Objective The aim of this study was to investigate the effects of an induced incomplete ossification of the humeral condyle (IOHC) lesion on ex vivo canine humeral condylar biomechanics.

Study Design Nine paired cadaveric elbows were collected from mature dogs weighing between 20 and 25 kg. Left and right limbs were randomized to IOHC or normal groups. Limbs were prepared for mechanical testing; ligaments were preserved and an IOHC lesion was created. Elbows were potted, positioned into a biomaterials testing system at an angle of 135 degrees and axially loaded to failure at a rate of 30 mm/minute.

Results Induced IOHC lesions reduced peak load (p = 0.02) when compared with an intact humerus. There was no difference between stiffness (p = 0.36) of intact humeri or humeri with an induced IOHC lesion. An induced IOHC lesion increased (p = 0.012) the probability of intracondylar fracture under load.

Conclusion Cadaveric humeri are weakened by the creation of an intracondylar osteotomy and fractures secondary to induced IOHC are similar to spontaneous humeral condylar fractures. These findings support the hypothesis that naturally occurring IOHC weakens the humeral condyle and may predispose to humeral condylar fracture.

目的 本研究的目的是研究肱骨髁（IOHC）损伤诱导的不完全骨化对离体犬肱骨髁生物力学的影响。

研究设计 从体重在 20 到 25 公斤之间的成年犬身上收集了九个成对的尸体肘部。左右肢随机分为 IOHC 组或正常组。四肢准备进行机械测试；韧带被保留并产生了 IOHC 病变。弯头被灌封，以 135 度角放置在生物材料测试系统中，并以 30 毫米/分钟的速度轴向加载至失效。

结果 与完整的肱骨相比， 诱导的 IOHC 病变降低了峰值负荷 ( p = 0.02)。 完整肱骨的刚度 ( p = 0.36) 或具有诱导 IOHC 病变的肱骨之间没有差异。诱发的 IOHC 损伤增加了 ( p  = 0.012) 负载下髁内骨折的可能性。

结论 髁内截骨术会削弱尸体肱骨，继发于诱导 IOHC 的骨折类似于自发性肱骨髁骨折。这些发现支持自然发生的 IOHC 削弱肱骨髁并可能导致肱骨髁骨折的假设。