Predictive pre-resection robotic ligament balancing in total knee arthroplasty is accurate across surgeons and patient factors.

Its accuracy across surgeons and patient factors remains unknown.

A robotic ligament tensioner applied 70-100 N medially and laterally before bony resections.

Overall, mean absolute was 1.1 mm medially and 1.3 mm laterally.

Increasing BMI was associated with lateral flexion gap tightening (-0.59 mm per 10 kg/m 2 increase, p = 0.018).