# The usability of robotic-assisted systems for total knee arthroplasty can be improved without hindering the accuracy of the bone cuts

## TL;DR

This study shows that improvements in robotic-assisted knee surgery systems don't reduce the accuracy of bone cuts.

## Contribution

The study demonstrates that system upgrades for robotic knee surgery maintain accuracy while improving usability.

## Key findings

- RMS values for bone cut errors were mostly below 2 mm or 2°, except for specific tibial positions.
- The largest error was in tibial external rotation (3.2°), but errors were consistent with prior system versions.
- System upgrades improved usability without compromising accuracy.

## Abstract

This study assessed the bone cuts accuracy of a robotic-assisted system for total knee arthroplasty (TKA) that was recently upgraded.

Three orthopaedic surgeons planned and executed TKA on 24 sawbones. Bone cut accuracy was assessed using CT scans, comparing the planning and the actual bone cuts in all six degrees-of-freedom.

The root-mean-square (RMS) values were below 2 mm or 2° for all error types, except for the medio-lateral position (2.4 mm) and internal-external rotation (2.3°) of the left tibias. The maximal amplitude of the 288 errors (6 degrees-of-freedom * 2 bones * 24 knees) was observed in tibial external rotation (3.2°). Most error types reported a bias, with limited variations among knees.

The errors were in the same range as those of the prior version of the system, suggesting that the improvements brought by the system upgrade were not obtained at the expense of accuracy.