The result shows that:(1)Micro-fibril angle increases gradually from the center to the edge in radial direction, and the surface area percentage of its fiber band has the same variability;
结果表明，微纤丝角径向自内向外略有减小，纤维股面积比径向自内向外逐渐增大；
2
The center-edgeangle can be used as an indicator of hip instability.