A Biomechanical Study On The Treatment Of Thoracolumbar Compressive Fracture With Posterior Short-segment Pedicle Instrumentationand Transpedicular Bone Grafting

Objective To study the biomechanical effects on the fracture segment and adjacent segments of youth thoracocolumbar compressive fracture with posterior instrumentation and transpedicular bone grafting.Methods18cadaver thoracocolumbar spine specimens were randomly divided into6group:Normal contral,Vertebral compressive fracture,Vertebral compressive fractures with transpedicular autologous bone grafting,Vertebral compressive fractures with transpedicular PMMA cement grafting,Vertebral compressive fractures with autologous bone grafting and reduction fixation.Vertebral compressive fractures with PMMA cement grafting and reduction fixation.Five simulations (axial compression, flexion, extension,left and right bending and axial rotation) were applied in the biomechanical testing. Data of the load-strain,load-displacement,intensity,rigidity and torque-torsion angle of fracture segment and adjacent segment were recorded and analyzed.Result Transpedicular autologous bone grafting and PMMA cement grafting could enhance the stability index of the fracture segment(P<0.05). Meanwhile they make the tiny tendency that the adjacent segment rigidity degrade and stress raise, but it is not significant difference (P>0.05), instrumentation could enhance the stability index of the fracture segment more obviously(P<0.05)and make the adjacent segment rigidity degrade and stress raise significant (P<0.05)Conclusion Compared with transpedicular autologous bone grafting or PMMA cement grafting,instrumentation and transpedicular bone grafting could enhance the stability of the fracture segment,at the same time,it has disadvantageous effect on the adjacent segment.Compared with PMMA cement grafting and reduction fixation,they are equal in the biomechanical property.