Hallux valgus in equino-planovalgus foot deformity in children with cerebral palsy and its etiopathogenesis: a review (part 1)

BACKGROUND: Hallux valgus in children with cerebral palsy is an understudied problem. Treatment approaches are generally applied as a secondary measure, often after the child starts complaining at an older age following correction of contractures and other foot deformities. Moreover, there are no established methods for the early prevention or treatment of hallux valgus. Understanding the fundamental mechanisms of etiopathogenesis and biomechanical disturbances during gait is crucial for developing preventive and therapeutic strategies for this patient population. AIM: To analyze international studies of foot deformities in children with cerebral palsy and compare these findings with biomechanical studies in patients with idiopathic hallux valgus without neurological pathology. METHODS: Sixty-four scientific articles and publications retrieved from multiple databases without time restrictions were reviewed. RESULTS: Equinoplanovalgus foot deformity is a major etiopathogenetic factor in the development of hallux valgus in children with cerebral palsy. Biomechanical alterations associated with hallux valgus are characterized by limited dorsiflexion of the hallux, excessive dorsiflexion of the first ray, restricted supination of the hindfoot and midfoot, and increased plantar flexion of the ankle joint during the terminal stance phase. In equinoplanovalgus deformity, excessive pronation of the hindfoot and midfoot cannot be compensated because of the limited range of motion of the midtarsal joint, causing restricted midfoot supination and the inability to activate the locking mechanisms of the midfoot and forefoot during terminal stance. CONCLUSION: Any biomechanical disturbance within the complex multisegmental structure of the lower extremity that reduces hindfoot and midfoot supination, causes first ray eversion, and limits hallux dorsiflexion may contribute to deformity. The diversity of motor disorders, contracture patterns, and deformities in children with cerebral palsy indicates the need for further research aimed at identifying the specific factors involved in hallux valgus formation. Such findings may be beneficial for developing preventive and therapeutic strategies for early-stage deformities.