US3552389A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Osteosynthetic pressure plate construction
Assignee: AO Technology AG
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Filing: 1967-06-16
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Granted: 1971-01-05
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Expires: 1987-06-16
Abstract
Abstract An osteosynthetic pressure plate includes a slot formation for receiving a bone-fixing screw which is adapted to be secured to a bone part which is to be mended. The slot is formed with an edge which includes an oblique portion or ramp having an inclination such that when it is engaged by the underside of a head portion of a bone-fixing screw there will be a displacement of the pressure plate in a direction to move the ramp portion away from the fixing screw and to cause the plate to apply a pressure to hold the bone parts in tight engagement. The plate is advantageously useable with screws having heads of spherical form or conical form, for example. The inclination of the ramp and the configuration of the walls bounding the slot of the pressure plate are such that there will be a uniform and even shifting of the plate having the slot when the ramp of the walls bounding the slot is engaged by the screw head to cause the desired displacement of the pressure plate in order to displace the bone fragment toward tighter engagement with the adjacent bone fragment and into pressure engagement therewith.
Inventors
- 👤 Martin Allgower
- 👤 Stefan Perren
- 👤 Max E Russenberger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:18
CPC Classifications
A; A61; A61B; A61B17/00; A61B17/56; A61B17/58; A61B17/68; A61B17/80; A61B17/8004; A61B17/8014; A61B2017/00526; Y; Y10; Y10T; Y10T409/00; Y10T409/30; Y10T409/303752; Y10T409/303808
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
184 words
An apparatus for securing bone fragments together in pressure contact using screws at least one of which has a head with an inwardly tapered undersurface, comprising a plate having a top side and a bottom side and at least two spaced longitudinally elongated slot openings extending therethrough for receiving the screws which are adapted to pass through the slot openings to engage into respective bone fragments, said plate having a wall bounding at least one of said slot openings which is inclined at an angle from said top side toward said bottom side to cause shifting of the plate in a direction to move the bone fragments together when engaged by the tapered undersurface of the head of the screw as said plate is being secured to its respective bone fragment, said inclined wall of said slot extending from said top surface inwardly and downwardly towards said bottom surface and defining an inclined planar surface from one end of the slot to the other which is displaceable by the tapered undersurface of the screw head when it is advanced into its respective bone fragment.
Claim 2
Independent Claim
184 words
An apparatus for securing bone fragments together in pressure contact using screws at least one of which has a head with an inwardly tapered undersurface, comprising a plate having a top side and a bottom side and at least two spaced longitudinally elongated slot openings extending therethrough for receiving the screws which are adapted to pass through the slot openings to engage into respective bone fragments, said plate having a wall bounding at least one of said slot openings which is inclined at an angle from said top side toward said bottom side to cause shifting of the plate in a direction to move the bone fragments together when engaged by the tapered undersurface of the head of the screw as said plate is being secured to its respective bone fragment, said inclined wall of said slot extending from said top surface inwardly and downwardly towards said bottom surface and defining an inclined planar surface from one end of the slot to the other which is displaceable by the tapered undersurface of the screw head when it is advanced into its respective bone fragment.
Claim 3
Dependent Claim
23 words
An apparatus, according to claim 1, including a threaded screw engaged through each slot opening adapted for insertion into a respective bone fragment.
Claim 4
Dependent Claim
38 words
An apparatus according to claim 1, wherein the wall of said plate bounding said slot opening which is inclined includes a portion opposite the inclined portion forming an abutment stop shaped to the configuration of the screw head.
Claim 5
Dependent Claim
53 words
An apparatus according to claim 1, including a threaded securing screw engaged through each slot opening adapted for insertion into a respective bone fragment and having a hemispherical countersunk head, said inclined wall portion comprising a surface complementary to said screw head and having an axis inclined to the plane of said plate.
Claim 6
Dependent Claim
47 words
An apparatus, according to claim 1, including a securing screw adapted to extend through each of said slot openings and to be threaded into the respective bone fragments and having a conically-shaped countersunk head, the inclined wall portion of said plate being formed as a conical surface.
Claim 7
Dependent Claim
60 words
An apparatus, according to claim 1, including at least one slot adapted to be located on each side of the fracture line of said bone fragments, and a threaded securing screw engaged through at least one of the slots adapted to be located on each side of the fracture line and adapted to be threaded into the respective bone fragment.
Claim 8
Dependent Claim
65 words
An apparatus, according to claim 6, wherein at least one of said slots is elongated sufficiently to permit an initial shifting of the plate upon contact of the inclined surface by the securing screw and an additional movement, and wherein at least one other slot is provided with an inclined wall portion engageable by a threaded securing screw for effecting additional movement of said plate.
Claim 9
Dependent Claim
93 words
An apparatus, according to claim 1, wherein said pressure plate includes at least two slot openings adjacent each end adapted to be oriented over the respective bone fragments adjacent each end, the slots having walls at the ends adjacent the respective ends of said plate inclined at an angle to cause shifting of the plate in the direction to move the bone fragments together when contacted by a securing screw and having at their opposite ends formed with an abutment complementary to the configuration of the bone-securing screw which is to be employed.
Claim 10
Dependent Claim
114 words
An apparatus, according to claim 1, including at least one slot adjacent one end of said plate and at least two additional slots adjacent the opposite end of said plate which are each elongated in a direction parallel to the longitudinal axis of said plate end which form an inclined portion arranged at an angle to cause relative shifting of the plate in directions toward the associated adjacent end, at least one of said slots adjacent one of said plate ends being elongated sufficiently to permit a shifting of said plate after it is threadedly secured by the associated screw after the tightening of the threaded securing screw in the other of said slots.
Claim 11
Dependent Claim
45 words
An apparatus, according to claim 1, wherein said inclined wall begins at one end of said slot which is inclined from said top surface inwardly and downwardly towards said bottom by a lesser distance than the remaining portions of said inclined wall bounding said slot.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-01-04 | 1974-07-06 | 1975-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-04 | 1978-07-06 | 1979-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-04 | 1982-07-06 | 1983-01-05 | $7700.00 | Window Closed / Lapsed |