065; A61F2002/30069; A61F2002/30108; A61F2002/3011; A61F2002/30112; A61F2002/30133; A61F2002/30316; A61F2002/30535; A61F2002/30563; A61F2/3094; A61F2002/30968; A61F2210/00; A61F2210/0071; A61F2230/00; A61F2230/0002; A61F2230/0004; A61F2230/0015; A61F2250/00; A61F2250/0014; A61F2250/0019; A61F2310/00; A61F2310/00389; A61F2310/00395; A61F2310/00407; A61F2310/00592; A61F2310/00796; A61F2310/00952
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
135 words
A biocompatible intervertebral spacer comprising: a central core of an unreinforced soft biocompatible elastomeric material shaped and sized so as to approximate the nucleus pulposus of a natural intervertebral disc; an outer ring of unreinforced stiffer elastomeric material surrounding said central core to approximate a natural annulus fibrosus, said outer ring and said central core forming a disc having upper and lower surfaces; and endplates comprised of a suitably stiff biocompatible material and affixed on one surface with additional elastomeric material, one to each end, to the upper and lower surfaces said endplates having a design modification on their outer surfaces which interdigitates with the adjacent bone; said spacer having a mean torsional stiffness of from 0.8 Nm/degree to 3.0 Nm degree and a mean axial stiffness of from 1000 newtons/mm to about 3000 newtons/mm.
Claim 2
Dependent Claim
135 words
A biocompatible intervertebral spacer comprising: a central core of an unreinforced soft biocompatible elastomeric material shaped and sized so as to approximate the nucleus pulposus of a natural intervertebral disc; an outer ring of unreinforced stiffer elastomeric material surrounding said central core to approximate a natural annulus fibrosus, said outer ring and said central core forming a disc having upper and lower surfaces; and endplates comprised of a suitably stiff biocompatible material and affixed on one surface with additional elastomeric material, one to each end, to the upper and lower surfaces said endplates having a design modification on their outer surfaces which interdigitates with the adjacent bone; said spacer having a mean torsional stiffness of from 0.8 Nm/degree to 3.0 Nm degree and a mean axial stiffness of from 1000 newtons/mm to about 3000 newtons/mm.
Claim 3
Dependent Claim
17 words
A spacer according to claim 1 wherein the endplates include metal spikes attached to their outer surfaces.
Claim 4
Dependent Claim
14 words
A spacer according to claim 1 wherein the endplates are comprised of elastomeric material.
Claim 5
Dependent Claim
16 words
A spacer according to claim 3 wherein the endplates are molded to provide dome-shaped outer surfaces.
Claim 6
Dependent Claim
16 words
A spacer according to claim 3 wherein the endplates include polymeric pegs on the outer surfaces.
Claim 7
Dependent Claim
18 words
A spacer according to claim 3 wherein the endplates include a polymeric inclined wedge on the outer surfaces.
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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) | 1999-08-13 | 2000-02-12 | 2000-08-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-08-13 | 2004-02-12 | 2004-08-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-08-13 | 2008-02-12 | 2008-08-13 | $7700.00 | Window Closed / Lapsed |