Comparison of Functional Recovery Between Restricted Inverse Kinematic Alignment and Adjusted Mechanical Alignment With Robotic-assisted Unilateral Total Knee Arthroplasty.

Restricted inverse kinematic alignment (restricted iKA) total knee arthroplasty is an alignment technique of total knee replacement surgery, aim to maintain the native coronal alignment within a HKA angle safe zone of 177° to 183°. This technique aims to 'resurface' the femur maintaining the native femoral joint line obliquity, with the flexion and extension gaps balanced by adjusting the tibial resection first. It is considered a more personalized approach because it aims to replicate the knee's pre-arthritic alignment and movement, believing that each patient's knee has a unique alignment.

The adjusted Mechanical Alignment (aMA) technique is an adaptation of the conventional MA technique but with undercorrection of constitutional coronal deformity, within a limit of ± 3°. The femoral resection is adjusted to preserve mild constitutional deformity and/or reduce more severe deformity while leaving the tibial component mechanically aligned. The tibial component was positioned with the aim to be perpendicular (90°) to the mechanical tibial axis.