The occupation ratio of spinal canal(OR)and decrease of Torg ratio(DTR)were calculated and analyzed. Result:There were significant differences in OR and DTR between ECDE group and non-ECDE group.

• 结果:两组数值间有统计学差异；硬膜外型椎间盘突出椎管侵占率?0.；45；椎管矢状径比减小值?0