Flynn M F, Edmiston D N, Roe S C, Richardson D C, DeYoung D J, Abrams C F
Department of Companion Animal and Special Species Medicine, College of Veterinary Medicine, North Carolina State University, Raleigh.
Vet Surg. 1994 Sep-Oct;23(5):311-21. doi: 10.1111/j.1532-950x.1994.tb00490.x.
Toggle pin stabilization is an accepted technique for the management of coxofemoral (CF) luxation in dogs. The purpose of this study was to determine, in vitro, the respective contributions of several aspects of toggle pin repair to the overall stability of fixation. Factors evaluated were the manner and frequency with which toggle pins oriented on insertion, effect of orientation on toggle pin strength, effect of suture type on ligament prosthesis strength and load sustained by the fixation, and comparison of repair using a modified toggle design to that of capsulorrhaphy. When placed in cadavers using standard technique, conventional toggle pins were found to orient significantly more frequently in one of two possible positions. Mechanical testing of fixations performed in experimentally luxated cadaver hips demonstrated a high (12/20) incidence of toggle pin failure using the conventional implant in the most common orientation. When tested alone, toggle pins were weakest mechanically in this orientation. Rotating the implant 180 degrees increased mean load to failure by 249%. There was no significant difference in load sustained by conventional toggle fixations using No. 2 braided polyester versus 50 lb test monofilament nylon as the suture ligament prosthesis. However, the higher stiffness of the polyester suture may be more favorable for use in this application. Fixation using a toggle rod designed to allow evaluation of construct stability when failure of the toggle is eliminated resulted in an increase in maximum load sustained before luxation (47% of the intact control hips). This load was not significantly different than the resistance to luxation afforded by capsulorrhaphy. This study suggests that when implanting conventional toggle pins, consideration should be given to ensuring placement in the strongest orientation.
肘节销固定术是治疗犬髋关节脱位的一种公认技术。本研究的目的是在体外确定肘节销修复的几个方面对固定整体稳定性的各自贡献。评估的因素包括肘节销插入时的定向方式和频率、定向对肘节销强度的影响、缝合线类型对韧带假体强度和固定承受负荷的影响，以及使用改良肘节设计的修复与关节囊缝合术的比较。当使用标准技术放置在尸体中时，发现传统肘节销在两个可能位置之一的定向频率明显更高。在实验性脱位的尸体髋关节上进行的固定力学测试表明，在最常见的定向中，使用传统植入物时肘节销失效的发生率很高（12/20）。单独测试时，肘节销在这个定向中机械强度最弱。将植入物旋转180度可使平均破坏负荷增加249%。使用2号编织聚酯线与50磅测试单丝尼龙线作为缝合韧带假体的传统肘节固定所承受的负荷没有显著差异。然而，聚酯缝合线较高的刚度可能更有利于此应用。使用一种设计用于在消除肘节失效时评估结构稳定性的肘节杆进行固定，导致脱位前承受的最大负荷增加（完整对照髋关节的47%）。该负荷与关节囊缝合术提供的抗脱位能力没有显著差异。本研究表明，在植入传统肘节销时，应考虑确保将其放置在最强的定向中。
