Symptomatic hallux valgus and dorsal bunion in adolescents with cerebral palsy: clinical and biomechanical factors.

AIM: The prevalence of severely symptomatic deformities of the first metatarsophalangeal (MTP) joint in adolescents with cerebral palsy (CP) requiring arthrodesis is unknown. Recent literature regarding these deformities is limited. We studied the presentation of severe, symptomatic deformities of the first ray in a large population of children and adolescents with CP and their association with gross motor function, CP subtype, and other musculoskeletal deformities. METHOD: We identified 41 patients with CP and a symptomatic deformity of the first MTP joint, managed by arthrodesis, from a large population based database over a 21-year period. Information recorded included demographics, CP subtype, Gross Motor Function Classification System (GMFCS), clinical presentation, and radiological features. RESULTS: Adolescents with spastic diplegia, at GMFCS levels II and III, were the most common group to develop symptomatic hallux valgus. In contrast, non-ambulant adolescents, at GMFCS levels IV and V, with dystonia or mixed tone, more commonly had dorsal bunions. INTERPRETATION: The type of first MTP joint deformity in patients with CP may be predicted by the type and distribution of movement disorder, and by GMFCS level. Specific patterns of associated musculoskeletal deformities may contribute to the development of these disorders and may provide a guide to surgical management. WHAT THIS PAPER ADDS: The prevalence of severe bunions requiring fusion surgery was 2%. The two types of bunion were hallux valgus and dorsal bunion. The type of bunion can be identified on both clinical and radiological grounds. The cerebral palsy subtype is predictive of the type of bunion.