2. The system of claim 1 , wherein the lateral coupling comprises: an arm adapted to extend from the second side of the spine toward the first side of the spine and to receive the second rod, a first flexible connector secured to the arm, and an adjuster adapted to be secured to the first rod and to shorten an effective length of the first flexible connector to tension the arm toward the first rod.
4. The system of claim 2 , wherein the third anchor includes a head defining a receptacle for receiving the second rod, a fixation member adapted to secure the head of the third anchor to the second side of the spine, and an arm extending from the head and adapted to extend from the second side of the spine to the first side of the spine.