The present invention relates to uses of resorbable medical implants that are metallic or semi-metallic, to produce soft tissues, membranous tissues, organs or organ parts within the body by fibrosis. The present invention further relates to such uses when the implants are made of specified alloys or metals, e.g. magnesium and its alloys. The present invention further relates to such uses when the implant is surface modified. The present invention further relates to such uses when the implant is pre-implanted at another part of the body before implantation into the target site.