​​ACL Injuries Symptoms and Causes

Everything You Need To Know About ​​ACL Injuries Symptoms and Causes


The anterior cruciate ligament (ACL) is a ligament of the knee joint that connects the femur to the tibia. A ligament is a complex, flexible tissue band that holds bones and cartilage together. The ACL links the femur (the bottom of the thighbone) and tibia (the top of the shinbone), keeping the knee stable.

The ACL helps prevent excessive forward movement of the tibia relative to the femur and hyperextension of the knee joint. It also plays a role in stabilizing the knee during side-to-side movements. Injuries to the ACL are common, especially among athletes who participate in sports that involve sudden stops, changes in direction, or jumping.

Stages of ​​ACL Injuries

ACL injuries are classified into the following grades:

  • Grade 1: These injuries comprise ACLs with mild damage. The ACL is mildly stretched yet capable of offering adequate stability to the knee joint.
  • Grade 2: These rare injuries are characterized by stretched and partially torn ACLs.
  • Grade 3: These tears result from an ACL torn in half and the inability to stabilize the knee joint.

Types of ACL Injury

ACL (anterior cruciate ligament) injuries can occur in different areas of the ligament, and the injury's location can affect the injury's severity and the course of treatment. The two main areas of the ACL where injuries can occur are:

  • Mid-substance ACL injuries: This type of injury occurs in the middle of the ligament and can be either partial or complete tears. Mid-substance injuries can be caused by sudden twisting or hyperextension of the knee or by direct trauma to the knee.
  • Avulsion ACL injuries: This type occurs when the ACL tears off the bone at its attachment point. This can happen at either the tibia (shinbone) or the femur (thighbone) and is often seen in children and adolescents whose bones are still growing.

Symptoms of ACL

When your ACL tears, you might hear a pop in your knee or feel like your knee has "given out." ACL (anterior cruciate ligament) injuries can cause various symptoms, ranging from mild to severe. Some of the most common symptoms of an ACL injury include:

Pain: ACL injuries can cause significant pain, which may be sudden and sharp or gradually worsening over time. The pain is usually felt around the knee joint and may be accompanied by swelling and tenderness. Swelling: ACL injuries can cause the knee joint to become swollen, making it difficult to move the knee or put weight on the affected leg.

Instability: ACL injuries can cause the knee joint to feel unstable or "wobbly," as if it may give out from under you. This can make walking, running, or engaging in physical activity challenging.

Loss of range of motion: ACL injuries can limit the range of motion of the knee joint, making it difficult to extend or bend the knee fully.

Difficulty bearing weight: ACL injuries can make it difficult or painful to put weight on the affected leg, making it difficult to walk or stand. in sports.

If you experience any of these symptoms after a knee injury or trauma, it is important to seek medical attention to determine the cause of your symptoms and receive appropriate treatment.

Causes of ​​ACL Injuries

Most ACL tears are known to be non-contact injuries, which are not caused by contact, such as another player kicking your knee or falling on it. ACL (anterior cruciate ligament) injuries can be caused by a variety of factors, including:

  • Sudden stops or changes in direction: ACL injuries are often seen in athletes who participate in sports that require sudden stops or changes in direction, such as basketball, soccer, football, and skiing.
  • Direct trauma: ACL injuries can be caused by a direct blow to the knee, such as a fall or collision.
  • Landing improperly from a jump: ACL injuries can occur when a person lands improperly after a jump, such as landing with the knee locked or on a bent knee.
  • Overuse: ACL injuries can occur due to overuse or repetitive strain on the knee joint, which can weaken the ligament over time.
  • Genetics: Some individuals may be genetically predisposed to ACL injuries due to differences in the shape or alignment of their knee joints.
  • Hormonal factors: Female athletes are more likely to experience ACL injuries than male athletes due in part to hormonal factors that can affect the strength and stability of the ligament.

It is important to note that ACL injuries can occur in people of all ages and activity levels, not just athletes. If you experience a knee injury or trauma, seeking medical attention to determine the cause of your symptoms and receiving appropriate treatment is essential.

Risk Factors

Several risk factors can increase the likelihood of an ACL (anterior cruciate ligament) injury. Some of the most common risk factors include:

  • Sports participation: Certain sports, such as soccer, basketball, football, and skiing, have a higher risk of ACL injury due to the nature of the movements involved.
  • Gender: Female athletes are at higher risk of ACL injury than male athletes due in part to differences in anatomy and hormonal factors.
  • Anatomy: Some individuals may have certain anatomical factors, such as a narrow intercondylar notch or a small ACL, that can increase the risk of ACL injury.
  • Poor conditioning: Individuals who are not in good physical condition may be more susceptible to ACL injury, as the muscles around the knee may be weaker and less able to support the joint.
  • Previous injury: Individuals who have previously experienced an ACL injury are at higher risk of experiencing another ACL injury.
  • Age: ACL injuries are more common in younger individuals, as their bones and joints may still be developing, and their muscles may not be as strong.
  • Environmental factors: Certain environmental factors, such as playing on uneven surfaces or wearing improper footwear, can also increase the risk of ACL injury.

While some of these risk factors may be beyond an individual's control, some steps can be taken to help prevent ACL injury, such as proper conditioning, appropriate training and technique, and wearing appropriate protective gear.

Complications And Associated Risks

Several complications can arise from an ACL (anterior cruciate ligament) injury, mainly if the injury is not treated correctly or if underlying factors exist. Some of the most common complications associated with ACL injury include:

  • Knee instability
  • Osteoarthritis
  • Meniscus tear
  • Limited mobility
  • Chronic pain
  • Delayed or incomplete recovery

It is essential for individuals who experience an ACL injury to seek prompt medical attention and to follow the recommended treatment plan closely to help minimize the risk of complications and promote the best possible outcomes.

Prevention from ACL

There are several steps that individuals can take to help prevent ACL (anterior cruciate ligament) injury. Some of the most effective prevention strategies include:

  • Proper conditioning: Maintaining good overall physical conditioning, including strength, flexibility, and endurance, can help to reduce the risk of ACL injury.
  • Appropriate training and technique: Learning proper techniques for sports and other activities can help to reduce the risk of ACL injury. This may involve developing safe and effective training programs with a coach or trainer.
  • Warm-up and cool-down: Warming up before physical activity and cooling down afterward can help to reduce the risk of injury.
  • Protective gear: Wearing appropriate protective gear, such as knee pads or braces, can help to reduce the risk of ACL injury.
  • Proper footwear: Wearing appropriate footwear for the activity can help reduce the risk of ACL injury and other types of injuries.
  • Avoid risky activities: Avoiding activities known to have a high risk of ACL injury, such as high-impact sports like basketball or soccer, can help reduce the risk of injury.
  • Strengthening exercises: Performing exercises that specifically target the muscles around the knee joint, such as squats and lunges, can help to strengthen the joint and reduce the risk of ACL injury.

By taking these steps, individuals can help to reduce their risk of ACL injury and promote overall joint health and safety.

Frequently Asked Questions

A minor injury or sprain can heal with physical therapy and medical assistance. However, a fully torn ACL will not repair itself with time. If left untreated, the knee joint may suffer from permanent damage and risk of arthritis.

No. Walking immediately after suffering a full ACL tear can be very painful. It is normal to feel unstable due to swelling in the knee, anterior instability, and loss of functioning of the quadriceps due to pain.

It is possible to live with a tear, depending on the severity. Stretching and strengthening exercises combined with a good knee brace can help you manage life with a tear. In case the condition interferes with daily activities and work, surgery is for you. Surgery is recommended for very active patients, mainly those involved in sports and related activities.

If the condition is left untreated, it may lead to arthritis. If you do not wish to go for surgery, it is suggested to restrict activities, strengthen leg muscles, and wear a brace if necessary.

The surgery should not be delayed as it can cause muscle wasting and stiffness in the knee. If the diagnosis is made late and the joint has gone stiff, doctors may suggest a few weeks of pre-habilitation to prepare the site for surgery.

No. This surgery should be done as soon as possible. Any delay in the procedure may lead to further damage and degeneration of the knee joint. The condition can result in stiffness, complicating the surgery further.

Reconstruction surgery for ACL is a minimally invasive procedure done with an arthroscope. Hence, no large incisions are required. The surgery is done with just 2-3 stitches which may be removed within two weeks after the surgery.

An ACL tear with another knee trauma can make an individual more vulnerable to developing arthritis in the knee.

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