No difference of gait parameters in patients with image-free robotic-assisted medial unicompartmental knee arthroplasty compared to a conventional technique: early results of a randomized controlled trial

Knee Surg Sports Traumatol Arthrosc. 2021 Apr 11. doi: 10.1007/s00167-021-06560-5. Online ahead of print.

Abstract

Purpose: In recent studies, robotic-assisted surgical techniques for unicompartmental knee arthroplasty (UKA) have demonstrated superior implant positioning and limb alignment compared to a conventional technique. However, the impact of the robotic-assisted technique on clinical and functional outcomes is less clear. The aim of this study was to compare the gait parameters of UKA performed with conventional and image-free robotic-assisted techniques.

Methods: This prospective, single-center study included 66 medial UKA, randomized to a robotic-assisted (n = 33) or conventional technique (n = 33). Gait knee kinematics was assessed on a treadmill at 6 months to identify changes in gait characteristics (walking speed, each degree-of-freedom: flexion-extension, abduction-adduction, internal-external rotation, and anterior-posterior displacement). Clinical results were assessed at 6 months using the IKS score and the Forgotten Joint Score. Implants position was assessed on post-operative radiographs.

Results: Post-operatively, the whole gait cycle was not significantly different between groups. In both groups, there was a significant improvement in varus deformity between the pre- and post-operative gait cycle. There was no significant difference between the two groups in clinical scores, implant position, revision, and complication rates.

Conclusion: No difference of gait parameters could be identified between medial UKA performed with image-free robotic-assisted technique or with conventional technique.

Level of evidence: Prospective randomized controlled trial. Level of evidence I.

Keywords: Forgotten joint score; Gait knee kinematics; KneeKG; Robotic-assisted surgery; Unicompartmental knee arthroplasty.