Gait analysis after successful mobile bearing total ankle replacement.
BACKGROUND
The effect of total ankle replacement on gait is not fully known in terms of joint kinematics, ground reaction force, and activity of the muscles of the lower leg.


METHODS
A comparative gait study was done in 10 patients after uneventful unilateral mobile-bearing total ankle replacement and 10 healthy controls. A rigid body model was used to describe the motion of the knee and the three-dimensional motion of the ankle-hindfoot complex during barefoot walking. An opto-electronic motion analysis system was used to analyze bilateral movement patterns, synchronized with recordings of the ipsilateral vertical ground reaction forces and the electromyographic activity of four lower leg muscles.


RESULTS
Velocity was 6% lower in the patient group. Dorsiflexion in the operated ankles was reduced (p < 0.001). No differences were found in the joint angular pattern of the knee joint and only minimal changes were found at the hindfoot-to-tibia and forefoot-to-hindfoot levels. The ground reaction force at midstance was somewhat increased (p = 0.005), while the magnitude of the vertical peak at terminal stance was decreased (p < 0.001). EMG activity patterns in the patient group were normal except for a higher activity of the gastrocnemius in early stance and the anterior tibial muscle in late stance.


CONCLUSIONS
There is a near normal gait pattern in terms of joint kinematics of the knee, ankle, and foot after uneventful mobile-bearing total ankle replacement. The ground reaction forces and the EMG activity, however, do not fully normalize.
Doets
H Cornelis
HC
Slotervaart Hospital, Department of Orthopaedics, Amsterdam, The Netherlands. kees.doets@slz.nl
van Middelkoop
Marienke
M
Houdijk
Han
H
Nelissen
Rob G H H
RG
Veeger
H E J Dirkjan
HE
D000328:Adult; D000368:Aged; D000843:Ankle Joint / Q000503:physiopathology* / Q000601:surgery*; D019643:Arthroplasty, Replacement; D005260:Female; D005684:Gait; D006801:Humans; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome; D016138:Walking / Q000502:physiology