[Quantitative histologic study of early osteoporosis induced by plate fixation]

Thirty New Zealand rabbits were used in the experiment. Three animals served as control and the other 27 were divided into 3 groups, in which the tibiae of the animals were fixed by methylmethacrylate, titanium, and stainless-steel plates respectively. 4, 8, and 12 weeks after operation, 3 animals in each group were killed. Image analysis of microsection of the cortical bone beneath and opposite the plate was performed by a digital image processing system. All of the 3 types of plates may lead to bone loss, which is proportional to the degree of the stress protection produced by the plate. In addition, the amount of bone loss in each group was all much greater beneath the plate than opposite it.