Pivotal bone anchor assembly with lock and release member vertically translatable with tooling

Abstract

A pivotal bone anchor assembly includes a first member having a central bore, a lower portion with a bottom opening, and a pair of upright arms defining an open channel and including vertically extending tool engagement structures configured for cooperating with tooling. The assembly also includes a shank comprising an anchor portion for fixation to the bone of a patient and a head portion for positioning into the lower portion of the first member. The assembly further includes a second member cooperating with the first member and having a center aperture alignable with the central bore, upward facing tool engagement structures offset with respect to the open channel, and an upwardly-facing surface engageable with a rod. The second member is downwardly compressed relative to the first member by the tooling, so as to lock an angular position of the shank relative to the first member in a locked configuration prior to securing the rod in the open channel with a closure.