Abstract: A bone dowel assembly for attaching a tissue to a bone includes an approximately cylindrical shank having a continuous borehole which extends axially from a free end of the shank to a second end of the shank, and two slots in the outside surface of the shank which communicate with the borehole and extend from the second end of the shank partially along its length to form reeds or tines which expand radially outwardly when an expansion part is forced into the borehole. The expansion part is conical and includes at least one aperture which extends through the expansion part transversely to the longitudinal axis of the shank. Before insertion into a hole drilled in the bone, the assembly is threaded from the free end of the shank through the borehole, out through one of the slots, past an outside portion of the expansion part, through the aperture, again past an outside portion of the expansion part, through the other slot, and back through the borehole to the free end of the shank.