What is an ACL Injury?
An ACL injury - which is an acronym for an anterior cruciate ligament injury - refers to an injury to a major knee ligament. The ACL itself connects the thigh bone (femur) to the shin bone (tibia). An ACL injury typically happens in sports which involve quick directional changes, such as football, tennis, basketball, skiing or squash.
Symptoms of ACL tear
The main symptom of an ACL injury is a 'popping sound' from the knee which occurs at the time when the injury is sustained. There are also other signs of an ACL injury, such as; the inability to put weight on the knee; severe pain; swelling; the knee having an inhibited range of movement; and being unable to continue an activity or sport.
Causes of ACL Injury
Usually, an ACL injury happens during sports and other high-intensity activities which put an excessive level of pressure on the knee. There are certain actions performed during sports which are known to potentially cause an ACL injury, including; sudden changes of direction; landing awkwardly after a jump; pivoting with the foot planted firmly on the floor, and direct blows or collisions.
Among the risk factors which are associated with sustaining an ACL injury are; playing sports which present a higher risk of suffering an ACL injury, such as football, tennis and basketball; being female; playing a sport with sub-standard equipment; playing sport on AstroTurf or other artificial surfaces, and poor muscle conditioning.
Treatment options for ACL Injury
Diagnosis of an ACL injury is usually made via a physical examination, which can test the function of the knee joint with a series of movements, as well as compare it to the uninjured joint. In some cases, tests such as x-ray, ultrasound and an MRI scan may be required.
There are a number of treatment options which can be used immediately after an ACL injury happens, focused on reducing swelling and pain. These include; ice treatment, applied indirectly about every two hours; rest, allowing the knee to heal and limiting the weight which is put on it; elevation, using props such as pillows to elevate the knees; and compression, which typically uses a bandage or compression wrap.
As part of rehab after an ACL injury, certain exercises can be recommended by a physical therapist to build up strength and improve range of motion.
Surgery can be advised for cases in which no weight can be put on the knee during everyday activities, or when several knee ligaments are damaged. ACL reconstruction surgery removes the damaged ligament and inserts replacement tissue (graft). The graft is typically taken from another part of the knee.