certain size range are preferred suitable small beads will have a mesh size of 45 60 0 009 inch to 0 011 inch suitable medium beads will have a mesh size of 25 30 0 016 inch to 0 027 inch suitable large beads will have a mesh size of 18 30 0 032 to 0 046 inch the size of the beads determines the porosity of the finished spacer 10 the larger the beads the greater the porosity in certain applications it may be desirable to mix beads of various sizes to obtain a finished spacer 10 having a variable porosity it is possible to intermix strips or strands of titanium wire mesh with the beads to form a spacer 10 having variable qualities of strength and porosity in general the use of titanium wire mesh results in a stronger less porous spacer 10 it also is possible to form the spacer 10 entirely of titanium wire mesh such mesh presently is used as a porous coating for knee shoulder and hip implants such mesh sometimes is referred to a spaghetti mesh and is commercially available from the zimmer company of warsaw ind one suitable method of fusing titanium beads to form the spacer 10 includes placing the beads into a cavity within a substantially purified graphite mold the mold is preferably a three piece mold forming a cavity of the finished dimensions of the spacer 10 the mold containing the titanium beads is then heated to a high temperature for example 2000 degrees f or higher until the sintering.