The bone screw (30) for use in an implant plate (12) comprises a screw head (34) comprising a compressible portion (36). Said compressible portion (36) is resilient and compressible when said bone screw (30) is screwed into bone and expandable so that said compressible portion (36) can expand and be received in at least one of a plurality of receiving areas (22a-28a) in said implant plate (12). Said compressible portion (36) of said screw head (34) is compressible when said bone screw (30) is screwed into bone and expandable after it is received in said implant plate (12) in order to prevent said screw (30) from withdrawing from said implant plate (12).