Abstract:Objective To analyze the biomechanics of modified McBride procedure combined with double metatarsal osteotomy to treat hallux valgus in adolescents. Methods Forty-five juvenile hallux valgus patients admitted to our hospital from April 2015 to August 2018 were randomly divided into control group (22 cases) and research group (23 cases). The control group was treated with modified McBride procedure, while the research group was treated with modified McBride procedure combined with double metatarsal osteotomy. The podiatry X-ray was taken to measure the hallux valgus angle (HVA), the first-second intermetatarsal angle (IMA) and the fourth-fifth intermetatarsal angle (IM 4-5) before and one year after the operation. The forefoot function was evaluated by American Orthopedic Foot and Ankle Society Score (AOFAS), and the pain was assessed by visual analogue score (VAS). The plantar pressure distribution was measured by plantar pressure measurement system. Results After 1 year of follow-up, the HVA, IMA, IM 4-5 and VAS of the research group were lower than those of the control group, and AOFAS of the research group was higher than that of the control group (P?0.05). The mean pressure peak of the first metatarsal bone in the research group was significantly lower than that in the control group (P?0.05), but there was no significant difference in the mean pressure peak of the other regions (P?>?0.05). Besides, the average impulses of the second to fifth phalanges, first metatarsal bone, medial heel and lateral heel in the research group were significantly lower than those in the control group (P?0.05), but there was no significant difference in the average impulse of other regions (P?>?0.05). Conclusions The modified McBride procedure combined with double metatarsal osteotomy may improve hallux valgus deformity by reducing the pressure and load of the first metatarsal region, which exhibits good prospects for clinical application.