Evaluation of porous polyethylene for external ear reconstruction

Autogenous rib cartilage and silicone rubber are materials currently used for ear reconstruction. Increased morbidity and operative time with rib cartilage grafts and a high rate of extrusion with silicone implants render them less than ideal for reconstruction of the human ear. The purpose of the current investigation is to determine the efficacy of porous polyethylene as an alternative synthetic material for ear reconstruction. Porous polyethylene and silicone rubber discs of equal sizes in two thicknesses were implanted in lieu of the cartilage in the external ear of eight baboons. Histological evaluation of the sites after nine weeks revealed excellent anchorage of the thin porous polyethylene implants (1.5 mm) in the surrounding tissues. Silicone rubber implants, however, were encapsulated in a thickened granulation tissue capsule. When thicker implants (3.0 mm) were used, exposure or extrusion occurred in all cases. Porous polyethylene implants demonstrated only partial exposure; half of the silicone rubber implants were extruded; and the other two silicone rubber implants were almost completely extruded. Porous polyethylene was thus better incorporated into the soft tissues than silicone rubber as long as the overlying soft tissues were not stressed by an oversized implant or inadequate soft tissue coverage.