胫骨平台切模的固定方法对胫骨平台截骨在内外翻和前后倾方面影响的研究

目的探讨胫骨平台切模的固定方法对胫骨平台截骨在内外翻和前后倾方面的影响,比较不同数目、不同位置钉子固定的平台切模在相同外力下发生的内外翻和前后倾的差异。方法以12根左侧下肢假骨和一个左侧半骨盆假骨为标本,连接红外线计算机导航系统,固定标本,固定股骨及胫骨发射器,输入数据,分别以不同数目及位置的钉固定平台切模于假骨,通过切模槽内用锯片予以相同外力,记录后倾角度、内外翻角度的变化。结果用2根钉固定胫骨平台切模前后倾角度摆幅平均超过3°,最高超过5°,内外翻角度摆幅平均超过1°,最高超过3°,3根钉固定平台不论在前后倾还是内外翻方面的稳定性都非常明显好于2根钉固定。4根钉固定在前后倾方面稳定性好于3根钉固定,内外翻方面的稳定性无明显差异。结论胫骨平台切模的固定方法对胫骨平台截骨在内外翻和前后倾方面有明显影响,3根钉固定稳定性较好且易于操作,推荐采用3根钉固定。

A study on the effects of tibial cutting jig fixation on the titial osteotomy of varus-valgus and anteroposterior slope

Objective To investigate the effects of tibial cutting jig fixation on the titial osteotomy of varus-valgus and anteroposterior slope. Different numbers of pins in different positions were used to fix the cutting jig onto the proximal tibia, the changes in varus-valgus position and anteroposterior slope were measured after standardized stress was applied to the tibial cutting jig. Methods 12 pieces of synthetic left lower limb and one synthetic left hemipelvis were used. The specimens were set up, optical arrays were fixed to the femur and tibia, the anatomical data points were then registered into a computer navigated system. Tibial cutting jigs were fixed to the tibia by different number of pins in different positions. Tile relative movements of the cutting jig were then measured after standardized stress was applied to a saw blade inserted into the slot of the cutting jig. Results If using two pins, the anteroposterior slope of the tibial cutting jig moved by more than 3 degrees; the varus-valgus position moved by more than one degree and might exceed 3 degrees. The movements were significantly reduced by inserting three pins instead of two. Using 4 pins, the movements of the anteroposterior slope could be further reduced. Conclusions There were the effects of methods of tihial cutting jig fixation on the varus-valgus position and anteroposterior slope. Using 3 pins is recommended because it can significantly reduced the movements of the anteroposterior slope and the varus-valgus position.