CPC A61B 17/70 (2013.01) [A61B 17/8605 (2013.01); A61B 17/8625 (2013.01); A61B 17/8685 (2013.01)] | 19 Claims |
1. A bone anchor assembly, comprising:
a bone anchor having a proximal head and a distal threaded shaft configured to engage bone;
a receiver member having a pair of spaced apart arms for receiving a spinal fixation element therebetween, the receiver member having a first lumen formed therethrough;
a base having a toroid body portion and a radially-extending protrusion with at least one auxiliary bone anchor opening to receive one or more auxiliary bone anchors therethrough, the base having a second lumen with a central longitudinal axis extending through the toroid body portion, the toroid body portion having an interior surface complementary to the proximal head such that the bone anchor can be retained within the toroid body portion and move polyaxially relative thereto,
wherein the base is received within the receiver member such that the base is configured to rotate relative to one or more of the receiver member or the bone anchor.
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