Patent US4735625A successfully refreshed from Google Patents.
US4735625A
Expired / Lapsed
US
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Bone cement reinforcement and method
Assignee: Smith and Nephew Inc
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Filing: 1985-09-11
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Granted: 1988-04-05
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Expires: 2005-09-11
Abstract
Abstract A reinforcing technique for bone cement used in the anchoring of prosthetic devices. The reinforced bone cement includes oriented reinforcement formed of a continuous fiber-like material that is embedded in the bone cement between at least a portion of the outer surface of the prosthetic device and the surrounding bone that defines the cavity in which the device is implanted. The reinforcement is preferably a polymeric mat embedded in a thin layer of bone cement forming a precoat on the outer surface of the implant.
Inventors
- 👤 James A. Davidson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:52
CPC Classifications
A; A61; A61B; A61B17/00; A61B17/56; A61B17/58; A61B17/88; A61B17/8802; A61F; A61F2/00; A61F2/02; A61F2/30; A61F2/30767; A61F2/30907; A61F2/3094; A61F2/30965; A61F2/32; A61F2/36; A61F2/3662; A61F2002/30001; A61F2002/30003; A61F2002/3006; A61F2002/30084; A61F2002/30909; A61F2002/30919; A61F2/3609; A61F2002/3625; A61F2002/3631; A61F2/46; A61F2002/4631; A61F2310/00; A61F2310/00389; A61F2310/00952
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
161 words
A prosthetic device with a reinforced composite precoat, comprising: a. a prosthetic device adapted to have at least a portion implanted in a cavity formed in animal bone; b. a relatively thin layer of cured bone cement precoated on the outer surface of the prosthetic device before implantation on at least part of the portion adapted to be implanted in the bone cavity; and c. a reinforcing fibrous mat formed of high strength polyolefin fibers encapsulated within the cured bone cement precoating so that the fibers define a reinforcement to the cured bone cement layer prior to implantation, the fibers being oriented in at least one direction and interconnected to form a flexible network; and d. the precoating outer layer defining a cured bone cement surface covering the fibers to provide a generally smooth outer layer so that the cured bone cement surface can be used to cary wet cement for forming a bond between the precoat and the animal bone.
Claim 2
Dependent Claim
161 words
A prosthetic device with a reinforced composite precoat, comprising: a. a prosthetic device adapted to have at least a portion implanted in a cavity formed in animal bone; b. a relatively thin layer of cured bone cement precoated on the outer surface of the prosthetic device before implantation on at least part of the portion adapted to be implanted in the bone cavity; and c. a reinforcing fibrous mat formed of high strength polyolefin fibers encapsulated within the cured bone cement precoating so that the fibers define a reinforcement to the cured bone cement layer prior to implantation, the fibers being oriented in at least one direction and interconnected to form a flexible network; and d. the precoating outer layer defining a cured bone cement surface covering the fibers to provide a generally smooth outer layer so that the cured bone cement surface can be used to cary wet cement for forming a bond between the precoat and the animal bone.
Claim 3
Dependent Claim
16 words
The invention of claim 1, wherein the layer of bone cement is about 1-2 mm thick.
Claim 4
Dependent Claim
86 words
The invention of claim 1, wherein the fibers are formed of polyethylene, having a weight average molecular weight at least about 500,000, with a tenacity of at least about 20 g/denier, a tensile modulus at least about 500 g/denier, a creep value no more than bout 5% (when measured at 10% of breaking load for 50 days at 23° C.), a porosity less than about 10% and a main melting temperature of at least 147° C. (measured to 10° C./min. heating rate by differential scanning calorimetry).
Claim 5
Dependent Claim
63 words
The invention of claim 1 wherein the fibers are formed of polyethylene being of a weight average molecular weight of at least about 1,000,000 and having a tensile modulus of at least about 1600 g/denier, a main melting temperature of at least about 147° C. (measured at 10° C./minute heating rate by differential scanning calorimetry) and an elongation-to-break of not more than 5%.
Claim 6
Dependent Claim
64 words
The invention of claim 1 wherein the fibers are formed of polypropylene being of a weight average molecular weight of at least about 750,000 and having a tenacity of at least about 8 g/denier, a tensile modulus of at least about 160 g/denier and a main melting temperature of at least about 168° C. (measured at 10° C./minute heating rate by differential scanning calorimetry).
Claim 7
Dependent Claim
18 words
The invention of claim 1 wherein the mat is formed of a blend of polyethylene and polypropylene fibers.
Claim 8
Dependent Claim
22 words
The invention of claim 1 wherein the fibers are formed into threads that are oriented in two general directions and woven together.
Claim 9
Dependent Claim
27 words
The invention of claim 1 wherein the mat is formed as a sock that is sized and shaped to fit over an elongated portion of a prosthesis.
Claim 10
Dependent Claim
13 words
The invention of claim 1 wherein the mat is formed rectilinear in shape.
Claim 11
Dependent Claim
14 words
The invention of claim 1, wherein the mat is impregnated with the bone cement.
Claim 12
Dependent Claim
51 words
The invention of claim 1, wherein the mat is bonded to the prosthetic device by first applying a first layer of bone cement to the device, placing the mat on the cement, and applying sufficient bone cement to the mat to bond with the first layer of cement through the fibers.
Claim 13
Dependent Claim
27 words
The invention of claim 1, wherein the mat is formed as a sock that is sized and shapted to fit over an elongated portion of the prosthesis.
Claim 14
Dependent Claim
29 words
The device of claim 1, further including a coating of a material on the outer surface of the precoat that is capable of becoming biologically attached to surrounding bone.
Claim 15
Dependent Claim
12 words
The device of claim 13, wherein the coating is formed of hydroxylapatite.
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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) | 1991-04-05 | 1991-10-05 | 1992-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-04-05 | 1995-10-05 | 1996-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-04-05 | 1999-10-05 | 2000-04-05 | $7700.00 | Window Closed / Lapsed |