Bone plate with a transfixation screw hole
A system for securing bones together across a joint includes a transfixation screw and a plate. The plate includes an elongate spine having a transfixation screw hole disposed along the spine. The transfixation screw hole includes an inner surface configured to direct the transfixation screw through the transfixation screw hole such that the transfixation screw extends alongside the bridge portion at a trajectory configured to pass through a first position on the first bone and a second position on the second bone once the plate is placed across the joint. The transfixation screw includes a head configured to abut the inner surface of the transfixation screw hole and a shaft configured to contiguously extend through the first bone, across the joint, and into the second bone.
1. A system for securing a first discrete bone and a second discrete bone together across a joint between the first discrete bone and the second discrete bone, the system comprising:
a plate comprising:
an elongate spine having a first end comprising at least one attachment point for attaching the first end to the first discrete bone on a first side of the joint, a second end comprising at least one attachment point for attaching the second end to the second discrete bone on a second side of the joint, and a bridge portion disposed between the first end and the second end, the bridge portion having a portion configured to span across the joint, the bridge portion further comprising a thickened portion having a thickness greater than at least a portion of a thickness of either the first end or the second end; and
an aperture defining a transfixation screw hole disposed along the spine at the thickened portion of the bridge portion, the transfixation screw hole comprising an inner surface configured to direct a transfixation screw through the transfixation screw hole such that the transfixation screw extends at a trajectory configured to pass through a first position on the first discrete bone and a second position on the second discrete bone once the plate is placed across the joint.
2. The system of claim 1 , further comprising a transfixation screw, said transfixation screw comprising a head configured to abut the inner surface of the transfixation screw hole and a shaft configured to contiguously extend through the first discrete bone, across the joint, and into the second discrete bone.
3. The system of claim 2 , wherein the transfixation screw comprises a lag screw having:
at a first end of the shaft adjacent to the head, an unthreaded portion configured to extend through the first discrete bone; and
at a second end of the shaft adjacent to a tip of the transfixation screw, a threaded portion configured to extend into the second discrete bone.
4. The system of claim 1 , wherein the inner surface of the transfixation screw hole is configured to lockably engage a head of a transfixation screw.
5. The system of claim 4 , wherein the inner surface of the transfixation screw hole is threaded to provide a locking interface with a transfixation screw.
6. The system of claim 1 , wherein the first position resides on a compression side of the joint and the second position resides on a tension side of the joint.
7. The system of claim 1 wherein the plate is configured to substantially conform to a geometry of the respective first and second discrete bones on which the plate is configured to be disposed.
8. The system of claim 1 , wherein:
a central axis of the inner surface of the transfixation screw hole defines the trajectory; and
the trajectory is configured to cross a neutral bending axis of the joint once the plate is placed across the joint.
9. The system of claim 8 wherein the trajectory is configured to pass through the joint at a transfixation angle between about 30 degrees and about 70 degrees measured from the neutral bending axis.