Magnetically integrated microporous implant: safety and efficacy of secondary posting.

Objective: To evaluate the surgical technique and morbidity related to secondary posting of a previously implanted 12-mm microporous high-density polyethylene implant (MEDPOR) and the enhanced motility associated with magnetic coupling of the prosthesis and the implant in a rabbit model.

Methods: Eight New Zealand rabbits underwent primary evisceration surgery with implantation of a 12-mm microporous high-density polyethylene implant. At 6 weeks, a 4 x 6-mm stainless steel, titanium-coated post was secondarily inserted in 6 rabbit eyes using a bilevel incision. Four weeks after the second surgery, 3 rabbits were fitted with a magnet-embedded prosthesis. Motility was measured by evaluating lateral prosthetic excursion during direct observation. At 3, 6, and 12 months the implants and surrounding tissues were harvested for histopathologic examination.

Results: Secondary placement of the post within the implant was accomplished without difficulty. No signs of erosion, dehiscence, or extrusion were found after a12-month follow-up in any of the study eyes. Clinical grading documented increased movement of the magnetically coupled prostheses compared with nonmagnetically integrated control eyes.

Conclusion: This study establishes the safety of secondary posting and the efficacy of magnetically integrated microporous high-density polyethylene implants in the rabbit model.

Clinical Relevance: This technique may offer an alternative to patients with previously implanted microporous high-density polyethylene implants seeking enhanced cosmesis and prosthetic motility.