Osteosynthetic pressure plate osteosynthetic compression plate

• US 5,002,544 A
• Filed: 07/26/1990
• Issued: 03/26/1991
• Est. Priority Date: 12/02/1987
• Status: Expired due to Term

• Current Assignee: Synthes USA LLC (Johnson & Johnson)
• Original Assignee: Synthes USA LLC (Johnson & Johnson)
• Inventors: Klaue, Kaj, Brunner, Hans, Perren, Stephan M.
• Primary Examiner(s): Hafer, Robert A.
• Assistant Examiner(s): BROWN, MICHAEL A
• Application Number:
  US07/559,376
• Time in Patent Office: 243 Days
• Field of Search: 606/69-71, 606/105, 606/76, 606/77, 606/78, 606/101
• US Class Current: 606/280
• CPC Class Codes: A61B 17/80 Cortical plates , i.e. bone plates; Instruments for holding or positioning cortical plates, or for compressing bones attached to cortical plates

Abstract

An osteosynthetic pressure plate having several holes for bone screws positioned along its longitudinal axis and having an underside with curved recesses, designed for positioning on the bone so that immediately upon implantation there are spaces between the bone and the pressure plate.

Claims

1. An osteosynthetic compression plate having a central longitudinal axis, an upper surface with two side edges generally parallel to the central axis, a lower surface for application to a bone, and a plurality of screw holes along the central axis, the edges of said upper surface being more remote from said central axis in a direction perpendicular to said central axis, than any other part of said plate, said plate having recesses in its lower surface extending both parallel to and transverse to the central axis to provide space between the lower surface of the plate and the bone.

2. An osteosynthetic compression plate as claimed in claim 1 wherein the cross section is in the shape of a section of a cylinder.

3. An osteosynthetic compression plate as claimed in claim 1 wherein the pressure plate has an oblong screw hole with its long sides in the same direction as the longitudinal axis of the plate, said hole having side walls adapted to form an abutment for a PG,14 screw head, enabling a screw head to slide parallel to the longitudinal axis of the plate.

4. An osteosynthetic compression pressure plate according to claim 1, wherein the recesses form an angle of about 12°

to about 28°

with the lower surface in the area between the screw holes.

5. An osteosynthetic compression pressure plate according to claim 4 wherein the angle is in the range of about 18°

to about 22°

.

6. An osteosynthetic compression pressure plate according to claim 1, wherein the upper portion of at least one hole is constructed as a spherical surface for receiving a screw head.

7. An osteosynthetic compression pressure plate according to claim 1, wherein the cross section profile has an approximately trapezoidal shape at one point along the longitudinal axis.

8. An osteosynthetic compression plate according to claim 1, wherein, on the lower surface of the plate, the width of the inter-hole areas and the sum of the widths of the two areas between the sides of each hole and the corresponding side of the plate, are equal and constant over the length of the plate.

9. An osteosynthetic compression pressure plate according to claim 8, wherein the width of the interhole area of the undersurface of the plate for contact with a bone is less than 4 mm.

10. The plate claimed in claim 8 wherein the width of the interhole area is less than 2 mm.

11. An osteosynthetic compression plate having an upper surface, a lower surface for application to a bone, a longitudinal axis, and a plurality of screw holes positioned along the longitudinal axis, the cross section of the plate transverse to the longitudinal axis at least at one point on said axis being wider toward the upper surface than toward the lower surface and said plate having recesses in the lower surface so that upon application to a bone there is space between the bone and the plate, wherein the area of the cross section is reduced between screw holes so that the bending resistance of the plate in the sections between holes is no greater than in the sections where holes are located.