Work

Intra- and interobserver reliability of femoral torsion measurement using ultrasound with inertial sensor in children aged 7–9 years

Year: 2025

Type: article

Abstract: Accurate assessment of femoral torsion in children is crucial for diagnosing and managing musculoskeletal conditions. Ultrasonography offers a non-invasive, cost-effective alternative to traditional imaging, but its reliability and validity remain underexplored. To evaluate the reliability of two ultrasonography-based methods—single- and dual-reference—for measuring femoral torsion in children aged 7–9 years, using an inertial sensor attached to the transducer. Additionally, the study examined inter-method differences, assessed biomechanical consistency via correlation with hip rotation, and evaluated children’s satisfaction with the procedure. A prospective study was conducted with 20 children (40 femora) between November 2023 and December 2024. The single-reference method assessed the proximal femur; the dual-reference also included the femoral condyles. Intra-observer reliability was tested with repeated measurements two weeks apart; inter-observer reliability was assessed between two independent raters. Intraclass correlation coefficients (ICC) and Spearman’s rho were used to evaluate reliability. Satisfaction was assessed via a five-level Faces Scale. Both the single-reference and dual-reference methods demonstrated excellent reliability, with intra-observer ICC (2,1) values of 0.962 and 0.952, and inter-observer values of 0.915 and 0.914, respectively. The single-reference method consistently produced higher torsion values (mean differences: 9.21° and 8.45°), though results were strongly correlated. Correlations with hip rotation ranged from ρ = 0.666 to −0.676 (P <.001). Satisfaction was high: 95% reported no or mild discomfort, 90% found the procedure comfortable, and 75% were willing to repeat it. Ultrasonography combined with inertial sensors provides a reliable, non-invasive method for assessing femoral torsion in children, with good clinical feasibility and high acceptance. • Both ultrasound-based methods for femoral torsion demonstrated excellent intra- and inter-observer reliability. • The single-reference method consistently yielded higher FT values, suggesting systematic differences. • FT values showed moderate correlation with hip rotation range, supporting biomechanical coherence. • Children reported high comfort and willingness to repeat the ultrasound-based assessment.

Source: Gait & Posture

DOI: 10.1016/j.gaitpost.2025.110046

Authors: Xavier Ruiz-Tarrazo, Andrea Coda, Carla Sánchez-Dueñas, Salomé Tárrega, Carles Escalona-Marfil

Institutions: Universitat de Vic - Universitat Central de Catalunya, Hunter Medical Research Institute, University of Newcastle Australia, Universitat Autònoma de Barcelona, Universitat de Girona

Language: English

Topic: Hip disorders and treatments

Subfield: Surgery

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: hybrid

Estimated APC paid: $3,510