Patent ID: 8740946

Claim:
A bone anchor, comprising: an anchor member having a head portion and a bone engaging portion; an anchor head having a top portion comprising sidewalls, a top opening, and at least one dimple and at least one groove located proximate the top opening and on the interior of the sidewalls, a bottom portion, a hollow interior bore extending from the top portion to the bottom portion, and a generally U-shaped opening through the sidewalls, the head portion of the anchor member being receivable within the hollow interior bore of the anchor head such that the anchor member is polyaxially rotatable with respect to the anchor head, wherein the at least one dimple comprises a recess formed between a stop surface and a retention surface and the at least one groove comprises an inclined surface; and a locking cap including a set screw and a main body comprising tabs and flanges comprising an inclined surface that corresponds to the inclined surface of the at least one groove, the set screw being rotatably mounted to the main body, the locking cap releasably engageable with the interior of the sidewalls of the top portion of the anchor head in an open position, wherein one of the tabs engages the at least one dimple so that the tab is seated in the recess when the main body is rotated with respect to the anchor head from the open position into a closed position and the stop surface prevents the tab from moving backward out of the recess, thereby preventing the main body from being rotated from the closed position back into the open position, and wherein one of the flanges engages the at least one groove, thereby preventing the locking cap from being lifted out of the anchor head from the closed position.