Biomechanical effect of bone cement volume and distribution on lumbar vertebral body with osteoporotic fracture / 中华骨科杂志

ABSTRACT

Objective To evaluate biomechanical effect of bone cement distribution on lumbar vertebral body with osteoporotic fracture.Methods Forty nine lumbar vertebrae (L1-L5) specimens were collected from 12 old cadavers.After exerting axial pressure load on every specimen,the initial intensity and stiffness were measured,and then vertebral body crush fracture models were established.According to zones where bone cement was injected in vertebrae,the specimens were divided into one control group and six experimental groupsA,B,C,D,E,F groups,i.e.unilateral anterior 2/3 group,unilateral posterior 2/3 group,unilateral whole group,bilateral anterior 2/3 group,bilateral posterior 2/3 group,and bilateral whole group,respectively,including 7 specimens in each group.In A,B,C groups,unipedicular balloon kyphoplasty was done,while in D,E,F groups,bipedicular balloon kyphoplasty was done.Then the maximum compressive strength and stiffness were measured.Results After percutaneous kyphoplasty,the maximum strength in all experimental groups was significantly greater than that in the control group.There were no significant differences in strength between A and B groups,between C,D and E groups.For the maximum strength,the results of comparison wereF group ＞ C group,D and C groups ＞ A and B groups.Except for F group,the stiffness in other 5 experimental groups was significantly lower than its initial value.There were no significant differences in stiffness between A,B,and C groups,between D and E groups.However,the stiffness in F group was greater than those in D and E groups,and it was greater in bilateral groups than those in unilateral groups.Conclusion Bone cement distribution in lumbar vertebral body can affect biomechanical property of vertebral body,and the bilateral distribution can cause better biomechanical effect than unilateral distribution.The ideal distribution zone of bone cement is in the anterior 2/3 of the vertebral body.