Early post-operative in vivo kinematics after total ankle arthroplasty using a total talar prosthesis: Three-dimensional analysis using the iterative closest point algorithm

The in vivo kinematics after combined total ankle arthroplasty (TAA) remains unknown. This study evaluated and compared the three-dimensional kinematics of the talar component between standard TAA, using the talar component where only the surface of the talar dome was replaced, and combined TAA, using the iterative closest point algorithm and computed tomography (CT). The combined TAA and standard TAA groups comprised 17 and 9 ankles, respectively. CT was performed with patients in active dorsiflexed and plantarflexed ankle positions at least 3 months post-operatively. From non-weight-bearing dorsiflexion to plantarflexion, a significant medial translation of the total talar prosthesis was observed in the combined TAA group compared with the standard TAA group. Rotation of the x-axis (inversion) and translation of the z-axis (lateral translation) were negatively correlated. Combined TAA results in greater inversion of the ankle joint during plantarflexion than standard TAA. • In vivo kinematics early after total ankle arthroplasty (TAA) was evaluated using CT. • All talar ligaments were resected for insertion of the total talar prosthesis. • Significant medial translation of total talar prosthesis in the combined TAA group compared with the standard TAA group. • No significant differences were observed in the other motions.