| CPC A61B 17/7037 (2013.01) [A61B 17/702 (2013.01); A61B 17/705 (2013.01); A61B 17/86 (2013.01)] | 21 Claims |

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1. A pivotal bone anchor assembly for securing a longitudinal connecting member to a bone of a patient via a closure, the pivotal bone anchor assembly comprising:
a receiver comprising a base portion defining a lower portion of a central bore centered about a vertical centerline axis and communicating with a bottom surface of the base portion through a bottom opening, and an upper portion defining a channel configured to receive the longitudinal connecting member, the central bore extending upward from the bottom opening through the channel to a top of the upper portion and including a support surface adjacent the bottom opening, a helically wound guide and advancement structure adjacent the top of the upper portion, and an integral non-threaded downward-facing surface below the helically wound guide and advancement structure;
a shank comprising a head portion and an anchor portion opposite the head portion configured for attachment to the bone, the head portion being positionable within the lower portion of the central bore and pivotably supported therein by the support surface with the shank extending downwardly through the bottom opening;
a unitary insert positionable within the central bore of the receiver, the insert comprising a center opening, a downward-facing lower surface configured to engage the head portion of the shank, at least one upward-facing surface located radially outward from the center opening, and at least one slot configured to make the insert resiliently axially compressible when the at least one upward-facing surface of the insert abuts the downward-facing surface of the central bore so as to apply a pre-lock friction fit pressure against the head portion of the shank,
wherein the insert is configured to engage both the head portion of the shank and the longitudinal connecting member when the head portion of the shank, the insert, and the longitudinal connecting member are positioned together in the receiver.
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