MAIN OUTCOME MEASURES: Lumbar facet joint angle and pathological changes through CR, digital radiophotography and CT.

两种腰椎滑脱椎小关角度，椎小关在影像学上病理改变。

The styles of the detachment structure are short antiform and synform structure mainly, and dome structure, nappe outlier and nappe tectonic window too.

滑脱断裂构造样式，以短轴背、向构造为主，另有穹窿构造、滑来峰构造、滑覆窗构造。