ORBITAL RECONSTRUCTION USING POROUS POLYETHYLENE SHEETS

Background: There has been growing interest in using porous alloplasti c implants for reconstructive orbital surgery because of their perceiv ed increased biocompatibility. One commercially available porous impla nt is high-density porous polyethylene (Medpor). It is made of pure pa rticles of polyethylene that form interconnecting pores and have excel lent handling characteristics. Methods: The authors performed 37 orbit al reconstructions using 0.85-, 1.5-, or 3-mm porous polyethylene shee ts to reconstruct internal orbital defects. Mean postoperative follow- up was 18.5 months. Four patients were treated for anophthalmic enopht halmos; there was one patient with spontaneous enophthalmos. In select ed patients, other implants also were used, including miniplates or mi croplates, silastic sheets, autologous bone, or nasal septal cartilage . In patients with enophthalmos, the implants were stacked to reverse the malposition evident at surgery. Results: Preoperatively, 27 patien ts had symptomatic diplopia. Postoperatively, the diplopia resolved in 15 patients and decreased in 7. No patients had induced diplopia or e xacerbation of preoperative diplopia. Enophthalmos resolved in 9 of 18 patients. Hypoglobus was normalized in nine of nine patients. There w as one major complication of orbital infection requiring explantation 1 week postoperatively. Minor complications included undercorrection, a symptomatically palpable implant, and transient postoperative chemos is. Conclusion: Porous polyethylene sheets offer several distinct adva ntages when used for orbital reconstruction. They are easy to handle, shape, contour, position, fixate, and use with other autogenous and al loplastic implants. In this series, these sheets permitted predictable , stable results with few complications.