主权项 |
1. A spine stabilization system comprising:
an elongate rod; a bone fastener having a rounded head; a coupling element comprising a coupling body and a cap; wherein the coupling body comprises sidewalls that define two upwardly extending arms which define two slots capable of receiving the elongate rod; wherein the coupling body and cap interact to capture the elongate rod in the coupling body, wherein a first and second protrusions configured on opposing sides of the cap and extending in a radial direction and a first and second recess configured in the two upwardly extending arms extending in a radial direction and wherein the first and second protrusions are configured and dimensioned to engage the first and second recess to limit movement of the cap with respect to the coupling body, when the cap is rotated from a first position to a second position, wherein the cap having a threaded opening for receiving a threaded locking element, the locking element capable of securely holding the elongated rod in a fixed position relative to the coupling element, wherein the cap further comprises at least one rim which extends radially outward from the top end of the perimeter of the cap, wherein a first of the upwardly extending arms includes a third recess positioned between the first recess and the upper surface of the first of the upwardly extending arms for receiving the at least one rim of the cap and a second of the upwardly extending arms includes a fourth recess for receiving the at least one rim of the cap, the fourth recess positioned between the second recess and the upper surface of the second of the upwardly extending arms and wherein the third recess extends along the length of an inner surface of the first of the upwardly extending arms and the fourth recess extends along the length of an inner surface of the second of the upwardly extending arms. |