US4795473A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Extramedullary femoral head-neck prosthesis and method of implanting same
Assignee: JAMES B GRIMES AND TRACIE LYNN GRIMES 1998 TRUST
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Filing: 1987-01-09
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Granted: 1989-01-03
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Expires: 2007-01-09
Abstract
Abstract An extramedullary femoral head-neck prosthesis for implantation in a femur, the latter having a shaft and a neck at the upper end of the shaft at the medial side of the femur. The prosthesis comprises a sideplate and screws for securing the sideplate to the lateral side of the femoral shaft. A barrel extends obliquely upwardly from the sideplate and has an open upper end. The barrel is adapted to be inserted in a bore extending obliquely upwardly through the femoral shaft from the lateral side of the shaft to the femoral neck. The prosthesis also includes a ball assembly comprising a ball stem adapted to be inserted coaxially into the barrel through the open upper end of the barrel and to be slideably received therein, a neck at the upper end of the stem adapted for face-to-face engagement with the femoral neck, and a ball on the neck. The ball stem is sized for a relatively close clearance fit in the barrel. The ball stem is retained and held against upward movement in the barrel so that the neck of the ball assembly presses against and compresses the femoral neck. A method of implanting such a prosthesis is also disclosed.
Inventors
- 👤 James B. Grimes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:23
CPC Classifications
A; A61; A61B; A61B17/00; A61B17/56; A61B17/58; A61B17/68; A61B17/74; A61B17/742; A61B17/746; A61B17/14; A61B17/15; A61B17/16; A61B17/17; A61B17/1739; A61B17/1742; A61B17/175; A61F; A61F2/00; A61F2/02; A61F2/30; A61F2/32; A61F2/36; A61F2/3601; A61F2/46; A61F2/4684; A61F2/3609; A61F2002/3625; A61F2002/3631; A61F2002/365; Y; Y10; Y10S; Y10S623/00; Y10S623/902; Y10S623/908
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
222 words
An extramedullary femoral head-neck prosthesis for implantation in a femur having a shaft and a neck at the medial side of the femur, comprising: a sideplate; means for securing the sideplate to the femur shaft at the lateral side of the femur; a barrel extending obliquely upwardly from the sideplate and having an open upper end, said barrel being adapted to be inserted in a bore extending obliquely upwardly through the shaft of the femur from the lateral side of the shaft to the neck of the femur; a ball assembly comprising a ball stem having a central longitudinal axis adapted to be inserted coaxially into the barrel through the open upper end of the barrel and to be slideably received therein, said ball stem being sized for a relatively closed clearance fit in said barrel, a collar at one end of the stem, constituting its upper end, adapted for face-to-face engagement with the neck of the femur, a neck on the collar, and a ball on the neck, said neck having a central longitudinal axis which is skewed relative to the central longitudinal axis of the stem so that the center of the ball is offset medially from the longitudinal axis of the stem; and retainer means for holding the ball stem against upward movement of the stem in the barrel.
Claim 2
Dependent Claim
222 words
An extramedullary femoral head-neck prosthesis for implantation in a femur having a shaft and a neck at the medial side of the femur, comprising: a sideplate; means for securing the sideplate to the femur shaft at the lateral side of the femur; a barrel extending obliquely upwardly from the sideplate and having an open upper end, said barrel being adapted to be inserted in a bore extending obliquely upwardly through the shaft of the femur from the lateral side of the shaft to the neck of the femur; a ball assembly comprising a ball stem having a central longitudinal axis adapted to be inserted coaxially into the barrel through the open upper end of the barrel and to be slideably received therein, said ball stem being sized for a relatively closed clearance fit in said barrel, a collar at one end of the stem, constituting its upper end, adapted for face-to-face engagement with the neck of the femur, a neck on the collar, and a ball on the neck, said neck having a central longitudinal axis which is skewed relative to the central longitudinal axis of the stem so that the center of the ball is offset medially from the longitudinal axis of the stem; and retainer means for holding the ball stem against upward movement of the stem in the barrel.
Claim 3
Dependent Claim
32 words
An extramedullary femoral head-neck prosthesis as set forth in claim 1 wherein said sideplate is an elongate member having a central longitudinal axis and is adapted to extend along the femur shaft.
Claim 4
Dependent Claim
36 words
An extramedullary femoral head-neck prosthesis as set forth in claim 2 wherein the central longitudinal axis of the barrel extends at an angle of approximately 150° with respect to the central longitudinal axis of the sideplate.
Claim 5
Dependent Claim
44 words
An extramedullary femoral head-neck prosthesis as set forth in claim 3 wherein when the ball stem is inserted in said barrel, the central longitudinal axis of the neck is skewed at an angle of about 25° to the central longitudinal axis of the stem.
Claim 6
Dependent Claim
19 words
An extramedullary femoral head-neck prosthesis as set forth in claim 1 wherein said sideplate and barrel are integrally formed.
Claim 7
Dependent Claim
60 words
An extramedullary femoral head-neck prosthesis as set forth in claim 1 wherein said retainer means comprises a set screw threadable into the lower end of the ball stem when the latter is inserted in the barrel, said set screw being engageable with the barrel for holding the ball stem against any substantial upward movement of the stem in the barrel.
Claim 8
Dependent Claim
36 words
An extramedullary femoral head-neck prosthesis as set forth in claim 1 wherein the central longitudinal axis of the neck is skewed at an angle of about 25° relative to the central longitudinal axis of the stem.
Claim 9
Dependent Claim
40 words
An extramedullary femoral head-neck prosthesis as set forth in claim 1 wherein said sideplate has an upper portion above the junction of the barrel and the sideplate, and a lower portion below the junction of the barrel and the sideplate.
Claim 10
Dependent Claim
51 words
An extramedullary femoral head-neck prosthesis as set forth in claim 1 wherein said collar has a downwardly-facing generally planar surface extending generally at right angles to the central longitudinal axis of the stem, said surface being adapted for face-to-face engagement with an upwardly-facing mating surface on the neck of the femur.
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) | 1992-01-03 | 1992-07-04 | 1993-01-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-01-03 | 1996-07-04 | 1997-01-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-01-03 | 2000-07-04 | 2001-01-03 | $7700.00 | Window Closed / Lapsed |