2023, Vol. 27 ›› Issue (27): 4283-4290

Construction of finite element model of hallux valgus foot and biomechanical analysis of the first metatarsophalangeal joint

Tang Zhi1, Lang Lei1, Wang Renyuan2, Gu Song2   

Abstract: BACKGROUND: Finite element model construction and biomechanical analysis make it possible to explore the formation of hallux valgus and the recovery of related structures and functions.  
OBJECTIVE: To establish a finite element model of moderate hallux valgus foot in the neutral position with load to analyze the changes of the angle of the first metatarsophalangeal joint and the stress distribution of the corresponding bones under the action of external forces of different parts and sizes.
METHODS: One female volunteer with moderate hallux valgus was selected, and CT image data were collected. The computer 3D imaging technology was used to conduct 3D finite element modeling to verify the validity of the model, and standardize the measurement method of the angle of the first metatarsophalangeal joint and the angle between the first and second metatarsal. Variables were controlled and the force was changed in turn to observe the changes of the above two angles, and analyze the stress distribution of the first metatarsal and proximal phalanx.  
RESULTS AND CONCLUSION: (1) An effective finite element model of moderate hallux valgus foot was established, which showed that a large stress concentration appeared in the first metatarsal. The distribution trend was from the medial middle and lateral middle of the bone body, gradually decreasing towards the dorsal and basal sides of the bone. (2) The feasibility of the method for determining the axis reference point of the first metatarsal, the second metatarsal and the proximal phalanx of the great toe was verified in finite element analysis. (3) The horizontal force acting on the lateral middle area of the distal phalanx of the first great toe has a direct effect on the change of the first metatarsophalangeal angle, but it has no linear effect. The regional force acting on the medial capsule of the metatarsophalangeal joint mainly affects the size of the first-second metatarsophalangeal angle. The horizontal force acting on the medial surface of the proximal metatarsal has little effect on the two angles.

Key words: hallux valgus, finite element model, biomechanical analysis, first metatarsophalangeal angle, first metatarsal