In the present paper, a new method for inserting cracks with out-of-plane features is presented. Starting point is an arbitrary reference structure and a crack of any shape. The final cracked structure is represented by hexahedral elements in the crack-front region and tetrahedral elements in the remaining structure domain. The tetrahedron is employed to take advantage of the versatile meshing capabilities and the collapsed quarter-point hexahedron gives good crack-tip behaviour. Stress intensity factors are calculated from the asymptotic stress field, retrieved from the integration points near the crack-tip.