| CPC A61B 17/7037 (2013.01) [A61B 17/7005 (2013.01); A61B 17/7008 (2013.01); A61B 17/702 (2013.01); A61B 17/7032 (2013.01); A61B 17/7038 (2013.01); A61B 17/7082 (2013.01); A61B 17/7091 (2013.01); A61B 17/864 (2013.01); A61B 2017/567 (2013.01); A61B 2017/681 (2013.01); A61B 2090/0808 (2016.02); Y10T 29/49826 (2015.01)] | 13 Claims |

|
1. A pivotal bone anchor assembly intended for securing an elongate rod to a bone of a patient, the pivotal bone anchor assembly comprising:
a receiver comprising a longitudinal axis, a base, and a pair of upstanding arms extending upwardly from the base with opposed interior surfaces defining an open channel configured for receiving the elongate rod, the opposed interior surfaces of the upstanding arms having a guide and advancement structure formed thereon, the base including a receiver cavity in communication with a bottom of the receiver through a lower opening and with the open channel to define a central bore centered about the longitudinal axis, at least one of the upstanding arms configured to slidably receive an insert compressing member in a direction parallel with the longitudinal axis;
a bone anchor having a capture portion with a spherical outer surface and an anchor portion configured for fixation to the bone, the capture portion configured to be pivotally disposed within the receiver cavity with the bone anchor extending downward through the lower opening; and
an insert configured for positioning within the central bore of the receiver above the capture portion of the bone anchor and thereafter configured for engagement and continuous downward pressing by the insert compressing member until the insert comes into a compressive contact with the spherical outer surface of the capture portion of the bone anchor so as to establish a pressable and releasable locking engagement of the bone anchor with respect to the receiver independent of a closure top,
wherein with the insert compressing member in a downward compression position, the elongate rod is receivable within the open channel of the receiver and lockable with the closure top to establish a final locked configuration of the pivotal bone anchor assembly, and
wherein with the closure top maintaining the elongate rod and pivotal bone anchor assembly together in the final locked configuration, the insert compressing member is slidably removable from the receiver in a direction parallel with the longitudinal axis.
|