A device is disclosed for securing a spinal rod to the spine which includes a head portion configured to receive a spinal rod, a locking cap configured to engage the head portion and the spinal rod upon rotation of the locking cap relative to the head portion to secure the position of the head portion relative to the spinal rod, and a fastener portion depending from the head portion and configured to engage the spine. The locking cap has discontinuous opposed engagement flanges that are received within opposed engagement slots of the head portion when the locking cap is rotated into a locked position.