Gait analysis after successful mobile bearing total ankle replacement

Area of Science:

• Orthopedic Surgery
• Biomechanics
• Gait Analysis

Background:

• The biomechanical effects of total ankle replacement (TAR) on gait remain incompletely understood.
• Key aspects like joint kinematics, ground reaction forces (GRF), and lower leg muscle activity require further investigation.

Purpose of the Study:

• To compare gait parameters between patients with mobile-bearing TAR and healthy controls.
• To analyze joint kinematics, GRF, and electromyographic (EMG) activity in the lower leg post-TAR.

Main Methods:

• A comparative gait analysis was performed on 10 patients post-TAR and 10 healthy controls.
• Utilized a rigid body model, opto-electronic motion analysis, and synchronized GRF and EMG recordings.
• Examined knee and ankle-hindfoot complex motion, along with EMG of four lower leg muscles during barefoot walking.

Main Results:

• Patients exhibited a 6% lower walking velocity and reduced ankle dorsiflexion (p < 0.001).
• Knee joint kinematics were largely unaffected, with minimal hindfoot and forefoot motion changes.
• GRF showed an increased midstance force (p = 0.005) and decreased terminal stance peak (p < 0.001).
• EMG revealed increased gastrocnemius activity in early stance and anterior tibial muscle activity in late stance.

Conclusions:

• Mobile-bearing TAR leads to near-normal gait kinematics of the knee, ankle, and foot.
• However, ground reaction forces and lower leg muscle activation patterns do not fully normalize after surgery.