US Patent 11399873 Medical implant threaded plug having a start structure

A medical implant assembly including a receiver and a fastener. The receiver having helically wound thread extending up to a top surface thereof. The fastener having an axis of rotation and a continuously helically wound thread form. The continuously helically wound thread form having a start structure and an upper loading surface extending between a root and a crest of the continuously helically wound thread form. The start structure having a leading face extending below the upper loading surface. The leading face including a partial curvate surface extending between the root and the crest. The start structure being configured as a single lead start structure and a dual lead start structure.