目的:探讨髋臼下螺钉的置入方式，并比较不同性别的置钉参数。方法:回顾性纳入2018年10月至2019年10月期间重庆医科大学附属第一医院的100例成人正常骨盆CT数据，男、女各50例，年龄为18~86岁，平均49.0岁。利用Mimics19.0软件三维重建骨盆并导入Geomagic Studio软件。测量髋臼下螺钉通道直径(IACD)及髋臼内侧壁最小厚度(MTMAW)，比较男、女性之间的差异，并分析IACD与MTMAW的关系。当IACD≥5 mm时置入3.5 mm全部埋入螺钉；当IACD<5 mm时，置入3.5 mm部分埋入螺钉。测量并比较男、女性置钉参数。结果:男性IACD、MTMAW[(6.15±1.24)、(4.40±1.23) mm]显著大于女性[(5.42±1.01)、(3.60±0.81) mm]，差异均有统计学意义（n P< 0.05)；IACD与MTMAW呈正相关（n r=0.859，n P0.05）。男性全部埋入螺钉与矢状面夹角内倾1.02°±6.31°，女性外倾8.19°±6.81°；男性部分埋入螺钉与矢状面夹角外倾1.48°±6.97°，女性外倾7.90°±5.45°，男、女性之间比较差异均有统计学意义（n P<0.05)。n 结论:通过术前CT测量MTMAW可确定髋臼下螺钉的置入方式。部分埋入螺钉的进钉点较全部埋入螺钉偏外、偏后约2 mm，女性髋臼下螺钉通道直径较男性偏小，与矢状面夹角较男性偏外倾。“,”Objective:To investigate the infra-acetabular screw placements and compare the differences in placement parameters between genders.Methods:The CT data of 100 normal adult pelves were retrospectively included, involving 50 males and 50 females, aged from 18 to 86 years (average, 49.0 years). The three dimensional pelves were reconstructed using Mimics 19.0 software and imported into Geomagic Studio software. The diameters of the infra-acetabular screw corridor(IACD) and the minimum thickness of t he medial acetabular wall (MTMAW) were measured to analyze the relationship between them. All-in screws with a diameter of 3.5 mm were placed when the IACD was greater than or equal to 5 mm while in-out-in screws with a diameter of 3.5 mm were placed when the IACD was less than 5 mm. Screw placement parameters were compared between genders.Results:The IACD and MTMAW in males (6.15 mm ± 1.24 mm and 4.40 mm ± 1.23 mm) were significantly larger than those in females (5.42 mm ± 1.01 mm and 3.60 mm ± 0.81 mm) (n P<0.05); IACD was linearly correlated with MTMAW (n r=0.859, n P0.05). The medial inclination angle between all-in screw and sagittal plane in males was 1.02°±6.31° and the lateral inclination angle 8.19°±6.81° in females; the lateral inclination angle between in-out-in screw and sagittal plane was 1.48°±6.97° in males and the lateral inclination angle 7.90°±5.45° in females. The differences between males and females were statistically significant (n P<0.05).n Conclusions:The mode of infra-acetabular screw placement can be determined by preoperative measurement of MTMAW on CT. The entry point of an in-out-in screw is more posterior and lateral by about 2 mm than that of an all-in screw. As females have a smaller diameter of IACD, the angle between screw and sagittal plane should be more lateral.