Muscle-tendon properties assessed by three-dimensional ultrasound in clinically well-performing clubfoot patients treated with the Ponseti method.

Abstract

Clubfoot is a congenital birth defect affecting musculoskeletal tissues of the affected lower legs, resulting in the typical appearance and changes in muscle-tendon properties. These properties change during development due to growth and activity, but how these properties differ across ages in clubfoot remains not fully understood. This study aimed to describe plantarflexor muscle-tendon volumes between affected and unaffected legs in unilateral clubfoot patients and explore the relationship between muscle volume and age. A prospective cross-sectional study was performed on unilateral clubfoot patients treated with the Ponseti method. Muscle-tendon volumes of the medial and lateral gastrocnemius, soleus, and Achilles tendons in both affected and unaffected legs of clubfoot patients were assessed using ultrasound. Volumetric reconstructions were made using three-dimensional ultrasound (3DUS). Statistical analyses compared muscle-tendon volume between legs and their relationship with age. A total of 25 clubfoot patients with good clinical status aged between 2.0 and 11.8 years were analyzed. Smaller plantarflexor muscle and greater Achilles tendon volumes were found in the affected leg compared to the unaffected leg. Furthermore, age was not significantly related to absolute muscle volume difference between the legs. The findings of this study indicate that changes in muscle and tendon volume are present in treated clubfoot patients of multiple ages, enhancing understanding of their muscle-tendon morphology. The clinical significance of muscle-tendon alterations and their adaptation to targeted interventions remains to be established. Further research should investigate the relationship between muscle-tendon morphology and clinical status of (relapsed) clubfoot patients.