Objective The aim of this study was to (1) evaluate bending structural properties of a machined short fibre epoxy (SFE) feline bone surrogate (FBS), (2) compare the bending behaviour of small angle-stable interlocking nails (I-Loc; Targon) and locking compression plates (LCP) and (3) evaluate the effect of implant removal on FBS bending strength.

Methods Part 1: Feline cadaveric femurs (n = 10) and FBS (n = 4) underwent cyclic four-point bending and load to failure. Part 2: Fracture gap FBS constructs (n = 4/group) were stabilized in a bridging fashion with either I-Loc 3 and 4, Targon 2.5 and 3.0, LCP 2.0 and 2.4, then cyclically bent. Part 3: Intact FBS with pilot holes, simulating explantation, (n = 4/group) underwent destructive bending tests. Bending compliance, angular deformation and failure moment (F_M) were statistically compared (p < 0.05).

Results Native bone and FBS were similar for all outcome measures (p > 0.05). The smallest and largest bending compliance and angular deformation were seen in the I-Loc 4 and LCP 2.0 respectively (p < 0.05). While explanted Targon FBS had the lowest F_M (p < 0.05), I-Loc and LCP constructs F_M were not different (p > 0.05).

Conclusion The similar bending properties of short fibre epoxy made FBS and native feline femurs suggest that this model could be used for mechanical testing of implants designed for feline long bone osteosynthesis. The I-Loc constructs smaller angular deformation which also suggests that these implants represent a valid alternative to size-matched Targon and LCP for feline fracture osteosynthesis. The significantly lower F_M of explanted Targon may increase the risk of secondary fracture following implant removal.

目的 本研究的目的是 (1) 评估机加工短纤维环氧树脂 (SFE) 猫骨替代物 (FBS) 的弯曲结构特性，(2) 比较小角度稳定互锁钉 (I-Loc; Targon) 和锁定加压板 (LCP) 和 (3) 评估植入物移除对 FBS 弯曲强度的影响。

方法 第 1 部分：猫尸体股骨 ( n  = 10) 和 FBS ( n  = 4) 经历循环四点弯曲和载荷至失效。第 2 部分：骨折间隙 FBS 构造（n  = 4/组）以桥接方式稳定，使用 I-Loc 3 和 4、Targon 2.5 和 3.0、LCP 2.0 和 2.4，然后循环弯曲。第 3 部分：带导向孔的完整 FBS，模拟外植，（n  = 4/组）进行了破坏性弯曲试验。对弯曲柔量、角变形和破坏力矩 (F _M ) 进行了统计比较 ( p  < 0.05)。

结果 所有结果测量的天然骨和 FBS 相似（p  > 0.05）。I-Loc 4 和 LCP 2.0 分别观察到最小和最大的弯曲柔量和角变形（p  < 0.05）。虽然外植的 Targon FBS 具有最低的 F _M ( p  < 0.05)，但 I-Loc 和 LCP 构建体 F _M没有差异 ( p  > 0.05)。

结论 短纤维环氧树脂制成的 FBS 和天然猫股骨的相似弯曲性能表明，该模型可用于为猫长骨接骨而设计的植入物的机械测试。I-Loc 构造更小的角度变形，这也表明这些植入物代表了尺寸匹配的 Targon 和 LCP 的有效替代品，用于猫骨折接骨术。取出的 Targon显着降低的 F _{M可能会增加植入物移除后继发性骨折的风险。}