Dynamic interbody cage anchor system

摘要

A system and method of securing an intervertebral fusion cage within the intervertebral space between adjacent vertebra in which one or more slots are provided in an anterior surface of the cage each extending from an oversized aperture. A retention plate having a post and enlarged head is advanced into each slot via the oversized aperture and captured therein. The post is advanced to the terminal end of the plate and secured to vertebral body at its distal end by a bone screw. A locking clip is slideably positioned on the retention plate to prevent withdrawal of the bone screw. The slots preferably extend to margins of the anterior surface of the cage in, for example, the pattern of an “X” or an “H”. Sliding of the posts in the slots prevents the system from carrying the vertebral load (load shielding) and permits reduction in the intervertebral space to promote bone growth and fusion by graft material retained in the spacer.

主权项

1. A system for securing a fusion cage with an anteriorly oriented surface between adjacent vertebrae comprising:
in said anteriorly oriented surface, an opening and at least two slots in operative engagement with said opening and extending therefrom, each of said at least two slots having a terminal segment aligned to have at least a vertical vector component; and in a first of said at least two slots, a first retaining member having a first end slideably retained in said terminal segment and a second end fixedly secured only to a superior adjacent vertebra by a bone screw in a second of said at least two slots, a second retaining member independent from said first retaining member and having a first end slideably retained in said terminal segment and a second end fixedly secured only to an inferior adjacent vertebra by a bone screw whereby engagement of said first ends of said retaining members in said terminal segments distributes a selective portion of a load on one of said adjacent vertebrae directly to another of said adjacent vertebrae.