ACL Tear - Symptoms, Causes, Prevention, Treatment

An anterior cruciate ligament (ACL) is one of the ligaments present in the knee joint of the leg.  A ligament is a flexible band of tissue responsible for holding bones and cartilage together. An overstretching of the anterior cruciate ligament (ACL) in the knee results in its tearing, which is called ACL injury or tears. This tear can be partial or complete. 

ACL injuries commonly occur during sports like soccer, basketball, football, and downhill skiing. These all sports involve rapid pauses or changes in direction, jumping, and landing that may result in ACL tears.

Grades of ACL injury

There are three grades in ACL, these are:-

1. Grade I sprain: Fibres of the ligaments are stretched but there is no tear. You may feel some soreness, tenderness and your knee might feel unstable.
2. Grade II sprain: Fibres of the ligaments are partially torn, and there is a little swelling and tenderness. It's painful and the joint might feel unstable.
3. Grade III sprain: Fibres of the ligaments are completely torn into two parts. You might feel a bit tenderness and maybe a little or a lot of swelling. Knee feels unstable but the pain is less.

Various signs and symptoms of an ACL injury are:

1. A popping sound with sensation in the knee when the injury occurs
2. Severe pain in the knee
3. Inability to move legs
4. Rapid swelling in the surrounding areas of the knee
5. Loss of range of motion
6. A feeling of instability in the knee 
7. In less severe cases, these symptoms may be mild; however, if the ACL is completely torn, the knee instability causes a feeling of sudden shifting or buckling.

The following conditions could cause an ACL tear:

1. Overextending your knee joint
2. An awkward landing after a jump
3. Twisting of knee while suddenly changing the direction 
4. Colliding with someone, for eg. during a football tackle

ACL injuries usually occur when playing sports and fitness activities which put stress on the knee:

1. Abruptly slowing down and changing direction (cutting)
2. Pivoting with your foot firmly planted
3. Jumping and landing awkwardly
4. Stopping suddenly
5. having a collision or a direct blow to the knee in a sport such as a football tackle

When a ligament is torn, it generally leads to a partial or complete tear of the tissue. A slight injury to the ligament partially stretches it but still leaves it intact.

Your doctor will examine your knee to detect any swelling and tenderness during the physical exam by comparing your injured one to the uninjured one. They may also move your knee into different positions to evaluate its range of motion and general function.

Often, a physical exam is enough to make a diagnosis; however, other types of testing are needed to rule out other causes and evaluate the severity of the injury. These tests may involve the following:

1. X-rays – X-rays are required to detect and rule out a bone fracture. However, X-rays cannot show any damage to soft tissues, such as ligaments and tendons.
2. Ultrasound – Ultrasound can examine for injuries in the knee's ligaments, tendons, and muscles by using sound waves to visualise interior structures.
3. Magnetic Resonance Imaging (MRI) – An MRI forms images of our body's hard and soft tissues using radio waves and a strong magnetic field. For example, an MRI can reveal the degree of an ACL injury and damage signs in other knee tissues, such as the cartilage.

Immediate first-aid care for the ACL injury can reduce pain and swelling in your knee. In addition, following the RICE model of self-care at home can be beneficial for the injured person, which includes:

1. Rest – Resting is necessary for healing as it limits the weight bearing on your knee.
2. Ice – Applying ice to your knee at the injury spot for at least 20 minutes every two hours can be beneficial.
3. Compression – Apply the elastic bandage or compression wrap around your knee to wrap the injury.
4. Elevation – Lying down with your knee propping up on pillows can also be helpful.

Non-surgical Treatment

An ACL tear can not heal completely without any surgery; however, specific non-surgical procedures can help reduce pain. These non-surgical procedures are specifically beneficial for those suitable for surgery, such as older people. These non-surgical procedures are also recommended by doctors in case of mild injury where the overall stability of the knee is intact.

1. Bracing – Your doctor may recommend a brace to protect your knee against instability. Crutches may also be prescribed to avoid putting weight on your leg, further protecting your knee.
2. Physical therapy – In physical therapy, careful rehabilitation is undertaken once the swelling has reduced. Specific workouts are performed under proper medical guidance to regain knee function and strengthen the leg muscles.

Treating ACL tears can help you prevent getting worse and leading to something like osteoarthritis. Moreover, it can give you a chance to have a normal knee again and do physical activities like exercise and games.

1. Timely treatment of ACL tear is essential as untreated ACL tear might lead to worsening of the symptoms.
2. Furthermore, it could also lead to the development of osteoarthritis.