Springs for use in bone implant assemblies where the spring is assembled to a bone implant body. The spring comprises first and second bands, biased against each other, by a spring leaf which extends between the bands, and resists compression of the bands toward each other. Securement of the spring to the implant body can provide for initial transverse movement of the entire length of the spring leaf, when one of the bands is urged toward the other. When assembled to an implant body, the bands extend into fastener receiving apertures in the implant body. A stud is installed in the implant body and extends into an aperture in the spring. A stud-receiving aperture in the spring is optionally elongate, with the length of such aperture extending along the width of the spring, thereby enabling distributing an external compressive force through substantially the entire body of the spring leaf.
