US4217666A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tibial prosthesis having a U-shaped intramedullary stem
Assignee: Biomet Inc
•
Filing: 1979-04-05
•
Granted: 1980-08-19
•
Expires: 1999-04-05
Abstract
Abstract A tibial prosthesis which interacts with a femoral prosthesis to provide a knee joint replacement is disclosed. The prosthesis comprises a tibial plateau platform provided with an intramedullary stem having a generally U-shaped cross section allowing for retention of the cruciate ligaments of the knee joint while still achieving adequate anchorage of the device to the proximal end of the tibia.
Inventors
- 👤 Robert G. Averill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:37
CPC Classifications
A; A61; A61F; A61F2/00; A61F2/02; A61F2/30; A61F2/38; A61F2/389; A61F2002/30001; A61F2002/30108; A61F2002/3011; A61F2002/30112; A61F2002/30131; A61F2230/00; A61F2230/0002; A61F2230/0004; A61F2230/0013
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
104 words
A tibial prosthesis for interaction with a femoral prosthesis having a central slot therein for passage of the cruciate ligaments, said tibial prosthesis comprising a generally U-shaped tibial plateau platform, a bearing insert removably attached to each leg of said U-shaped platform for sliding contact with the condylar surface of said femoral prosthesis, an intramedullary fixation stem attached to said platform along one edge thereof, said stem having a generally tapered U-shaped cross section, the attachment area of said stem to said platform being U-shaped to thereby define a central opening to allow for passage of and permit unimpeded action of the cruciate ligaments.
Claim 2
Dependent Claim
104 words
A tibial prosthesis for interaction with a femoral prosthesis having a central slot therein for passage of the cruciate ligaments, said tibial prosthesis comprising a generally U-shaped tibial plateau platform, a bearing insert removably attached to each leg of said U-shaped platform for sliding contact with the condylar surface of said femoral prosthesis, an intramedullary fixation stem attached to said platform along one edge thereof, said stem having a generally tapered U-shaped cross section, the attachment area of said stem to said platform being U-shaped to thereby define a central opening to allow for passage of and permit unimpeded action of the cruciate ligaments.
Claim 3
Dependent Claim
18 words
A tibial prosthesis according to claim 1 wherein said platform is fabricated from a metal or metal alloy.
Claim 4
Dependent Claim
16 words
A tibial prosthesis according to claim 2 wherein the bottom surface of said platform is texturized.
Claim 5
Dependent Claim
19 words
A tibial prosthesis according to claim 1 wherein said bearing insert is fabricated from a physiologically acceptable plastic material.
Claim 6
Dependent Claim
33 words
A tibial prosthesis according to claim 1 wherein said intramedullary fixation stem has a constant "radius" as it diminishes in depth from the attachment area to a tapered point at its free end.
Claim 7
Dependent Claim
27 words
A tibial prosthesis according to claim 5 wherein said intramedullary fixation stem has a cross section which diminishes in thickness from said attachment area to said point.
Claim 8
Dependent Claim
17 words
A tibial prosthesis according to claim 6 wherein the end of said point is flattened or rounded.
Claim 9
Dependent Claim
20 words
A tibial prosthesis according to claim 7 wherein said intramedullary fixation stem is fabricated from a metal or metal alloy.
Claim 10
Dependent Claim
17 words
A tibial prosthesis according to claim 8 wherein the surfaces of said intramedullary fixation stem are texturized.
Claim 11
Dependent Claim
55 words
A tibial prosthesis according to claim 1 wherein the cross section of said intramedullary fixation stem is lunate, has a constant radius as it diminishes in depth and thickness from the attachment area to a tapered point having a rounded end, is fabricated from a metal or metal alloy and the surface thereof are texturized.
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) | 1983-08-19 | 1984-02-18 | 1984-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-08-19 | 1988-02-18 | 1988-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-08-19 | 1992-02-18 | 1992-08-19 | $7700.00 | Window Closed / Lapsed |