Combined 3D analysis of lower-limb morphology and function in children with idiopathic equinovarus clubfoot: A preliminary study

Abstract

tIntroduction: In children treated for idiopathic equinovarus clubfoot (EVCF), the relation between mor-phologic defects on clinical examination and standard X-ray on the one hand and functional abnormalitieson the other is difficult to objectify. The aim of the present study was to demonstrate the feasibility ofcombined 3D analysis of the foot and lower limb based on biplanar EOS radiographs and gait analysis.The study hypothesis was that this provides better understanding of abnormalities in form and function.Methods: Ten children with unilateral EVCF and “very good” clinical results were included. They under-went gait analysis on the Rizzoli Institute multisegment foot model. Kinematic data were collected forthe hip, knee, ankle and foot (hindfoot/midfoot, midfoot/forefoot and hindfoot/forefoot). Biplanar EOSradiographs were taken to determine anatomic landmarks and radiological parameters.Results: Complete acquisition time was around 2 hours per patient. No significant differences were foundbetween EVCF and healthy feet except for calcaneal incidence, tibiocalcaneal angle and hindfoot/midfootand hindfoot/forefoot inversion.Discussion: The feasibility of the combined analysis was confirmed. There were no differences in rangeof motion, moment or power between EVCF and healthy feet in this series of patients with very goodresults. The functional results are related to radiological results within the normal range. The protocolprovided anatomic and kinematic reference data. A larger-scale study could more objectively assess thecontribution of EOS radiography using optoelectronic markers.Level of evidence: II, low-power prospective study.