Patent US5092898A successfully refreshed from Google Patents.
US5092898A
Expired / Lapsed
US
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Artificial joint
Assignee: Niterra Co Ltd
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Filing: 1989-05-31
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Granted: 1992-03-03
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Expires: 2009-05-31
Abstract
Abstract An artificial femoral head having outer casing and generally spherical head inserted therein with a plurality of bearings inserted therebetween, permitting rotation with a coefficient of friction substantially equal to that of human cartilage. An artificial hip joint having a cup-shaped socket, capable of either being threaded or cemented into a bone cavity, having a generally spherical head inserted therein, having a plurality of bearings therebetween permitting rotation. Another embodiment of the hip joint includes a slide bearing inserted therebetween in addition to the plurality of bearings, permitting rotation in a range up to 120°.
Inventors
- 👤 Katsutoshi Bekki
- 👤 Kiyoshi Shinjo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:19
CPC Classifications
A; A61; A61F; A61F2/00; A61F2/02; A61F2/30; A61F2/32; A61F2/36; A61F2/3609; A61F2002/30001; A61F2002/30316; A61F2002/30329; A61F2002/30476; A61F2002/305; A61F2002/30535; A61F2002/30563; A61F2002/30621; A61F2002/30639; A61F2002/30667; A61F2002/30673; A61F2002/30682; A61F2002/30685; A61F2/30767; A61F2/30771; A61F2002/3085; A61F2002/3208; A61F2002/3233; A61F2002/3241; A61F2/34; A61F2002/3412; A61F2002/3414; A61F2002/3445; A61F2002/3448; A61F2002/3611; A61F2/46; A61F2002/4631; A61F2310/00; A61F2310/00005; A61F2310/00161; A61F2310/00179; A61F2310/00185; A61F2310/00203; A61F2310/00239; A61F2310/00269; A61F2310/00281; A61F2310/00299; A61F2310/00317
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
227 words
An artificial femoral head, comprising: a casing having an outer surface for attachment to a human bone and a smooth inner arcuate surface having a predetermined diameter defining an opening therein, and a groove formed in the inner surface encircling said opening; a generally spherical head member disposed in the opening of the casing, said head member having a smooth outer surface opposing the inner surface of said casing and having a diameter smaller than the predetermined diameter of said casing; a plurality of bearing members disposed between the inner surface of the casing and the outer surface of the head member for permitting rotation between the head member and the casing; a fixing ring surrounding the opening of said casing mounted between the inner surface of said casing and the outer surface of said head member, said fixing ring having an outer perimeter projecting into the groove formed in the inner surface of the casing, and an inner perimeter adjacent the head member, the inner perimeter having a diameter less than the diameter of said head member, preventing removal of said head member through the opening in said casing; and a retaining ring engaging at least a portion of said plurality of bearing members, for retaining said plurality of bearing members between the inner surface of the casing and the outer surface of the head member.
Claim 2
Dependent Claim
227 words
An artificial femoral head, comprising: a casing having an outer surface for attachment to a human bone and a smooth inner arcuate surface having a predetermined diameter defining an opening therein, and a groove formed in the inner surface encircling said opening; a generally spherical head member disposed in the opening of the casing, said head member having a smooth outer surface opposing the inner surface of said casing and having a diameter smaller than the predetermined diameter of said casing; a plurality of bearing members disposed between the inner surface of the casing and the outer surface of the head member for permitting rotation between the head member and the casing; a fixing ring surrounding the opening of said casing mounted between the inner surface of said casing and the outer surface of said head member, said fixing ring having an outer perimeter projecting into the groove formed in the inner surface of the casing, and an inner perimeter adjacent the head member, the inner perimeter having a diameter less than the diameter of said head member, preventing removal of said head member through the opening in said casing; and a retaining ring engaging at least a portion of said plurality of bearing members, for retaining said plurality of bearing members between the inner surface of the casing and the outer surface of the head member.
Claim 3
Dependent Claim
37 words
The femoral head of claim 1, further including an arcuate retainer element disposed between said casing and said head member, having a plurality of apertures for receiving the bearing members in axial spaced relation to one another.
Claim 4
Dependent Claim
16 words
The femoral head of claim 2 wherein said plurality of bearings and retainer element are metallic.
Claim 5
Dependent Claim
16 words
The femoral head of claim 2 wherein said plurality of bearings and retainer element are ceramic.
Claim 6
Dependent Claim
14 words
The femoral head of claim 1, wherein said plurality of bearings include ball bearings.
Claim 7
Dependent Claim
15 words
The femoral head of claim 1, wherein said plurality of bearings include cylindrical roller bearings.
Claim 8
Dependent Claim
22 words
The femoral head of claim 1, wherein the outer surface of said casing is threaded for rotatable insertion into the human bone.
Claim 9
Dependent Claim
24 words
The femoral head of claim 1, wherein the outer surface of said casing is smooth for attachment to the human bone with bone cement.
Claim 10
Dependent Claim
25 words
The femoral head of claim 1, further including an arcuate buffer plate disposed between said inner surface of said socket and said plurality of bearings.
Claim 11
Dependent Claim
16 words
The femoral head of claim 1, further including a synovial fluid for lubricating said bearing members.
Claim 12
Dependent Claim
11 words
The femoral head of claim 1, wherein said casing is ceramic.
Claim 13
Dependent Claim
12 words
The femoral head of claim 1, wherein said head member is ceramic.
Claim 14
Dependent Claim
12 words
The femoral head of claim 1, wherein said bearing members are ceramic.
Claim 15
Dependent Claim
26 words
The femoral head of claim 1, wherein said bearing members rollingly abut the inner surface of the casing and the outer surface of the head member.
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) | 1995-03-03 | 1995-09-02 | 1996-03-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-03-03 | 1999-09-02 | 2000-03-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-03-03 | 2003-09-02 | 2004-03-03 | $7700.00 | Window Closed / Lapsed |