An ACL tear occurs when one of the ligaments in the knee known as the anterior cruciate ligament (ACL) tears. A ligament is a band of tissue connecting bones, and the ACL is one of the ligaments that connects the thigh bone to the shinbone and crosses the middle area of the knee. This kind of injury often occurs in sports or activities that require jumping or sudden movements.
Some of the causes for this type of injury include any activity that puts undue stress on the knee. This stress can take the form of pivoting with the foot too firmly planted, jumping and landing in an unusual position, suddenly stopping after running, quickly changing direction when running or moving, and a physical blow to the knee or the area below it.
An ACL tear can feel like the knee pops out of place at the moment it occurs. There is often severe pain immediately and generally a person won’t be able to continue the activity. Redness around the area and swelling will likely happen fairly soon after the injury; the affected area may also feel warm to the touch. Limited range of motion also happens after this kind of injury. In addition to pain ranging from moderate to severe, the torn ACL will make the leg feel unstable when pressure is put on it.
ACL tears are sudden and can generally be traced back to a specific incident. There are a variety of treatments for this kind of injury.