目的:探讨经第2骶骨翼髂骨螺钉（Sn 2AI）固定技术在不稳定型骨盆后环损伤治疗中的适应证，并评估该技术的可行性及其临床疗效。n 方法:回顾性分析2017年9月至2020年12月期间南方医科大学南方医院骨科-创伤骨科和南华大学附属第一医院创伤骨科应用Sn 2AI固定技术治疗的18例不稳定型骨盆后环损伤患者资料。男8例，女10例；平均年龄为40岁（20~64岁）；骨盆骨折根据Tile分型：B2型3例，C1型10例，C2型5例。合并骶神经损伤3例，根据Gibbons神经损伤分级：Ⅱ级2例，Ⅲ级1例。受伤至手术时间平均为11 d（4~21 d）。6例患者采用短节段Sn 1-Sn 2AI固定，1例患者行对侧Sn 1-Sn 2AI固定，5例患者采用腰椎骨盆固定，6例患者采用骶髂三角固定。术后应用CT根据Shillingford法评价Sn 2AI置入的精确性，记录患者的骨折复位质量及并发症发生情况等。n 结果:18例患者术后获平均19.8个月（12~36个月）随访。术后所有患者骨折均获骨性愈合。18例患者共置入21枚Sn 2AI，术中未发生神经、血管损伤等并发症，术后CT发现2枚Sn 2AI穿破髂骨皮质。根据Matta评分标准评定骨折复位质量：优10例，良7例，可1例。术前3例合并骶神经损伤患者术后2例Ⅱ级损伤恢复为Ⅰ级，1例Ⅲ级损伤恢复为Ⅱ级。术后2例患者出现切口部位浅表感染，无一例患者出现内固定物突出、断裂或松动等并发症。n 结论:Sn 2AI固定技术能够灵活应用于多种类型骨盆后环损伤，可对骨盆环和腰骶结合部提供坚强固定，并发症发生率较低。n “,”Objective:To explore the fixation with Sn 2 alar iliac screws (Sn 2AI) for unstable injury to the pelvic posterior ring.n Methods:The clinical data of 18 patients were analyzed retrospectively who had been treated for unstable injury to the posterior pelvic ring by Sn 2AI screw fixation at Division of Orthopaedics and Traumatology, Department of Orthopaedics, Nanfang Hospital, Southern Medical University and at Department of Orthopaedics and Traumatology, The First Affiliated Hospital to University of South China from September 2017 to December 2020. They were 8 males and 10 females, with an average age of 40 years (from 20 to 64 years). According to Tile classification, there were 3 cases of type B2, 10 cases of type C1 and 5 cases of type C2. Sacral nerve injury was complicated in 3 patients (2 cases of Gibbons grade Ⅱ and one of Gibbons grade Ⅲ). Short-segment Sn 1-Sn 2AI fixation was used in 6 cases, contralateral Sn 1-Sn 2AI fixation in one case, lumbar-pelvic fixation in 5 cases, and sacroiliac triangle fixation in 6 cases. The accuracy of Sn 2AI placement was evaluated by CT after operation according to the Shillingford method; the reduction quality of pelvic fractures and complications were documented.n Results:All the 18 patients were followed up for 19.8 months (from 12 to 36 months). Bony union was achieved in all fractures. A total of 21 Sn 2AI were implanted in the 18 patients without intraoperative neurovascular injury. Postoperative CT found penetration into the iliac cortex by Sn 2AI in 2 cases. According to the Matta criteria, the fracture reduction was excellent in 10 cases, good in 7 and fair in one. Of the 3 patients with preoperative sacral nerve injury, 2 with grade Ⅱ injury recovered to grade Ⅰ and one with grade Ⅲ injury recovered to grade Ⅱ after operation. Superficial infection occurred at the incision site in 2 patients after operation, and complications such as protrusion, rupture or loosening of implants were observed in none of the patients.n Conclusion:Sn 2AI fixation can be flexibly applied to various types of posterior pelvic ring injury and can provide the pelvic ring and the lumbosacral junction with rigid fixation, leading to a low complication rate.n