Abstract: As the core functional units of weight-bearing and walking in the human body,the foot and ankle possess intricate structures and complex functions.Foot and ankle deformities often result from disorders of bones,muscles,tendons,and neurovascular structures.Their correction requires attention to both morphological reconstruction and dynamic functional balance.External fixation,with its advantages of minimal invasiveness,adjustability,and tissue regeneration,has become an important treatment modality for complex foot and ankle deformities.This article systematically elaborates the core principles of external fixation for correcting foot and ankle deformities-tissue distraction and regeneration based on the tension-stress principle along with stress control,as well as three derived treatment principles:the overall balance principle targeting a plantigrade foot,the individualized configuration principle guided by the apex of deformity,and the sequential regulation principle involving the time dimension.The article focuses on discussing the principles of external fixation for foot and ankle deformity correction,and the key roles of osteotomy and soft tissue balancing procedures in deformity correction.It systematically introduces clinical application strategies for soft tissue distraction correction,osteotomy and orthoplasty,and the Ilizarov external fixator.Treatment characteristics for foot and ankle deformities of different etiologies are specifically categorized and elaborated.The importance of the sequential treatment model of external fixation-orthosis-orthopedic insole and standardized postoperative rehabilitation is emphasized.The external fixation strategy for foot and ankle orthopedics,developed on the basis of Qin Sihe's concept of natural reconstruction,the Ilizarov technique,Paley's principles of orthopedic surgery,and traditional Chinese medicine theory of tendons and bones,provides a reference for standardized clinical application and serves as an important foundation for ensuring treatment efficacy.

Key words: external fixation, foot and ankle deformity, natural reconstruction concept, Ilizarov technique, soft tissue balance, sequential treatment, theory of sinew and bone