Finite Element Analysis Of Different Amount Of Bone Cement Perfusion In Osteoporotic Vertebral Compression Fracture

Objective:Through the construction of T₁₀-L₃finite element model,the optimal amount of bone cement perfusion during vertebroplasty for vertebral compression fracture of thoracolumbar osteoporosis was discussed,so as to provide theoretical guidance for clinical practice.Research data and methods:We established a three-dimensional finite element model of thoracolumbar so as to simulate theosteoporosis induced vertebral compression fractures of L₁after percutaneous vertebroplasty（PVP）.Addtionally,we performed different amount of bone cement with 5%,10%,15%,20%,25%measuring effects of stress distribution in inter-vertebral body,via the neutral,bending forward,stretching around and rotation positions.Results:In the neutral position,the stress of the vertebral nucleus pulposus is very small,and the stress is mainly distributed in the vertebral endplate and annulus fibrosus,and the endplate bears most of the stress.In neutral position,with the increase of the injection amount of bone cement,the maximum stress of the endplate under T₁₂and the endplate on L₂did not increase significantly.In the flexion and extension state,the stress on the lower end plate of T₁₂and the upper end plate of L₂of the adjacent vertebral bodies of the injured vertebra was greater than that on the upper end plate of L₂.When the injection amount of bone cement increased,the stress on the lower end plate of T₁₂and the upper end plate of L₂began to decrease.When the injection amount was more than 15%,the stress tended to increase.It is suggested that the injection amount of bone cement is 15%,which may not increase the stress of adjacent vertebra.Under the lateral flexion and rotation position,vertebral body under more stress than neutral position before and after flexor stretch,in comparison with all locations,T₁₂endplate bear under the greatest stress,indicate a higher risk of fractures,bone cement injection quantity of vertebral body is less than 15%,the volume increased along with the bone cement refraction,T₁₂end plate and end plate on the L₂withstand the maximum stress is reduced,bone cement injection of minimum 15%of the volume of vertebral body,bone cement injection of more than 15%,with the increase of amount of bone cement injection,T₁₂end plate and end plate under maximum stress increase in L₂.Conclusion:Small volume bone cement perfusion may not significantly increase the stress on the adjacent vertebral body,while 15%bone cement perfusion may be relatively safe for the vertebral body and adjacent vertebral bodies.More than 15%bone cement perfusion may increase the stress on the endplate of adjacent vertebral bodies,and may increase the probability of fracture of adjacent vertebral bodies.