The posterior cruciate ligament(PCL) is a ligament within the knee. Ligaments are tough bands of tissue that connect bones.
The PCL — similar to the anterior cruciate ligament (ACL) — connects the thigh bone (femur) to your shin bone (tibia). Although it is larger and stronger than the ACL, the PCL can be torn.
PCL tears make up less than 20% of injuries to knee ligaments. Injuries that tear the PCL often damage some of the other ligaments or cartilage in the knee, as well. In some cases, the ligament can also break loose a piece of underlying bone.