Shear Wave Tensiometry Can Detect Loading Differences Between Operated and Unaffected Achilles Tendon
Authors: Alessandro Schneebeli 1, 2, Marco Barbero 2, Giuseppe Filardo 3, 4, Enrique Testa 3, 4, Martin Riegger 3, 4, Alessandro Sangiorgio 3, Corrado Cescon 2, Emiliano Soldini 5, Deborah Falla 1
- Centre of Precision Rehabilitation for Spinal Pain (CPR Spine), School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
- Rehabilitation Research Laboratory 2rLab, Department of Business Economics, Health and Social Care, University of Applied Sciences and Arts of Southern Switzerland, Manno, Switzerland
- Service of Orthopaedics and Traumatology, Department of Surgery, EOC, Lugano, Switzerland
- Faculty of Biomedical Sciences, Universita della Svizzera Italiana, Lugano, Switzerland
- Competence Centre for Healthcare Practices and Policies, Department of Business Economics, Health, and Social Care, University of Applied Sciences and Arts of Southern Switzerland, Manno, Switzerland
Journal: Foot & Ankle International - November 2023, Online First (DOI: 10.1177/10711007231201156)
Background: The clinically relevant healing process of a ruptured and repaired Achilles tendon (AT) can last more than a year. The purpose of this cross-sectional study was to test if shear wave tensiometry is able to detect AT loading changes between a surgically managed AT rupture versus the unaffected contralateral tendon. Our secondary aims were to evaluate differences in mechanical properties when measured with myotonometry and morphological properties of the tendons measured with ultrasonographic imaging.
Methods: Twenty-one patients with surgically treated AT ruptures were investigated 12-37 months after surgery. Tendon load was measured using a shear wave tensiometer composed of an array of 4 accelerometers fixed on the tendon. Shear wave speed along the Achilles tendon was evaluated at different levels of ankle torque for both the operated and the unaffected side. Mechanical properties of the tendons were evaluated using MyotonPRO and morphological properties using ultrasonographic imaging. Friedman test was used to assess differences in AT wave speed, stiffness, thickness, and cross-sectional area between the operated and the unaffected tendon.
Results: We found a significant shear wave speed difference between sides at every ankle joint torque (P < .05) with a large effect size for the lowest ankle torque and small to medium effect sizes for higher ankle torque. Stiffness, thickness, and cross-sectional area of the operated tendon remained significantly higher compared to the unaffected side.
Conclusion: In this cohort, we found that shear wave tensiometry can detect differences between operated and unaffected AT during a standardized loading procedure. The shear wave speed along the operated tendon, as well as the mechanical and morphologic properties, remains higher for 1-3 years after a rupture.
Level of Evidence: Level III, case-control study.
Keywords: shear wave tensiometry, Achilles tendon rupture
Shear wave tensiometry can precisely detect differences between operated and unaffected AT during a standardized loading procedure. The shear wave speed along the operated tendon remains higher in the long-term after a rupture. This study represents the first step toward the implementation of this technology in clinical settings in order to monitor the evolution of the mechanical properties of the AT over time for patients affected by AT rupture and other tendon pathologies.