Lock washer for bone plate osteosynthesis
First Claim
1. Lock washer for use in attaching a bone screw to a bone plate having a bore hole, said washer comprising a substantially cylindrical body having a central axis, a bore hole having internal threading for receiving a bone screw, a lower section having a surface adapted to abut the surface of a bone and an upper section, wherein the upper section is shaped to be retained in the plate bore hole and is curvedly tapered to form a surface shaped to engage a corresponding surface in the plate bore hole, and the lower section is smaller in average width than the upper section.
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Accused Products
Abstract
A lockwasher is provided for attaching a bone screw to a bone plate, thus making up an osteosynthetic system. The washer has a threaded screw hole, a lower section with a surface to be applied to a bone and an upper section shaped to be retained in a plate borehole, the lower section being of less than average width than the upper section.
254 Citations
16 Claims
- 1. Lock washer for use in attaching a bone screw to a bone plate having a bore hole, said washer comprising a substantially cylindrical body having a central axis, a bore hole having internal threading for receiving a bone screw, a lower section having a surface adapted to abut the surface of a bone and an upper section, wherein the upper section is shaped to be retained in the plate bore hole and is curvedly tapered to form a surface shaped to engage a corresponding surface in the plate bore hole, and the lower section is smaller in average width than the upper section.
- 6. An osteosynthetic fixation system comprising a bone plate having an upper surface, a lower surface for positioning to face a bone, and a plate bore hole extending from said upper surface to said lower surface, in combination with a lock washer having a body having a bore hole with internal threading for receiving a bone screw, a lower section having a surface adapted to abut the surface of a bone and an upper section, said upper section being curvedly tapered to form a surface shaped to engage a corresponding surface in the plate bore hole from said lower surface, said lower section being smaller in average width than said upper section.
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11. An osteosynthetic fixation system comprising a bone plate having an upper surface, a lower surface for positioning to face a bone, and a plate bore hole extending from said upper surface to said lower surface, in combination with a lock washer having a body having a bore hole with internal threading for receiving a bone screw, a lower section having a surface adapted to abut the surface of a bone and an upper section, said upper section being adapted for insertion in the plate bore hold from said lower surface, said lower section being smaller in average width than said upper section, wherein the body has an asymmetric configuration with respect to a transverse plane through and including the central axis of the washer bore hole, so that when the upper section is inserted in the plate bore hole, the axis of the washer bore hole forms an angle with the axis of the plate bore hole.
- 12. Bone fixation device comprising a bone plate having an upper surface, a lower surface, and a bore hole, a bone screw and a lock washer, said lock washer having a body with an upper section and a lower section wherein the upper section is curvedly tapered to form a surface shaped to engage a corresponding surface in the plate bore hole and the lower section is smaller in average width than the upper section and has a surface adapted to abut the surface of a bone.
- 15. An osteosynthetic fixation system comprising a bone plate having an upper surface, a lower surface for positioning to face a bone, and a plate bore hole extending from said upper surface to said lower surface, in combination with a lock washer having a body having a bore hole with internal threading for receiving a bone screw, a lower section having a surface adapted to abut the surface of a bone and an upper section, said upper section being adapted for insertion in the plate bore hole from said lower surface, said lower section being smaller in average width than said upper section, wherein the plate bore hole narrows between the upper and lower plate surfaces and at its narrowest point has securing elements for retaining the lock washer.
Specification