A body, such as a grain, for providing ingrowth and growth of bone tissue and/or connective tissue. The body consists of a plastic or non-essentially elastic biocompatible material, preferably metal or metal alloy. It is also porous, having the following porosity characteristics: (a) the porosity is continuous and (b) the opening of cavities/indentations/pockets and the ducts connecting them has the width of >about 50 .mu.m for bone tissue and >about 10 .mu.m for connective tissue. In a method of making such a body, the body has been produced by blowing gas into a melt of metal. An advantageous use of bodies according to the invention is enclosing thereof in a casing, formed with openings, for making an implant, such as a spinal implant.