Total Ankle Arthroplasty Kinematics Using a Symmetric Bicondylar Talar Component Design: A Cadaveric Gait Simulation...

Area of Science:

• Orthopedic surgery
• Biomechanics
• Biomedical engineering

Background:

• Increasing availability of total ankle arthroplasty (TAA) systems with varied talar geometry.
• Unclear influence of talar geometry on ankle and hindfoot joint motion.
• Need to assess kinematics with contemporary TAA systems.

Purpose of the Study:

• Assess ankle and hindfoot kinematics using a TAA system with a symmetric bicondylar talar component.
• Compare joint motion between intact and post-TAA conditions.

Main Methods:

• TAA performed on eleven mid-tibia cadaveric specimens.
• Robotic simulation of the stance phase for intact and post-TAA conditions.
• Calculation and comparison of ankle, subtalar, and talonavicular joint kinematics and ROM.

Main Results:

• Ankle showed decreased dorsiflexion and increased inversion during early stance.
• Talonavicular joint exhibited increased eversion during late stance.
• Ankle ROM in the transverse plane increased post-TAA; subtalar and talonavicular joints showed no significant changes.

Conclusions:

• TAA with a symmetric talar condylar design modestly altered ankle and hindfoot kinematics and ROM.
• This TAA system closely replicated native ankle and hindfoot joint motion.
• Symmetric talar components may result in smaller transverse-plane ROM increases compared to asymmetric designs.