CPC A61B 17/7037 (2013.01) [A61B 17/7001 (2013.01); A61B 17/7007 (2013.01); A61B 17/708 (2013.01); A61B 17/7032 (2013.01); A61B 17/7082 (2013.01); A61B 17/7083 (2013.01); A61B 17/863 (2013.01); A61B 17/8615 (2013.01); A61B 17/8625 (2013.01); A61B 17/7041 (2013.01); A61B 17/7076 (2013.01); A61B 17/864 (2013.01); A61B 2090/031 (2016.02); A61B 2090/037 (2016.02)] | 20 Claims |
1. A bone anchor assembly, comprising:
a receiver member having proximal and distal ends that define a central proximal-distal axis, the receiver member having a cavity formed therein, the cavity being open to the distal end of the receiver member;
a shank having a head portion configured to be disposed in the cavity by passing through the open distal end of the receiver member;
a compression cap disposed in the cavity and configured to contact the head portion of the shank; and
an insert attached to the receiver member to retain the head portion of the shank within the receiver member;
wherein the insert is prevented from moving proximally or distally relative to the receiver member by an annular ridge of the insert received within a groove formed in the receiver member;
wherein the insert is monolithic;
wherein the insert defines an outer surface that extends distally from the annular ridge and forms a radially inward step distal to the annular ridge; and
wherein a distal portion of an inner sidewall of the cavity extends distally from the groove along at least a portion of the outer surface of the insert, the distal portion preventing radially outward movement of the insert.
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