US5316550A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Prosthesis with flexible intramedullary stem
Assignee: IMPLANTOLOGY LLC
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Filing: 1992-01-03
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Granted: 1994-05-31
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Expires: 2012-01-03
Abstract
Abstract An implant for a hip or other joint is provided. Briefly stated, a intramedullary stem is provided having flexibility which is comparable to that of the surrounding bone. A bore is disposed in the stem portion with the stem wall thickness uniform or varying from the proximal end to the distal end, depending upon the amount of flexibility desired. This flexibility therefore distributes the loading forces from the joint more uniformly over the supporting cortical bone with the result that bone degeneration from stress shielding is minimized or eliminated.
Inventors
- 👤 Mark Forte
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 11:52
CPC Classifications
A; A61; A61F; A61F2/00; A61F2/02; A61F2/30; A61F2/32; A61F2/36; A61F2/30767; A61F2002/30001; A61F2002/30316; A61F2002/30317; A61F2002/30324; A61F2002/30667; A61F2002/30677; A61F2/30771; A61F2002/30772; A61F2002/30784; A61F2002/30785; A61F2/3662; A61F2002/3678; A61F2002/368; A61F2002/3694; A61F2250/00; A61F2250/0014; A61F2250/0036
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
103 words
A hip prosthesis comprising: a stem for implantation into a femur, said stem having a proximal end and a distal end, said stem having a longitudinally extending tapered bore therein defined by a surrounding wall and extending from said proximal end at least part way to said distal end, said stem having a lateral side and a medial side, and a longitudinal slit directly extending from said proximal end along said wall at said lateral side and being in communication with said bore; and a femoral head for implantation into a hip socket and connected with said stem at the medial side thereof.
Claim 2
Dependent Claim
103 words
A hip prosthesis comprising: a stem for implantation into a femur, said stem having a proximal end and a distal end, said stem having a longitudinally extending tapered bore therein defined by a surrounding wall and extending from said proximal end at least part way to said distal end, said stem having a lateral side and a medial side, and a longitudinal slit directly extending from said proximal end along said wall at said lateral side and being in communication with said bore; and a femoral head for implantation into a hip socket and connected with said stem at the medial side thereof.
Claim 3
Dependent Claim
23 words
A hip prosthesis according to claim 1, wherein said slit has a width which tapers from said proximal end toward said distal end.
Claim 4
Dependent Claim
22 words
A hip prosthesis according to claim 1, wherein said slit extends the entire way from said proximal end to said distal end.
Claim 5
Dependent Claim
30 words
A hip prosthesis according to claim 1, wherein said wall of said stem has a thickness which tapers in a direction extending from said proximal end toward said distal end.
Claim 6
Dependent Claim
17 words
A hip prosthesis according to claim 4, wherein said wall tapers at an angle up to 5°.
Claim 7
Dependent Claim
20 words
A hip prosthesis according to claim 1, further comprising a neck portion connected between said femoral head and said stem.
Claim 8
Dependent Claim
37 words
A hip prosthesis according to claim 1, wherein said stem further includes at least one aperture in the wall of said stem and in communication with said bore to permit dispersal of bioactive substances in said stem.
Claim 9
Dependent Claim
22 words
A hip prosthesis according to claim 7, wherein said bioactive substances are disposed in said at least one aperture in said stem.
Claim 10
Dependent Claim
19 words
A hip prosthesis according to claim 1, further including a porous coating on an exterior surface of said stem.
Claim 11
Dependent Claim
38 words
A hip prosthesis according to claim 1, wherein said bore being open at said proximal end; and wherein a closure plug is inserted in said bore in a tight fitting manner at said proximal end of the stem.
Claim 12
Dependent Claim
35 words
A hip prosthesis according to claim 10, wherein said bore is open at said distal end, and further including a closure plug inserted in said bore in a tight fitting manner at said distal end.
Claim 13
Dependent Claim
30 words
A hip prosthesis according to claim 10, wherein said wall of said stem has a thickness which tapers in a direction extending from said proximal end toward said distal end.
Claim 14
Dependent Claim
17 words
A hip prosthesis according to claim 12, wherein said wall tapers at an angle up to 5°.
Claim 15
Dependent Claim
20 words
A hip prosthesis according to claim 10, further comprising a neck portion connected between said femoral head and said stem.
Claim 16
Dependent Claim
37 words
A hip prosthesis according to claim 10, wherein said stem further includes at least one aperture in the wall of said stem and in communication with said bore to permit distal of bioactive substances in said stem.
Claim 17
Dependent Claim
22 words
A hip prosthesis according to claim 15, wherein said bioactive substances are disposed in said at least one aperture in said stem.
Claim 18
Dependent Claim
19 words
A hip prosthesis according to claim 10, further including a porous coating on an exterior surface of said stem.
Claim 19
Dependent Claim
52 words
A hip prosthesis according to claim 1, with said wall at said lateral side and at said proximal end having a thickness less than that at said medial side and at said proximal end, and with a closure plug inserted in said bore in a tight fitting manner at said proximal end.
Claim 20
Dependent Claim
134 words
A hip prosthesis comprising: a stem for implantation into a femur, said stem having a proximal end and a distal end, said stem having a longitudinally extending tapered bore therein defined by a surrounding wall and extending from said proximal end at least part way to said distal end, said stem having a lateral side and a medial side, and a longitudinal slit extending along said wall at said lateral side and being in communication with said bore; and a femoral head for implantation into a hip socket and connected with said stem at the medial side thereof, wherein said bore is open at said proximal end; wherein a closure plug is inserted in said bore in a tight fitting manner at said proximal end of the stem, and wherein said plug is porous.
Claim 21
Dependent Claim
134 words
A hip prosthesis comprising: a stem for implantation into a femur, said stem having a proximal end and a distal end, said stem having a longitudinally extending tapered bore therein defined by a surrounding wall and extending from said proximal end at least part way to said distal end, said stem having a lateral side and a medial side, and a longitudinal slit extending along said wall at said lateral side and being in communication with said bore; and a femoral head for implantation into a hip socket and connected with said stem at the medial side thereof, wherein said bore is open at said proximal end; wherein a closure plug is inserted in said bore in a tight fitting manner at said proximal end of the stem, and wherein said plug is porous.
Claim 22
Dependent Claim
169 words
A hip prosthesis comprising: a stem for implantation into a femur, said stem having a proximal end and a distal end, said stem having a longitudinally extending tapered bore therein defined by a surrounding wall and extending from said proximal end at least part way to said distal end, said stem having a lateral side and a medial side, and a longitudinal slit extending along said wall at said lateral side and being in communication with said bore; and a femoral head for implantation into a hip socket and connected with said stem at the medial side thereof, wherein said bore is open at said proximal end; wherein a closure plug is inserted in said bore in a tight fitting manner at said proximal end of the stem, wherein said bore is open at said distal end, and further including a second closure plug inserted in said bore in a tight fitting manner at said distal end, and wherein said second closure plug at said distal end is porous.
Claim 23
Dependent Claim
169 words
A hip prosthesis comprising: a stem for implantation into a femur, said stem having a proximal end and a distal end, said stem having a longitudinally extending tapered bore therein defined by a surrounding wall and extending from said proximal end at least part way to said distal end, said stem having a lateral side and a medial side, and a longitudinal slit extending along said wall at said lateral side and being in communication with said bore; and a femoral head for implantation into a hip socket and connected with said stem at the medial side thereof, wherein said bore is open at said proximal end; wherein a closure plug is inserted in said bore in a tight fitting manner at said proximal end of the stem, wherein said bore is open at said distal end, and further including a second closure plug inserted in said bore in a tight fitting manner at said distal end, and wherein said second closure plug at said distal end is porous.
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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) | 1997-05-30 | 1997-11-29 | 1998-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-05-30 | 2001-11-29 | 2002-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-05-30 | 2005-11-29 | 2006-05-31 | $7700.00 | Window Closed / Lapsed |