Said Hatem Galal, Fetih Tarek Nabil, Abd-Elzaher Hosam Elsayed, Lambert Simon Martin
Professor, Orthopaedics and Traumatology Department, Assiut University, 71515 Assiut, Egypt.
Assistant lecturer, Orthopaedics and Traumatology Department, Assiut University, 71515 Assiut, Egypt.
SICOT J. 2020;6:9. doi: 10.1051/sicotj/2020008. Epub 2020 May 5.
Coracoid fractures have the potential to lead to inadequate shoulder function. Most coracoid base fractures occur with scapular fractures and the posterior approaches would be utilized for surgical treatment. We investigated the possibility of fixing the coracoid through the same approach without an additional anterior approach.
Multi-slice CT scans of 30 shoulders were examined and the following measurements were performed by an independent specialized radiologist: posterior coracoid screw entry point measured form infraglenoid tubercle, screw trajectory in coronal plane in relation to scapular spine and lateral scapular border, screw trajectory in sagittal plane in relation to glenoid face bisector line and screw length. We used the results from the CT study to guide postero-anterior coracoid screw insertion under fluoroscopic guidance on two fresh frozen cadaveric specimens to assess the reproducibility of accurate screw placement based on these parameters. We also developed a novel fluoroscopic projection, the anteroposterior (AP) coracoid view, to guide screw placement in the para-coronal plane.
The mean distance between entry point and the infraglenoid tubercle was 10.8 mm (range: 9.2-13.9, SD 1.36). The mean screw length was 52 mm (range: 46.7-58.5, SD 3.3). The mean sagittal inclination angle between was 44.7 degrees (range: 25-59, SD 5.8). The mean angle between screw line and lateral scapular border was 47.9 degrees (range: 34-58, SD 4.3). The mean angle between screw line and scapular spine was 86.2 degrees (range: 75-95, SD 4.9). It was easy to reproduce the screw trajectory in the para-coronal plane; however, multiple attempts were needed to reach the correct angle in the parasagittal plane, requiring several C-arm corrections.
This study facilitates posterior fixation of coracoid process fractures and will inform the "virtual visualization" of coracoid process orientation.
喙突骨折有可能导致肩部功能不足。大多数喙突基底部骨折与肩胛骨骨折同时发生，手术治疗将采用后路入路。我们研究了通过相同入路固定喙突而无需额外前路入路的可能性。
对30个肩部的多层CT扫描进行检查，由一名独立的专业放射科医生进行以下测量：从肩胛下结节测量的喙突后螺钉进针点、冠状面相对于肩胛冈和肩胛外侧缘的螺钉轨迹、矢状面相对于关节盂面平分线的螺钉轨迹以及螺钉长度。我们利用CT研究结果在荧光透视引导下对两个新鲜冷冻尸体标本进行前后向喙突螺钉置入，以评估基于这些参数准确螺钉置入的可重复性。我们还开发了一种新的荧光透视投影，即前后位（AP）喙突视图，以引导螺钉在副冠状面的置入。
进针点与肩胛下结节之间的平均距离为10.8毫米（范围：9.2 - 13.9，标准差1.36）。平均螺钉长度为52毫米（范围：46.7 - 58.5，标准差3.3）。矢状面平均倾斜角度为44.7度（范围：25 - 59，标准差5.8）。螺钉线与肩胛外侧缘之间的平均角度为47.9度（范围：34 - 58，标准差4.3）。螺钉线与肩胛冈之间的平均角度为86.2度（范围：75 - 95，标准差4.9）。在副冠状面很容易重现螺钉轨迹；然而，在矢状面需要多次尝试才能达到正确角度，需要几次C形臂校正。
本研究有助于喙突骨折的后路固定，并将为喙突方向的“虚拟可视化”提供信息。
