US5258033A
Expired / Lapsed
US
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Total hip replacement femoral component
Assignee: HOWMEDICA INTERNATIONAL S DE RL
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Filing: 1991-07-26
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Granted: 1993-11-02
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Expires: 2011-07-26
Abstract
Abstract A total hip replacement femoral component has an outer surface shaped to conform to an acetabular socket and has an internal bore adapted to receive a femoral head. The head has been shaped and dimensioned to provide a spigot to enter the bore and be locked in place by a cement mantle between the bone and the walls of the bore. The head allows the hip component to move further over said spigot and re-lock should the cement creep or thereby any movement in the bone after assembly. The internal bore is inwardly tapered. Thus the taper can be co-axial with the femoral neck, but there may be advantages in orientating the axis of the taper as close to vertical as possible when in position so that it is closer to the average force vector acting on the femoral head during human activity.
Inventors
- 👤 Peter Lawes
- 👤 Robin S. M. Ling
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 08:18
CPC Classifications
A; A61; A61F; A61F2/00; A61F2/02; A61F2/30; A61F2/32; A61F2/36; A61F2/3601; A61F2/3603; A61B; A61B17/00; A61B17/56; A61B17/58; A61B17/88; A61B17/8802; A61B17/8805; A61B17/8808; A61F2/30721; A61F2/30724; A61F2002/30001; A61F2002/30108; A61F2002/30199; A61F2002/302; A61F2002/30205; A61F2002/30217; A61F2002/30289; A61F2002/30316; A61F2002/30329; A61F2002/30331; A61F2002/30332; A61F2002/30405; A61F2002/30535; A61F2002/30593; A61F2/30734; A61F2002/30738; A61F2/30767; A61F2/30771; A61F2002/3082; A61F2002/30878; A61F2/30907; A61F2002/30919; A61F2/34; A61F2002/3429; A61F2/3609; A61F2002/365; A61F2/46; A61F2002/4631; A61F2220/00; A61F2220/0025; A61F2220/0033; A61F2230/00; A61F2230/0063; A61F2230/0065; A61F2230/0067; A61F2230/0091; A61F2310/00; A61F2310/00005; A61F2310/00353; A61F2310/00389; A61F2310/00952
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
155 words
A femoral prosthesis adapted to be cemented to a prepared natural femoral head, the prepared head having a conically tapered outer surface, comprising: a ball-shaped component having an outer surface conforming to an acetabular socket, said ball-shaped outer component having a blind bore formed therein, said bore tapering inwardly from a larger diameter at an open distal end thereof to a smaller diameter at the blind end of the bore, said taper generally matching the taper of the prepared head; and a deformable spacer for insertion into said bore having an outer diameter larger than said smaller diameter at the blind end of said bore, and smaller than said larger diameter at the open end of said bore, whereby said spacer prevents admission of bone cement into said bore and creates a void at the blind end of said bore after insertion therein and cementation of said ball-shaped component to the prepared natural femoral head.
Claim 2
Dependent Claim
155 words
A femoral prosthesis adapted to be cemented to a prepared natural femoral head, the prepared head having a conically tapered outer surface, comprising: a ball-shaped component having an outer surface conforming to an acetabular socket, said ball-shaped outer component having a blind bore formed therein, said bore tapering inwardly from a larger diameter at an open distal end thereof to a smaller diameter at the blind end of the bore, said taper generally matching the taper of the prepared head; and a deformable spacer for insertion into said bore having an outer diameter larger than said smaller diameter at the blind end of said bore, and smaller than said larger diameter at the open end of said bore, whereby said spacer prevents admission of bone cement into said bore and creates a void at the blind end of said bore after insertion therein and cementation of said ball-shaped component to the prepared natural femoral head.
Claim 3
Dependent Claim
16 words
The femoral prosthesis as set forth in claim 1 wherein said spacer is made of polymethylmethacrylate.
Claim 4
Dependent Claim
28 words
The femoral prosthesis as set forth in claim 1 wherein said spacer is cup-shaped with side walls extending to the distal end of said bore after insertion therein.
Claim 5
Dependent Claim
23 words
The femoral prosthesis of claim 1 wherein said ball-shaped component includes a means for preventing rotation thereof around the prepared natural femoral head.
Claim 6
Dependent Claim
37 words
The femoral prosthesis as set forth in claim 4 wherein the natural femoral head is prepared with a raised key and said means for preventing rotation is a keyway formed in said bore of said ball-shaped component.
Claim 7
Dependent Claim
39 words
The femoral prosthesis as set forth in claim 4 wherein the natural femoral head is prepared with a flat face and said means for preventing rotation is a corresponding flat face formed on said bore of said ball-shaped component.
Claim 8
Dependent Claim
180 words
A prosthetic femoral component for implantation on a conically tapered prepared end of a natural femur with bone cement, comprising: a deformable spacer having a disc-shaped base and a conical wall extending from said base and having an inner and outer surface tapering inwardly toward said base from a larger diameter of said spacer at an open end thereof, said conical walls of said spacer defining an opening for receiving the conically tapered prepared end of a natural femur; and a ball-shaped component having a blind bore formed therein, said bore tapering inwardly from a larger diameter at an open end thereof to a smaller diameter at the blind end thereof, said open end of said bore having a diameter large enough to receive said spacer therein and having a taper generally corresponding to said taper of said conical wall of said spacer, wherein said spacer prevents admission of bone cement into said bore and creates a void at the blind end of said bore after insertion therein and cementation of said ball-shaped component to the prepared natural femoral head.
Claim 9
Dependent Claim
180 words
A prosthetic femoral component for implantation on a conically tapered prepared end of a natural femur with bone cement, comprising: a deformable spacer having a disc-shaped base and a conical wall extending from said base and having an inner and outer surface tapering inwardly toward said base from a larger diameter of said spacer at an open end thereof, said conical walls of said spacer defining an opening for receiving the conically tapered prepared end of a natural femur; and a ball-shaped component having a blind bore formed therein, said bore tapering inwardly from a larger diameter at an open end thereof to a smaller diameter at the blind end thereof, said open end of said bore having a diameter large enough to receive said spacer therein and having a taper generally corresponding to said taper of said conical wall of said spacer, wherein said spacer prevents admission of bone cement into said bore and creates a void at the blind end of said bore after insertion therein and cementation of said ball-shaped component to the prepared natural femoral head.
Claim 10
Dependent Claim
16 words
The femoral prosthesis as set forth in claim 7 wherein said spacer is made of polymethylmethacrylate.
Claim 11
Dependent Claim
23 words
The femoral prosthesis of claim 7 wherein said ball-shaped component includes a means for preventing rotation thereof around the prepared natural femoral head.
Claim 12
Dependent Claim
39 words
The femoral prosthesis as set forth in claim 7 wherein the natural femoral head is prepared with a flat face, and said means for preventing rotation is a corresponding flat face form on said bore of said ball-shaped component.
References Cited (Backward Citations)
FR2304324A1
Cited
US4005495A
Cited
FR2361861A1
Cited
US4123806A
Cited
US4332036A
Cited
US4846841A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-11-01 | 1997-05-03 | 1997-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-11-01 | 2001-05-03 | 2001-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-11-01 | 2005-05-03 | 2005-11-02 | $7700.00 | Window Closed / Lapsed |