Diffo Kaze Arnaud, Maas Stefan, Belsey James, Hoffmann Alexander, Seil Romain, van Heerwaarden Ronald, Pape Dietrich
Faculty of Science, Technology and Communication, University of Luxembourg, 6, rue R. Coudenhove-Kalergi, L-1359, Luxembourg, Luxembourg.
Department of Orthopedic Surgery, Centre Hospitalier de Luxembourg, L-1460, Luxembourg, Luxembourg.
J Exp Orthop. 2019 Nov 7;6(1):43. doi: 10.1186/s40634-019-0209-1.
This study aimed to assess the mechanical static and fatigue strength provided by the FlexitSystem plate in medial opening wedge high tibial osteotomies (MOWHTO), and to compare it to six previously tested implants: the TomoFix small stature, the TomoFix standard, the ContourLock, the iBalance, the second generation PEEKPower and the size 2 Activmotion. Thus, this will provide surgeons with data that will help in the choice of the most appropriate implant for MOWHTO.
Six fourth-generation tibial bone composites underwent a MOWHTO and each was fixed using six FlexitSystem plates, according to standard techniques. The same testing procedure that has already been previously defined, used and published, was used to investigate the static and dynamic strength of the prepared bone-implant constructs. The test consisted of static loading and cyclical loading for fatigue testing.
During static testing, the group constituted by the FlexitSystem showed a fracture load higher than the physiological loading of slow walking (3.7 kN > 2.4 kN). Although this fracture load was relatively small compared to the average values for the other Implants from our previous studies, except for the TomoFix small stature and the Contour Lock. During fatigue testing, FlexitSystem group showed the smallest stiffness and higher lifespan than the TomoFix and the PEEKPower groups.
The FlexitSystem plate showed sufficient strength for static loading, and average fatigue strength compared to the previously tested implants. Full body dynamic loading of the tibia after MOWHTO with the investigated implants should be avoided for at least 3 weeks. Implants with a wider T-shaped proximal end, positioned onto the antero-medial side of the tibia head, or inserted in the osteotomy opening in a closed-wedge construction, provided higher mechanical strength than implants with small a T-shaped proximal end, centred onto the medial side of the tibia head.
本研究旨在评估FlexitSystem钢板在内侧开口楔形高位胫骨截骨术（MOWHTO）中提供的机械静态和疲劳强度，并将其与六种先前测试过的植入物进行比较：TomoFix小身材型、TomoFix标准型、ContourLock、iBalance、第二代PEEKPower和2号Activmotion。因此，这将为外科医生提供数据，有助于他们选择最适合MOWHTO的植入物。
六块第四代胫骨骨复合材料进行了MOWHTO，并根据标准技术，每块使用六个FlexitSystem钢板进行固定。采用先前已经定义、使用和发表的相同测试程序，来研究制备好的骨-植入物结构的静态和动态强度。测试包括静态加载和用于疲劳测试的循环加载。
在静态测试期间，由FlexitSystem组成的组显示出的骨折负荷高于慢走的生理负荷（3.7 kN ＞ 2.4 kN）。尽管与我们先前研究中其他植入物的平均值相比，该骨折负荷相对较小，但TomoFix小身材型和Contour Lock除外。在疲劳测试期间，FlexitSystem组显示出最小的刚度，并且比TomoFix组和PEEKPower组具有更长的使用寿命。
FlexitSystem钢板显示出足以承受静态加载的强度，与先前测试的植入物相比，其疲劳强度处于平均水平。MOWHTO后使用所研究的植入物对胫骨进行全身动态加载，至少3周内应避免。近端为较宽T形、位于胫骨头前内侧或通过闭合楔形结构插入截骨开口的植入物，比近端为小T形、位于胫骨头内侧中心的植入物提供更高的机械强度。
