Normative data on lower extremity entheseal tendon thicknesses in healthy children: an ultrasound study correlating age, sex, anthropometry.

Objectives: This study aims to establish normative data on lower extremity entheseal tendon thicknesses in healthy children and examine correlations with age, gender, and anthropometric measures using musculoskeletal ultrasound. The secondary objective of the study is to investigate the power Doppler properties of entheseal tendons.

Methods: A total of 192 healthy children, aged 5-18 years, participated in this cross-sectional study. Participants underwent detailed physical and ultrasonographic examinations. Entheseal tendon thickness measurements were taken from five specific regions: distal quadriceps tendon (DQT), proximal patellar ligament (PPL), distal patellar ligament (DPL), Achilles tendon (AT), and plantar fascia (PF). Correlations between thicknesses and age, weight, height, and body mass index (BMI) were analyzed. Intra-tendinous vascularity was evaluated using power Doppler. Interobserver and intraobserver agreements were assessed using intraclass correlation coefficients (ICC).

Results: Normative data on lower extremity entheseal tendon thicknesses according to age, weight, height, and BMI have been established. Significant positive correlations were found between thicknesses and age, weight, height, and BMI. Weight was identified as the most influential factor, particularly for the DPL and AT. Right side tendons (AT and PF) are statistically thicker. Minimal Doppler activity was detected in 10.6% of the entheseal DQTs in the group of children aged 5-9 years. The study achieved high to excellent interobserver and intraobserver agreement.

Conclusion: This study examined the ultrasonographic characteristics of lower extremity entheseal tendons in healthy children using B-mode and power Doppler, provided normative data on their thicknesses, and demonstrated significant correlations between thicknesses and age, sex, and anthropometry.