The cruciate ligaments are an essential part of a healthy dog’s knee, also called a stifle joint. There are two of them: the cranial cruciate ligament (CCL) and the caudal cruciate ligament (CaCL). These ligaments are bands of tissue that wrap around and stabilize the dog’s knee. They allow the knee to open and close as a hinge joint, but keep it from moving side-to-side. The two ligaments cross over each other in the stifle joint to keep the femur and tibia bones stacked correctly. They’re called cruciate ligaments because they “cross over” each other in the knee joint, resembling a crucifix.