Fig. 2From: Augmented reality-aided unicompartmental knee arthroplastyThe surgeon aligns the cutting block of the proximal tibia while viewing the varus/valgus alignment, posterior slope, and medial resection depth on the smartphone display. Based on preoperative planning, the surgeon set the cutting block on the varus angle of 0.1°, posterior slope of 6.6°, and medial depth of 5 mm (red arrow). First, one fixation pin (white arrow) is inserted parallel to the anteroposterior axis to fix the extramedullary guide. Second, another pin (white arrowhead) is inserted to fix the cutting block. Note that no extra pins are required to attach the sensor of the AR-based navigation system compared with standard extramedullary guide and cutting blockBack to article page