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

Area of Science:

• Biomechanics
• Musculoskeletal Research
• Medical Imaging

Background:

• Achilles tendon (AT) rupture and surgical repair involve a lengthy recovery, often exceeding one year.
• Understanding long-term changes in tendon mechanics and morphology post-surgery is crucial for patient outcomes.
• Assessing functional differences between surgically repaired and contralateral ATs is clinically relevant.

Purpose of the Study:

• To evaluate the efficacy of shear wave tensiometry in detecting Achilles tendon loading differences post-surgical repair.
• To compare mechanical properties using myotonometry and morphological characteristics via ultrasonography between operated and un-operated tendons.
• To investigate long-term adaptations in tendon properties following Achilles tendon rupture.

Main Methods:

• Cross-sectional study involving 21 patients surgically treated for AT rupture, 12-37 months post-operation.
• Shear wave tensiometry utilized an accelerometer array to measure shear wave speed under varying ankle torques.
• Myotonometry and ultrasonography assessed tendon mechanical and morphological properties, respectively.

Main Results:

• Significant differences in shear wave speed were observed between operated and unaffected ATs across all tested ankle torques.
• Effect sizes for shear wave speed differences ranged from small to large depending on ankle torque.
• Operated tendons exhibited significantly greater stiffness, thickness, and cross-sectional area compared to the unaffected side.

Conclusions:

• Shear wave tensiometry effectively identifies altered Achilles tendon loading post-surgical repair.
• Mechanical and morphological properties of the operated Achilles tendon remain elevated 1-3 years after rupture.
• These findings highlight persistent changes in tendon biomechanics following surgical intervention for rupture.