The posterior cruciate ligament (PCL) is one of the key ligaments in the knee, located at the back of the joint. It connects the femur (thigh bone) to the tibia (shin bone) and helps stabilize the knee by preventing the tibia from sliding too far backward. Injuries to the PCL can occur due to sports activities, falls, or car accidents. Symptoms may include pain, swelling, and difficulty in moving the knee. Treatment options range from physical therapy to surgery, depending on the severity of the injury.