Differences in Intersegmental Foot and Ankle Motion Between Patients With Varus and Valgus Ankle Osteoarthritis

Area of Science:

• Orthopedics
• Biomechanics
• Gait Analysis

Background:

• Ankle osteoarthritis (OA) frequently presents as varus alignment, with valgus OA being less common.
• Both varus and valgus ankle OA necessitate distinct compensatory strategies to maintain a plantigrade gait.

Purpose of the Study:

• To investigate and compare intersegmental foot and ankle motion variations between patients with varus and valgus ankle OA.
• To elucidate the functional adaptations and compensatory mechanisms employed in different coronal alignments of ankle OA.

Main Methods:

• Utilized multisegment foot gait analysis on 55 patients with varus and 13 with valgus end-stage ankle OA.
• Employed the DuPont foot model for intersegmental foot and ankle kinematics and analyzed temporospatial gait parameters.

Main Results:

• Both groups showed similar temporospatial gait parameters.
• Varus ankle OA group exhibited reduced sagittal range of motion (ROM) in forefoot and hindfoot, but increased forefoot coronal ROM.
• Valgus ankle OA group demonstrated greater hindfoot coronal ROM; distinct forefoot/hindfoot motions and hallux dorsiflexion were observed in the varus group.

Conclusions:

• Despite similar talar tilt angles, significant differences in ROM and intersegmental positions highlight unique compensatory mechanisms in varus versus valgus ankle OA.
• Kinematic analysis is valuable for assessing functional adaptations related to coronal alignment in ankle osteoarthritis.