Development of foot length in children with congenital clubfoot up to 7 years of age: a prospective follow-up study

Abstract

Background Clubfeet are typically shorter than normal feet. This study aimed first to describe the development of foot length in a consecutive series of children with congenital clubfoot and second to relate foot length to development of relapse and motion quality. Methods Foot length was measured every 6 months in 72 consecutive children with congenital clubfoot (29 bilateral) aged from 2 to 7 years. The initial treatment was nonsurgical followed by standardized orthotic treatment. Foot length growth rate was calculated every half year. In children with unilateral clubfeet, the difference in foot length between the clubfoot and the contralateral foot was calculated. Motion quality was evaluated by the Clubfoot Assessment Protocol (CAP). Student’s t test, the Mann–Whitney U test and Spearman’s correlation were used for group comparisons. Bonferroni correction was used when multiple comparisons were performed. Results Clubfeet were smaller (P < 0.001) than reference feet at all ages but had a similar growth rate up to age 7. Unilateral clubfeet with greater difference in size compared with the contralateral foot at the first measurement, relapsed more frequently (P = 0.016) and correlated with poorer motion quality (r = 0.4; P = 0.011). Conclusions As previously reported, clubfeet were smaller than reference feet at all ages. The growth rate, however, was similar between clubfeet and reference feet. Children with unilateral clubfeet and greater foot length difference at 2 years of age had a higher tendency to relapse and poorer motion quality at 7 years of age, indicating that foot length could be used as a prognostic tool.

The foot drawing method: reliability of measuring foot length and outward rotation in children with clubfoot

“…4 ). Until the age of 7 years, feet with clubfeet grow about 1.2 cm per year [ 15 ]. The LoA observed in the Bland–Altman analysis indicate that changes > 6 mm are clinically detectable.…”

“…This implies that the FL could be useful for follow-up as the child grows. A previous study showed that FL at the age of 2 years could be used as a prognostic tool as children with unilateral clubfoot with smaller FL compared with the contralateral foot at 2 years of age had a higher tendency to relapse and poorer motion quality at 7 years of age [ 15 ]. Small clubfeet are also associated with difficulties at the initial correction and a higher tendency to relapse [ 10 , 11 , 18 ].…”

“…The other hand adjusts the thigh so that the tibial tuberosity is pointing straight forward. The foot is then placed down on the paper in its natural position [ 12 , 15 ]. A line is drawn around the foot holding the pen vertically, and the medial and lateral malleoli are marked on the paper.…”

“…The measurements are performed as follows. Foot length: FL is measured as described by Manousaki et al in 2021 [ 15 ] as the distance between two parallel lines, drawn distally and proximally on the footprint: The proximal line is perpendicular to an imaginary line passing through the middle of the hindfoot. The distal line is parallel to the proximal line.…”

“…A recent study of foot length (FL) in children with clubfoot showed that feet with clubfoot normally grow regularly over time and that feet with a shorter length than expected are more susceptible to relapse [ 15 ]. Thus, a reliable method of measuring the FL is of clinical importance.…”