Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, Georgia, United States.
Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida, United States.
Vet Comp Orthop Traumatol. 2021 Jul;34(4):279-286. doi: 10.1055/s-0041-1726082. Epub 2021 May 12.
The aim of this study was to compare the biomechanical properties of a hybrid external skeletal fixator (HESF) construct to the placement of paired interfragmentary Kirschner wires alone, and pin and tension band wire (PTBW) fixation for the stabilization of simulated tibial tuberosity fractures in dogs.
Tibias were harvested from 12 skeletally mature dog cadavers weighing 20 to 30 kg. An osteotomy was made through the base of the tibial tuberosity, which was subsequently repaired with either paired Kirschner wires, PTBW fixation or a HESF. A tensile load was applied to the tibial tuberosity until failure occurred. Mode of failure was described and biomechanical parameters obtained were compared between fixation groups.
The PTBW fixation and HESF construct afforded greater stiffness and load at 3 mm of axial displacement compared with fixation with Kirschner wires alone. There was no significant difference in stiffness and load at 3 mm displacement between PTBW and HESF fixation. Failure occurred by bending and pullout of the Kirschner wires for all fixation groups, preceded by untwisting of the knot in PTBW specimens.
The HESF may provide a favourable alternative to PTBW fixation for tibial tuberosity avulsion fracture stabilization in dogs with substantial remaining growth potential.
本研究旨在比较混合外骨骼固定器（HESF）结构与单独使用成对的骨间克氏针、钉和张力带钢丝（PTBW）固定治疗犬模拟胫骨结节骨折的生物力学性能。
从 12 只体重 20 至 30kg 的骨骼成熟犬的尸体中取出胫骨。在胫骨结节底部进行切开，然后用成对的克氏针、PTBW 固定或 HESF 修复。对胫骨结节施加拉伸载荷，直至发生失效。描述失效模式，并比较固定组之间的生物力学参数。
与单独使用克氏针固定相比，PTBW 固定和 HESF 结构在轴向位移 3mm 时提供了更大的刚度和载荷。在 3mm 位移时，PTBW 和 HESF 固定的刚度和载荷没有显著差异。所有固定组均因克氏针弯曲和拔出而失效，之前在 PTBW 标本中出现了结的扭转。
对于具有较大生长潜力的犬胫骨结节撕脱骨折，HESF 可能是一种比 PTBW 固定更有利的选择。
