ABSTRACT
Thirty-six aluminum oxide laminated discs were implanted into 12 young rabbits (18 with a 0.5-mm porous layer and 18 with 1 mm) to determine whether implants that are porous only on one side could fixate to subcutaneous tissue. After 3 months, discs were encased within thin pouches (0.02-0.14 mm) of fibrous connective tissue, as would have been expected of a completely porous implant. Solid sides showed no, while the porous sides showed little, attachment to pouches. Forty-seven percentage (17) of the discs had moved 1.4 +/- 0.8 cm beyond the 4.7 + 1 cm they had moved due to normal skin growth, while two others had moved between 6.2 and 6.5 cm beyond this measure. The proportion of 1 mm porous layer discs migrating within subcutaneous tissue was no greater than the proportion of 0.5 mm layer discs migrating (p = 0.15). Porous layer height and disc migration did not affect the attachment strength of pouch to surrounding tissues (68 +/- 23 N, p = 0.34). Pouch thickness, which has been associated to the level of applied forces in other studies, increased with migration distance (p = 0.054). Results indicate that one-sided porous discs are likely easier to retrieve than completely porous ones, but cannot be prevented from migrating in loose tissue of young animals. Data is being used to design subdermal radio frequency devices for endangered marine animals.
