Patent US4759769A successfully refreshed from Google Patents.
US4759769A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Artificial spinal disc
Assignee: Health & Research Services Inc
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Filing: 1987-06-22
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Granted: 1988-07-26
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Expires: 2007-06-22
Abstract
Abstract An artificial disc for a human spine. The disc has upper and lower members hinged together at their rear portions and biased apart at their fronts by stiff coil springs. Rear stop surfaces limit the opening movement of the members. Vertically projecting tabs at the front and side of each member are rigidly screwed to the adjacent vertebrae. Tolerances in the hinge allow limited side to side rocking. The disc and screws are made of titanium alloy or cobalt chrome alloy. In a modified version a hinge pin is replaced by cables tying the members together.
Inventors
- 👤 Thomas P. Hedman
- 👤 John P. Kostuik
- 👤 Geoffrey R. Fernie
- 👤 Brian E. Maki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:29
CPC Classifications
A; A61; A61F; A61F2/00; A61F2/02; A61F2/30; A61F2/44; A61F2/442; A61F2/4425; A61F2002/30001; A61F2002/30316; A61F2002/30329; A61F2002/30462; A61F2002/30535; A61F2002/30565; A61F2002/30566; A61F2002/30568; A61F2002/30576; A61F2002/30578; A61F2002/30621; A61F2002/30624; A61F2002/443; A61F2220/00; A61F2220/0025; A61F2220/0075
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
208 words
An artificial disc for a human spine, said disc being adapted to replace a natural disc and to be located between two vertebrae, said disc comprising: (a) upper and lower members, each having a rear portion and a front portion, (b) said upper and lower members having hinge-like means adapted to permit a hinging motion of said upper and lower members relative to each other about said rear portions, (c) spring means positioned between said upper and lower members and biasing said front portions apart, (d) means securing said upper and lower members together and for permitting said hinging motion, (e) said upper member having means for rigidly securing said upper member to a first vertebrae above said upper member, and said lower member having means for rigidly securing said lower member to a second vertebrae below said lower member, (f) said means for rigidly securing said upper member comprising an upwardly extending projection adapted for mechanically locking said first member to said first vertebrae, and said means for rigidly securing said lower member comprising a downwardly extending projection adapted for mechanically locking said lower member to said second vertebrae, (g) said upper and lower members and said spring means all being made of a biocompatible metal alloy.
Claim 2
Dependent Claim
208 words
An artificial disc for a human spine, said disc being adapted to replace a natural disc and to be located between two vertebrae, said disc comprising: (a) upper and lower members, each having a rear portion and a front portion, (b) said upper and lower members having hinge-like means adapted to permit a hinging motion of said upper and lower members relative to each other about said rear portions, (c) spring means positioned between said upper and lower members and biasing said front portions apart, (d) means securing said upper and lower members together and for permitting said hinging motion, (e) said upper member having means for rigidly securing said upper member to a first vertebrae above said upper member, and said lower member having means for rigidly securing said lower member to a second vertebrae below said lower member, (f) said means for rigidly securing said upper member comprising an upwardly extending projection adapted for mechanically locking said first member to said first vertebrae, and said means for rigidly securing said lower member comprising a downwardly extending projection adapted for mechanically locking said lower member to said second vertebrae, (g) said upper and lower members and said spring means all being made of a biocompatible metal alloy.
Claim 3
Dependent Claim
97 words
An artificial disc according to claim 1 wherein said upwardly extending projection comprises at least two upwardly projecting tabs adapted to overlie the side surfaces of said first vertebrae, said means for rigidly securing said upper member further comprising screws adapted to extend through said tabs and into said first vertebrae, and said downwardly extending projection comprises at least two downwardly projecting tabs adapted to overlie the side surfaces of said second vertebrae, said means for rigidly securing said lower member further comprising screws adapted to extend through said downwardly projecting tabs and into said second vertebrae.
Claim 4
Dependent Claim
40 words
An artificial disc according to claim 2 wherein for each member, one of said tabs is substantially at the center of the front of such member and a second one of said tabs is at the side of such member.
Claim 5
Dependent Claim
27 words
An artificial disc according to claim 3 wherein said second tab is substantially aligned in a front to rear direction with the axis of said hinge-like means.
Claim 6
Dependent Claim
23 words
An artificial disc according to claim 4 wherein all of said screws are of length sufficient to penetrate substantially entirely through said vertebrae.
Claim 7
Dependent Claim
29 words
An artificial disc according to claim 2 wherein said tabs have holes therein at different levels for receiving said screws, to prevent said screws from interfering with each other.
Claim 8
Dependent Claim
49 words
An artificial disc according to claim 1 wherein said hinge-like means includes means for permitting at least a limited amount of side to side rocking of said upper and lower members relative to each other about a vertical front to rear plane extending through the center of said members.
Claim 9
Dependent Claim
21 words
An artificial disc according to claim 1 wherein said means securing said upper and lower members together comprises a hinge pin.
Claim 10
Dependent Claim
67 words
An artificial disc according to claim 1 wherein said means securing said upper and lower members together comprises a hinge pin extending through aligned holes in said upper and lower members, said holes having sufficient tolerance to allow a limited amount of side to side rocking of said members relative to each other about a vertical front to rear plane extending through the center of said members.
Claim 11
Dependent Claim
73 words
An artificial disc according to claim 1 wherein said means securing said upper and lower members together comprises a hinge pin extending through aligned holes in said upper and lower members, said holes having sufficient tolerance to allow a limited amount of side to side rocking of said members relative to each other about a vertical front to rear plane extending through the center of said members, said hinge pin having tapered ends.
Claim 12
Dependent Claim
39 words
An artificial disc according to claim 1 wherein said means securing said upper and lower members together comprises a pair of cables, one at each side of said members, each cable being secured to said upper and lower members.
Claim 13
Dependent Claim
19 words
An artificial disc according to claim 11 wherein said cables extend through holes in said upper and lower members.
Claim 14
Dependent Claim
32 words
An artificial disc according to claim 1 wherein said upper and lower members have cooperating stop means at said rear portions to limit the amount of opening hinging movement between said members.
Claim 15
Dependent Claim
20 words
An artificial disc according to claim 1 wherein said spring means comprises coil springs located forwardly of said hinge-like means.
Claim 16
Dependent Claim
48 words
An artificial disc according to claim 1 wherein said spring means comprises two pairs of coil springs, said pairs being located side by side and forwardly of said hinge-like means, each pair comprising an inner coil spring and an outer coil spring concentric with said inner coil spring.
Claim 17
Dependent Claim
37 words
An artificial disc according to claim 1 wherein said upper and lower members and said spring means are all made of a bio-compatible alloy selected from titanium-6 aluminum-4 vanadium ELI alloy and a cobalt chrome molybdenum alloy.
Claim 18
Dependent Claim
30 words
An artificial disc according to claim 1 wherein said spring means has the same stiffness as the in vitro physiologic stiffness in a sagittal plane of a natural spinal disc.
Claim 19
Dependent Claim
26 words
An artificial disc according to claim 1 wherein said spring means creates a resistive torque of between 1.0 and 1.65 foot pounds per degree of compression.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-07-26 | 1992-01-25 | 1992-07-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-07-26 | 1996-01-25 | 1996-07-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-07-26 | 2000-01-25 | 2000-07-26 | $7700.00 | Window Closed / Lapsed |