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

两种腰滑关节面的角度，关节在影像学上的病理改变。

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

滑断裂的构造样式，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。