Applied Analysis Of Pedicle Parameter Measurement Before Lumbar 1 Vertebroplasty

Background The thoracolumbar vertebra is the segment with the greatest range of motion of the human spine,and it is also the bearing segment of the spine.The thoracolumbar juntion(T12-L2)is the transition area of the spine.It is the most common site of vertebral compression fracture,especially in patients with osteoporosis.The thoracic vertebra is physiologically kyphotic,less mobile,and has the greatest intrinsic stability due to the support of the ribs and sternum.In contrast,the lumbar spine is physiologically lordotic,more dynamic than the thoracic spine,and has the greatest ability to bend and extend due to the agittal orientation of the articular surface.Thoracolumbar junction is a biomechanical weak spot connecting rigid kyphotic thoracic vertebra and active lordoconvex lumbar vertebra,and its biomechanical stress is large.The body’s center of gravity is lacated in front of the thoracolumbar junction,which creates compression forces on the vertebrae and tension on the posterior spine in the upright position.Although it is widely believed that thoracolumbar kyphosis is associated with vertebral compression fractures,the exact severity of the kyphosis is not known.It has been reported in the literature that ninety percent of all spine fractures are related to the thoracolumbar region.The causes of thoracolumbar fracture are different depending on patient’s age.In younger patients,fracture is more likely to occur due to a high-energy trauma,such as motor vehicle accident and falling injury.However,in elderly,even falls from standing position to ground can cause fractures due to osteoporosis and decreased cognition.Twenty to forty percent of fractures are associated with neurologic injuries.If the patients involve in a severe trauma,the complications,such as paralysis and deformity,may occur after that accident.Even if the patients do not experience any complications,there could be limits of daily activities or difficulty to return to work due to chronic pain.Therefore,the appropriate treatment for the thoracolumbar fracture is important.The primary goals of treatment are to protect or restore neurological function,to achieve stability by reconstructing the anatomic alignment of the spine,to prevent pathological collapse or deformity of the spine,and to maximize clinical outcomes.In this study,the anatomical structure of thoracolumbar vertebrae was analyzed in order to find out whether it is significant for guiding the puncture path and bone cement injection of the T12,L1,L2(especially L1)vertebrae.Objective Compare the included angle of the line connecting the outermost edge of the pedicle and the front edge of the centreline at T12,L1 and L2 axial positions before surgery(set as the incidence angle of the pedicle α),the distance(CD)beween the outermost edge of the pedicle and the junction point of transverse process(set as point C)and the horizontal line to the junction point of the inner edge of the pedicle(set as point D)in axial position,to explore the advantages and feasibility of guiding puncture and bone cement injection in L1 vertebral body surgery.Methods Retrospective analysis the clinical data of 91 cases with osteoporotic vertebral compression fracture of L1 vertebral body and vertebroplasty(PVP)diagnosed in the interventional vascular Department of Chuzhou first people’s Hospital from January2018 to November 2021,measure the axial position of L1 vertebral body and its adjacent vertebral body α/CD,record the amount of bone cement injected during the operation,the leakage rate of bone cement,the visual analog score(VAS)of pain before and after the operation.Results L1 axial position α is(20.43±1.61)°,CD is(5.37±1.08)mm.The bone cement leakage rate of L1 vertebral body through unilateral approach and bilateral approach was 35% and 12% respectively,with a statistically significant difference(χ2=6.08,P<0.05);There was no statistically significant difference in the amount of bone cement injected between the unilateral and bilateral approaches of L1 vertebral body(P>0.05).There was no statistically significant difference in VAS scores before and after bilateral and unilateral approaches to L1 vertebral body(both P>0.05).Conclusion Comparing with adjacent vertebral body,L1 vertebral axial position α and CD are smaller,which is of great significance for selecting puncture path and reducing leakage of bone cement injection during operation.