“…Therefore, in contemporary chronic total occlusion (CTO) intervention scenarios (Figure 2), the knuckle wire is used mostly as a last resort only to create subintimal dissection, and reentry is assisted by CrossBoss™ catheter-Stingray™ LP system (Boston Scientific Corp., Marlborough, MA, USA), controlled antegrade and retrograde tracking (CART), or reverse CART 4,5 . The knuckle technique, when performed antegrade or retrograde, helps in long occlusions, especially with calcification, to maintain the guidewire position in the subintimal space within the vessel architecture [6][7][8][9] .…”