Objective: To investigate the distance between two screw entrance points of pedicle of thoracolumbar vertebral arch and the best relative TSA and determine the exact data for the surgical procedure.

• 目的:研究确定胸腰椎同一椎体的椎弓根进钉点间距离及其相关的最佳内倾进钉角(最佳TSA),为手术操作提供一准确的数据。