踝关节后外侧结构对踝关节稳定性的研究

Currently,the scientific research of ankle instability is mainly focusing on medial ankle instability and lateral instability caused by the medial ligament injury and lateral ligament injury respectively,but there are very few studies concerning posterior ankle structures. The clinic signs of ankle instability involving posteriolateral structure are found in our daily practice,therefore we presume whether there might be posterior ankle instability. We are continuing to collect so-called obvious posterior ankle instability patients,especially for the neurofunctional causes and congenital or developmental causes. These patients will be assessed by clinical examinations and laboratory tests.By means of integrated motional function tests,the stability maintaining effect of the posteriolateral muscles and tendons will be estimated.Thereby the diagnostic reliability of posterior ankle instability will be concluded. Meanwhile,in order to clinically mimic the posterior instability of the patient,the biomechanical experiments using normal cadaveric ankle specimen will be conducted.In the experiments, with the ankle in different positions, the posteriolateral ligaments will be cut off step by step.And thus we can understand the biomechanical characters of posteriolateral ankle ligaments using progressively circulating loading tests. We hope to find out the relationship of posteriolateral ankle ligaments and their stabilization functions,and we also anticipate to discover the correlation between these ligament structures and ankle instability.

目前对于踝关节不稳定的研究集中在踝关节内、外侧韧带结构上，对踝关节后方韧带结构涉及较少。在大量的临床实践的基础上，我们发现有些患者不稳定的体征偏重于后外侧。在对这些患者的手术中发现，其距腓前韧带完好，而后外侧韧带松弛。因此我们推测存在踝关节后方不稳定。我们拟在临床上积累后方不稳定的患者，特别是那些由于神经功能性或先天发育性畸形所导致的明显的后方不稳定患者，对其进行详细的临床检查，并通过四合一运动机能检查来判断后外侧肌肉、肌腱结构在维持稳定性方面的作用，术中观察其后外侧韧带结构的受损程度。同时，我们拟采用踝关节尸体标本进行生物力学检测，模拟临床上后方不稳定的力学表现，在踝关节不同位置下依次切断踝关节后外侧韧带结构，通过逐级加载的方法来研究踝关节后外侧韧带的生物力学特性，了解踝关节后外侧韧带在维持关节稳定性方面的作用，探讨这些韧带结构与踝关节不稳定之间的关系，以及踝关节后外侧不稳定的发生机制。

踝关节扭伤是最常见的运动损伤，急性踝关节扭伤患者中，即使接受了整个疗程的正规保守治疗，仍有10-40%患者会发展成为慢性踝关节不稳定。长期慢性踝关节不稳定会导致踝关节炎的严重后果。踝关节后外侧不稳定是由于踝关节后方或后外侧的稳定结构损伤而引起。本项研究通过离体新鲜踝关节尸体标本的生物力学测试方法，研究踝关节后外侧结构在不同姿势加载不同方向、强度的负荷后的反应，通过测定骨骼间相对位移，研究踝关节后外侧韧带对于踝关节稳定性所起作用。研究发现胫腓下联合后韧带、跟腓韧带对于维持胫腓下联合距离至关重要，跟腓韧带作用大于胫腓下联合后韧带。同时，跟腓韧带对于维持外踝与距骨间距离最为重要；下胫腓后韧带对于维持外踝与跟骨间距离、胫骨远端与跟骨间距离、距骨与跟骨间距离均至关重要。另外通过建立相应有限元模型验证，同样发现跟腓韧带、胫腓下联合后韧带对于维持踝关节后外侧稳定性起重要作用。同时我们选取了23例踝关节后外侧不稳定患者，术前应力位下前抽屉试验距骨前移平均值为13.2±4.5mm，术后为4.7±2.4mm，术前患者距骨内翻角度平均值为15.6.2±4.1度，术后为5.1±2.5度。两组数据术前术后对比，差异均有统计学意义。患者足踝部AOFAS评分从术前平均65.4±6.3分改善到术后平均93.5±5.6分。