In Group 2, the mean maximum pull out strength of the GSS screws was 127% of that of the CCD control screws, while the mean maximum pull out strength of the TSRH screws was 64% of that of the CCD control screws.

• 第二组GSS螺钉最大轴向拔出力为CCD螺钉的127%25,TSRH螺钉为CCD螺钉的64%25;