[Muscle biomechanics in total ankle replacement]

Area of Science:

• Orthopaedic Surgery
• Biomechanics
• Musculoskeletal Research

Context:

• Ankle osteoarthritis (OA) significantly impairs quality of life and mobility.
• Total ankle replacement (TAR) is a surgical option for end-stage ankle OA.
• Evaluating post-surgical muscle function is crucial for assessing TAR outcomes.

Purpose:

• To assess and compare muscle function in total ankle replacement (TAR) patients one year after surgery.
• To evaluate clinical outcomes including pain, ankle scores, and range of motion (ROM).
• To perform biomechanical analysis of lower leg muscle torque and electromyography (EMG) activity.

Summary:

• Clinical assessments showed significant improvements in pain scores (6.7 to 0.8), AOFAS ankle scores (35.6 to 92.3), and ROM one year post-TAR.
• Biomechanical analysis revealed significant increases in dorsiflexion (17.0 to 25.8 Nm) and plantar flexion torque (15.7 to 24.6 Nm) in the TAR-treated ankle.
• While muscle function improved compared to pre-operative arthritic conditions, EMG analysis indicated lower frequency content and similar intensity to the contralateral healthy leg, suggesting incomplete functional recovery.

Impact:

• Total ankle replacement enhances muscle function and clinical outcomes in ankle OA patients compared to their pre-operative state.
• The study highlights that despite significant improvements, full functional recovery to healthy leg levels is not achieved one year after TAR.
• Findings provide valuable insights for patient expectations and rehabilitation strategies following total ankle replacement.