Abstract
The use of robotic-assisted surgery (RAS) in total knee arthroplasty (TKA) is becoming
increasingly popular due to better precision, potentially superior outcomes and the
ability to achieve alternative alignment strategies. The most commonly used alignment
strategy with RAS is a modification of mechanical alignment (MA), labeled adjusted
MA (aMA). This strategy allows slight joint line obliquity of the tibial component
to achieve superior balancing. In the present study, we compared coronal alignment
after TKA using RAS with aMA and computer-assisted surgery (CAS) with MA that has
been the standard in the center for more than 10 years. We analyzed a prospectively
collected database of patients undergoing TKA in a single center. Lateral distal femoral
angle (LDFA) and medial proximal tibial angle (MPTA) were compared for both techniques.
In 140 patients, 68 CASs and 72 RASs, we observed no difference in postoperative measurements
(median 90 degrees for all, LDFA p = 0.676, MPTA p = 0.947) and no difference in outliers <2 degrees (LDFA p = 0.540, MPTA p = 0.250). The present study demonstrates no benefit in eliminating outliers or achieving
neutral alignment of both the femoral and the tibial components in robotic-assisted
versus computer-assisted TKA if MA is the target. To utilize the precision of RAS,
it is recommended to aim for more personalized alignment strategies. The level of
evidence is level III retrospective study.
Keywords
arthroplasty - robotics - navigation
