US4781183A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Surgical prosthesis
Assignee: Smith and Nephew Inc
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Filing: 1986-08-27
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Granted: 1988-11-01
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Expires: 2006-08-27
Abstract
Abstract A bone fixation device is disclosed. The device comprises an absorbable homopolymer of 1-lactide or d1-lactide, or a copolymer of 1-lactide, and a reinforcement material. The reinforcement material can be a particulate filler of hydroxyapatite or a plurality of alumina fibers.
Inventors
- 👤 Donald J. Casey
- 👤 Peter K. Jarrett
- 👤 David W. Wang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:42
CPC Classifications
A; A61; A61L; A61L31/00; A61L31/14; A61L31/148; A61L31/12; A61L31/125; A61L31/127; A61L2430/00; A61L2430/02
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
49 words
A bone fixation device comprising an absorbable polymer matrix, said matrix obtained from the polymerization of 1-lactide, and a reinforcement material being a filler in a particulate, non-fiber form being suspended throughout the matrix and being selected from the group consisting of tricalcium phosphate, hydroxyapatite, and a mixture thereof.
Claim 2
Dependent Claim
49 words
A bone fixation device comprising an absorbable polymer matrix, said matrix obtained from the polymerization of 1-lactide, and a reinforcement material being a filler in a particulate, non-fiber form being suspended throughout the matrix and being selected from the group consisting of tricalcium phosphate, hydroxyapatite, and a mixture thereof.
Claim 3
Dependent Claim
11 words
A device of claim 1 wherein the particulate filler is hydroxyapatite.
Claim 4
Dependent Claim
55 words
A semi-absorbable bone fixation device comprising an absorbable polymer, said polymer obtained from the polymerization of 1-lactide, and a nonabsorbable reinforcement material providing increased structural integrity to said bone fixation device and being manufactured from a plurality of fibers selected from the group consisting of alumina, poly(p-phenylene terephthalamide), polyethylene terephthalate and ultra high modulus polyethylene.
Claim 5
Dependent Claim
55 words
A semi-absorbable bone fixation device comprising an absorbable polymer, said polymer obtained from the polymerization of 1-lactide, and a nonabsorbable reinforcement material providing increased structural integrity to said bone fixation device and being manufactured from a plurality of fibers selected from the group consisting of alumina, poly(p-phenylene terephthalamide), polyethylene terephthalate and ultra high modulus polyethylene.
Claim 6
Dependent Claim
12 words
A device of claim 3 wherein the fiber is poly (p-phenylene terephthalamide).
Claim 7
Dependent Claim
11 words
A device of claim 3 wherein the fiber is polyethylene terephthalate.
Claim 8
Dependent Claim
10 words
A device of claim 3 wherein the fiber is alumina.
Claim 9
Dependent Claim
11 words
A device of claim 6 wherein the fiber is alpha alumina.
Claim 10
Dependent Claim
66 words
A semi-absorbable bone fixation device comprising an absorbable polymer, said polymer obtained from the polymerization of dl-lactide, and a non-absorbable reinforcement material manufactured from a plurality of ultra high modulus polyethylene fibers to increase the structural integrity of the bone fixation device, said device having a flexural strength of about 10,000 to 25,000 psi, and a flexural modulus of about 1×10 6 to 5×10 6 psi.
Claim 11
Dependent Claim
66 words
A semi-absorbable bone fixation device comprising an absorbable polymer, said polymer obtained from the polymerization of dl-lactide, and a non-absorbable reinforcement material manufactured from a plurality of ultra high modulus polyethylene fibers to increase the structural integrity of the bone fixation device, said device having a flexural strength of about 10,000 to 25,000 psi, and a flexural modulus of about 1×10 6 to 5×10 6 psi.
Claim 12
Dependent Claim
164 words
A semi-absorbable laminated bone fixation device comprising an impregnating agent consisting of an absorbable polymer matrix, said matrix obtained from the polymerization of 1-lactide and having an inherent viscosity of about 1.5 to 3.5 dl/g (0.5 g/dl in CHCl 3 ), and a nonabsorbable reinforcement material to provide increased structural integrity to the bone fixation device consisting essentially of at least one alumina fiber such that the bone fixation device has a matrix with sufficiently high molecular weight to provide the desired strength retention time and sufficiently low molecular weight to provide adequate strength and modulus, said device having a flexural strength of about 10,000 to 25,000 psi; a flexural modulus of about 1×10 6 to 5×10 6 psi; a loss of about 30% of its initial flexural strength during 3 months in vivo and 60% during 6 months in vivo; and a loss of about 25% of its initial flexural modulus during 3 months in vivo and 45% during 6 months in vivo.
Claim 13
Dependent Claim
164 words
A semi-absorbable laminated bone fixation device comprising an impregnating agent consisting of an absorbable polymer matrix, said matrix obtained from the polymerization of 1-lactide and having an inherent viscosity of about 1.5 to 3.5 dl/g (0.5 g/dl in CHCl 3 ), and a nonabsorbable reinforcement material to provide increased structural integrity to the bone fixation device consisting essentially of at least one alumina fiber such that the bone fixation device has a matrix with sufficiently high molecular weight to provide the desired strength retention time and sufficiently low molecular weight to provide adequate strength and modulus, said device having a flexural strength of about 10,000 to 25,000 psi; a flexural modulus of about 1×10 6 to 5×10 6 psi; a loss of about 30% of its initial flexural strength during 3 months in vivo and 60% during 6 months in vivo; and a loss of about 25% of its initial flexural modulus during 3 months in vivo and 45% during 6 months in vivo.
Claim 14
Dependent Claim
16 words
A device of claim 9 wherein said reinforcement material is a plurality of alpha alumina fibers.
Claim 15
Dependent Claim
20 words
A device of claim 10 wherein the fibers comprise about 10 to 60 percent of the volume of said device.
Claim 16
Dependent Claim
20 words
A device of claim 10 wherein the fibers comprise about 15 to 40 percent of the volume of said device.
Claim 17
Dependent Claim
15 words
A device of claim 12 having a flexural strength of about 15,000 to 25,000 psi.
Claim 18
Dependent Claim
16 words
A device of claim 13 having a flexural modulus of up to about 3×10 6 psi.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1991-11-01 | 1992-05-02 | 1992-11-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-11-01 | 1996-05-02 | 1996-11-01 | $3760.00 | Window Closed / Lapsed |
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