PURPOSE: To verify if a Medpor porous polyethylene orbital implant (PPOI) (Porex Surgical, Atlanta, GA, U.S.A.), once vascularized, will tolerate a partially exposed titanium screw on its anterior surface. METHODS: Ten New Zealand white rabbits were enucleated and given Medpor PPOIs. Eight weeks postoperatively, Medpor Motility Coupling Posts (MCPs) (Porex Surgical) were placed into the orbital implants. Clinical tissue tolerance and histologic response to the new device were noted. RESULTS: The titanium screws were well tolerated by the animals. No case of post-operative infection, conjunctival inflammation, conjunctival erosion, MCP dislocation, or PPOI fragmentation was noted. A fibrous tissue growth over the titanium head was noted in all screws with a head height of 2.5 mm. The fibrous tissue overgrowth was not observed in screws with a head height of 4 mm or more. CONCLUSION: During the 6-month observation period, all implanted Medpor MCPs demonstrated favorable tissue tolerance and stable interfaces between the MCP and the conjunctiva and between the MCP and the PPOI.
PURPOSE: To verify if a Medpor porous polyethylene orbital implant (PPOI) (Porex Surgical, Atlanta, GA, U.S.A.), once vascularized, will tolerate a partially exposed titanium screw on its anterior surface. METHODS: Ten New Zealand white rabbits were enucleated and given Medpor PPOIs. Eight weeks postoperatively, Medpor Motility Coupling Posts (MCPs) (Porex Surgical) were placed into the orbital implants. Clinical tissue tolerance and histologic response to the new device were noted. RESULTS: The titanium screws were well tolerated by the animals. No case of post-operative infection, conjunctival inflammation, conjunctival erosion, MCP dislocation, or PPOI fragmentation was noted. A fibrous tissue growth over the titanium head was noted in all screws with a head height of 2.5 mm. The fibrous tissue overgrowth was not observed in screws with a head height of 4 mm or more. CONCLUSION: During the 6-month observation period, all implanted Medpor MCPs demonstrated favorable tissue tolerance and stable interfaces between the MCP and the conjunctiva and between the MCP and the PPOI.