Simultaneous Correction of Juvenile Hallux Valgus and Flexible Flatfoot in Children: Outcomes of Combined First Metatarsal Hemiepiphysiodesis and Calcaneal-Stop Procedure

<b>Background/Objectives</b>: Juvenile hallux valgus (JHV) and flexible flatfoot (FFF) often coexist in children, yet their combined surgical management remains poorly explored. This study evaluates clinical and radiographic outcomes following a simultaneous approach using lateral hemiepiphysiodesis of the first metatarsal (LHFM) and calcaneal-stop (C-Stop) procedures in skeletally immature patients. <b>Methods</b>: A retrospective cohort of 24 bilateral patients (48 feet) aged 10-12 underwent LHFM and C-Stop between 2017 and 2023. Radiographic evaluation included Hallux Valgus Angle (HVA), Intermetatarsal Angle (IMA), Meary's angle (MA), and transverse TaloCalcaneal (Kite's) Angle (tTCA). The Foot and Ankle Disability Index (FADI) and the Tegner Activity Scale (TAS) were administered at the most recent follow-up and complications were recorded. <b>Results</b>: The mean follow-up was 3.7 years. Postoperative radiographs showed significant improvements in all parameters, with correction inversely correlated to baseline deformity severity. Full normalization of flatfoot parameters was achieved in 68.8% of feet, with mild residual deformity in the remainder. Males showed greater radiographic correction than females. IMA and HVA improved in most cases, reaching full normalization in 53.1% and 50% of feet, respectively. Clinically, all patients showed corrected hindfoot alignment and medial arch restoration; 90% achieved the maximum FADI score and 88% resumed recreational sports. Two cases of screw migration occurred, with one revision; no further complications were reported. <b>Conclusions</b>: Simultaneous correction of FFF and JHV using C-Stop and LHFM proved effective, yielding significant radiographic improvements and excellent functional outcomes in most cases, with minimal complications. However, full hallux alignment was achieved in only half of the cases, suggesting that additional distal metatarsal procedures may be needed for more severe deformities.