A system and method for stabilizing a spine of an animal subject involving a transverse rod installation instrument assembly for inserting a transverse rod on the spine of a subject percutaneously comprising: a first rod clamp extender mounted on a ipsilateral rod clamp and a second rod clamp extender mounted on a contralateral rod clamp wherein the ipsilateral rod clamp and the contralateral rod clamp are secured to a vertebra at the ipsilateral and contralateral pedicle； and a pivoting installation instrument pivotably mounted to the first rod clamp extender and the second rod clamp extender to pass a transverse rod percutaneously through a head portion of the ipsilateral side rod clamp and to the head portion of the contralateral rod clamp after passing through a spinous process of the vertebra through pivot axis “A” such that the transverse rod is secured at the head portion of the ipsilateral rod clamp and the head portion of the contralateral rod clamp.
