Anchor and method for fixing a screw in bone
AssigneeAsahi Kogaku Kogyo Kabushiki Kaisha
InventorsSatoshi Ojima, Masahiro Kohketsu
Life of this patent
Estimating the term…
Abstract
An anchor including a shank formed from a hardened product of a calcium phosphate compound. The anchor having a strength capable of retaining its original shape, before, during and after insertion into a pre-drilled hole of a bone, and a brittleness capable of causing its original shape to disintegrate as a result of a breakage of the shank upon an application of a driving force from the screw to the shank during a driving of the screw through the anchor inserted in the bone. The present invention also relates to a method for fixing a screw in a bone. Using the anchor of the present invention, it becomes possible to easily and reliably fix a screw in a bone having a reduced strength.
Claims17
An anchor to be inserted into a pre-drilled hole of a bone, thereby assisting a fixation of a screw in the bone, comprising in combination:
- a shank composed of hardened product of calcium phosphate compound;
- said shank comprising a screw-receiving hole and having a strength capable of retaining an original shape, before, during and after insertion into said pre-drilled hole;
- and
- said shank further having a brittleness capable of causing said original shape to disintegrate as a result of a breakage of said shank upon application of a driving force from said screw to said shank when said screw is driven through said anchor inserted in the bone;
- and
- a screw, said screw comprising a portion sized to be insertable into said hole and a portion having a diameter greater than the diameter of said hole.
A method of fixing a screw in a bone, comprising:
- drilling a hole in a predetermined site in the bone;
- inserting an anchor into said pre-drilled hole, wherein said anchor comprises a shank composed of hardened product of calcium phosphate compound, said shank having a strength capable of retaining an original shape, before, during and after insertion into said pre-drilled hole, said shank also having a brittleness capable of causing said original shape to disintegrate as a result of a breakage of said shank upon application of a driving force from said screw to said shank when said screw is driven through said anchor inserted in the bone;
- and
- driving said screw through said anchor inserted in said bone to disintegrate said anchor.
Dependencies are inferred from the claim text.