Comparative analysis of femoral component rotational accuracy in robotic-assisted versus navigation-assisted total knee arthroplasty.

Background: Misalignment and improper implant positioning in total knee arthroplasty (TKA) are key predictors of early prosthesis loosening and failure. Correct femoral component rotation is essential for proper patellar tracking, balanced flexion gap, and correct limb alignment during flexion. The objective of this study is to assess and compare the precision of femoral component rotational placement between robotic-assisted TKA (RA-TKA) and navigation-assisted TKA (NA-TKA) surgeries.

Methods: This single-surgeon retrospective case-control study involved 60 knees from 37 patients, with 30 knees in the robotic-assisted group and 30 knees in the navigation-assisted group. The procedures utilized either a semi-active robotic system (MAKO) or an image-free eNlite navigation system. Femoral component rotational placement and limb alignment were assessed using computed tomography scans and full-length standing anterior-posterior radiographs.

Results: The NA-TKA group had a higher proportion of female patients (80%) and was younger on average (64.9 ± 18.4 years), while the RA-TKA group had 65% female patients with an average age of 68.4 ± 8.1 years. There were no significant differences in the absolute errors between intraoperative plans and postoperative alignment of the femoral component in the axial plane between RA-TKA (0.9°±1.9°) and NA-TKA (0.6°±1.6°). Postoperative hip-knee-ankle angles were similarly restored in both groups (RA-TKA: 0.2°±2.6°, NA-TKA: 0.9°±1.7°; p = 0.22). The NA-TKA group had fewer outliers (> 3°) for femoral component rotational placement (p = 0.45).

Conclusion: Our study indicates that RA-TKA achieves similar accuracy in femoral component rotational placement compared to NA-TKA. While RA-TKA aims for the highest accuracy in femoral component placement, it may not necessarily surpass the accuracy of navigation-assisted techniques.

Level Of Evidence: Level III.