Shear Wave Tensiometry Can Detect Loading Differences Between Operated and Unaffected Achilles Tendon

Abstract

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.

A Single-Sensor Approach for Noninvasively Tracking Phase Velocity in Tendons during Dynamic Movement

“…Unlike shear wave elastography, which is an ultrasonic technique used to measure soft tissue behavior [ 6 , 7 , 8 ], the shear wave tensiometry approach has a rapid update rate, making it suitable for tracking changes in tendon loading during dynamic movements with rapidly changing forces. Previous studies have successfully employed tensiometry to monitor tendon loading during various activities [ 9 , 10 , 11 , 12 ].…”