US5037442A
Expired / Lapsed
US
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Fixing stem for a prosthesis
Assignee: Sulzer AG
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Filing: 1989-08-11
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Granted: 1991-08-06
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Expires: 2009-08-11
Abstract
Abstract The stem of the endoprosthesis comprises a core which provides the necessary strength to the endoprosthesis and a jacket or sleeve of thermoplastic having a softening temperature below 60° C. The jacket can be made flowable upon heating so that during implantation, the jacket can be adapted to the bone cavity. In addition, the jacket can be heated at any subsequent time to return to a plastically deformable state in order to facilitate re-operations.
Inventors
- 👤 Erich Wintermantel
- 👤 Manfred Flemming
- 👤 Otto Frey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:42
CPC Classifications
A; A61; A61L; A61L27/00; A61L27/50; A61F; A61F2/00; A61F2/02; A61F2/30; A61F2/3094; A61F2/30965; A61F2/32; A61F2/36; A61F2/3662; A61L27/28; A61L27/34; A61F2/30942; A61F2/28; A61F2002/2817; A61F2002/2821; A61F2002/30001; A61F2002/30003; A61F2002/3006; A61F2002/30065; A61F2/30767; A61F2/30907; A61F2002/30909; A61F2210/00; A61F2210/0071
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
55 words
A fixing stem for a prosthesis comprising a rigid core capable of being heated; and a thermoplastic jacket peripherally surrounding said core and having a softening temperature below a predetermined physiological critical value and wherein said predetermined physiological critical value is less than or equal to 75° C. for softening upon heating of said core.
Claim 2
Dependent Claim
55 words
A fixing stem for a prosthesis comprising a rigid core capable of being heated; and a thermoplastic jacket peripherally surrounding said core and having a softening temperature below a predetermined physiological critical value and wherein said predetermined physiological critical value is less than or equal to 75° C. for softening upon heating of said core.
Claim 3
Dependent Claim
23 words
A fixing stem as set forth in claim 1 wherein said temperature is in the range of from 45° C. to 60° C.
Claim 4
Dependent Claim
16 words
A fixing stem as set forth in claim 1 wherein said jacket is of constant thickness.
Claim 5
Dependent Claim
18 words
A fixing stem as set forth in claim 1 wherein said core is made of fiber reinforced plastic.
Claim 6
Dependent Claim
42 words
A fixing stem as set forth in claim 4 wherein said core has a non-uniform shape including a central zone and a mechanically workable shaping zone about said central zone, each said zone having a different fiber density from the other zone.
Claim 7
Dependent Claim
21 words
A fixing stem as set forth in claim 1 wherein said core and said jacket are made of the same plastic.
Claim 8
Dependent Claim
33 words
A fixing stem as set forth in claim 1 wherein at least one of said core and said jacket is electrically conductive to permit electrical heating of said jacket to said softening temperature.
Claim 9
Dependent Claim
19 words
A fixing stem as set forth in claim 1 wherein said jacket contains a substance to stimulate bone ingrowth.
Claim 10
Dependent Claim
27 words
A fixing a stem as set forth in claim 1 which further comprises multilayer wire meshes in at least some zones of said jacket for bone ingrowth.
Claim 11
Dependent Claim
26 words
A fixing stem as set forth in claim 1 which further comprises a non-softening closure element at a distal end of said core abutting said jacket.
Claim 12
Dependent Claim
25 words
A fixing stem as set forth in claim 1 which further comprises an electrical heating loop disposed in said core for heating of said jacket.
Claim 13
Dependent Claim
58 words
A fixing stem for a prosthesis comprising a rigid elongated core of fiber reinforced plastic; and a thermoplastic jacket surrounding said core and having a softening temperature below a predetermined physiological critical value and wherein said predetermined physiological critical value is less than or equal to 75° C. for softening upon heating thereof during implantation in a bone.
Claim 14
Dependent Claim
58 words
A fixing stem for a prosthesis comprising a rigid elongated core of fiber reinforced plastic; and a thermoplastic jacket surrounding said core and having a softening temperature below a predetermined physiological critical value and wherein said predetermined physiological critical value is less than or equal to 75° C. for softening upon heating thereof during implantation in a bone.
Claim 15
Dependent Claim
23 words
A fixing stem as set forth in claim 12 wherein said temperature is in the range of from 45° C. to 60° C.
Claim 16
Dependent Claim
42 words
A fixing stem as set forth in claim 13 wherein said core has a non-uniform shape including a central zone and a mechanically workable shaping zone about said central zone, each said zone having a different fiber density from the other zone.
Claim 17
Dependent Claim
33 words
A fixing stem as set forth in claim 13 wherein at least one of said core and said jacket is electrically conductive to permit electrical heating of said jacket to said softening temperature.
Claim 18
Dependent Claim
26 words
A fixing stem as set forth in claim 13 which further comprises a non-softening closure element at a distal end of said core abutting said jacket.
Claim 19
Dependent Claim
53 words
A fixing stem for a prosthesis comprising a rigid core of fiber reinforced plastic having an electrical heating loop herein for heating of said core; and a thermoplastic jacket peripherally surrounding said core for heating by said core and having a softenable temperature in a range of from 45° C. to 60° C.
Claim 20
Dependent Claim
53 words
A fixing stem for a prosthesis comprising a rigid core of fiber reinforced plastic having an electrical heating loop herein for heating of said core; and a thermoplastic jacket peripherally surrounding said core for heating by said core and having a softenable temperature in a range of from 45° C. to 60° C.
Claim 21
Dependent Claim
26 words
A fixing stem as set forth in claim 17 wherein said jacket is electrically conductive to permit electrical heating of said jacket to said softening temperature.
Claim 22
Dependent Claim
89 words
A fixing stem for a prosthesis comprising a rigid elongated core of fiber reinforced plastic having at least one of carbon and copper filaments therein to be electrically conductive; and a thermoplastic jacket surrounding said core and having a softening temperature below a predetermined physiological critical value and wherein said predetermined physiological critical value is less than or equal to 75° C., said jacket having at least one of carbon and copper filaments therein to be electrically conductive to permit electric heating of said jacket to said softening temperature.
Claim 23
Dependent Claim
89 words
A fixing stem for a prosthesis comprising a rigid elongated core of fiber reinforced plastic having at least one of carbon and copper filaments therein to be electrically conductive; and a thermoplastic jacket surrounding said core and having a softening temperature below a predetermined physiological critical value and wherein said predetermined physiological critical value is less than or equal to 75° C., said jacket having at least one of carbon and copper filaments therein to be electrically conductive to permit electric heating of said jacket to said softening temperature.
Claim 24
Dependent Claim
23 words
A fixing stem as set forth in claim 19 wherein said temperature is in the range of from 45° C. to 60° C.
References Cited (Backward Citations)
US4195367A
Cited
US4362681A
Cited
FR2425237A1
Cited
GB2045082A
Cited
EP0071658A1
Cited
US4366183A
Cited
US4562598A
Cited
US4570271A
Cited
US4506681A
Cited
US4532660A
Cited
EP0145339A2
Cited
US4609551A
Cited
US4778474A
Cited
US4904534A
Cited
US4750905A
Cited
WO1987004916A1
Cited
US4812120A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-08-05 | 1995-02-04 | 1995-08-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-08-05 | 1999-02-04 | 1999-08-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-08-05 | 2003-02-04 | 2003-08-06 | $7700.00 | Window Closed / Lapsed |