A spinal stabilization rod includes a first rod portion having a proximal end and a distal end and having a first cross-sectional area. The second rod portion extends from the distal end of the first rod portion and has a second minimum cross-sectional area smaller than the first cross-sectional area. The second rod portion is formed of a first material and a different second material, with the first material being more resistant in shear than the second material. The implant also includes a slider portion disposed about and movable relative to the second rod portion.
