Finite element study on quantitative correlation between the displacement of osteotomy end and metatarsalgia during forefoot loading pattern in percutaneous minimal invasion surgery of hallux valgus

Abstract

Objective To investigate the quantitative correlation between the osteotomy end displacement and the occurrence of transfer metatarsalgia in percutaneous minimal invasion surgery of bunion during forefoot loading pattern. Methods The preoperative and postoperative finite element models of the foot were established during the forefoot loading pattern period of percutaneous minimal invasion surgery of hallux valgus, followed by simulation of the displacement of the osteotomy end of hallux valgus during percutaneous minimal invasion surgery. Thus, maximum pressure was obtained under the first and second metatarsal before and after the operation, and analyze the quantitative correlation between the displacement direction and displacement of the distal end of osteotomy and the occurrence of transfer metatarsalgia. Results The forefoot loading pattern of the gait cycle assessed in the finite element model before and after percutaneous minimal invasion surgery of hallux valgus showed that when the horizontal displacement is 4 mm, the correlation between the pressure x at the distal end of osteotomy (under the first metatarsal) and the corresponding pressure y under the second metatarsal is negative, the R value is -0.894, and the quantitative correlation is y=-0.6504x + 0.5232 with the increase of vertical displacement. When the vertical displacement is 4 mm, the stress under the first metatarsal increases with the increase in horizontal displacement. Conversely, the pressure under the second metatarsal decreases. Both have a high correlation with horizontal displacement, with R values of 0.981 and − 0.890. Also, in this interval, the pressure x at the distal end of osteotomy (under the first metatarsal) has the highest correlation with the corresponding pressure y under the second metatarsal head, the R value is -0.830, and the quantitative correlation equation is y=-0.4528x + 0.4159. Conclusion When the distal end of the first metatarsal osteotomy is shifted outwards by 4 mm and the metatarsal side is shifted by 4 mm through bone setting manipulation during operation, percutaneous minimal invasion surgery of hallux valgus can reduce or cure hallux valgus and complicated metatarsal pain during forefoot loading pattern and avoid the occurrence of transfer metatarsalgia after hallux valgus operation in traditional Chinese and Western medicine.