微型钛板不同放置位置固定足跖骨骨折的生物力学研究
Biomechanical Study of Mini-Titanium Plate in Different Placement for Fixing Metatarsals Fractures

目的：对比研究微型钛板不同放置位置固定足跖骨骨折的相关生物力学性能，为提高微型钛板治疗手足部骨折的临床疗效提供可靠的生物力学依据。方法：采集成人足部标本，男3例，女3例，年龄23岁~50岁，平均41岁，排除足骨明显损伤、骨病、骨质疏松等。剥离皮肤、肌肉、肌腱等软组织后用生理盐水浸湿纱布包裹双层塑料袋密封，于？20摄氏度冰箱保存备用。实验前将足冷冻标本置于室温下自然解冻，制成第2~5跖骨标本54个(除外第一跖骨)。制作骨折(横行、中段)模型。实验模型建立后分两组：A组和B组。A组采用Medicon2.0系列四孔直型微型钛板放置于跖骨背面固定，B组放置于跖骨侧面固定。将标本夹锁于微型特制夹具上，安置于微机控制电子万能材料试验机、扭转试验机测试台内，进行三点弯曲、拉伸和扭转实验，测试其生物力学特性并进行比较。结果：生物力学测试结果：微型钛板背面组三点弯曲强度测量明显高于侧面组(p < 0.05)，轴向拉伸、扭转强度测量对比无显著差异(p > 0.05)。结论：微型钛板固定跖骨骨折三点弯曲强度比较：背面放置大于侧面放置，微型钛板内固定放置位置不同影响骨折固定的生物学强度。

Objective: To study relevant biomechanical performance of mini-titanum-plate in different placement of treatment of foot fracture, and evaluate the effects of mini-plate applied to fractures of hands and feet. Method: Six adult cadaver foots made in metatarsals fracture model (transverse fracture of the middle, from the second toe to the fifth toe), including 3 males and 3 females, with an average of 41 years old (ranged from 23 to 50 years old). All 54 Metatarsals were divided into 2 groups randomly and made inner fixed with Medicon mini-plate in dorsal (A group) and lateral (B group) side according grouping respectively then fracture model fixed in special fixture applied by Electronic universal testing machine and Torsion testing machine for biomechanical test. Biomechanical tests including axial com- pression, tension, then A and B group. Tree-point bend, and torsion were made in each model, then compared between. Result: Comparison in biomechanics: the strength of three point bend in dorsal group is higher than lateral group obvi- ously (p < 0.05)，and the strength of axial compression, tension and torsion test showed no significant differences be- tween the two groups (p > 0.05). Conclusion: The comparison of the strength of three-point bend for metatarsals frac- ture fixed by Mini-plate: the strength of dorsal placement is higher than lateral placement and the different placement affects biomechanical strength.