[Effect of fixative duration on recovery of local osteoporosis induced by rigid plate].

Sixty-four New Zealand rabbits were used in this experiment. Four animals served as controls and the other 60 were plated on their left tibia with stainless steel plates. They were divided into 3 groups, from which the plates were removed 2, 3 and 4 months after implantation respectively. Four animals in each group were sacrificed immediately after plate removal and the others were killed 1, 2, 3 and 4 months later. Image analysis of microsection of the cortical bone underneath the plate was performed by an automatic image analysis instrument. Results showed that prolonged plate fixation would greatly retard the recovery rate of the local osteoporosis induced by plate fixation. To reduce the incidence of refracture of the plated bone, the rigid plate should be removed as soon as a fracture is closed.