3.5和4.5mm钢板固定治疗胫骨平台双髁骨折的生物力学比较研究

A biomechanical comparison between locked 3.5 and 4.5 mm plates for treatment of simple bicondylar tibial plateau fractures

目的评价3.5和4.5 mm钢板固定治疗胫骨平台双髁骨折的生物力学差异。方法将24个复合人工骨模型分为胫骨平台内、外髁骨折(SchatzkerⅤ型)组和胫骨平台髁骨折伴干骺端分离骨折(SchatzkerⅥ型)组,每组12个。每组6个模型采用3.5 mm胫骨近端锁定钢板固定,6个用4.5mm胫骨近端锁定钢板固定。测试方法包括施加500 N垂直载荷、荷载循环10 000次及固定失效时荷载。结果 SchatzkerⅤ型模型10、100、1 000和10 000次荷载循环后,钢板向下位移和塑性变形比较差异无统计学意义。4.5 mm钢板固定失效时荷载更高(P=0.05)。SchatzkerⅥ型模型10、100、1 000和10 000次荷载循环后,钢板向下位移和弹性变形比较差异有统计学意义。4.5 mm钢板固定失效时轴向荷载更高,但差异无统计学意义(P=0.214)。结论 3.5和4.5 mm固定钢板在循环载荷、弹性和塑性变形方面比较,差异无统计学意义。但3.5 mm钢板尺寸小、耗损低,从生物力学角度考虑是胫骨平台双踝骨折重建的较好选择。

[Objective] To biomechanically assess any significant differences between 3.5 and 4.5 mm locked tibial plateau plates in a simple bicondylar fracture model. [Methods] A total of 24 synthetic compo site bone model （12 Schatzker V and 12 Schatzker VI） specimens were tested. In each group, 6 specimens were fixed with a 3.5 mm locked proximal tibia plate and 6 specimens were fixed with a 4.5 mm locking plate. Testing measures included axial ramp loading to 500 N, cyclic loading to 10,000 cycles and axial load to failure. [Results] In the Schatzker Vmodel, there were no significant differences in the inferior displacement or plastic deformation after 10, 100, 1,000 and 10,000 cycles. In regards to axial load, the 4.5 mm plate exhibited a significantly higher load to failure （P= 0.05）. In the Schatzker VI model, there were significant differences in the inferior displacement and elastic deformation after 10, 100, 1,000 and 10,000 cycles. In regards to axial load, the 4.5 mm plate again exhibited a higher load to failure, but there was no significant difference （P= 0.214）. [Conclusions] In the advance of technology, periarticular locking plate technology has offered an invaluable option in treating bicondylar tibial plateau fractures. In our testing construct, the smaller and lower-profile 3.5 mm plate seems to be a biomechanically sound option in the reconstruction of bicondylar plateau fractures.