PurposeTo describe a new quasi-integrated porous polyethylene orbital implant that combines the advantages of host tissue incorporation and improved motility with a single-stage surgery.MethodsTwenty-four consecutive patients undergoing primary or secondary orbital implantation received the quasi-integrated porous polyethylene implant. Approximately 6 weeks after implantation, a custom-fitted prosthesis was made by an impression technique to provide a “lock-and-key” fit with the orbital implant. Postoperative complications and motility of the prosthetic shell were evaluated.ResultsDuring the 27-month period between December 1998 and March 2001, 24 patients received the quasi-integrated porous polyethylene implant as a buried orbital implant. Thirteen patients received the implant as a primary orbital implant after either evisceration or enucleation and 11 patients received the implant as a secondary orbital implant. Follow-up ranged from 3 months to 30 months, with an average of 16.9 months. All patients were considered to have good motility of their prosthetic shell at their final follow-up visit. No cases of implant extrusion or migration were noted. Two patients required deepening of their inferior fornix to accommodate the increased motility of their prosthesis.ConclusionsThe new quasi-integrated porous polyethylene orbital implant provides improved motility without the need for secondary placement of pegs or screws. It has the advantage of biocompatibility, allowing host tissue incorporation to resist implant migration and extrusion. The implant is available in three sizes: small, medium, and large, approximating the volume of a 16-, 18-, and 20-millimeter sphere, respectively.