Griffin H, Toombs J P, Bronson D G, Ross J D, Browne R H
Hall Griffin, DVM, IMEX Veterinary, Inc., 1001 McKesson Drive, Longview, TX 75604, USA.
Vet Comp Orthop Traumatol. 2011;24(4):257-61. doi: 10.3415/VCOT-10-04-0054. Epub 2011 May 20.
An in vitro mechanical study was performed to compare the stiffness, maximum load, and cyclic load-to-failure of a new external fixation half-pin design utilizing a tapered thread-run-out (TRO) feature with currently available positive profile thread (PP) half-pins. Five different sizes of each of the two pin types were evaluated. Under static loading, TRO pins were significantly stiffer and had a higher maximum load compared to the similar sized PP pins (p <0.0001 for all comparisons). In cyclic fatigue testing, TRO pins lasted 2.3- to 4.9-fold more cycles than PP pins of similar size (p <0.0001 for all comparisons). The increased pin stiffness and improved cyclic lifespan provided by TRO pins may be especially valuable in the stabilization of biologically and mechanically challenging fracture cases where healing is prolonged.
进行了一项体外力学研究，以比较一种采用锥形螺纹收尾（TRO）特征的新型外固定半针设计与目前可用的正型螺纹（PP）半针的刚度、最大载荷和循环载荷失效情况。对两种销钉类型的五种不同尺寸进行了评估。在静态加载下，与尺寸相似的PP销相比，TRO销明显更硬，最大载荷更高（所有比较的p<0.0001）。在循环疲劳测试中，TRO销的循环次数比尺寸相似的PP销多2.3至4.9倍（所有比较的p<0.0001）。TRO销提高的销钉刚度和改善的循环寿命在稳定生物和机械方面具有挑战性且愈合时间延长的骨折病例中可能特别有价值。
