125. CONGENITAL PARALYTIC EQUINOVARUS CLUB FOOT OF UNKNOWN AETIOLOGY: A MULTICENTRIC ANALYSIS OF 42 FEET WITH A NEW CLINICAL ENTITY

Abstract

Purpose of the study: Among the causes of secondary congenital equinovarus club foot, neurological disorders predominate. The entity we examine here corresponds to irreversible pure motor paralysis with no sensorial disorder affecting the lateral compartment predominantly and sometimes associated with involvement of the anterior compartment. There is no literature on this entity. Beyond the question of the aetiology, the demonstration of this pathological condition can modify therapeutic strategy in order to prevent recurrence.

Material and methods: We examined 42 congenital equinovarus club feet with persistent pure motor paralysis involving the lateral compartment and sometimes the anterior compartment with a mean 10 years follow-up. The Dimeglio classification was used and an analytical muscle score was noted for each patient. Complementary tests included an electromyogramme when possible. Conservative treatment was the rule either using a functional method or the Ponseti method; surgery was then proposed when necessary for posteromedial release with or without palliative muscle transfer. The following procedures were performed: posteromedial release (n=33) and muscle transfer (n=26): tibialis posterior (n=22), tibialis anterior (n=3); hemisoleus (,n=1); tibialis posterior associated with flexor digitorum longus (n=3).

Results: Conservative treatment was used for all feet but all presented recurrence and required secondary surgery (33 posteromedial releases and 26 muscle transfers).

Discussion: This study opens the discussion on the similarity between idiopathic and arthrogryoposis club foot since the electromyography sometimes reveals an anomaly of the anterior horn. Thus club foot with pure motor and persistent paralysis involving the lateral and/or anterior compartment will not respond sufficiently to nocturnal contention if an adapted muscle transfer is not associated.

Conclusion: Muscle transfer to reactivate dorsal flexion of the foot enables a better functional outcome. First intention conservative treatment can be instituted while waiting for potential recovery. If the paralysis persists beyond one year, muscle transfer is indicated before the deformity recurs and requires an associated posteromedial release.