Methods 62 lumbar lateral films were reviewed,42 of which with the diagnosis of spondylolisthesis at L4 or L5 level and 20 of which as controls. The spinous process step sign at every L4-5 and L3-4 segments was scored by three doctors.

• 方法回顾分析62帧腰椎侧位片,42例诊断为第4或第5腰椎滑脱,余20例作为对照,分别由3位医师对每一帧侧位片中L3,L4和L4,L5棘突间的阶梯征进行评价记分。