Devices, systems and methods for use in spinal surgeries. The system may include a fastener system comprising a fastener, a staple, and a locking cap. A cord may extend along the spine and through at least one fastener system. An instrument may be provided for tensioning the cord. The system may, for example, apply fixation on the convexity of the scoliotic vertebrae to limit growth on the convex side and allow unilateral growth on the concave side.
