The orthotic treatment of juvenile hallux valgus
Pronation of the foot is proposed as a possible aetiological factor in hallux valgus. Root type foot orthoses have been shown to restrict foot pronation and therefore have been used to treat hallux valgus. A controlled prospective 3 year trial tested the value of a Root foot orthosis in the treatment of juvenile hallux valgus. Six thousand nine year old Kettering children were screened for hallux valgus using goniometric and clinical examination. A clinical diagnosis of hallux valgus was made in 150 children and confirmed using radiography in 122 cases. Pes planus was as common in children with hallux valgus as children with no hallux valgus. The biomechanical examination of hallux valgus children revealed that a plantarflexed first metatarsal was the only consistent biomechanical abnormality. The sagittal plane position of the first metatarsal did not however relate to the degree of metatarsus primus varus which is apparent in the unaffected feet of children with unilateral hallux valgus prior to the development of hallux valgus in both feet. The 122 children with hallux valgus were randomised into a non-treatment control group and a treatment group where Root foot orthoses were worn for three years. Compliance and fit of the orthoses were checked every 4 to 6 months. At the end of the 3 year period, 96 children underwent a second weight bearing radiograph of both feet. The same observer measured the intermetatarsal and hallux valgus angle on all radiographs. The hallux valgus had deteriorated significantly in both the control and treatment group. Though not statistically significant, the deterioration was slightly more marked in the treatment group. A Root foot orthosis prescribed to restrict foot pronation will not significantly alter the progression of juvenile hallux valgus. This may indicate that pronation of the foot is not an important aetiological factor in juvenile hallux valgus.