US6183515B1
Expired / Lapsed
US
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Artificial bone implants
Assignee: The University of Texas System
•
Filing: 1997-04-04
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Granted: 2001-02-06
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Expires: 2017-04-04
Abstract
Abstract A process for making bone implants from calcium phosphate powders is disclosed. This process involves selectively fusing layers of calcium powders that have been coated or mixed with polymer binders. The calcium powder mixture may be formed into layers and the polymer fused with a laser. Complex three-dimensional geometrical shapes can be automatically replicated or modified using this approach.
Inventors
- 👤 Joel W. Barlow
- 👤 Goonhee Lee
- 👤 Richard H. Crawford
- 👤 Joseph J. Beaman
- 👤 Harris L. Marcus
- 👤 Richard J. Lagow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 21:18
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/622; C04B35/626; C04B35/628; A; A61; A61F; A61F2/00; A61F2/02; A61F2/28; A61F2/30; A61F2/3094; A61F2/30942; A61L; A61L27/00; A61L27/40; A61L27/44; A61L27/46; B; B29; B29C; B29C64/00; B29C64/10; B29C64/141; B29C64/153; B29C64/165; B33; B33Y; B33Y70/00; B33Y80/00; C04B35/01; C04B35/447; C04B35/63; C04B35/632; C04B35/634; C04B35/63404; C04B35/63424; A61F2/2875; A61F2002/30001; A61F2002/30108; A61F2002/30199; A61F2/30767; A61F2002/30929; A61F2002/30952; A61F2002/30968; A61F2230/00; A61F2230/0063; A61F2310/00; A61F2310/00005; A61F2310/00179; A61F2310/00293; B29L; B29L2031/00; B29L2031/753; B29L2031/7532; B33Y10/00; C04B2235/00; C04B2235/02; C04B2235/30; C04B2235/32; C04B2235/3201; C04B2235/3205; C04B2235/3208; C04B2235/3212; C04B2235/36; C04B2235/50; C04B2235/54; C04B2235/5409; C04B2235/5418; C04B2235/5436; C04B2235/60; C04B2235/602; C04B2235/6026; C04B2235/608; C04B2235/61; C04B2235/616; C04B2235/65; C04B2235/658; C04B2235/6583; C04B2235/6584; C04B2235/66; C04B2235/665; C04B2235/70; C04B2235/74; C04B2235/77; C04B2235/80; C04B2235/96; C04B2235/9607; C04B2235/9615
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
106 words
An implant produced by a. forming a mixture of a calcium phosphate composition and a binder; b. selectively fusing the binder to form an implant green part; and c 1 . infiltrating the implant green part; or c 2 . sintering the implant green part to form an implant, wherein the calcium phosphate composition does not decompose to produce water during step b, and the implant replicates a naturally complex bone geometry, has a complex three-dimensional shape with a well-defined cavity, the cavity replicating internal complex bone geometry, has a controlled, interconnected porosity, and has a mole ratio of calcium to phosphorus of 0.5 to 1.
Claim 2
Dependent Claim
106 words
An implant produced by a. forming a mixture of a calcium phosphate composition and a binder; b. selectively fusing the binder to form an implant green part; and c 1 . infiltrating the implant green part; or c 2 . sintering the implant green part to form an implant, wherein the calcium phosphate composition does not decompose to produce water during step b, and the implant replicates a naturally complex bone geometry, has a complex three-dimensional shape with a well-defined cavity, the cavity replicating internal complex bone geometry, has a controlled, interconnected porosity, and has a mole ratio of calcium to phosphorus of 0.5 to 1.
Claim 3
Dependent Claim
85 words
An implant produced by selectively fusing a calcium phosphate composition with a binder to form an implant green part; and sintering the implant green part to form an implant, wherein the calcium phosphate composition does not decompose to produce water during fusing, and the implant replicates a naturally complex bone geometry, has a complex three-dimensional shape with a well-defined cavity, the cavity replicating internal complex bone geometry, has a controlled, interconnected porosity, and has a mole ratio of calcium to phosphorus of 0.5 to 1.
Claim 4
Dependent Claim
85 words
An implant produced by selectively fusing a calcium phosphate composition with a binder to form an implant green part; and sintering the implant green part to form an implant, wherein the calcium phosphate composition does not decompose to produce water during fusing, and the implant replicates a naturally complex bone geometry, has a complex three-dimensional shape with a well-defined cavity, the cavity replicating internal complex bone geometry, has a controlled, interconnected porosity, and has a mole ratio of calcium to phosphorus of 0.5 to 1.
Claim 5
Dependent Claim
14 words
The implant of claim 2 further including infiltrating the green part or the implant.
Claim 6
Dependent Claim
88 words
An implant produced by selectively fusing a calcium phosphate composition with a binder to form an implant green part; infiltrating the green part, and sintering the green part to form an implant, wherein the calcium phosphate composition does not decompose to produce water during fusing, and the implant replicates a naturally complex bone geometry, has a complex three-dimensional shape with a well-defined cavity, the cavity replicating internal complex bone geometry, has a controlled, interconnected porosity, and has a mole ratio of calcium to phosphorus of 0.5 to 1.
Claim 7
Dependent Claim
88 words
An implant produced by selectively fusing a calcium phosphate composition with a binder to form an implant green part; infiltrating the green part, and sintering the green part to form an implant, wherein the calcium phosphate composition does not decompose to produce water during fusing, and the implant replicates a naturally complex bone geometry, has a complex three-dimensional shape with a well-defined cavity, the cavity replicating internal complex bone geometry, has a controlled, interconnected porosity, and has a mole ratio of calcium to phosphorus of 0.5 to 1.
Claim 8
Dependent Claim
140 words
An implant produced by a. forming a mixture of particles of a calcium phosphate composition and a binder; b. forming a layer of the mixture; c. selectively fusing the binder; d. repeating steps b. and c. a desired number of times to form a plurality of layers, wherein each layer is fused to adjacent layers to form the implant green part; and e 1 . infiltrating the implant green part; or e 2 . sintering the implant green part to form an implant, wherein the calcium phosphate composition does not decompose to produce water during step c, and the implant replicates a naturally complex bone geometry, has a complex three-dimensional shape with a well-defined cavity, the cavity replicating internal complex bone geometry, has a controlled, interconnected porosity, and has a mole ratio of calcium to phosphorus of 0.5 to I.
Claim 9
Dependent Claim
140 words
An implant produced by a. forming a mixture of particles of a calcium phosphate composition and a binder; b. forming a layer of the mixture; c. selectively fusing the binder; d. repeating steps b. and c. a desired number of times to form a plurality of layers, wherein each layer is fused to adjacent layers to form the implant green part; and e 1 . infiltrating the implant green part; or e 2 . sintering the implant green part to form an implant, wherein the calcium phosphate composition does not decompose to produce water during step c, and the implant replicates a naturally complex bone geometry, has a complex three-dimensional shape with a well-defined cavity, the cavity replicating internal complex bone geometry, has a controlled, interconnected porosity, and has a mole ratio of calcium to phosphorus of 0.5 to I.
Claim 10
Dependent Claim
27 words
The implant of claim 1 , 2 , 4 , or 5 wherein the calcium phosphate composition is prepared at a temperature greater than about 200° C.
Claim 11
Dependent Claim
22 words
The implant of claim 1 , 2 , 4 , or 5 wherein the binder is selectively fused with a laser beam.
Claim 12
Dependent Claim
24 words
The implant of claim 1 , 2 , 4 , or 5 or wherein the binder is selectively fused with a thermal mask system.
Claim 13
Dependent Claim
24 words
The implant of claim 1 , 2 , 4 , or 5 wherein the binder is selectively fused to form a desired geometrical shape.
Claim 14
Dependent Claim
19 words
The implant of claim 1 , 2 , 4 , or 5 wherein the binder is a polymer binder.
Claim 15
Dependent Claim
45 words
The implant of claim 10 , wherein the polymer binder has a T g of between about 40° C. and about 100° C., and a melt flow index of between about 1 and about 50 g/10 minutes at 200° C. and 75 psi extrusion pressure.
Claim 16
Dependent Claim
18 words
The implant of claim 10 wherein the polymer binder comprises a homopolymer, copolymer, or terpolymer of methyl methacrylate.
Claim 17
Dependent Claim
19 words
The implant of claim 1 , 2 , 4 , or 5 wherein the binder is a liquid binder.
Claim 18
Dependent Claim
20 words
The implant of claim 1 , 2 , 4 , or 5 wherein the binder is coating calcium phosphate particles.
Claim 19
Dependent Claim
20 words
The implant of claim 2 or 4 wherein the binder is applied to the calcium phosphate composition as a spray.
Claim 20
Dependent Claim
52 words
The implant of claim 1 , 2 , 4 , or 5 wherein the calcium phosphate composition is calcium metaphosphate, calcium pyrophosphate, calcium phosphate with from about 25 percent to about 45 percent by weight calcium oxide, or calcium phosphate with from about 0.5 to about 2 percent by weight sodium oxide.
Claim 21
Dependent Claim
21 words
The implant of claim 1 , 3 , 4 , or 5 wherein the infiltrating is with a calcium phosphate solution.
Claim 22
Dependent Claim
26 words
The implant of claim 1 , 2 , 4 , or 5 wherein the binder is selectively fused by spraying of a liquid binder and solvent.
Claim 23
Dependent Claim
113 words
An implant produced by a. forming a mixture of a calcium phosphate composition and a binder; b. selectively fusing the binder to form an implant green part; and c 1 . infiltrating the implant green part; or c 2 . sintering the implant green part to form an implant, wherein the calcium phosphate composition does not decompose to produce water during step b, and the implant has a designed complex three-dimensional shape with a well-defined cavity, the cavity having an opening to a surface, the opening having a smaller cross sectional area than the cavity, has a controlled, interconnected porosity, and has a mole ratio of calcium to phosphorus of 0.5 to 1.
Claim 24
Dependent Claim
113 words
An implant produced by a. forming a mixture of a calcium phosphate composition and a binder; b. selectively fusing the binder to form an implant green part; and c 1 . infiltrating the implant green part; or c 2 . sintering the implant green part to form an implant, wherein the calcium phosphate composition does not decompose to produce water during step b, and the implant has a designed complex three-dimensional shape with a well-defined cavity, the cavity having an opening to a surface, the opening having a smaller cross sectional area than the cavity, has a controlled, interconnected porosity, and has a mole ratio of calcium to phosphorus of 0.5 to 1.
Claim 25
Dependent Claim
92 words
An implant produced by selectively fusing a calcium phosphate composition with a binder to form an implant green part; and sintering the implant green part to form an implant, wherein the calcium phosphate composition does not decompose to produce water during fusing, and the implant has a designed complex three-dimensional shape with a well-defined cavity, the cavity having an opening to a surface, the opening having a smaller cross sectional area than the cavity, has a controlled, interconnected porosity, and has a mole ratio of calcium to phosphorus of 0.5 to 1.
Claim 26
Dependent Claim
92 words
An implant produced by selectively fusing a calcium phosphate composition with a binder to form an implant green part; and sintering the implant green part to form an implant, wherein the calcium phosphate composition does not decompose to produce water during fusing, and the implant has a designed complex three-dimensional shape with a well-defined cavity, the cavity having an opening to a surface, the opening having a smaller cross sectional area than the cavity, has a controlled, interconnected porosity, and has a mole ratio of calcium to phosphorus of 0.5 to 1.
Claim 27
Dependent Claim
95 words
An implant produced by selectively fusing a calcium phosphate composition with a binder to form an implant green part; infiltrating the green part, and sintering the green part to form an implant, wherein the calcium phosphate composition does not decompose to produce water during fusing, and the implant has a designed complex three-dimensional shape with a well-defined cavity, the cavity having an opening to a surface, the opening having a smaller cross sectional area than the cavity, has a controlled, interconnected porosity, and has a mole ratio of calcium to phosphorus of 0.5 to 1.
Claim 28
Dependent Claim
95 words
An implant produced by selectively fusing a calcium phosphate composition with a binder to form an implant green part; infiltrating the green part, and sintering the green part to form an implant, wherein the calcium phosphate composition does not decompose to produce water during fusing, and the implant has a designed complex three-dimensional shape with a well-defined cavity, the cavity having an opening to a surface, the opening having a smaller cross sectional area than the cavity, has a controlled, interconnected porosity, and has a mole ratio of calcium to phosphorus of 0.5 to 1.
Claim 29
Dependent Claim
147 words
An implant produced by a. forming a mixture of particles of a calcium phosphate composition and a binder; b. forming a layer of the mixture; c. selectively fusing the binder; d. repeating steps b. and c. a desired number of times to form a plurality of layers, wherein each layer is fused to adjacent layers to form the implant green part; and e 1 . infiltrating the implant green part; or e 2 . sintering the implant green part to form an implant, wherein the calcium phosphate composition does not decompose to produce water during step c, and the implant has a designed complex three-dimensional shape with a well-defined cavity, the cavity having an opening to a surface, the opening having a smaller cross sectional area than the cavity, has a controlled, interconnected porosity, and has a mole ratio of calcium to phosphorus of 0.5 to 1.
Claim 30
Dependent Claim
147 words
An implant produced by a. forming a mixture of particles of a calcium phosphate composition and a binder; b. forming a layer of the mixture; c. selectively fusing the binder; d. repeating steps b. and c. a desired number of times to form a plurality of layers, wherein each layer is fused to adjacent layers to form the implant green part; and e 1 . infiltrating the implant green part; or e 2 . sintering the implant green part to form an implant, wherein the calcium phosphate composition does not decompose to produce water during step c, and the implant has a designed complex three-dimensional shape with a well-defined cavity, the cavity having an opening to a surface, the opening having a smaller cross sectional area than the cavity, has a controlled, interconnected porosity, and has a mole ratio of calcium to phosphorus of 0.5 to 1.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-02-06 | 2004-08-07 | 2005-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-02-06 | 2008-08-07 | 2009-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-02-06 | 2012-08-07 | 2013-02-06 | $7700.00 | Window Closed / Lapsed |