Grevenstein David, Meyer Carolin, Wegmann Kilian, Hackl Michael, Bredow Jan, Eysel Peer, Prescher Andreas, Scheyerer Max J
Department for Orthopaedic and Trauma Surgery, Faculty of Medicine, University Hospital of Cologne, Joseph-Stelzmann Strasse 24, 50931 Cologne, Germany.
Institute of Molecular and Cellular Anatomy, University Hospital Aachen, Pauwelsstrasse 30, 52074 Aachen, Germany.
Clin Biomech (Bristol). 2019 May;65:100-104. doi: 10.1016/j.clinbiomech.2019.04.007. Epub 2019 Apr 15.
Bicortical screw fixation is an established technique to increase screw strength in vertebral bodies, although it is associated with several complications, for example screw-loosening. Cement augmentation can increase stability of screw-fixation but can also cause various complications, such as cement-leakage or cement embolism. In this study, we tested a new, multicortical screw fixation technique in the sacrum.
Four fresh-frozen sacrums were used. In group 1, standard screw insertion, with sagittal parallel and axial convergent screw-drive was performed. In group 2, the screw-drive of the first screw was similar to the screw-drive in group 1. In addition, a second screw was inserted descending into the intended hole in the head of the screw and at a stable angle. Therefore, the screws of the multiloc humerus nail-system (Synthes) were used. The specimens were connected to a testing-machine and underwent cyclic axial loading with an increase in the load after each completed stage.
Multicortical screw fixation leads to a significant increase in the number of completed cycles and a significantly increased load until failure.
Multicortical screw fixation in the sacrum offers a stronger attachment of the screws. In the future, multicortical implants, which fulfil the criteria demanded in spine surgery, can offer higher stability and may decrease the loosening rates of the implanted screws.
双皮质螺钉固定是一种已确立的增加椎体螺钉强度的技术，尽管它与多种并发症相关，例如螺钉松动。骨水泥强化可增加螺钉固定的稳定性，但也会引发各种并发症，如骨水泥渗漏或骨水泥栓塞。在本研究中，我们在骶骨测试了一种新的多皮质螺钉固定技术。
使用了四个新鲜冷冻的骶骨。在第1组中，采用矢状平行和轴向汇聚的螺钉置入方式进行标准螺钉插入。在第2组中，第一枚螺钉的置入方式与第1组相似。此外，以稳定角度向下插入第二枚螺钉至第一枚螺钉头部的预定孔中。因此，使用了多锁髓内钉系统（辛迪斯公司）的螺钉。将标本连接到试验机上，并在每个完成阶段后增加负荷的情况下进行循环轴向加载。
多皮质螺钉固定导致完成循环次数显著增加，直至失效的负荷也显著增加。
骶骨多皮质螺钉固定可使螺钉的附着更强。未来，符合脊柱手术要求标准的多皮质植入物可提供更高的稳定性，并可能降低植入螺钉的松动率。
