108 patients scheduled for total knee arthroplasty were randomized to have the procedure completed with either custom cutting blocks (VISIONAIRE; Smith & Nephew) or standard intramedullary and extramedullary guides. Patients were assessed for mean and incidence of outliers in hip-knee-ankle angle, medial distal femoral angle (MDFA), and medial proximal tibial angle (MPTA) on long-leg standing radiographs, and mean femoral flexion angle and tibial slope on lateral radiographs. Operative time was also measured as a primary outcome. Secondary outcomes related to perioperative blood loss and function after 2 years were also collected. Results demonstrated that, while there were minor, significant differences in mean MDFA and MPTA between groups, overall lower limb alignment and incidence of outliers did not significantly differ between groups. A significant difference in operative time was observed between groups, with an approximate 11-minute reduction in the CCB group compared to the standard group. No significant difference in any secondary outcome was observed.