US4156296A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Great (large) toe prosthesis and method of implanting
Assignee: Roche Diagnostics Corp
•
Filing: 1977-04-08
•
Granted: 1979-05-29
•
Expires: 1997-04-08
Abstract
Abstract An endoprosthetic device for a prosthesis between metatarsal and phalangeal bones comprising proximal and distal components which are engageable with each other. The proximal component has a convex, part-spherical bearing surface and a stem projecting from this surface for securing the proximal component into the end of the first metatarsal. The distal component has a concave, part-spherical bearing surface and a stem projecting from this surface for securing the distal component into the end of the phalanx adjacent to the first metatarsal. The engagement of the two components forms a less-than-hemispherical articulation.
Inventors
- 👤 Kenneth A. Johnson
- 👤 Allan Vegell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 01:56
CPC Classifications
A; A61; A61F; A61F2/00; A61F2/02; A61F2/30; A61F2/42; A61F2/4225; A61F2/30767; A61F2/30771; A61F2002/3082; A61F2002/30878; A61F2002/4233; A61F2310/00; A61F2310/00005; A61F2310/00011
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
166 words
An endoprosthetic device for replacement of a joint in fingers and toes which comprises only two components, said two components being mutually engageable and including a proximal component and a distal component, the proximal component having a convex, part-spherical bearing surface and a first stem projecting from the rear of said proximal component for affixing into a bone, the maximum transverse dimension of said convex bearing surface equaling the maximum transverse dimension of said proximal component, the distal component having a concave, part-spherical bearing surface and a second stem projecting from the rear of said distal component for affixing into a bone, said convex, part-spherical bearing surface having a surface area noticeably larger than the surface area of said concave, part-spherical bearing surface, the engagement of the convex, part-spherical bearing surface with the concave, part-spherical bearing surface forming a less-than-hemispherical area of contact, said engaging bearing surfaces being free to slide relative to each other in a universal manner and being free of any stop surfaces.
Claim 2
Dependent Claim
166 words
An endoprosthetic device for replacement of a joint in fingers and toes which comprises only two components, said two components being mutually engageable and including a proximal component and a distal component, the proximal component having a convex, part-spherical bearing surface and a first stem projecting from the rear of said proximal component for affixing into a bone, the maximum transverse dimension of said convex bearing surface equaling the maximum transverse dimension of said proximal component, the distal component having a concave, part-spherical bearing surface and a second stem projecting from the rear of said distal component for affixing into a bone, said convex, part-spherical bearing surface having a surface area noticeably larger than the surface area of said concave, part-spherical bearing surface, the engagement of the convex, part-spherical bearing surface with the concave, part-spherical bearing surface forming a less-than-hemispherical area of contact, said engaging bearing surfaces being free to slide relative to each other in a universal manner and being free of any stop surfaces.
Claim 3
Dependent Claim
19 words
The endoprosthetic device of claim 1 in which each stem has a pair of concave recesses in spaced-apart relationship.
Claim 4
Dependent Claim
27 words
The endoprosthetic device of claim 2 in which the proximal components is made of a substantially, physiologically inert metal and the distal component is made of polyethylene.
Claim 5
Dependent Claim
29 words
The endoprosthetic device of claim 3 in which the proximal and distal components are of a size suitable for a prosthesis of the metatarso-phalangeal joint of the first metatarsal.
Claim 6
Independent Claim
190 words
A method of implanting a prosthetic device having only two components, a proximal component and a distal component, into a metatarsal and a proximal phalanx for replacement of a metatarso-phalangeal joint which comprises the steps of: making a dorsomedial incision over the metatarso-phalangeal joint; removing a portion of bone from the end of the metatarsal adjacent said joint; inserting the proximal component into the metatarsal at said end, said proximal component having a convex, part-spherical bearing surface, the maximum transverse dimension of said convex, part-spherical bearing surface equaling the maximum transverse dimension of said proximal component; removing a portion of bone from the end of the proximal phalanx adjacent said joint; inserting the distal component into the proximal phalanx at said end, said distal component having a concave, part-spherical bearing surface with a surface area noticeably smaller than the surface area of the convex, part-spherical bearing surface of the proximal component, the engagement of said bearing surfaces forming a less-than-hemispherical area of contact, said engaging bearing surfaces being free to slide relative to each other in a universal manner and being free of any stop surfaces; and closing the incision.
Claim 7
Independent Claim
190 words
A method of implanting a prosthetic device having only two components, a proximal component and a distal component, into a metatarsal and a proximal phalanx for replacement of a metatarso-phalangeal joint which comprises the steps of: making a dorsomedial incision over the metatarso-phalangeal joint; removing a portion of bone from the end of the metatarsal adjacent said joint; inserting the proximal component into the metatarsal at said end, said proximal component having a convex, part-spherical bearing surface, the maximum transverse dimension of said convex, part-spherical bearing surface equaling the maximum transverse dimension of said proximal component; removing a portion of bone from the end of the proximal phalanx adjacent said joint; inserting the distal component into the proximal phalanx at said end, said distal component having a concave, part-spherical bearing surface with a surface area noticeably smaller than the surface area of the convex, part-spherical bearing surface of the proximal component, the engagement of said bearing surfaces forming a less-than-hemispherical area of contact, said engaging bearing surfaces being free to slide relative to each other in a universal manner and being free of any stop surfaces; and closing the incision.
Claim 8
Dependent Claim
34 words
The method of implanting a prosthetic device as recited in claim 5 comprising the additional steps of affixing each component into the bone by means of a grouting compound subsequent to each inserting step.
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) | 1982-05-28 | 1982-11-27 | 1983-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-05-28 | 1986-11-27 | 1987-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-05-28 | 1990-11-27 | 1991-05-29 | $7700.00 | Window Closed / Lapsed |