Birks Ryan R, Kowaleski Michael P
Department of Clinical Sciences, Cummings School of Veterinary Medicine, Tufts University, North Grafton, Massachusetts, United States.
Vet Comp Orthop Traumatol. 2018 Feb;31(2):124-130. doi: 10.1055/s-0038-1625973. Epub 2018 Mar 13.
The purpose of this study is to compare the load at failure and mode of failure between (1) tibial plateau levelling osteotomy (TPLO) and combined TPLO and tibial tuberosity transposition (TPLO-TTT) (Phase I) and (2) TPLO-TTT and tibial tuberosity transposition (TTT) (Phase II).
Seven pairs of cadaveric tibiae were tested in each of the Phase I (TPLO vs. TPLO-TTT) and Phase II (TPLO-TTT vs. TTT) experiments. One limb of each pair was randomly assigned to one of two groups for each experimental phase. A tensile force was applied to the patellar ligament until construct failure occurred.
There was a significant difference in mean load at failure between TPLO (2092.8 N) and TPLO-TTT (1067.8 N), = 0.004. All TPLO constructs failed by fracture of the tibial crest. The TPLO-TTT constructs failed by cranial displacement of the distal tibial crest. Additionally, the tibial plateau was displaced in the majority of limbs. There was a significant difference in mean load at failure between TPLO-TTT (1157.6 N) and TTT (1394.0 N), = 0.025. The TTT constructs demonstrated a similar mode of failure as TPLO-TTT.
Although ex vivo mechanical testing does not replicate the postoperative clinical scenario, these results demonstrate reduced construct strength of the combined TPLO-TTT technique compared with TPLO or TTT alone. When performing TPLO-TTT, meticulous technique and implants of adequate strength must be employed to create a robust construct and minimize postoperative tibial crest fixation failure.
本研究的目的是比较（1）胫骨平台水平截骨术（TPLO）与TPLO联合胫骨结节转位术（TPLO-TTT）（第一阶段）以及（2）TPLO-TTT与胫骨结节转位术（TTT）（第二阶段）之间的失效负荷和失效模式。
在第一阶段（TPLO与TPLO-TTT）和第二阶段（TPLO-TTT与TTT）实验中，对七对尸体胫骨进行测试。每对中的一个肢体在每个实验阶段随机分配到两个组中的一组。对髌韧带施加拉力直至结构失效。
TPLO（2092.8 N）和TPLO-TTT（1067.8 N）之间的平均失效负荷存在显著差异，P = 0.004。所有TPLO结构均因胫骨嵴骨折而失效。TPLO-TTT结构因胫骨远端嵴的颅侧移位而失效。此外，大多数肢体的胫骨平台发生移位。TPLO-TTT（1157.6 N）和TTT（1394.0 N）之间的平均失效负荷存在显著差异，P = 0.025。TTT结构表现出与TPLO-TTT相似的失效模式。
尽管体外力学测试不能复制术后临床情况，但这些结果表明，与单独的TPLO或TTT相比，联合TPLO-TTT技术的结构强度降低。在进行TPLO-TTT时，必须采用细致技术和足够强度的植入物，以构建坚固的结构并尽量减少术后胫骨嵴固定失败。
