lattice sections 56 which extend between the lattice points 54 are bent in the direction of the sponge structure which is parallel to the lattice sections i e in the direction of the plane 52 correspondingly the lattice sections which extend between the lattice points 58 are angled toward the sponge structure which is parallel to the lattice sections 60 i e in the direction of the plane 50 the lattice sections 56 and 60 contact one another in the bending sites 62 the sponge structure 36 is thus formed by a three dimensional network which has a multitude of openings into which the bone can grow fig7 a shows a single lattice element which is built between 3 planes four lattice rods 54 protrude at equal angular distances from the lattice point 54 towards the next parallel plane the lattice element is formed by twelve equal lattice rods 55 in all lattice rods 55 the neutral fiber is the same fig7 b shows a net which is constructed from multiple lattice elements and which extends in the x y plane at an angle of 90 u00b0 it is shifted in the z plane by 45 u00b0 fig5 also shows a perspective view onto the tibia implant 26 wherein the fastening loops 42 can be clearly recognized they protrude from the support.