The influence of a rigid plate on the structure of intact tubular bone
was studied in forty adult rabbits using a four-hole commercial-steel
DCP-ASIF plate attached to each tibiofibular bone, with and without
compression. The morphological changes in the bone underlying the plate
were examined and were assessed quantitatively at one day to thirty-six
weeks after operation. The rigid plate induced porotic changes in the
cortical bone, which were evident three weeks after the operation and
increased rapidly between twelve and eighteen weeks. At thirty-six weeks,
resorption cavities occupied 40.6 per cent of the cortical wall of the
bones plated with compression and 41.2 per cent of the wall of those plated
without compression. The changes were visible slightly earlier in the
presence of compression. A rigid plate brought about a statistically
significant increase both in the outer diameter of the bone and in the
diameter of the medullary space as a result of subperiosteal new-bone
formation and concomitant subendosteal bone resorption.