Trauma Hospital Graz, Austria.
Injury. 2013 Oct;44(10):1346-57. doi: 10.1016/j.injury.2012.10.022. Epub 2012 Nov 24.
In this in vivo study a new generation of locking screws was tested. The design of the dynamic locking screw (DLS) enables the dynamisation of the cortex underneath the plate (cis-cortex) and, therefore, allows almost parallel interfragmentary closure of the fracture gap. A 45° angle osteotomy was performed unilaterally on the tibia of 37 sheep. Groups of 12 sheep were formed and in each group a different osteotomy gap (0, 1 and 3mm) was fixed using a locking compression plate (LCP) in combination with the DLS. The healing process was monitored radiographically every 3 weeks for 6, respectively 12 weeks. After this time the sheep were sacrificed, the bones harvested and the implants removed. The isolated bones were evaluated in the micro-computed tomography unit, tested biomechanically and evaluated histologically. The best results of interfragmentary movement (IFM) were shown in the 0mm configuration. The bones of this group demonstrated histomorphometrically the most distinct callus formation on the cis-cortex and the highest torsional stiffness relative to the untreated limb at 12 weeks after surgery. This animal study showed that IFM stimulated the synthesis of new bone matrix, especially underneath the plate and thus, could solve a current limitation in normal human bone healing. The DLS will be a valuable addition to the locking screw technology and improve fracture healing.
在这项体内研究中，测试了新一代的锁定螺钉。动态锁定螺钉（DLS）的设计使钢板下的皮质（皮质内）能够动态化，因此允许骨折间隙几乎平行地闭合。在 37 只绵羊的胫骨上进行了单侧 45°角截骨。将 12 只羊分为一组，在每组中，使用锁定加压板（LCP）结合 DLS 固定不同的截骨间隙（0、1 和 3mm）。使用 X 射线每隔 3 周监测愈合过程 6 或 12 周。在此时间后，将绵羊处死，取出骨骼并移除植入物。将分离的骨骼在微计算机断层扫描单元中进行评估，进行生物力学测试并进行组织学评估。在 0mm 配置下，界面运动（IFM）的结果最佳。该组的骨骼在组织形态计量学上在术后 12 周时在皮质内显示出最明显的骨痂形成，并且相对于未处理的肢体具有最高的扭转刚度。这项动物研究表明，IFM 刺激了新骨基质的合成，特别是在钢板下，因此可以解决正常人类骨愈合的当前局限性。DLS 将是锁定螺钉技术的有价值的补充，并改善骨折愈合。
