Characterization of Ankle Kinematics and Constraint Following Ligament Rupture in a Cadaveric Model

Area of Science:

• Orthopedics
• Biomechanics
• Sports Medicine

Background:

• Ankle sprains are prevalent injuries requiring significant rehabilitation.
• Understanding the biomechanical consequences of ligamentous injury is key for effective treatment.

Purpose of the Study:

• To describe the biomechanics of the ankle joint complex (AJC) after anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL) rupture.
• To identify kinematic alterations and changes in tendon loading post-ligament injury.

Main Methods:

• Manual manipulation of ten cadaveric ankles to define the envelope of motion.
• Use of a radial basis function for interpolating ankle mobility under various load and torque conditions.
• Examination of ankle kinematics during tendon loading to assess performance changes.

Main Results:

• ATFL rupture caused significant internal rotation and anterior translation.
• Combined ATFL and CFL rupture led to greater changes in rotation, translation, and inversion compared to isolated ATFL injury.
• Achilles tendon load increased by 24% post-rupture, indicating reduced efficiency.

Conclusions:

• Isolated ATFL injury presents with primarily internal rotation laxity.
• Damage to both ATFL and CFL results in multi-directional instability.
• Increased Achilles load suggests calf muscle overload, highlighting the importance of targeted rehabilitation.