髋臼方形区安全置钉的数字化测量研究

Digital measurement of safe screw placement in the quadrilateral plate of the acetabulum

[目的]通过对成人完整骨盆CT三维重建及数字化测量,明确髋臼方形区骨质分布特点,为前路钢板治疗髋臼方形区骨折安全置钉提供解剖学参考依据。[方法]收集2015年1月~2015年6月于本院行CT检查的27例成人完整骨盆CT断层扫描数据,男13例,女14例;平均54.9岁。应用Mimcs 10.01和Geomagic Studio 12.0软件对骨盆数据进行三维重建,＂抽壳＂、＂加厚＂处理髋臼并与骨盆重组,根据髋臼方形区厚度将方形区分为不可置钉区、相对可置钉区和可置钉区,测量置钉危险区（包括不可置钉区和相对可置钉区）边界上特殊点（B、P点）与骨盆界线（ALP）、闭孔（OF）间的绝对距离（B-ALP、B-OF、P-ALP、P-OF）及其沿界线方向上、垂直界线方向上的分布范围（PA、BT）,并将结果转换为相对方形区宽（w）和高（d）的相对数。比较左、右侧骨盆及男、女性别之间数据的差异。[结果]左右侧骨盆数据对比差异无统计学意义（P〉0.05）。方形区表面不可置钉区平均位于距界线（33.80±4.32）mm以内、范围为（15.32±6.69）mm或距闭孔（29.09±4.05）mm以内、范围为（17.84±7.42）mm的区域,该区占方形区宽和高的比例分别约为1/3（0.27）、1/4（0.24）;可置钉区平均位于距界线（39.75±4.53）mm以下或距闭孔（34.79±4.47）mm以远的区域;不可置钉区和可置钉区之间为相对可置钉区,该区占方形区宽和高的比例分别约为1/2（0.52）、1/2（0.45）。男、女性间比较差异有统计学意义（P〈0.05）。[结论]在髋臼方形区置钉时,应考虑不同性别间的差异,并根据方形区骨质分布特点在不同的置钉区域选择合适的置钉方式。

[Objective]To figure out bone distribution in the quadrilateral plate of the acetabulum by three- dimensional（ 3D） computed tomography（ CT） reconstruction and digital measurement of adult intact pelvis,and to provide an anatomical basis for safe screw placement in anterior plate fixation of acetabular quadrilateral plate fractures. [Method]Pelvic CT scan data were collected from 27 adults undergoing CT scan in our hospital from January to June,2015. The subjects consisted of 13 males and 14 females and were 54. 9 years old on average. The 3D pelvic model was reconstructed from the raw data using Mimics 10. 01 and Geomagic Studio 12. 0. The acetabular model was extracted,shelled,and recombined into the pelvic model. According to the distribution of thickness,the quadrilateral plate was divided into absolutely dangerous zone,relatively dangerous zone,and safe zone for screw placement. The distance from the special points（ B and P） on the boundary of dangerous zones（ absolutely dangerous zone and relatively dangerous zone） to the arcuate line of the pelvis（ ALP） and obturator foramen（ OF） were measured and recorded as B- ALP,B- OF,P- ALP,and P- OF,respectively. The ranges of the special points parallel and perpendicular to the pelvic brim were measured and recorded as PA and BT,respectively. All results were converted to the relative width（ w） and depth（ d） of the quadrilateral plate. Comparison of the above indices was made between the left and right sides of the pelvis as well as between males and females. [Result]There were no significant differences in the above indices between the left and right sides of the pelvis（ P 〉 0. 05）. For the absolutely dangerous zone,B- ALP,BT,P- OF,PA,PA / w,and BT / d were 33. 80 ± 4. 32 mm,15. 32 ± 6. 69 mm,29. 09 ± 4. 05 mm,17. 84 ± 7. 42 mm,0. 27（ 0. 24- 0. 30）,and 0. 24（ 0. 21- 0.27）,respectively. The safe zone for screw placement was located 39. 75 ± 4. 53 mm below the pelvic brim and 34. 79 ± 4. 47 mm away from the obturator canal. The relatively dangerous zone was located between the absolutely dangerous zone and the safe zone. For the relatively dangerous zone,PA / w and BT / d were 0. 52（ 0. 51- 0. 54） and 0. 45（ 0. 42- 0. 48）,respectively.There were significant differences in PA / w and BT / d between males and females（ P 〈 0. 05）. [Conclusion]During screw placement in the quadrilateral plate of the acetabulum,differences between males and females should be taken into account. Moreover,based on the bone distribution characteristics in the quadrilateral plate,appropriate approaches for screw placement should be used in different regions.