Wu Xiaobo, Chen Wei, Zhang Qi, Su Yanling, Guo Mingke, Qin Di, Wang Liqin, Zhang Yingze
Department of Orthopaedic Surgery, Third Hospital of Hebei Medical University, Shijiazhuang, China.
J Trauma. 2010 Aug;69(2):423-31. doi: 10.1097/TA.0b013e3181ca05f6.
The article aims to delineate the width of posterior column, the thickness of posterior wall, and safe angles for screw placement in the posterior wall to avoid intraarticular screw penetration.
The computed tomography (CT) images of 32 cadaveric adult bony hemipelvic specimens were initially obtained for the purpose of the study. Each specimen was sectioned at 1-cm intervals, and each plane of the crosssection was perpendicular to the surface of posterior column. By analyzing the CT images postprocessed with multiplanar reconstruction, the width of posterior column, the thickness of posterior wall, and the modified safe angle for screw placement in the posterior wall were measured and recorded. To validate the data obtained from the cadaveric model, this method was applied on 30 adult volunteers. The corresponding data were recorded and compared with those acquired from the cadaveric bony hemipelvis. In efforts to approve the usefulness of this method in practice, we have performed screw insertions in another 10 acetabular specimens and two operative cases by using the data from analyzing the CT images.
The width of posterior column, the thickness of posterior wall, and the safe angles for screw insertion in the posterior wall were measured and recorded in both specimens and volunteers. Comparison of the corresponding data was made between specimens and volunteers, and no significant difference was found in the same gender and side (p > 0.05). The corresponding width of posterior column, thickness of posterior wall, and safe angles for screw placement was found to be statistically different between males and females in both specimens and volunteers (p < 0.05). In specimens group, the safe angles for the entry points 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 cm medial to the lateral acetabular brim were 49.23 degrees +/- 11.54 degrees, 42.48 degrees +/- 8.97 degrees, 29.53 degrees +/- 7.86 degrees, 23.68 degrees +/- 6.20 degrees, 18.42 degrees +/- 5.41 degrees and 15.91 degrees +/- 4.37 degrees in males and the corresponding angles for the entry points 0.5, 1.0, 1.5, 2.0, and 2.5 cm medial to the lateral acetabular brim were 45.02 degrees +/- 8.82 degree, 35.98 degrees +/- 7.60 degrees, 23.77 degrees +/- 6.29 degrees, 19.96 degrees +/- 4.36 degrees, and 14.68 degrees +/- 3.48 degrees in females, respectively. CT images of 10 acetabular specimens and two cases with posterior wall fractures show all screws were inserted into the posterior wall without penetration into the joint space.
The oblique multiplanar reconstruction images perpendicular to the surface of posterior column were selected to describe the safe angle for screw insertion into posterior wall, which can provide consistent results in both specimens and volunteers. The method can be applied in practice both on acetabular specimens and operative cases and is helpful to make individual perioperative planning for safer fixation of posterior wall fracture.
本文旨在描绘后柱的宽度、后壁的厚度以及后壁螺钉置入的安全角度，以避免螺钉穿入关节内。
最初获取32个成年尸体半骨盆标本的计算机断层扫描（CT）图像用于本研究。每个标本以1厘米的间隔进行切片，每个横断面平面均垂直于后柱表面。通过分析经多平面重建后处理的CT图像，测量并记录后柱的宽度、后壁的厚度以及后壁螺钉置入的改良安全角度。为验证从尸体模型获得的数据，将该方法应用于30名成年志愿者。记录相应数据并与从尸体半骨盆获得的数据进行比较。为证实该方法在实际应用中的有效性，我们利用分析CT图像得到的数据，在另外10个髋臼标本和2例手术病例中进行了螺钉置入。
在标本和志愿者中均测量并记录了后柱的宽度、后壁的厚度以及后壁螺钉置入的安全角度。对标本和志愿者的相应数据进行了比较，在相同性别和侧别中未发现显著差异（p>0.05）。在标本和志愿者中，发现男性和女性在后柱的相应宽度、后壁的厚度以及螺钉置入的安全角度上存在统计学差异（p<0.05）。在标本组中，髋臼外侧缘内侧0.5、1.0、1.5、2.0、2.5和3.0厘米处进针点的安全角度在男性中分别为49.23°±11.54°、42.48°±8.97°、29.53°±7.86°、23.68°±6.20°、18.42°±5.41°和15.91°±4.37°，在女性中，髋臼外侧缘内侧0.5、1.0、1.5、2.0和2.5厘米处进针点的相应角度分别为45.02°±8.82°、35.98°±7.60°、23.77°±6.29°、19.96°±4.36°和14.68°±3.48°。10个髋臼标本和2例后壁骨折病例的CT图像显示所有螺钉均置入后壁且未穿入关节间隙。
选择垂直于后柱表面的斜多平面重建图像来描述螺钉置入后壁的安全角度，在标本和志愿者中均可得到一致的结果。该方法可应用于髋臼标本和手术病例的实际操作中，有助于制定个体化的围手术期计划，以更安全地固定后壁骨折。
