Spinal plate with compression locking

摘要

A spinal plate system includes a screw, spinal plate and cap. A head of the screw includes a portion of a first sphere that has a first center and a portion of a second sphere that has a second center approximately concentric with the first center. A body of the screw extends from the first sphere. The spinal plate includes an opening through the spinal plate and an associated recess in the spinal plate that is eccentric with the opening. The cap includes an alignment opening and is configured to be rotationally engaged in the recess between a first rotational configuration and a second rotational configuration. In the first rotational configuration, the body threads into a vertebra in a selected trajectory through the alignment opening and the opening in the spinal plate and the head engages at least a portion of the opening in the selected trajectory. In the second rotational configuration, the cap compresses the second sphere into the first sphere approximately through its center such that the head is compressed into the engaged portion of the opening.

主权项

1. A spinal plate system, the system comprising:
a screw including a head and a threaded body, the head including a portion of a first sphere that has a first center and a portion of a second sphere that has a second center approximately concentric with the first center, the body extending from the portion of the first sphere; a spinal plate including an opening through the spinal plate and an associated recess in the spinal plate that is eccentric with the opening; and a cap including an alignment opening, the cap configured to be rotationally engaged in the recess between a first rotational configuration and a second rotational configuration, the first rotational configuration enabling the threaded body to be threaded into a vertebra in a selected trajectory through the alignment opening and the opening in the spinal plate and the head to engage at least a portion of the opening in the selected trajectory, the second rotational configuration enabling the cap to compress the portion of the second sphere into the portion of the first sphere approximately through its center such that the head is compressed into the engaged portion of the opening.