PurposeThis study aimed to investigate the efficacy of orthopedic insoles, specifically three-dimensional (3D)-printed orthopedic insoles, for treatment of symptomatic flexible flatfoot in school-age children. MethodsA systematic review of PubMed and China National Knowledge Infrastructure (CNKI) from database inception to March 2024 was conducted to determine additional studies. This single-center study included 38 participants, including 20 who chose ordinary orthopedic insoles and 18 who chose 3D printed orthopedic insoles, presented from January 2021 to December 2022. Pain symptom relief was compared between the two groups after 1 year of follow-up. ResultsA systematic review identified an additional six publications, involving 206 samples, and meta-analysis indicated that the force-bearing area, arch index, and heel valgus angle after treatment were 0.74 (95 % confidence interval [CI]: 0.65–1.01), 0.20 (95 % CI: 0.03–1.35), and 0.10 (95 % CI: 0.03–0.28) of those before treatment, respectively. The 1-year follow-up study revealed that because of its good comfort, 3D printed orthopedic insole can significantly improve the wearing time of both male (P < 0.001) and overweight participants (P < 0.001) and significantly reduce the pain score (P = 0.032). ConclusionsOrthotic insoles are effective in helping the recovery of flexible flatfoot. Among them, the 3D-printed orthopedic insoles have a better effect on relieving pain symptoms and have a great development potential.