Improved Vascularization Rate of Porous Polyethylene Orbital Implants Containing Synthetic Bone Graft Particulate

Abstract

Abstract: : Purpose: To compare fibrovascular ingrowth within porous polyethylene orbital implant (Medpor) with and without synthetic bone graft particulate (NovaBone) using magnetic resonance imaging (MRI). Design: Prospective, comparative, masked trial. Participants: Fourteen Yucatan pigs underwent unilateral enucleation. 7 received implantation of a 20-mm porous polyethylene implant and 7 received a 20-mm porous polyethylene implant with 30% by weight synthetic bone graft particulate. Methods: Serial MRI’s with Gadolinium were obtained at 2 week intervals following implantation until completely vascularized. The percentage area of implant with fibrovascular ingrowth was calculated by a single masked neuroradiologist. Results: Two pigs from each group were excluded from the study due to death from anesthesia or implant infection/extrusion. No statistically significant difference in vascular ingrowth was found between the two implant types at weeks 2 and 4. By week 6, the porous polyethylene/NovaBone group demonstrated more extensive vascularization. 4 of the 5 NovaBone implants showed complete vascularization by week 6, whereas no implants with only porous polyethylene showed complete vascular ingrowth by week 10. Conclusions: Porous Polyethylene orbital implants containing 30% NovaBone C/M TM by weight are safe, well-tolerated & effective orbital implants. These implants appear to provide more rapid vascularization than porous implants alone.

Keywords: orbit • imaging/image analysis: clinical