Modular screw head assemblies
AssigneeGlobus Medical, Inc.
InventorsDavid Leff, Matthew Bechtel, Caelan Allen, George Yacoub
Life of this patent
Estimating the term…
Abstract
Orthopedic fixation devices, assemblies, and methods for securing a spinal rod. The orthopedic fixation device may include a tulip head with one or more internal components configured to secure a bone fastener. The tulip head may house a breakable shear clip that has an initial solid form. When the bone fastener is loaded into the tulip head, the shear clip breaks forming a split ring that expands radially outward to accept the screw head. Then, the shear clip collapses around the screw head, thereby securing the bone fastener to the tulip head. A spinal rod may be secured in the tulip head, for example, with a locking cap.
Claims14
A method of installing an orthopedic fixation assembly, the method comprising:
- providing an orthopedic fixation assembly having:
- a tulip head having two arms defining a rod slot therebetween and a bore extending therethrough;
- a saddle receivable in the bore of the tulip head, the saddle having an upper surface defining a rod seat aligned with the rod slot;
- a bearing washer positionable below the saddle;
- a shear clip positionable over the bearing washer;
- and
- a support clip configured to retain the shear clip in the tulip head, wherein the shear clip is breakable at a fracture site upon application of a force,
- wherein the bearing washer is configured to center the shear clip within the tulip head to limit translation;
- and
- inserting a bone fastener having a head into a bottom of the tulip head.
A method of installing an orthopedic fixation assembly, the method comprising:
- providing an orthopedic fixation assembly comprising:
- a tulip head having two arms defining a rod slot therebetween, each of the arms defining a threaded portion along an interior surface, the tulip head having a bore extending therethrough;
- a breakable shear clip positioned in the bore of the tulip head;
- and
- a bone fastener including a screw head receivable in the tulip head and a shaft configured for engaging bone,
- wherein the breakable shear clip has an initial solid form, and when the bone fastener is loaded into the tulip head, the shear clip breaks forming a split ring that expands radially outward to accept the screw head, and then the shear clip collapses around the screw head, thereby securing the bone fastener to the tulip head,
- wherein a bearing washer housed in an internal groove in the tulip head, the bearing washer including a split ring with a radial neck protruding outward from the split ring and a plurality of slits defined through the top of the neck downward into the split ring;
- inserting a bone fastener having a head into a bottom of the tulip head.
Dependencies are inferred from the claim text.