RELATION BETWEEN MECHANICAL STIFFNESS AND VIBRATION TRANSMISSION OF FRACTURE CALLUS - AN EXPERIMENTAL-STUDY ON RABBIT TIBIA

It has been suggested that the vibration transmission across a fractur e is affected by the stages of healing of the fracture callus. This st udy aims to correlate the change in vibration transmission with mechan ical stiffness of the callus measured by three-point bending. The righ t tibiae of male, three-month old local albino rabbits were osteotomiz ed and stabilized by intramedullary fixation following open reduction. The intramedullary rods were removed on the 15th, 28th, 42nd and 90th days postoperatively and the tibiae were excised for vibration, three -point bending and bone mineral density analysis by quantitative compu terized tomography (QCT). Optimum time for clinical weight bearing was determined by checking the convergence of the vibration parameters of the fractured tibia to those of the unfractured contralateral. The co nclusions obtained from curvature analysis, based on vibration experim ents, were in considerable correlation (Spearman's rank correlation co efficient r = 0.93, p = 0.003) with the conclusions obtained from the three-point bending test data which reflected the mechanical condition of the bone by direct means. However, no correlation between bone min eral density change and vibration transmission was noted.