Gait analysis following MobilityTM total ankle replacement (TAR)

J.R. Ramaskandhan, P. Hewart, M.S. Siddique

Introduction: There is paucity of literature on Gait analysis following Total Ankle Replacement (TAR). We aimed to study changes to gait after successful Mobility TAR.

Methods: 20 patients who underwent a primary TAR, with a diagnosis of either OA or PTOA were recruited between October 2008 and March 2011. Gait analysis was carried out using the Helen Hayes marker system with VICON 3D opto-electric system pre-operatively, 3, 6 and 12 months post-operatively. Ankle kinematics and spatio-temporal parameters of gait were studied.

Results: 20 patients were included. Mean age was 63.6 years (Range 43-84), mean BMI was 29.6 ± 4.08. Diagnosis was OA in 12 (52.2%) and PTOA in 8 (34.8%). Results showed increase in average and maximum range of dorsiflexion from (3° to 7°) and (11° to 17°) respectively from pre-op to 1 year, but statistically not significant (p>0.05). Of the temporal variables, Average Cadence increased from Pre-op to 1 year (102 to 106 steps/min); double support (0.35% to 0.31%), single support (0.41% to 0.39%) and toe off point at gait cycle (63.9% to 62.4%) decreased from pre-op to 1 year, but failed to achieve statistical significance (p>0.05). For distance variables, Step length showed a significant increase from pre-op to 1 year (0.21m/s to 0.58m/s; p< 0.001); stride length increased (1.05m/s to 1.13m/s), step time and stride time decreased (0.60secs to 0.58secs) and (1.19 to 1.14secs) respectively and Walking speed increased (0.90m/s to 1.00m/s) from pre-op to 1 year, but statistically not significant (P>0.05).

Conclusion: There was significant improvement in step length after TAR from pre-op to 1 year. Although the results showed a trend for improvement in average dorsiflexion, average cadence, stride length, walking speed, decreased step and stride length times, which showed improvement in walking pattern in these group of patients, but failed to achieve statistical significance.