RESUMO
BACKGROUND: The double-rod of bridge-link type combined internal fixation system belongs to eccentric fixation, which may lead to the weakening of longitudinal fixation and the decrease of transverse anti-torsion after operation. OBJECTIVE: To compare the biomechanical characteristics of bridge-link type combined internal fixation system with mixed-rod and double-rod in the treatment of femoral and tibial fractures. METHODS: Twenty human long bone diaphysis models were made by 40 short polyformaldehyde materials. Of these, 10 were fixed by mixed-rod, and the rest with bridge-link type combined internal fixation system. Axial compression tests and radial torsion tests were carried out (five models were selected from each group). The changes of axial compression forces and displacements and transverse torque and angle were observed. The maximum load was recorded when the curve had a break point or in a horizontal state, and then the yield load was calculated. RESULTS AND CONCLUSION: (1) When the axial compression load was