Spine Center, The Second Affiliated Hospital of Nanchang University, Nanchang, China.
Department of Orthopaedic Surgery, The Affiliated Ganzhou Hospital of Nanchang University, Ganzhou, China.
J Orthop Surg (Hong Kong). 2020 Sep-Dec;28(3):2309499020967110. doi: 10.1177/2309499020967110.
Sacropelvic fixation continues to present challenges when involved in the adult spinal deformity correction. The S2 alar iliac (S2AI) fixation is commonly used in sacropelvic fixation. Several techniques, including intraoperative navigation and freehand technique, were used for S2AI screws placement. The aim of this study is to analyze the anatomic parameters for S2AI screw trajectory in Asian population and introduce a novel technique described as a three-dimensional printed template guided technique (TGT). Meanwhile, the accuracy and safety of this technique were compared with the conventional freehand technique.
The S2AI trajectory parameters were measured in 100 Asian adult volunteers. Parameters were compared between different genders. Forty-eight adult patients who underwent S2AI screw placement were reviewed: 28 patients received freehand technique and 20 patients received TGT technique. Postoperative computed tomography was used to assess the accuracy of screw trajectory and cortex violation-related complications were recorded.
The cephalocaudal angles (CAs), maximal length of screw pathway, narrowest width of pathway within the iliar teardrop, distance from the center of teardrop to sciatic notch, and distance of the start point distal to S1 dorsal foramen showed significant gender-related difference ( < 0.05). All 48 patients were placed S2AI screws bilaterally (40 screws in TGT vs. 56 screws in freehand). One screw penetrated iliac cortex in the TGT group but 10 screws penetrated iliac cortex in the freehand group (3% vs. 17.9%) ( < 0.05).
Approximately 30-35° of CA and 39° mediolateral angle are appropriate for S2AI screw placement in Asian patients. Either freehand or TGT technique is safe for S2AI screw placement. TGT technique is more accurate compared with the conventional freehand technique.
This is a retrospective study.
骶骨盆固定在成人脊柱畸形矫正中仍然存在挑战。S2 髂骨翼（S2AI）固定在骶骨盆固定中常用。几种技术，包括术中导航和徒手技术，用于 S2AI 螺钉放置。本研究旨在分析亚洲人群 S2AI 螺钉轨迹的解剖参数，并介绍一种新的技术，即三维打印模板引导技术（TGT）。同时，将该技术的准确性和安全性与传统的徒手技术进行比较。
在 100 名亚洲成年志愿者中测量了 S2AI 轨迹参数。比较了不同性别之间的参数。回顾性分析了 48 例接受 S2AI 螺钉植入的成年患者：28 例接受徒手技术，20 例接受 TGT 技术。术后 CT 用于评估螺钉轨迹的准确性，并记录皮质侵犯相关并发症。
颅尾角（CA）、螺钉路径的最大长度、髂骨泪滴内最窄路径宽度、泪滴中心至坐骨切迹的距离以及 S1 背侧孔远端起始点的距离在性别上存在显著差异（<0.05）。所有 48 例患者均双侧植入 S2AI 螺钉（TGT 组 40 枚，徒手组 56 枚）。TGT 组有 1 枚螺钉穿透髂骨皮质，而徒手组有 10 枚螺钉穿透髂骨皮质（3%对 17.9%）（<0.05）。
在亚洲患者中，S2AI 螺钉植入的 CA 约为 30-35°，MLA 约为 39°。徒手或 TGT 技术均可安全地进行 S2AI 螺钉植入。与传统的徒手技术相比，TGT 技术更准确。
这是一项回顾性研究。
