US3886599A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Surgically implantable total ankle prosthesis
Assignee: Individual
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Filing: 1974-07-25
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Granted: 1975-06-03
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Expires: 1994-07-25
Abstract
Abstract An implantable total ankle prosthesis consists of an upper portion formed of highly polished metal having a stem which is firmly attached to a correspondingly shaped slot formed in the tibia, and a lower portion formed of ultra-high density polyethelyne and having a shank shaped to be sunk into a cavity formed in the surface of the body of the talus. The confronting surfaces of the upper and lower portions are both convex, thereby to provide a bi-plane sliding joint having minimal friction and allowing simultaneous rotational movement. The prosthesis is implantable through an anterior or anterior-medial incision, this approach leaving the ligaments on the lateral and medial side of the ankle joint essentially undisturbed so as to preserve the normal medial-lateral stability of the articulation.
Inventors
- 👤 Allen P Schlein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 10:41
CPC Classifications
A; A61; A61F; A61F2/00; A61F2/02; A61F2/30; A61F2/42; A61F2/4202
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
97 words
Prosthesis for total replacement of the ankle joint of humans comprising, first and second bearing members each having a convex surface and adapted to engage each other along a line contact, said first bearing member being formed of a metal alloy which is essentially non-reactive with body tissue and having a stem adapted to be received in a cavity formed in the tibia, and said second bearing member being formed of high density plastic material and including an integral shank adapted to be received in a cavity formed in the surface of the head of the talus.
Claim 2
Dependent Claim
97 words
Prosthesis for total replacement of the ankle joint of humans comprising, first and second bearing members each having a convex surface and adapted to engage each other along a line contact, said first bearing member being formed of a metal alloy which is essentially non-reactive with body tissue and having a stem adapted to be received in a cavity formed in the tibia, and said second bearing member being formed of high density plastic material and including an integral shank adapted to be received in a cavity formed in the surface of the head of the talus.
Claim 3
Dependent Claim
97 words
Prosthesis for total replacement of the ankle joint of humans comprising, first and second bearing members each having a convex surface and adapted to engage each other along a line contact, said first bearing member being formed of a metal alloy which is essentially non-reactive with body tissue and having a stem adapted to be received in a cavity formed in the tibia, and said second bearing member being formed of high density plastic material and including an integral shank adapted to be received in a cavity formed in the surface of the head of the talus.
Claim 4
Dependent Claim
97 words
Prosthesis for total replacement of the ankle joint of humans comprising, first and second bearing members each having a convex surface and adapted to engage each other along a line contact, said first bearing member being formed of a metal alloy which is essentially non-reactive with body tissue and having a stem adapted to be received in a cavity formed in the tibia, and said second bearing member being formed of high density plastic material and including an integral shank adapted to be received in a cavity formed in the surface of the head of the talus.
Claim 5
Dependent Claim
55 words
Prosthesis in accordance with claim 1 wherein said first bearing member comprises a generally rectangular block of said metal alloy, one surface of which has a predetermined radius of curvature defining its convex bearing surface, and wherein said stem is of T-shape and extends upwardly from the surface of the block opposite the convex surface.
Claim 6
Dependent Claim
29 words
Prosthesis in accordance with claim 2, wherein the convex surface of said second bearing member is of trapezoidal shape, with the posterior dimension being narrower than the anterior dimension.
Claim 7
Dependent Claim
28 words
Prosthesis in accordance with claim 3, wherein the shank on said second bearing member depends from the surface thereof opposite the convex surface and is of circular cross-section.
Claim 8
Dependent Claim
35 words
Prosthesis in accordance with claim 2, wherein said T-shaped stem has at least one groove formed therein for increasing the holding power of the cement with which said bearing member is secured to the tibia.
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) | 1978-06-02 | 1978-12-02 | 1979-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-02 | 1982-12-02 | 1983-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-02 | 1986-12-02 | 1987-06-03 | $7700.00 | Window Closed / Lapsed |