Pediatric Pes Planovalgus and Femoral Antetorsion: Understanding a Biomechanical Unit: A Narrative Review of the Proximal-to-Distal Kinetic Chain in Childhood Flatfoot

Background: Pes planovalgus affects 44–54% of preschool children and represents one of the most common concerns in pediatric orthopedic practice. Aim: This narrative review synthesizes the evidence linking increased femoral antetorsion to pediatric flatfoot deformity. Methods: A comprehensive literature search was conducted in PubMed, Scopus, and Web of Science through January 2026. The initial search yielded 847 records; after screening, 52 studies were included, 29 of which are directly cited. Search terms included combinations of: “femoral antetorsion” OR “femoral anteversion” AND “flatfoot” OR “pes planovalgus” AND “children” OR “pediatric”. Results: Strong correlations exist between flatfoot and increased internal hip rotation (as a proxy for femoral antetorsion) in preschool children (r = 0.53–0.77), suggesting an association, though direct causation remains unproven. Both deformities share similar developmental trajectories with spontaneous resolution by school age. The biomechanical model proposes that elevated antetorsion reduces gluteus medius moment arms by 40–50%, necessitating compensatory hip internal rotation; however, this derives from computational models and cerebral palsy populations, with limited direct validation in typically developing children. Femoral derotation osteotomy improves the foot progression angle, though transfer efficiency is incomplete (~54% of surgical correction manifests distally). Conclusions: Femoral antetorsion and pes planovalgus are strongly associated in preschool children, though whether this represents a direct mechanistic cascade or parallel manifestations of common developmental factors remains uncertain. This understanding supports watchful waiting in preschool children and, in persistent cases, prioritizes the assessment of the entire rotational profile before intervention.