US4645503A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Moldable bone-implant material
Assignee: LIFE CORE BIOMEDICAL Inc
•
Filing: 1985-08-27
•
Granted: 1987-02-24
•
Expires: 2005-08-27
Abstract
Abstract A moldable bone-implant material containing between about 65%-95% hard filler particles and a binder composed of between about 35%-5% of a biocompatible, biodegradable, thermoplastic polymer which has fluidic flow properties at or below about 60° C. One preferred binder is polylactic acid having a molecular weight between about 400 and 5,000 daltons, and a preferred hard filler is hydroxylapatite. In use, the material is warmed to a temperature which allows molding, and the bone site is filled with the moldable material, which then forms a contour-fitting, semi-rigid implant. The implant retains its contour fit and acquires a rigid final state as the binder in the implant is gradually biodegraded and replaced through tissue ingrowth from the surrounding bone site.
Inventors
- 👤 Steve T. Lin
- 👤 Seshadri Conjeevaram
- 👤 Don J. Henderson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 00:30
CPC Classifications
A; A61; A61L; A61L27/00; A61L27/50; A61L27/58; A61F; A61F2/00; A61F2/02; A61F2/28; A61L27/40; A61L27/44; A61L27/46; A61L2430/00; A61L2430/02
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
28 words
A moldable bone-implant material comprising a cohesive mixture of hard filler particles and a biocompatible, biodegradable thermoplastic polymeric binder having fluid-flow properties at or below about 60° C.
Claim 2
Dependent Claim
28 words
A moldable bone-implant material comprising a cohesive mixture of hard filler particles and a biocompatible, biodegradable thermoplastic polymeric binder having fluid-flow properties at or below about 60° C.
Claim 3
Dependent Claim
9 words
The material of claim 1, wherein particles are hydroxylapatite.
Claim 4
Dependent Claim
18 words
The material of claim 1, wherein the binder constitutes less than about one-third of the material's total volume.
Claim 5
Dependent Claim
14 words
The material of claim 1, wherein the binder is biodegradable to normal biochemical metabolite(s).
Claim 6
Dependent Claim
29 words
The material of claim 4, wherein the polymer is biodegradable over a period of about three days to six weeks, with the material operatively placed in a bone site.
Claim 7
Dependent Claim
27 words
The material of claim 4, wherein the binder is selected from the group consisting of polylactic acid, polyglycolic acid, polyhydroxybutyric acid, polymalic acid, polyglutamine acid, and polylactone.
Claim 8
Dependent Claim
20 words
The material of claim 6, wherein the polymer includes polylactic acid having molecular weights between about 400 and 5,000 daltons.
Claim 9
Dependent Claim
36 words
The material of claim 7, which is moldable by hand at a selected temperature at or below about 37° C., and the polylactic acid is in the molecular weight range between about 400 and 2,000 daltons.
Claim 10
Dependent Claim
41 words
The material of claim 7, which is moldable by hand at a selected temperature above about 40° C., and substantially rigid below about 37° C., and the polylactic acid is in the molecular weight range between about 2,000 and 5,000 daltons.
Claim 11
Dependent Claim
33 words
A moldable bone-implant material comprising between about 65%-95% hydroxylapatite particles; and a binder composed of between about 35%-5% of a polylactic acid polymer having a molecular weight between about 400 and 5,000 daltons.
Claim 12
Dependent Claim
33 words
A moldable bone-implant material comprising between about 65%-95% hydroxylapatite particles; and a binder composed of between about 35%-5% of a polylactic acid polymer having a molecular weight between about 400 and 5,000 daltons.
Claim 13
Independent Claim
71 words
A method of filling a bone site with a contour-fitting, rigid-particle bone implant, comprising providing hard filler particles in the form of a moldable bone-implant material composed of a cohesive mixture of the particles and a biocompatible, biodegradable, thermoplastic polymer binder which has fluid-flow properties at a selected temperature at or below about 60° C., heating the material to a temperature which allows the material to be molded by hand, and
Claim 14
Independent Claim
71 words
A method of filling a bone site with a contour-fitting, rigid-particle bone implant, comprising providing hard filler particles in the form of a moldable bone-implant material composed of a cohesive mixture of the particles and a biocompatible, biodegradable, thermoplastic polymer binder which has fluid-flow properties at a selected temperature at or below about 60° C., heating the material to a temperature which allows the material to be molded by hand, and
Claim 15
Dependent Claim
16 words
filling the bone site with the moldable material to form a contour-fitting implant at the site,
Claim 16
Dependent Claim
16 words
filling the bone site with the moldable material to form a contour-fitting implant at the site,
Claim 17
Dependent Claim
23 words
where gradual biodegradation of the binder and concommitant ingrowth of surrounding tissue acts to rigidify the implant over a period of several weeks.
Claim 18
Dependent Claim
23 words
where gradual biodegradation of the binder and concommitant ingrowth of surrounding tissue acts to rigidify the implant over a period of several weeks.
Claim 19
Dependent Claim
45 words
The method of claim 11, wherein the binder is formed of a polymer having molecular chain sizes which produce such fluid-flow properties at the selected temperature, and allow gradual polymer biodegradation over about three days to six weeks, with the material in the bone site.
Claim 20
Dependent Claim
28 words
The method of claim 12, wherein the binder is formed by synthesizing the polymer and terminating polymerization when the polymer exhibits such fluid-flow properties at the selected temperature.
Claim 21
Dependent Claim
33 words
The method of claim 13, wherein the binder is formed by polymerizing a lactide to form polylactic acid under conditions which lead to polymers in the molecular weight range between about 400-5,000 daltons.
Claim 22
Dependent Claim
21 words
The method of claim 11, wherein said providing includes mixing hydroxylapatite particles with no more than about one-third volume of binder.
Claim 23
Dependent Claim
31 words
The method of claim 11, wherein the material becomes moldable only above a temperature of about 40° C., and following said filling, the material cools to form a relatively rigid implant.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-02-23 | 1990-08-25 | 1991-02-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-02-23 | 1994-08-25 | 1995-02-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-02-23 | 1998-08-25 | 1999-02-24 | $7700.00 | Window Closed / Lapsed |