Cruciate ligaments are ligaments in a joint that cross each other, forming an X-shape. In the human body, examples can be found in the neck, the knee, and the foot. Many animals also have cruciate ligaments in some key joints of their bodies. One of the most common medical issues involving a cruciate ligament is a tear, where strain causes the fibers in the ligament to separate. Tears are usually very painful, and they limit range of motion for the patient until they can be addressed, typically with surgery to repair the torn ligament.
These ligaments act to stabilize the joint by counterbalancing each other while also allowing a full range of motion in the joint. They are located in joints that are subjected to high levels of strain, such as the highly mobile ankle joint and the commonly stressed knee. Without these paired ligaments, these joints would not be as strong and they also would not move as freely.
In the knee, there are two sets of cruciate ligaments, labeled anterior and posterior respectively. The ligaments are housed deep inside the knee joint. Like other ligaments in the body, they are made of very tough fibrous material that is dense and extremely strong. This tissue is designed to withstand considerable strain and pressure. In the knee, damage to these ligaments can occur as a result of pushing the knee past its normal range of motion or engaging in high impact exercise. Anterior cruciate ligament (ACL) tears are a common form of knee injury.
In the foot, the cruciate ligament is located at the front of the ankle to stabilize the ankle and its connection with the foot. The ligaments in the neck are located in the atlanto-axial joint and are known as the cruciate ligaments of dens. The articulation of the joints in the neck requires strength to support and stabilize the head as well as flexibility to support a range of motion so that people can turn their heads freely.
Tears to the cruciate ligaments typically result in inflammation of the joint. The joint will swell and become hot and tender, while putting weight on it can be difficult. The range of motion will be limited and discomfort can increase if the patient attempts to move or flex the joint. Medical imaging studies can be used to examine the joint and develop a plan for addressing the tear. Surgery is commonly required to repair the ligament, followed by rest and physical therapy to help the patient recover.