US4170794A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bone joint endoprosthesis
Assignee: Ceramtec GmbH
•
Filing: 1978-04-28
•
Granted: 1979-10-16
•
Expires: 1998-04-28
Abstract
Abstract A bone joint endoprosthesis comprises a spherical body of the joint with hole in it for receiving a shaft spigot; a shaft is embedded in bone; the shaft has a spigot which is received in the hole; a spreader, comprised of a material that swells when it is wetted, is wrapped over the spigot in the hole or is inside the spigot and the spreader expands radially in the hole or inside the spigot to secure the joint; shaping and profiling of the spigot and the wall of the hole for effective retention of the spreader are disclosed.
Inventors
- 👤 Anton Zeibig
- 👤 John T. Scales
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:20
CPC Classifications
F; F16; F16B; F16B4/00; F16B4/002; A; A61; A61F; A61F2/00; A61F2/02; A61F2/30; A61F2/32; A61F2/36; A61F2/3609; A61F2002/30001; A61F2002/30003; A61F2002/3006; A61F2002/30075; A61F2002/30316; A61F2002/30329; A61F2002/30331; A61F2002/30332; A61F2002/30337; A61F2002/30354; A61F2002/30405; A61F2002/30474; A61F2002/30476; A61F2002/30487; A61F2002/30535; A61F2002/30581; A61F2002/30593; A61F2/30767; A61F2/30771; A61F2002/30795; A61F2002/30797; A61F2002/3611; A61F2002/3625; A61F2002/3631; A61F2002/3647; A61F2002/365; A61F2210/00; A61F2210/0061; A61F2220/00; A61F2220/0025; A61F2220/0033
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
117 words
A bone joint endoprosthesis, comprising: a body of the bone joint; said body having a side and having a hole extending into said body from said side thereof; said body hole being defined in said body by a side wall; a shaft for being received in a bone; said shaft having an end with a spigot defined thereon; said spigot being received in said body hole and being shaped to fit therein; a spreader in said body hole; said spreader being comprised of a material that swells in the presence of a fluid; said spreader being placed such that as it swells, it applies clamping forces to hold said body of the joint securely to said spigot.
Claim 2
Dependent Claim
117 words
A bone joint endoprosthesis, comprising: a body of the bone joint; said body having a side and having a hole extending into said body from said side thereof; said body hole being defined in said body by a side wall; a shaft for being received in a bone; said shaft having an end with a spigot defined thereon; said spigot being received in said body hole and being shaped to fit therein; a spreader in said body hole; said spreader being comprised of a material that swells in the presence of a fluid; said spreader being placed such that as it swells, it applies clamping forces to hold said body of the joint securely to said spigot.
Claim 3
Dependent Claim
20 words
The bone joint endoprosthesis of claim 1, wherein said spreader comprises a sleeve around said spigot and in said hole.
Claim 4
Dependent Claim
65 words
The bone joint endoprosthesis of claim 2, wherein said spigot has an exterior and said spreader is in engagement with said exterior of said spigot; said spigot being inside said spreader; said spreader being in engagement with said side wall of said hole; whereby said spreader exerts radial forces against said spigot and said side wall of said hole in said joint body upon swelling.
Claim 5
Dependent Claim
45 words
The bone joint endoprosthesis of claim 3, wherein at least one of the exterior of said spigot and said side wall of said hole has an unevenness so that as said spreader swells, it becomes anchored by form locking of said spreader in said unevenness.
Claim 6
Dependent Claim
14 words
The bone joint endoprosthesis of claim 4, wherein said unevenness comprises a screw thread.
Claim 7
Dependent Claim
22 words
The bone joint endoprosthesis of claim 4, wherein both of said spigot exterior and said hole side wall have an unevenness thereon.
Claim 8
Dependent Claim
45 words
The bone joint endoprosthesis of claim 6, wherein said unevenness comprises said spigot having an external thread defined on it and said side wall of said hole having an internal thread on it and said spreader being held to said threads when said spreader swells.
Claim 9
Dependent Claim
53 words
The bone joint endoprosthesis of claim 7, wherein prior to being swelled, said spreader has an internal thread and said spreader internal thread is screwed onto said spigot external thread and said spreader has an external thread and said spreader external thread is screwed into said joint body internally threaded side wall hole.
Claim 10
Dependent Claim
25 words
The bone joint endoprosthesis of claim 3, wherein said spigot includes a surface positioned to block longitudinal expansion of said spreader as said spreader swells.
Claim 11
Dependent Claim
58 words
The bone joint endoprosthesis of any one of claims 1 or 2, wherein said spigot has a respective particular cross-sectional shape and said hole in said joint body has a particular cross-sectional shape and said spreader prior to swelling, has a cross-sectional shape to mate with said spigot cross-sectional shape and with said joint body hole cross-sectional shape.
Claim 12
Dependent Claim
38 words
The bone joint endoprosthesis of claim 1, wherein said spigot has a recess in it in which said spreader is received, such that when said spreader swells, said spreader presses said spigot against said body hole side wall.
Claim 13
Dependent Claim
27 words
The bone joint endoprosthesis of claim 11, wherein said spigot has an end inside said body hole; said body of said spigot extends around said spigot recess.
Claim 14
Dependent Claim
30 words
The bone joint endoprosthesis of claim 12, wherein said spreader tapers narrower toward said spigot end, and said spigot recess tapers narrower in a complementary manner toward said spigot end.
Claim 15
Dependent Claim
45 words
The bone joint endoprosthesis of claim 12, wherein said spigot recess has a reservoir space at the bottom end thereof for containing fluid; said spreader having a channel therethrough which communicates with said reservoir space for transmitting fluid from said reservoir space through said spreader.
Claim 16
Dependent Claim
24 words
The bone joint endoprosthesis of any one of claims 1, 3 or 11, wherein said spreader is at least partially comprised of a polyamide.
Claim 17
Dependent Claim
25 words
The bone joint endoprosthesis of any one of claims 1, 3 or 11, wherein said spreader is at least partially comprised of an organic material.
Claim 18
Dependent Claim
25 words
The bone joint endoprosthesis of any one of claims 1, 3 or 11, wherein said spreader is at least partially comprised of an inorganic material.
Claim 19
Dependent Claim
43 words
The bone joint endoprosthesis of one of claims 1, 4 or 9, wherein said spreader contains fibers imbedded therein and extending in the longitudinal direction of said spreader and of said spigot, for reducing swelling of said spreader in the longitudinal direction thereof.
References Cited (Backward Citations)
US3102536A
Cited
GB1334584A
Cited
DE2059381B1
Cited
GB1371335A
Cited
DE2340734A1
Cited
US3973278A
Cited
DE2451275A1
Cited
US4012795A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-10-15 | 1983-04-16 | 1983-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-10-15 | 1987-04-16 | 1987-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-10-15 | 1991-04-16 | 1991-10-16 | $7700.00 | Window Closed / Lapsed |