Ankle stability in simulated lateral ankle ligament injuries

Area of Science:

• Orthopedic biomechanics
• Sports medicine
• Anatomy

Background:

• Lateral ankle ligament injuries are common, often involving the anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL).
• Accurate diagnosis of isolated vs. combined ligament injuries is crucial for effective treatment.
• Cadaveric models allow for controlled investigation of ligamentous injury biomechanics.

Purpose of the Study:

• To differentiate the biomechanical effects of isolated ATFL injury versus combined ATFL/CFL injury on ankle-hindfoot complex stability.
• To evaluate the utility of internal rotation and inversion torque testing in identifying specific lateral ankle ligament injuries.

Main Methods:

• A laboratory-based study using normal cadaveric ankle specimens.
• Simulated injuries to the ATFL and CFL were created sequentially.
• An ankle stability testing device applied inversion and internal rotation torques, with 3D motion analysis of the talus and calcaneus relative to the tibia.

Main Results:

• Sectioning the ATFL significantly increased tibiotalar internal rotation.
• Subsequent sectioning of the CFL did not further increase internal rotation but significantly increased motion during inversion testing.
• Increased inversion motion primarily occurred at the tibiotalar joint level.

Conclusions:

• Isolated ATFL injury is characterized by increased talar-tibial internal rotation, not inversion.
• Combined ATFL/CFL injury can be distinguished from isolated ATFL injury using inversion torque.
• Internal rotation and inversion torque testing may be key to differentiating specific lateral ankle ligament injuries.