SECURING FASTENERS

摘要

A polyaxial fastener is secured within an implant with a retaining ring. The ring is assembled onto a circumferential groove formed in the fastener head. The groove and ring are positionable, when the fastener is installed into an implant, at a wide portion of the mating polyaxial aperture in the implant. The ring is compressible into the groove to form a narrowed diameter, which is passable into a narrow diameter of the aperture, near an entrance to the aperture. The ring is released to expand and increase an overall diameter of the head and ring assembly, thereby rending the assembly too wide to pass by the narrow entrance to the aperture, thereby securing the assembly within the implant.

主权项

1. A spinal implantation system comprising:
a plate comprising a first aperture for receiving a first fastener and a second aperture for receiving a second fastener; a first fastener extendable through the first aperture, wherein the first fastener comprises a head portion and an extension portion, wherein the head portion comprises a groove; and a retaining ring received in the groove of the first fastener, wherein the retaining ring is configured to have a compressed configuration and a relaxed configuration, wherein when the retaining ring is in the compressed configuration the first fastener is insertable into the first aperture, wherein when the retaining ring is in the relaxed configuration the first fastener is prevented from back out of the first aperture.