目的　为临床前路手术治疗骶髂关节骨折脱位提供解剖学依据。  方法　成年防腐盆部标本20具（40侧），解剖观察髂内动静脉、髂腰动静脉与骶髂关节的位置关系，测量L4、5神经前支及腰骶干与骶髂关节的毗邻关系。  结果　髂内动脉横跨骶髂关节处的外径左侧为(5.92±0.7)mm，右侧为(5.38±　0.7)mm，起始处距骨壁距离左侧为(11.91±2.4)mm，右侧为(12.52±2.9)mm，髂腰动脉横跨骶髂关节处的外径为(2.54±0.39)mm，起始处距骨壁的距离为(2.50±0.41)mm。骶髂关节从后上到前下的不同平面到L4、5神经前支及腰骶干的距离逐渐减小，L4神经根前支距离骶骨翼骨面的垂直距离亦逐渐减小，L5神经根出椎间孔后，几乎紧贴骶骨翼骨面行走。  结论　骶髂关节骨折脱位前路手术要特别注意医源性血管神经的损伤，L5神经根易受损伤，安全放置钢板的位置是骶骨翼中上部，距骶骨翼边缘20 mm以内。

Objective　To provide anatomic evidence for treating fracture dislocation of iliosacral articulation through the anterior approach.　Methods　The study was performed in 20 adult antiseptic pelvic specimen（from 40 corpses）. The relationship of the internal iliac vessels and the lumbar vessels with acroiliac articulation were explored. The distances from the anterior branches of L4,5 spinal nerves to the lumbosacral trunk and sacroiliac joint were measured.　Results　The external diameters of the left and right internal iliac arteries were (5.92±0.7)mm and (5.38±0.7)mm respectively, at the crossing point of the artery with sacroiliac joint. The distances from the arterial origin to pelvic wall were (11.91±2.4)mm and (12.52±2.9)mm for left and right sides respectively. The external diameters of iliolumbal artery when it passed through sacroiliac articulation was about (2.54±0.39)mm, with the distance from the origin to pelvic wall of (2.50±0.41)mm. The distance from the different sacroiliac articulation planes extended posterosuperiorly to anteroinferiorly to anterior branches of L4,5 spinal nerves and the lumbosacral trunk decreased gradually, as well the distances from anterior branch of L4 nerve root to ala sacralis. L5 nerve root closed to ala sacralis during it's course after leaving corresponding intervertebral foramen.　Conclusions　Iatrogenic injury to vessels and nerves during anterior operation for treating fracture dislocation of iliosacral articulation should be avoided．For avoiding the damage of L5 nerve root, the middle and superior parts of ala sacri, which is far away from the border of ala sacri about 20mm, are safe position for steel plate fixation.