Porous high-density polyethylene implants in auricular reconstruction

Abstract

Objective: To evaluate the ability of porous high-density polyethylene (Medpor) implants to tolerate exposure and support skin grafts when used to reconstruct defects in auricular cartilage in an animal model.

Design: Polyethylene implants placed in surgically created defects in auricular cartilage and covered with a skin flap were then exposed at either 4, 7, or 21 days after implantation. The exposed implants were then allowed to heal secondarily or received a skin graft 1 week later. The ability of polyethylene implants to tolerate exposure and support skin grafts was observed clinically and via histological study of the implantation sites.

Subjects: Nine adult New Zealand rabbits.

Results: Polyethylene implants demonstrated excellent ability to tolerate wound exposure as early as 4 days after implantation, with extrusion of 1 of the 36 implants placed. The degree of secondary wound healing increased as the interval from implantation to exposure increased from 4 to 21 days. Exposed polyethylene implants in all groups also supported all 18 skin grafts placed 1 week after exposure of the implant surface.

Conclusions: Polyethylene implants are well tolerated as replacements for native cartilage in auricular reconstruction. Polyethylene implants tolerated wound exposure as early as 4 days after implantation and demonstrated the ability to heal by secondary intention and support skin grafts. This is likely because of the extent of fibrovascular ingrowth from surrounding tissue, which allows the material to behave more like native tissue and less like a foreign body in this setting.