US4021864A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ankle prosthesis
Assignee: University of California, San Diego
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Filing: 1976-04-14
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Granted: 1977-05-10
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Expires: 1996-04-14
Abstract
Abstract A partial prosthesis for a human ankle joint has a metal tibial member with a flat triangular stem, which is implanted in the tibia. The base of the tibial member has a hollow toroidal section in its bottom. The talar member has an upper toroidal section which is engaged by that in the tibial member to provide articulation in the lateral/medial plane and in the anterior/posterior plane with inherent torsional stability.
Inventors
- 👤 Theodore Rogers Waugh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 05:44
CPC Classifications
A; A61; A61F; A61F2/00; A61F2/02; A61F2/30; A61F2/42; A61F2/4202; A61F2002/30001; A61F2002/30108; A61F2002/3011; A61F2002/30112; A61F2002/30113; A61F2002/30118; A61F2002/30138; A61F2002/30156; A61F2/30767; A61F2/30771; A61F2002/30772; A61F2002/30836; A61F2002/30841; A61F2002/30843; A61F2002/30845; A61F2002/30878; A61F2002/30884; A61F2/46; A61F2002/4631; A61F2230/00; A61F2230/0002; A61F2230/0004; A61F2230/0006; A61F2230/0017; A61F2230/0023; A61F2310/00; A61F2310/00005; A61F2310/00011; A61F2310/00029
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
140 words
A partial prosthesis for a human ankle joint having a tibia and a talus comprising a tibial member, said tibial member having a tibial base, a tibial stem substantially centrally disposed upon the tibial base and extending upwardly therefrom to provide means for connecting said tibial member of the tibia, a concave toroidal section in the bottom of said tibial base, a talar member, a talar stem substantially centrally disposed upon the talar base extending downwardly for attaching it to said talus, a substantially convex toroidal section upon the upper surface of said talar member, said prosthesis having lateral/medial and anterior/posterior planes of movement, said toroidal sections each having a longer radius of curvature in said anterior/posterior plane than the radius of curvature in said lateral/medial plane whereby articulation is provided between the members in both planes with inherent stability.
Claim 2
Dependent Claim
140 words
A partial prosthesis for a human ankle joint having a tibia and a talus comprising a tibial member, said tibial member having a tibial base, a tibial stem substantially centrally disposed upon the tibial base and extending upwardly therefrom to provide means for connecting said tibial member of the tibia, a concave toroidal section in the bottom of said tibial base, a talar member, a talar stem substantially centrally disposed upon the talar base extending downwardly for attaching it to said talus, a substantially convex toroidal section upon the upper surface of said talar member, said prosthesis having lateral/medial and anterior/posterior planes of movement, said toroidal sections each having a longer radius of curvature in said anterior/posterior plane than the radius of curvature in said lateral/medial plane whereby articulation is provided between the members in both planes with inherent stability.
Claim 3
Dependent Claim
36 words
A prosthesis as set forth in claim 1 wherein the major portion of the tibial base is comprised of biocompatible metal and an insert including the concave toroidal section is comprised of ultrahigh molecular weight polyethylene.
Claim 4
Dependent Claim
23 words
A prosthesis as set forth in claim 2 wherein said tibial stem is substantially flat with a triangular shape in said anterior/posterior plane.
Claim 5
Dependent Claim
21 words
A prosthesis as set forth in claim 3 wherein the sides of said tibial stem are toothed by truncated pyramidal projections.
Claim 6
Dependent Claim
19 words
A prosthesis as set forth in claim 4 wherein said tibial stem also includes a hole for assisting retention.
Claim 7
Dependent Claim
15 words
A prosthesis as set forth in claim 1 wherein said tibial base is substantially rectangular.
Claim 8
Dependent Claim
40 words
A prosthesis as set forth in claim 6 wherein central portions of the bottom of the tibial base in said anterior/posterior plane are disposed lower than the outer portions whereby they engage over the toroidal section on the talar member.
Claim 9
Dependent Claim
28 words
A prosthesis as set forth in claim 1 wherein retaining surface means are provided on said talar base and the retaining surface means is comprised of arcuate teeth.
Claim 10
Dependent Claim
34 words
A prosthesis as set forth in claim 8 wherein said arcuate teeth are disposed convexly away from each other on both sides of said centrally-positioned stem projecting from the bottom of said talar member.
Claim 11
Dependent Claim
17 words
A prosthesis as set forth in claim 1 wherein said talar member is comprised of biocompatible metal.
Claim 12
Dependent Claim
18 words
A prosthesis as set forth in claim 1 wherein the tibial base has a substantially flat upper surface.
Claim 13
Dependent Claim
19 words
A prosthesis as set forth in claim 11 wherein the tibial base surface is toothed by truncated pyramidal projections.
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) | 1980-05-09 | 1980-11-08 | 1981-05-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-09 | 1984-11-08 | 1985-05-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-09 | 1988-11-08 | 1989-05-10 | $7700.00 | Window Closed / Lapsed |