Spinal fixator
First Claim
1. A bone immobilization device for connecting bone to bone comprising:
- housing means defining a perimeter;
at least two, separate crown means mounted inside the perimeter of the housing means, each crown means defining at least one outwardly extending tooth means; and
means including a core member extending through the housing means and having nut means movably attached to external threads thereon for retracting the at least two, separate crown means inside the perimeter and for extending the at least two, separate crown means outside the perimeter, the at least one tooth means adapted to penetrate bone.
4 Assignments
0 Petitions
Accused Products
Abstract
An adjustable spinal fixator for insertion between adjacent vertebrae comprises a contoured housing defining convex edges to fit within the concavity of the vertebral body. An externally threaded core extends through the housing, and a pair of internally threaded nut assemblies attach to the core member. Four crown members with teeth are separately mounted within the housing and retract and variably extend with the movement of the movable nuts on the core member. Two of the crown members extend and retract from the top of the housing, and the remaining two crown members extend and retract from the bottom of the housing. The spinal fixator is positioned between adjacent vertebrae with the crown members retracted so that the teeth are below the convex edges of the housing. Following placement, the crown members are extended outwardly from the top and bottom of the housing by rotation of the core member which causes the teeth to penetrate the bone at an angle to secure the spinal fixator in position. Preferably, a bone graft surrounds the implanted spinal fixator which defines apertures for bony ingrowth. Several sizes of spinal fixators exist to accommodate differing anatomies of the spine.
-
Citations
3 Claims
-
1. A bone immobilization device for connecting bone to bone comprising:
-
housing means defining a perimeter; at least two, separate crown means mounted inside the perimeter of the housing means, each crown means defining at least one outwardly extending tooth means; and means including a core member extending through the housing means and having nut means movably attached to external threads thereon for retracting the at least two, separate crown means inside the perimeter and for extending the at least two, separate crown means outside the perimeter, the at least one tooth means adapted to penetrate bone. - View Dependent Claims (2, 3)
-
Specification