AUVA - Trauma Hospital (UKH) Styria | Graz, Göstinger Straße 24, 8020, Graz, Austria.
Department of Orthopaedics and Trauma, Medical University of Graz, Auenbruggerplatz 5, 8036, Graz, Austria.
Injury. 2021 Sep;52 Suppl 5:S58-S62. doi: 10.1016/j.injury.2020.07.039. Epub 2020 Jul 19.
Application of supraacetabular Schanz screws is usually performed under image intensifier guidance. The aim of this study was to perform it without imaging, with the hypothesis that, respecting anatomical landmarks, pre- and intraoperative fluoroscopy can be avoided.
MATERIAL & METHODS: Insertion of the supra-acetabular Schanz screws was performed by two trauma surgery residents in a study sample of 14 human adult cadavers which had been embalmed by use of Thiel`s method. With cadavers placed in supine position, the anterior superior iliac spine (ASIS) was palpated. Starting from this landmark, 2 cm were measured in a distal and 2 cm in the medial direction. At this point, a 2 cm long oblique skin incision was performed. Through this approach, 150 mm Schanz screws were drilled bilaterally into the supra-acetabular corridor with an angulation of 20° to distal as well as 20° to medial. Following screw application, combined obturator oblique-outlet views (COOO) were taken bilaterally in each specimen by use of an Arcadis© Orbic 3D C-arm to prove the screw position. Six of the specimens underwent a 3D-CT-scan. Images were evaluated concerning correct screw positioning by a further traumatologist. Skin and subcutaneous tissues were removed in the ilioinguinal region and possible lesions to the lateral femoral cutaneous nerve (LFCN) or to the joint capsule were evaluated.
The sample consisted of eight pelves from female and six pelves from male cadavers. During radiographic evaluation of the COOO-scans (14 specimens) and the 3D-scans (6 specimens), the Schanz screws were placed inside the supra-acetabular corridor in all specimens (14/14). During dissections, no intracapsular screw placements or LFCN lesions were found.
According to the described anatomical data, we defined a 2-2-2-20-20 concept, starting with a 2 cm skin incision 2 cm distal and 2 cm medial to the ASIS with a drill angulation of 20° inferior and 20° lateral orientation. Using this technique, all Schanz screws could be sufficiently inserted without intraprocedural x-ray imaging.
髋臼上 Schanz 螺钉的应用通常在影像增强器引导下进行。本研究旨在在不进行成像的情况下进行操作，假设在尊重解剖学标志的前提下，可以避免术前和术中透视。
两名创伤外科住院医师在一项研究中，对 14 具经过 Thiel 法防腐处理的成人尸体进行了髋臼上 Schanz 螺钉的插入。将尸体置于仰卧位，触诊髂前上棘 (ASIS)。从这个标志开始，在远端测量 2cm，在内侧测量 2cm。在此处，做一个 2cm 长的斜向皮肤切口。通过这个入路，双侧髋臼上通道用 20°向远端和 20°向内侧的角度钻入 150mm 的 Schanz 螺钉。螺钉应用后，在每个标本中使用 Arcadis©Orbic 3D C 臂双侧拍摄联合闭孔斜出口视图 (COOO)，以证明螺钉位置。其中 6 个标本进行了 3D-CT 扫描。另一位创伤外科医生对图像进行评估，以确定螺钉的正确定位。在髂腹股沟区域去除皮肤和皮下组织，并评估可能对侧股皮神经 (LFCN) 或关节囊造成的损伤。
样本包括 8 具女性骨盆和 6 具男性骨盆。在 COOO 扫描（14 个标本）和 3D 扫描（6 个标本）的放射学评估中，所有标本（14/14）的 Schanz 螺钉均置于髋臼上通道内。在解剖过程中，未发现关节内螺钉放置或 LFCN 损伤。
根据描述的解剖数据，我们定义了一个 2-2-2-20-20 概念，从 ASIS 远端 2cm 和内侧 2cm 处开始，做一个 2cm 的皮肤切口，钻头角度为 20°向下方和 20°向外侧。使用这种技术，所有的 Schanz 螺钉都可以在不进行术中 X 线成像的情况下充分插入。
