Patent ID: 8915735

Claim:
Threaded implant for obtaining reliable anchoring in bone substance, the bone substance being provided with a hole in whose side wall an internal threading may be established which can cooperate with an external threading on the implant for reliable anchoring and healing-in of the implant in the bone substance, wherein the implant threading is arranged to force the bone substance out in essentially radial directions as a function of the extent to which the implant is screwed into the hole, that the implant threading has a slight conicity which extends along most or part of the length of the implant and which cooperates with a circular cylindrical hole in the bone substance to effect greater forcing out of the bone substance at the outer parts of the hole than at the inner parts of the hole, the degree of forcing out being adapted in relation to the softness of the bone substance in order to achieve the reliable anchoring, and that said conical threading of the threading having the slight conicity comprises two or more thread spirals which provide a tight threading which permits effective integration with the bone substance during the healing-in process and counteracts deformation or breaking-up of fine bone trabeculae which surround the hole in the bone, wherein a tip portion of the implant is designed with a conical thread which has a conicity exceeding the conicity of the threading having the slight conicity, and wherein the tip portion of the implant has a length or height of about 10-30% of the length of the threaded part of the implant.