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 stay medial with single-prong retractor (do not go lateral to PCL) popliteal artery is a lateral structure at the level of the joint line do not insert retractor more >1cm into posterior soft tissues hyperflexion displaces artery and can avoid injury excessive hyperextension brings the artery closer to the knee increases likelihood of injury during bone cuts 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 lies posterior to the posterior horn of the lateral horn of the lateral meniscus lies directly behind posterior capsule branches within knee at supracondylar ridge gives branches the provide blood supply to the knee above knee joint branches include medial and lateral sural arteries cutaneous branch middle genicular artery at level of knee joint branches include medial genicular artery lateral genicular artery exit of knee anchor as artery exits knee it is anchored by soleus tendon (originates form medial aspect of tibial plateau) distal branches branches into anterior and posterior tibial arteries at distal popliteus muscles Presentation Intraoperative brisk bleeding loss of pulses Postoperative ischemia sensory changes loss of distal pulses skin mottling Imaging Intraoperative angiogram indications if brisk intraoperative bleeding and/or loss of pulses than obtain immediate vascular surgery consultation. vascular consultation will dictate intraoperative imaging, including angiogram. Postoperative CT angiogram indications signs of ischemia loss of pulses skin mottling sensory changes Treatment Immediate vascular surgery consultation indications whenever a concern for injury to the popliteal artery modalities may include nonoperative and observation closed suction drainage is associated with increased incidence of transfusion stent placement bypass endarterectomy prophylactic fasciotomy may be indicated to avoid reperfusion compartment syndrome Complications Compartment syndrome Amputation Mortality Socioeconomic consequences increased length of stay increased cost