The plantar intrinsic musculature to support the arch during gait remains largely unknown. In gait, maintenance of the arch depends on both static ligamentous support and dynamic function of the plantar fascia, intrinsic muscles, and extrinsic muscles ( 27). Therefore, pain and instability remain the primary indications for the treatment of the pes valgus deformity. Without a secure lateral column, the foot functions with significant instability as significant talonavicular subluxation may often accompany cuboid abduction.
Lateral column instability, abduction or dorsiflexion of the cuboid on the calcaneus, may be more indicative of a pathologic condition. The presence of medial column instability may be less significant because of the medial column’s primary function as a pronating mobile adapter. In their milder forms, some aspects of medial column instability, such as talonavicular or naviculocuneiform sags, an elevated first metatarsal, and increased talar declination, may represent variations of physiologic flatfeet. The low arch foot is not at all synonymous with the unstable hypermobile pes valgus deformity. Subjective complaints are helpful in establishing the diagnosis of a pathologic pes valgus deformity however, it is the objective presence of instability that is the major factor in securing the diagnosis as pathologic.
Understanding that the pes valgus deformity can result in significant abnormality, the determination between physiologic form, requiring no intervention, and pathologic forms, often requiring treatment, becomes paramount. Is there any other structure in the body in which such a wide deviation from normal joint alignment is accepted as normal variation? Those authors who dismiss pes valgus deformity as trivial, normal, or something that is “outgrown” over time invariably neglect to connect this condition with the many disabling conditions it creates ( Fig. Is a flatfoot or a pes valgus deformity a pathologic condition that affects foot function? If so, how can we determine which patients to treat and how aggressively to treat them? What is the difference between a benign flatfoot and a pathologic pes valgus deformity? In the pediatric population, it is difficult to predict which of the flatfeet will progress to the disabling end-stage pes valgus condition in the adult. When confronted with the pes valgus deformity, certain questions must be raised. From the pediatric calcaneovalgus to the adolescent tarsal coalition and “adult acquired flatfoot,” its importance and management have been the subject of debate for many years ( 1). The flatfoot or pes valgus deformity is one of the most common problems challenging the foot and ankle surgeon today.