Lameilhé Veterinary Clinic, Castres, France.
University of Lyon, VetAgro Sup, Interactions Cellules Environnement (ICE), Marcy l'Etoile, France.
J Feline Med Surg. 2022 Oct;24(10):e360-e369. doi: 10.1177/1098612X221114851. Epub 2022 Sep 8.
The aim of our study was to describe a biomechanical testing protocol to reproduce ex vivo craniodorsal hip luxation specific to the feline model, and evaluate the biomechanical properties of an intact hip joint compared with the fixation strength of two different techniques of extra-articular hip stabilisation.
Eighteen hip joints (femur and hemipelvis) were harvested from nine mature feline cadavers. CT was performed for each hip joint so that a biomechanical base specific to each joint morphotype could be created using computer-aided design. The biomechanical bases were then produced using a three-dimensional printer to secure the hip joints during testing. A total of 34 biomechanical compression tests were performed. Eighteen compression tests were performed in the control group, of which two fractured. The remaining 16 hip joints were then randomly assigned either to group A (hip joints stabilised with an extra-articular ultra-high molecular weight polyethylene (UHMWPE) implant secured by an interference screw [n = 8]) or to group B (hip joints stabilised with a UHMWPE iliofemoral suture [n = 8]).
Mean ± SD yield, failure load and linear stiffness in the control group were 616 ± 168 N, 666 ± 158 N and 231 ± 50 N/mm, respectively. The relative fixation strength (% of intact joint) before hip luxation in groups A and B was 43.8% and 34.7%, respectively. No statistical difference was found between groups A and B for yield and failure load. However, the reoccurrence of craniodorsal hip luxation was higher in group B than in group A, in 5/8 and 0/8 tests, respectively. Moreover, in group A, the extra-articular UHMWPE implant induced caudodorsal hip luxation, reported as failure mode in 7/8 cases.
This modified biomechanical protocol for testing craniodorsal hip luxation in a feline model was validated as repeatable and with acceptable variance. The extra-articular UHMWPE implant stabilisation technique proved to be more efficient in avoiding reoccurrence of craniodorsal hip luxation than UHMWPE iliofemoral suture.
本研究的目的是描述一种生物力学测试方案，以重现特定于猫模型的颅背侧髋关节脱位，并评估完整髋关节与两种不同关节外髋关节稳定技术的固定强度的生物力学特性。
从 9 个成熟猫尸体中采集了 18 个髋关节（股骨和半骨盆）。对每个髋关节进行 CT 检查，以便使用计算机辅助设计创建特定于每个关节形态的生物力学基础。然后使用三维打印机制作生物力学基础，以在测试过程中固定髋关节。总共进行了 34 次生物力学压缩测试。在对照组中进行了 18 次压缩测试，其中两次发生了骨折。其余 16 个髋关节随后随机分配到 A 组（用通过干扰螺钉固定的关节外超高分子量聚乙烯（UHMWPE）植入物稳定的髋关节，[n=8]）或 B 组（用 UHMWPE 髂股缝线稳定的髋关节[n=8]）。
对照组的平均屈服强度、失效载荷和线性刚度分别为 616±168N、666±158N 和 231±50N/mm。A 组和 B 组在髋关节脱位前的相对固定强度（完整关节的%）分别为 43.8%和 34.7%。A 组和 B 组在屈服强度和失效载荷方面无统计学差异。然而，B 组髋关节颅背侧脱位的再发率高于 A 组，分别为 5/8 和 0/8 次测试。此外，在 A 组中，关节外 UHMWPE 植入物引起了尾背侧髋关节脱位，在 7/8 例中报告为失效模式。
本研究修改后的用于猫模型颅背侧髋关节脱位测试的生物力学方案被验证为可重复且具有可接受的变异性。关节外 UHMWPE 植入物稳定技术在避免颅背侧髋关节脱位的再发方面比 UHMWPE 髂股缝线更有效。
