Foot and Ankle Kinematics in Rheumatoid Arthritis: Influence of Foot and Ankle Joint and Leg Tendon Pathologies

Introduction From early onset of the disease, patients with rheumatoid arthritis (RA) suffer from walking impairments. Clinically, pathologic effects of RA on foot and ankle structures have been studied, but little is know how they relate to kinematic changes during gait. The aim of this study was to explore the relationship between clinically observed pathologies of foot and ankle joints and leg tendons and the corresponding gait kinematics. Methodology Gait of 25 subjects with varying stages of RA disease was recorded and foot and ankle kinematics were assessed. Magnetic resonance imaging was performed of each subject: first metatarsal-phalange (MTP I), midfoot and hindfoot synovitis and erosion scores and leg tendon involvement were determined. The Joint Alignement and Motion score represented daily clinical assessment. The 95% confidence intervals (CI) of the correlation coefficient of the Spearman correlation tests were used to explore the relationships between the clinical and kinematic parameters. Results Maximum MTP I dorsiflexion at pre-swing was related to reduced MTP I passive motion, MTP I synovitis and erosion, midfoot synovitis and erosion and hindfoot erosion. Midfoot pronation range of motion during single-stance was related to subtalar alignment and Achilles tendon involvement. Hindfoot eversion range of motion during single-stance was related to subtalar alignment and peroneus longus tendon involvement. Involvement of the tibialis posterior tendon could not be identified as an independent factor influencing foot or ankle kinematics. Conclusions Our findings suggest moderate to strong relationships between foot and ankle gait kinematics and structural pathologies. © 2012 by the American College of Rheumatology