summary TKA Vascular Injury and Bleeding, is a rare, potentially devastating, complication that may occur during TKA most commonly as a result of direct injury to the popliteal artery. Diagnosis is made with visual inspection for significant arterial bleeding and a change in patient hemodynamic status. Treatment is recognization of the injured vessel, hemostasis and vascular consultation. Epidemiology Incidence 0.017%-0.2% Risk factors revision surgery peripheral vascular disease Etiology Causes direct laceration sharp dissection in posterior compartment of knee blunt trauma posterior retractor placement login to view 4 more bullets excessive hyperextension brings the artery closer to the knee login to view 1 more bullet thrombosis Anatomy Popliteal artery origin before knee a continuation of the superficial femoral artery transition is at hiatus of adductor magnus muscle anchored by insertion of adductor magnus as enters region of posterior knee course in posterior knee relation to anatomy structures of knee login to view 2 more bullets branches within knee at supracondylar ridge gives branches the provide blood supply to the knee login to view 7 more bullets exit of knee anchor login to view 1 more bullet distal branches login to view 1 more bullet Presentation Intraoperative brisk bleeding loss of pulses Postoperative ischemia sensory changes loss of distal pulses skin mottling Imaging Intraoperative angiogram indications login to view 2 more bullets Postoperative CT angiogram indications login to view 4 more bullets Treatment Immediate vascular surgery consultation indications whenever a concern for injury to the popliteal artery modalities may include nonoperative and observation login to view 1 more bullet stent placement bypass endarterectomy prophylactic fasciotomy login to view 1 more bullet Complications Compartment syndrome Amputation Mortality Socioeconomic consequences increased length of stay increased cost