Snapshot A 35-year-old man presents to the emergency department after sustaining an injury to the knee while playing football. An opposing player's helmet collided with his anterior proximal tibia. After the event, the patient experienced posterior knee pain, mild swelling, and limped off the football field. Physical examination is notable for antalgic gait and a positive posterior drawer test. Preparations are made to obtain a magnetic resonance imaging of the affected knee. Introduction Clinical definition injury of the posterior cruciate ligament (PCL) Associated conditions high-energy trauma can result in PCL injury as well as injury to the posterolateral corner anterior cruciate ligament medial collateral ligament Epidemiology Risk factors high-energy trauma (e.g., motor vehicle accident) sport activities Etiology Trauma that posteriorly translates the proximal tibia Pathoanatomy normal anatomy the largest intraarticular ligament in the knee originates from the lateral portion of the medial femoral condyle and inserts at the fovea centralis (PCL facet) pathology posteriorly directed shear force when the knee is flexed login to view 5 more bullets Presentation Symptoms may present with posterior knee pain athletes may continue playing sports and not seek medical care Physical exam posterior drawer test the proximal tibial is pushed posteriorly to assess for PCL laxity while the knee is flexed at 90 degrees login to view 1 more bullet mild-to-moderate effusion slight limp or antalgic gait may have impaired terminal knee flexion Imaging Radiography indication performed initially to assess for fractures Magnetic resonance imaging (MRI) indication typically performed in all patients presenting with acute PCL injury login to view 1 more bullet Studies Making the diagnosis a presumptive diagnosis can be made based on clinical presentation MRI can definitively diagnose acute or subacute PCL injury Differential Anterior cruciate ligament injury distinguishing factor patients typically hear a "pop" after injury and there is typically significant edema and joint effusion patients have a positive anterior drawer test Treatment Conservative rest, ice, compression, and elevation (RICE) therapy indication login to view 4 more bullets Operative reconstructive surgery indication login to view 1 more bullet Complications May result in osteoarthritis Prognosis Insufficient evidence to determine the true prognosis