METHODS: Eight volunteers were recruited to accept CT scans in six extreme wrist positions. The images of DICOM mode were imput into the Mimics analytical system, the segmented scaphoid, lunate and radius were exported in mode of ASCII STL and were opened in the software of Geomagic studio. We created four planes based on anatomic markers on the surface of the radius and scaphoid to confine the proximal scaphoid to form the so-called non-contact regions. We measured and compared the areas in six targeted positions.
RESULTS: Amidst six extreme wrist positions, area of the non-contact region in extreme dorsal extension (59.81 ± 26.46 mm2) was significantly the smallest, and it in extreme palmar flexion significantly was largest (170.51 ± 30.44 mm2). The non-contact regions increased in order of dorsal extension, supination, ulnar deviation, radial deviation, pronation and palmar flexion. As for two-group comparison, the non-contact region showed significantly larger (p < 0.05) in palmar flexion than the others except for in pronation individually, and in radial deviation (p < 0.05) than in dorsal extension.
CONCLUSIONS: Sufficient space was available for the screw started from the dorsal approach despite the wrist positions.
方法:招募了8名志愿者,以6种极端的手腕体位接受CT扫描。将DICOM模式的图像输入模拟分析系统,分段的舟骨,lunate和radius以ASCIISTL模式导出,并在Geomagicstudio的软件中打开。我们基于半径和舟骨表面上的解剖标记创建了四个平面,以限制近端舟骨形成所谓的非接触区域。我们测量并比较了六个目标位置的区域。
结果:在六个极端的手腕位置中,在极端的背部延伸(59.81±26.46mm2)的非接触区域的面积显著最小,极掌屈曲时最大(170.51±30.44mm2)。非接触区域按背侧延伸的顺序增加,仰卧起坐,尺位偏差,径向偏差,前旋和手掌屈曲。至于两组比较,除个别内旋外,非接触区域的手掌屈曲明显大于其他区域(p<0.05),径向偏差(p<0.05)高于背侧延伸。
结论:尽管有腕部位置,但从背侧入路开始的螺钉仍有足够的空间。