[Multi-point contact (MPC) osteosynthesis plate. 1: Animal experiment histomorphologic studies in the Göttingen minipig].

Based on the results of clinical and animal studies as reported in the literature, the subimplant cortex becomes porous underneath conventional osteosynthesis plates with a flat surface. To solve this problem, we developed an implantable plate which creates multiple contact points between plate and bone, called the multi-point contact or MPC plate. In an experimental animal study conducted on 16 Göttingen minipigs we investigated the bone reaction beneath 2 different types of osteosynthesis plates: the conventional type with a flat interface versus the multi-point contact type. Both epiperiostal and subperiostal plating was performed on pig's intact tibiae. After an implantation period of 16 weeks, the results were documented and compared. It was shown that the osteal remodeling activity of the cortical bone adjacent to the plate increased under both plates up to the twelfth week, but declined towards the end of the study period. Compared to the MPC plate, a conspicuous remodeling front accompanied by porosis of the cortical bone adjacent to the plate was found underneath the conventional osteosynthesis plates with a flat surface-to-bone interface. The different subimplant reactions between the 2 plates can be best explained by the fact that intracortical implant-induced viscoelastic osteocyte diffusion is better under the MPC plate, whereas it is impaired under the conventional flat plate.