US4255820A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Artificial ligaments
Assignee: Individual
•
Filing: 1979-07-24
•
Granted: 1981-03-17
•
Expires: 1999-07-24
Abstract
Abstract An improved artificial ligament is tubular in overall configuration with flared ends, which have a graduated pore density to permit controlled hard and soft tissue ingrowth, and a central portion which prevents tissue ingrowth. The central section of the ligament is elongatable along its longitudinal axis to permit the needed elasticity in use.
Inventors
- 👤 Joel E. Rothermel
- 👤 Robert J. Pawluk
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:33
CPC Classifications
A; A61; A61F; A61F2/00; A61F2/02; A61F2/08
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
73 words
A ligament prosthesis comprising: a central tubular portion of fabric, said central portion being elongatable along its longitudinal axis; and tubular end portions joined to each end of said central portion, said end portions including pores graduated in size to form a small pore structure proximate to said central portion and a larger pore structure at the end distal to said central portion, thereby to permit controlled tissue ingrowth within said end portions.
Claim 2
Dependent Claim
73 words
A ligament prosthesis comprising: a central tubular portion of fabric, said central portion being elongatable along its longitudinal axis; and tubular end portions joined to each end of said central portion, said end portions including pores graduated in size to form a small pore structure proximate to said central portion and a larger pore structure at the end distal to said central portion, thereby to permit controlled tissue ingrowth within said end portions.
Claim 3
Dependent Claim
21 words
The ligament prosthesis as claimed in claim 1, wherein said end portions flare from a narrowest portion adjacent said central portion.
Claim 4
Dependent Claim
24 words
The ligament prosthesis as claimed in claim 1, wherein at least one of said central and said end portions comprises a woven polyester fabric.
Claim 5
Dependent Claim
35 words
The ligament prosthesis as claimed in claim 1, wherein said pore structure of said end portions proximate to said central portion is sufficient to permit ingrowth of soft tissue without permitting ingrowth of hard tissue.
Claim 6
Dependent Claim
28 words
The ligament prosthesis as claimed in claim 4, wherein said pore structure of said flared portion of said distal end is sufficient to permit ingrowth of hard tissue.
Claim 7
Dependent Claim
17 words
The ligament prosthesis as claimed in claim 5, wherein said central portion further includes a cylindrical insert.
Claim 8
Dependent Claim
25 words
The ligament prosthesis as claimed in claim 6, wherein said central portion has pores of a dimension sufficiently small to resist the ingrowh of tissue.
Claim 9
Dependent Claim
21 words
The ligament prosthesis as claimed in claim 7, further including an intermediate section joining said end section and said central section.
Claim 10
Dependent Claim
28 words
The ligament prosthesis as claimed in claim 1, wherein said pore structure of said flared portion of said distal end is sufficient to permit ingrowth of hard tissue.
Claim 11
Dependent Claim
17 words
The ligament prosthesis as claimed in claim 9, wherein said central portion further includes a cylindrical insert.
Claim 12
Dependent Claim
25 words
The ligament prosthesis as claimed in claim 10, wherein said central portion has pores of a dimension sufficiently small to resist the ingrowth of tissue.
Claim 13
Dependent Claim
21 words
The ligament prosthesis as claimed in claim 11, further including an intermediate section joining said end section and said central section.
Claim 14
Dependent Claim
25 words
The ligament prosthesis as claimed in claim 1, wherein said central portion has pores of a dimension sufficiently small to resist the ingrowth of tissue.
Claim 15
Dependent Claim
21 words
The ligament prosthesis as claimed in claim 13, further including an intermediate section joining said end section and said central section.
Claim 16
Dependent Claim
18 words
The ligaments prothesis as claimed in claim 1, wherein said central portion and said end portion are integral.
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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) | 1984-03-16 | 1984-09-15 | 1985-03-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-16 | 1988-09-15 | 1989-03-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-16 | 1992-09-15 | 1993-03-17 | $7700.00 | Window Closed / Lapsed |