Tissue reactions around two alloplastic ligament substitute materials: experimental study on rats with carbon fibres and polypropylene

The early connective tissue reactions around two alloplastic and prosthetic materials, carbon fibre and polypropylene were examined in 30 rats. Each of the materials was implanted into three sites: under the skin, intraperitoneally and into a femoral bone tunnel. Microscopic and scanning electron microscopic findings at 1, 3, 6, 9 and 12 wk post-operatively are described. The amount of granulation tissue around the carbon fibres was more prominent in all the environments, but the connective tissue remained less mature and less organized during the whole follow-up compared to that of the polypropylene. There was no ingrowth of bone between the bundles of the artificial materials in the bony tunnels. The differences in the early cellular reactions and scar tissue maturation in the interstices of these two materials are probably due to the structural differences rather than to the surface properties of the materials.