A bone screw is used for locking an articular facet between the superior and inferior articular processes of two vertebral bodies and is provided with a threaded shaft, a screw head and a central axis. The liquefiable products present in the resulting intermediate reaction product mixture are selectively hydrogenated over a suitable catalyst, such as 5% ruthenium on carbon, so as selectively to hydrogenate reactive carbonyl-containing by-products to the corresponding alcohols. The termination element may further include a first ground contact coupling the first end of the resistive body to a ground potential, and a second ground contact coupling the second end of the resistive body to the ground potential.