Kaisidis Aristotelis, Pantos Panagiotis G, Bochlos Dimitrios, Lindner Horst
Shoulder Department, Klinik Maingau, Rotes Kreuz,Frankfurt am Main,Germany.
Königsee Implantate GmbH, Aschau,Germany.
Open Orthop J. 2018 Jun 29;12:218-228. doi: 10.2174/1874325001812010218. eCollection 2018.
The incidence of isolated greater tuberosity fractures has been estimated to be 20% of all proximal humeral fractures. It is generally accepted that displaced (>5 mm) fractures should be treated surgically but the optimal surgical fixation of greater tuberosity fractures remains unclear.
The goal of this study was to simulate the environment of application of a new plate system (Kaisidis plate, Fa Königsee) for fractures of greater tuberosity, and to demonstrate the stability of the plate.
A Finite Element Method (FEM) simulation analysis was performed on a Kaisidis plate fixed with nine screws, in a greater tuberosity fracture model. Solid Works 2015 simulation software was used for the analysis. The Kaisidis plate is a bone plate intended for greater tuberosity fractures. It is a low profile plate with nine holes for 2,4 mm diameter locking screws, eight suture holes and additional K-wire holes for temporary fixation of the fragment.The supraspinatus tendon has the greatest effect on the fracture zone, and as such, was the primary focus for this study. For this study, we performed only linear calculations.
The calculations were performed in a way so that the total applied force resulted in a maximum stress of 816 N/mm. The findings indicated that the most critical points of the Kaisidis system are the screws that are connected to the bone. The maximal force generated by the supraspinatus tendon was 784 N, which is higher than the minimal acceptable force.The results of the FEM analysis showed that the maximal supraspinatus force was 11.6% higher than the minimal acceptable force. As such, the load would exceed twice the amount of maximal force required to tear the supraspinatus tendon, before the screw or the plate would show first signs of plastic deformation.
Based on the results of this analysis and the fulfilment of our acceptance criterion, the FEM model indicated that the strength of the Kaisidis plate exceeded that of the proposed maximum loads under non-cycli loading conditions.
据估计，单纯的肱骨大结节骨折发生率占所有肱骨近端骨折的20%。一般认为，移位（>5mm）骨折应接受手术治疗，但肱骨大结节骨折的最佳手术固定方式仍不明确。
本研究的目的是模拟一种新型钢板系统（凯西迪斯钢板，法 Königsee）应用于大结节骨折的环境，并证明该钢板的稳定性。
在一个大结节骨折模型中，对用9枚螺钉固定的凯西迪斯钢板进行有限元方法（FEM）模拟分析。使用Solid Works 2015模拟软件进行分析。凯西迪斯钢板是一种用于大结节骨折的骨板。它是一种低轮廓钢板，有9个用于直径2.4mm锁定螺钉的孔、8个缝线孔和用于临时固定骨折块的额外克氏针孔。冈上肌腱对骨折区域影响最大，因此是本研究的主要关注点。本研究仅进行线性计算。
计算方式使得总施加力产生的最大应力为816N/mm²。结果表明，凯西迪斯系统最关键的点是与骨骼相连的螺钉。冈上肌腱产生的最大力为784N，高于最小可接受力。有限元分析结果表明，最大冈上肌力量比最小可接受力高11.6%。因此，在螺钉或钢板出现塑性变形的最初迹象之前，负荷将超过撕裂冈上肌腱所需最大力的两倍。
基于该分析结果和我们验收标准的达成情况，有限元模型表明，在非循环加载条件下，凯西迪斯钢板的强度超过了建议的最大负荷强度。
