Ninety-nine patients with osteoarthritis undergoing primary total knee arthroplasty were randomized to receive either mechanical alignment (n = 50) or kinematic alignment (n = 49). The primary outcome was patient-reported outcome measures (PROMs), including the Knee Society Score, Oxford Knee Score, WOMAC, Forgotten Joint Score, and EQ-5D. Secondary outcomes included survivorship free from revision for any cause, reoperation, and radiographic loosening. Outcomes were assessed at 2, 5, and 10 years postoperatively. Overall, the results of the study revealed no statistically significant differences in any PROM scores or survivorship outcomes at 10 years. The findings suggest that mechanical and kinematic alignment offer similar long-term clinical and radiographic results in TKA.