Markwardt Jutta, Pfeifer Günther, Eckelt Uwe, Reitemeier Bernd
Klinik für Mund-, Kiefer- und Gesichtschirurgie, Technische Universität Dresden, Germany.
Onkologie. 2007 Mar;30(3):121-6. doi: 10.1159/000098848. Epub 2007 Feb 13.
In a retrospective study, risk factors for complications after the bridging of mandibular defects using reconstruction plates were reviewed. Especially the loosening of the plate-screw-mandible complex should be analyzed with a finite element model in order to reduce plate complications in future.
We examined 60 patients who underwent a treatment with reconstruction plates after tumor resection during a period of 10 years. The problem of screw loosening was additionally reviewed by means of a finite element study, and a model for the loosening process was developed.
Our postoperative examination showed that 26 patients suffered from complications that required an early removal of the plate. These complications were oral or extraoral plate exposures, the looseness of screws with or without plate displacement, and plate fractures. Thereby, we noticed that maxillary and mandibular areas of opposing teeth, the size of the mandible defect, and the crossing of the orofacial midline are all risk factors for plate complications. On the basis of the finite element model, a modified arrangement of the screws was derived. Hence, a new type of resection plate was established.
By repositioning the screw holes along the long axis of the plate, the transition from tensile force to torque force of the screws in the screw-plate-bone complex can be minimized. Thereby, the complication of screw loosening will be considerably reduced.
在一项回顾性研究中，对使用重建钢板修复下颌骨缺损后并发症的危险因素进行了评估。特别是应通过有限元模型分析钢板-螺钉-下颌骨复合体的松动情况，以便未来减少钢板并发症。
我们检查了60例在10年期间肿瘤切除术后接受重建钢板治疗的患者。通过有限元研究进一步评估了螺钉松动问题，并建立了松动过程的模型。
我们的术后检查显示，26例患者出现了需要早期取出钢板的并发症。这些并发症包括口腔内或口腔外钢板暴露、螺钉松动伴或不伴钢板移位以及钢板骨折。由此，我们注意到对颌牙的上颌和下颌区域、下颌骨缺损的大小以及口面中线的交叉都是钢板并发症的危险因素。基于有限元模型，得出了螺钉的改良排列方式。因此，建立了一种新型的切除钢板。
通过沿钢板长轴重新定位螺孔，可以使螺钉-钢板-骨复合体中螺钉从拉力向扭矩力的转变最小化。从而，螺钉松动的并发症将大大减少。
