Shear mechanical properties of lumbar trabecular bone in aged people / 中国组织工程研究

ABSTRACT

BACKGROUND:Shear mechanical properties of lumbar trabecular bone should be understood in treating osteoporosis,bone remodeling,bone reconstruction,as well as the choice of fracture fixed equipment.OBJECTIVE:To explore whether the shear mechanical properties of lumbar trabecular bone is different in young and aged normal fresh cadavers.METHODS:Experimental samples were from 4 normal fresh corpse,aged 22,28,70 and 75 years,were provided by Department of Anatomy,Norman Bethune Medical University.Spinal column thoracic vertebra L_2-L_5 specimen were obtained from corpse within 1 hour and cut into 40 min×5 mm×5 mm pieces.The specimen were tested on electronic universal testing machine with speed of 5 mm/min,the shear load,stress,strain and other data would be printed automatically,and the morphology of fracture surface was observed.RESULTS AND CONCLUSION:Majority of the fracture surfaces were comminuted,minority were transverse or oblique fracture.The macroscopic observation showed that trabecular arranged compact in the thoracic vertebra cancellous bone of the youth group,which was sparse arrangement and presented with senile osteoporosis in the aged group.The shear force,shear stress and strain of the youth group was greater than that of the aged group[(37.19±3.25),(28.34±3.42) N;(1.49+0.13),(1.13±0.14) MPa;(1.40±0.50)%,(0.90±0.20)%,P＜0.05].It demonstrated that the impact mechanics properties of thoracic vertebra cancellous bone are different between the youth and aged groups.