Patent ID: 7404818

Claim:
An apparatus for attachment to a vertebra and a spinal rod, comprising: a bone anchor portion having a threaded shaft with a longitudinal axis and a neck, said threaded shaft having cancellous threads suited to connection to a vertebra; a substantially C-shaped receiving portion having a lower leg integrally connected to said neck of said bone anchor portion and an upper leg and an intermediate portion, said receiving portion having a channel substantially perpendicular to said axis into which a rod can be placed in said receiving portion, said channel having a mouth for introduction of said rod, said receiving portion further including an internally threaded aperture through said upper leg, said receiving portion further including an opening in said lower leg and said intermediate portion, said receiving portion further including at least one exterior imprint adapted for accommodating a holding tool; an internal piece connected to said receiving portion so that at least a portion of said internal piece is within said opening of said receiving portion, said internal piece having a post portion extending into said intermediate portion of said receiving portion, and a seat portion having a first end and a second end, said first end of said seat portion being attached to said post portion of said internal piece, said second end having a flat portion, said seat portion having a substantially cylindrical inner surface having an arc of up to about 120 degrees, and said post portion having a groove; and a ring member surrounding at least a portion of said post portion of said internal piece such that at least a portion of said ring member is within said groove, wherein said ring member is positioned so that said internal piece and said receiving portion are rotatable with respect to each other and so that said post portion of said internal piece and said ring member cannot be withdrawn from said opening of said receiving portion.