Ultrasound Elastography of the Triceps Surae and Achilles Tendon in Children with Flatfoot

Background. Hypermobile flatfoot with short Achilles tendon and flexible planovalgus foot are clinically heterogeneous forms of flatfoot in children. Traditional diagnostic methods are not sensitive enough to reflect the mechanical properties of the triceps surae and Achilles tendon, sufficient for differential diagnosis and personalized management.

Objective: To compare the elastographic parameters of the triceps surae and Achilles tendon in children with hypermobile flatfoot with short Achilles tendon and flexible planovalgus foot using shear wave ultrasound elastography (SWE).

Methods: Prospective cohort study included 222 children: 118 children with hypermobile flatfoot with short Achilles tendon and 104 children with flexible flatfoot. A standardized SWE protocol was used to assess tissue stiffness in the medial and lateral gastrocnemius, soleus, tendon-muscle junction, and Achilles tendon.

Results. Children with hypermobile flatfoot with short Achilles tendon showed significantly higher stiffness ​​of the soleus muscle, medial gastrocnemius and Achilles tendon, as well as decreased stiffness at the tendon-muscle junction. Medial head stiffness correlated positively with pain (ρ=0.54; p<0.001) and negatively with dorsiflexion (ρ=–0.60; p<0.001).

Conclusion. SWE revealed significant changes in the mechanical properties of the triceps surae and Achilles tendon in children with different forms of flatfoot. The data obtained can be considered as a basis for further studies of the pathogenesis of various forms of flatfoot in children and differentiated approach to the management.