先天性马蹄内翻足矫形后距舟骨畸形的成因分析

目的]探索先天性马蹄内翻足经矫形后距、舟骨畸形的病理成因与生物力学基础。方法]在动物模型的基础上和采用CT图像重建足内侧纵弓和外侧纵弓的三维模型，采用有限元方法建立正常足与马蹄足内侧纵弓（第2序列）的生物力学模型。结果]距骨在胚胎阶段即出现发育不良，距骨、跟骨间重叠不良和跟骨内翻；正常足与异常足第2序列的应力主要集中于第2跖骨与足底腱膜。足弓结构异常、跖筋膜切断都将加剧应力集中程度、增加足弓背屈变形，应力传导导致舟骨、距骨变形。结论]先天性马蹄内翻足在胚胎发育期即有足的马蹄内翻且畸形程度随生长发育而逐步加重，距骨在胚胎阶段即出现发育不良。距、舟骨继发畸形与经矫形后应力集中、足弓背屈变形有关。

Analysis of causing of talus and navicular abnormalities after corrections of congenital clubfoot

Objective ] To explore the possible pathological correlation and biomechanics basis of congenital clubfoot. Method] Eighty-three female Wistar rats were administered with retinoic acid on the 10^th day after pregnancy. From February 2001 to February 2004,15 feets were analyzed with finite element analysis and biomechanical experiment study. Result] Persistence of the embryonic position of the talus and tibia in fetuses was observed. Poor overlapping between talus and calcaneus was seen. Abnormal stress conduction may result in talus and navicular distortion. Conclusion ] Congenital clubfoot is correlated closely with defects of neural tube and spinal cord. Talus is hypogenesis during embryonic stage and the abnormalities extents are aggravated with following growth.