Semi - constrained anchoring system for correcting a spinal deformity

SEMI - CONSTRAINED ANCHORING SYSTEM FOR CORRECTING A SPINAL DEFORMITY There is disclosed a method of correcting a spinal deformity, the method comprising securing a first rod anchor (14A) to a first vertebra (26A) of a spine and a second rod anchor (14B) to a second vertebra (26B) of the spine; slidably receiving a rod (12) through a first pivot point (P1) in the first rod anchor (14A) and receiving the rod (12) through a second pivot point (P2) in the second rod anchor (14B), such that the rod (12) is secured against substantial lateral translation relative to the first and second rod anchors (14A, 14B) and the rod (12) is free to slide axially relative to the first rod anchor (14A) and change in pitch and yaw about the first and second pivot points (P1, P2) during a correction of the spinal deformity; securing an anchor arm (18A) to a portion of the spine having an abnormal curvature in need of correction; connecting a force directing member (22) to at least a portion of the anchor arm (18A) and a coupler (20A), the coupler (20A) connecting the force directing member (22) to the rod (12); and correcting the abnormal curvature by adjusting a distance between the rod (12) and the anchor arm.