Fig. 4

Schematic representation of the two design concepts. a Concept 1 features a low-porous layer which is 4 mm undersized in the direction of insertion. The highly porous deformable layer is 8 mm oversized in the direction of insertion, resulting in 4 mm oversized implants. b Concept 2 features a low-porous layer which is 6 mm undersized in the direction of insertion. This concept requires a separate deformable mesh with a thickness off 10 mm which also results in 4 mm oversized implants. \(\mathrm{x}\) = depth of the defect in the direction of implant insertion