a dynamic spinal rod system for semi - restrained holding of the vertebrae with respect to each other in a corrected position while providing varying degrees of vertebral body freedom of movement . a first or “ male ” component has an enlarged proximal end with a bio - compatible elastic polymer insert through which an anchoring component , such as a pedicle screw , may be placed for attachment , and a cylindrical distal end . a second or “ female ” component includes a similar enlarged proximal end with a bio - compatible elastic polymer insert through which an anchoring component may be placed for attachment , but has a distal end with a colleted portion into which the distal end of the first component may be inserted and retained to form a joined system . a third “ interconnector ” component may be used to attach to the proximal end of either of the first two components .