APPARATUS FOR INSERTING FACET SCREWS

摘要

An apparatus includes a bone screw (5650), a nut (5610), and a washer (569O). The bone screw has a first threaded portion (5676), a second threaded portion (5663), and a recessed portion (5673) disposed between the first threaded. portion and the second threaded portion. The first threaded portion is configured to be threaded into a bone tissue. The nut is threadedly coupled to the second threaded portion of the bone screw. The nut having a tool engagement portion (5625) and a seating portion (5630). The washer is disposed about the bone screw such that" a first surface (5694) of the washer is disposed about the seating portion of the nut and a retention portion (5695) is disposed within the recessed portion of the bone screw. The washer is configured to rotate (QQ) about an axis substantially normal to a longitudinal axis (A) of the bone screw.