Pivotal bone anchor assembly with receiver having horizontal tool engagement grooves and insert alignment structures

Abstract

A pivotal bone anchor assembly includes a receiver comprising a base portion defining a cavity and an upper portion with upright arms extending upward abov the base portion to define an open channel for receiving a rod, with the cavity communicating with the open channel to define a central bore having opposed inwardly-extending insert abutment structures below a guide and advancement structure, and tool engagement recesses extending horizontally around side outer surfaces of the upright arms. The assembly also includes a shank comprising a proximal capture portion configured for positioning within the cavity and a distal anchor portion configured for attachment to the bone. The assembly further includes a pressure insert positionable within the central bore of the receiver, with side surfaces of the pressure insert engageable with the abutment structures to inhibit movement of the pressure insert within the receiver.