Biomechanical changes of lateral malleolus defect before and after reconstruction

Objective To measure biomechanical changes of lateral malleolus defect before and after reconstruction.Methods 12 fresh freezing limb specimens were experimentally tramatized to result in lateral malleolus defect.Three metatarsal base bone flaps repairing lateral malleolus was carried on.Test groups were divided into two groups: the group of lateral malleolus defect(group A),and the group of lateral malleolus after reconstruction(group B),and the group of collecting data and doing analysis(group C).Modals were built to test out the mechanics changes through loading strain-reaction,loading strain displacement,strength and rigid respectively.Results The change of loading-strain,rigid and strength under 1 000 N showed significant difference between group A and group B(P0.05).The contact area of group A was less than group B under 1 000 N(P0.05).The contact pressure of group A was more than group B(P0.05).Conclusion The defect of lateral malleolus can lead to severe instability of ankle,and can be recovered its stability by using the second metatarsal base bone flap.This is an effective operative method.