80 patients scheduled for minimally invasive total knee arthroplasty (MIS-TKA) were randomized to undergo the procedure with the use of a new hand-held navigation device (iAssist group) or not. The purpose of the study was to compare radiographic outcomes of alignment and positioning of the prosthesis, as well as surgical outcomes (operative time, bone cutting time, blood loss). The results of the study indicated that the iAssist group was associated with fewer outliers in frontal alignment measure, as well as tibial slope. There were no significant differences between the two groups in terms of femoral component flexion, operative time, bone cutting times, or blood loss.