抗滑动钢板治疗LetenneurⅠ型Hoffa骨折的生物力学研究

Anti-sliding plating for Letenneur type I Hoffa fractures

目的通过对LetenneurⅠ型Hoffa骨折使用抗滑动钢板（使用锁定螺钉和松质骨螺钉两组）与松质骨螺钉（由前向后和由后向前固定两组）四种固定方式固定LetenneurⅠ型Hoffa骨折的力学进行比较，探讨抗滑动钢板在Hoffa骨折中的应用。方法20个模型股骨造成相同的LetenneurⅠ型Hoffa骨折，随机分为四组，每组5个。A组使用由前向后两枚松质骨螺钉固定，B组使用由后向前两枚松质骨螺钉固定，c组使用抗滑动钢板加锁定螺钉固定，D组使用抗滑动钢板加松质骨螺钉固定。所有标本通过循环负荷试验和最大失效负荷试验，对最大位移平均值和最大失效负荷平均值进行比较。结果在循环负荷试验中，第10、100、1000、10000周期下，四组骨折块最大位移平均值间差异均无统计学意义（P〉0．05）。而在最大失效负荷试验中，A组[（1224±72）N]和C[（2183±227）N1、D组[（2124±235）N]差异有统计学意义（P〈0．05），B组[（1405±235）N]和C、D组差异有统计学意义（P〈0．05），A组和B组、C组和D组差异均无统计学意义（P〉0．05）。结论对于简单的Hoffa骨折，固定后初期给予适当保护条件，四种固定方式都能取得满意的力学稳定性和强度。但对于预计骨折愈合时间长、体质量指数大、患者依从性差的患者，建议使用抗滑动钢板。

Objective To explore the anti-sliding plating for Hoffa fractures by comparing the mechanical properties of anti-sliding plates and cancellous bone screws. Methods Twenty cases of the same type of Hoffa fracture in the model femur were randomly divided into 4 even groups. Group A used 2 antegrade cancellous bone screws; Group B used 2 retrograde cancellous bone screws forwards; Group C used anti-sliding plate and locking screw fixation; Group D used anti-sliding plate and cancellous bone screw fixation. All the samples were subjected to the cycle fatigue and the maximum failure load tests. Results The fatigue test revealed no significant difference in the mean maximum displacements at the 10, 100, 1000, 10 000 cycles between the 4 groups. In the maximum failure load test, there were significant differences between Group A [ （1224 ± 72） N] and Groups C and D [ （2183 ± 227） N and （2124 ± 235） N], as well as between Groups B [（1405 ±235） N] and Groups C and D; there was no significant difference between Group A and Group B, neither between Group C and Group D. Conclusions In the initial period after secure fixation for Hoffa fractures, anti-sliding plates and cancellous bone screws can all provide satisfactory mechanical stability and strength. But anti-sliding plating is recommended for cases of long healing expected, patients with great body mass index, and patients with poor compliance.