What are the other Names for this Condition? (Also known as/Synonyms)

• ACL Injury
• Sprained Anterior Cruciate Ligament
• Torn ACL 

What is Anterior Cruciate Ligament (ACL) Injury? (Definition/Background Information)

• The anterior cruciate is a ligament located on the inside of the knee joint. An Anterior Cruciate Ligament (ACL) Injury is a sprain or tear to the anterior cruciate ligament in the knee
• Individuals who participate in athletic sports, such as football or basketball, have a higher risk of injuring their anterior cruciate ligament
• Treatment for this condition depends on the type and severity of injury and involves both surgical and nonsurgical treatment methods
• The prognoses of Anterior Cruciate Ligament Injuries are usually excellent with appropriate treatment 

Depending on the severity of the injury, physicians usually classify an Anterior Cruciate Ligament Injury into three different grades. These grades include:

• Grade I Anterior Cruciate Ligament Injury: Grade I occurs when only a small number of ligament fibers have been stretched, but not torn
• Grade II Anterior Cruciate Ligament Injury: Grade II occurs when the ligament fibers have been partially torn
• Grade III Anterior Cruciate Ligament Injury: Grade III is a complete rupture of the ligament fibers in the knee

Who gets Anterior Cruciate Ligament (ACL) Injury? (Age and Sex Distribution)

• Older adults are higher prone to Anterior Cruciate Ligament Injuries
• ACL Injuries are three times more common in females than males
• It is race and ethnicity non-specific

What are the Risk Factors for Anterior Cruciate Ligament (ACL) Injury? (Predisposing Factors)

Risk factors of an Anterior Cruciate Ligament Injury may include:

• Participation in any sports that involves a violent change of direction such as with football, cricket, or basketball
• Females are more likely to sustain an ACL Injury than males

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others. 

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider. 

What are the Causes of Anterior Cruciate Ligament (ACL) Injury? (Etiology)

The following factors may lead to an Anterior Cruciate Ligament Injury.

• Participation in any sports that cause the knee to twist forcefully or rotate
• Squatting or lifting heavy objects
• Sudden directional change causing abnormal pressure on the knee
• Direct trauma to the front of the knee
• Hyperextension of the knee
• Landing awkwardly on one’s knee 

What are the Signs and Symptoms of Anterior Cruciate Ligament (ACL) Injury?

The signs and symptoms of an Anterior Cruciate Ligament Injury may include:

• Decreased range of motion in the knee, difficulty walking
• Pain in the knee
• Noticeable swelling in the knee
• A loud popping sound may be heard at the time of the injury

How is Anterior Cruciate Ligament (ACL) Injury Diagnosed?

An Anterior Cruciate Ligament (ACL) Injury is diagnosed using the following methods:

• Physical examination: During a physical examination, the physician may check for any signs of tenderness and swelling in the knee. A physician may also test the range of motion in the knee. In addition to this, a complete medical history can aid in arriving at a definitive diagnosis
• X-ray of the knee: Although ACL Injuries do not show up on x-rays, they can help rule out other causes of knee injuries and help confirm the diagnosis
• Magnetic resonance imaging (MRI) of the knee: An MRI is a more detailed scan that uses a magnetic field to produce images, which allows a physician to view any damage to the bones and soft tissue to confirm the diagnosis
• Ultrasound imaging of the knee: High-frequency sound waves are used to generate a more detailed image of the knee. This can help determine if any loose cartilage is caught in the knee

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis. 

What are the possible Complications of Anterior Cruciate Ligament (ACL) Injury?

The complications of an Anterior Cruciate Ligament Injury may include:

• Chronic knee instability
• Prolonged and chronic pain
• Degenerative joint disease, such as osteoarthritis

How is Anterior Cruciate Ligament (ACL) Injury Treated?

Both nonsurgical and surgical methods may be used to treat an Anterior Cruciate Ligament Injury. However, treatment depends on the severity of the injury. 

Nonsurgical treatment for Anterior Cruciate Ligament Injury may include: 

The RICE method is effective for a high percentage of sports-related injuries. RICE is an acronym for Rest, Ice, Compression, and Elevation.

• Rest: Any activity that aggravates the knee condition should be avoided. The physician usually advises individuals to refrain from activities, until the symptoms get better
• Ice: Applying ice to the knee may help decrease pain and reduce swelling
• Compression: Wearing an elastic compression bandage can help stop additional swelling and loss of blood
• Elevation: Elevating the knee helps to decrease swelling
• Non-steroidal anti-inflammatory medication, such as ibuprofen and naproxen, can help decrease the pain in the knee
• Physical therapy may help restore strength, as well as flexibility in the muscles

Surgical treatment for Anterior Cruciate Ligament Injury may include:

• Knee arthroscopy: Arthroscopic surgery is a minimally-invasive surgical procedure that is used to visualize, diagnose, and repair the anterior cruciate ligament using small instruments. During this procedure, a surgeon inserts a thin tube attached to a camera (a fibro-optic camera) into the joint via a small incision on the skin of the joint. Visualizing the joint via a camera helps the physician view the inside of the knee and to determine the treatment
• Knee ligament repair: Knee ligament repair is a procedure to repair or replace the anterior cruciate ligament with surgery

How can Anterior Cruciate Ligament (ACL) Injury be Prevented?

A few recommendations to help prevent Anterior Cruciate Ligament Injuries include:

• Improve conditioning and strengthen the hamstrings. It has been proven that exercising regularly to strengthen the hamstrings and surrounding structures around the knee is very effective in decreasing the risk of an ACL Injury
• Wear appropriate safety equipment, such as a knee brace, while participating in certain high impact sports, like football, cricket, basketball. Individuals, who participate in such sports, should ensure that any safety equipment worn is properly adjusted and correctly fitted to provide support for the knee
• Warming-up prior to exercising
• Use proper techniques while exercising so that there is a decreased stress on the knee

What is the Prognosis of Anterior Cruciate Ligament (ACL) Injury? (Outcomes/Resolutions)

• Approximately 90% of the individuals with an Anterior Cruciate Ligament Injury make a complete recovery
• However, complications, such as osteoarthritis of the knee, may develop in some individuals with a Grade III ACL Injury
• When properly diagnosed and treated, individuals usually regain their full strength and range of motion in the injured knee

Additional and Relevant Useful Information for Anterior Cruciate Ligament (ACL) Injury:

The following DoveMed website link is a useful resource for additional information:

https://www.dovemed.com/health-topics/orthopedc-disorders/