Thirty-eight patients (76 knees) with end-stage arthritis were randomized to receive computer-navigated total knee arthroplasty (TKA) using constitutional alignment (n=38 knees) or mechanical alignment (n=38 knees). The primary outcome was the accuracy of component positioning and restoration of native knee alignment. Secondary outcomes included clinical measures such as the Hospital for Special Surgery (HSS) scores, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores, and radiographic alignment metrics. Outcomes were assessed at intervals up to 42 months. Overall, the study revealed that the navigated constitutional alignment group achieved higher radiographic accuracy and better early clinical outcomes, particularly in cases with severe preoperative deformity. These findings suggest that navigation with constitutional alignment may optimize early functional and alignment outcomes in TKA.