view of a seventh embodiment of a bone screw and a partial cross section of an orthopedic implant lock made of cortical bone. [0026]FIG. 7B is a top plan view of the trailing end of the screw in FIG. 7A. [0027] FIGS. 8-10 are side elevation views of an eighth embodiment of a bone screw, and a screw lock made of cortical bone, and a partial cross section of an orthopedic implant. [0028]FIG. 11 is a