A method for installing a surgical device on a spine for applying corrective forces thereon comprises installing at least one anchor on a first vertebra and at least another anchor on a second vertebra. At least one connector is installed on at least one of the first and the second vertebrae. A flexible tether is fixed to one of the anchors. The flexible tether is tensioned about a surface of the at least one connector. The flexible tether is fixed to the other one of the anchors to maintain a tension in the flexible tether to apply corrective forces to the vertebrae interconnected by the tether. A method for installing a staple device with rotational joints in the vertebrae is also provided.
