Anterior Knee Ligament Injury

Anterior Knee Ligament Injury

An anterior knee ligament injury or anterior cruciate ligament (ACL) injury is damage or tearing of the anterior knee ligament. The anterior knee ligament is a ligament that connects the lower thigh bone with the shin bone to keep the knee stable.

Compared to other knee injuries, anterior knee ligament injuries are more common. The anterior knee ligament can be torn when the leg makes a sudden change of motion, for example stopping suddenly while running, or when the knee and leg collide with a hard object.

Causes of Anterior Knee Ligament Injury

The anterior knee ligament is a ligament that crosses the middle of the knee. This ligament serves to connect the lower thigh bone with the shin bone and maintain the stability of the knee.

Anterior knee ligament injuries often occur when someone performs a movement that puts pressure on the knee. Movements that are at risk of causing an ACL include:

  • Run fast then stop suddenly
  • Change the direction of movement of the legs and knees suddenly
  • Changing position from stationary to a jumping or rotating position suddenly
  • Excessively stretching the knee
  • Jumping and landing with incorrect foot position
  • Experiencing an impact in the knee area, for example being hit by a tackle while playing football

Risk factors for anterior knee ligament injury

There are several things that can increase a person's risk of suffering from an anterior knee ligament injury, among others:

  • Female gender, due to possible differences in muscle strength with men and hormonal factors
  • Decreased muscle mass due to aging ( sarcopenia ) and lack of exercise
  • Exercising or playing on slippery surfaces
  • Play soccer, basketball, badminton, or gymnastics
  • Having disproportionate leg muscle size
  • Wearing ill-fitting footwear

Symptoms of Anterior Knee Ligament Injury

Sufferers of anterior knee ligament injuries will usually hear a sound like " pop " when the ligament is torn. In addition, there are some common symptoms that are felt when suffering from an anterior knee ligament injury, among others:

  • Great pain in the knee
  • Knees are difficult to move and stretch
  • The knee feels unstable
  • Difficulty walking
  • The knee swells quickly in 6 hours

The symptoms that appear are also influenced by the severity of the injury. The following is the division of anterior knee ligament injuries based on the level of anterior ligament damage that occurs:

  • Level 1
    The anterior knee ligament is slightly damaged. At this level, an ACL injury generally does not affect the knee's ability to bear weight.
  • Level 2
    The anterior knee ligament is pulled and partially torn. At this level the knee joint begins to be unstable. Patients with level 2 ACL injuries will need time to stabilize the knee for a while before walking or standing.
  • Level 3
    The anterior knee ligament is severely damaged and completely torn. Sufferers of a 3rd degree ACL injury will feel a really unstable knee.
  • Avulsion
    The anterior knee ligament is pulled and detached from one of the bones surrounding it, either the femur or the shin.

When should you go to the doctor?

Check yourself with  a doctor  or  a hip and knee orthopedic doctor  when symptoms like those mentioned above appear. The doctor will find out the severity level and provide treatment as soon as possible.

Immediately check with a doctor if your feet feel cold and appear blue after an injury. This could be a sign that the knee joint is dislocated or injured in the blood vessels of the leg. Joint dislocation or injury to blood vessels is an emergency that needs to be dealt with immediately.

Diagnosis of Anterior Knee Ligament Injury

Diagnosis of anterior knee ligament injury can be done by a doctor, one of whom is a sports medicine specialist . The doctor will ask about the patient's complaints, including history of movement, sports, and previous activities.

Next, the doctor will perform a physical examination of the leg and knee area by checking for swelling, measuring strength, and evaluating the range of motion that the patient is able to perform.

To confirm the diagnosis, the doctor will perform the following supporting tests:

  • X- ray , to check for cracks or fractures in the knee area
  • MRI , to see problematic bones and soft tissues
  • Arthroscopy , to examine the joint using a special tool in the form of a small tube (arthroscope) equipped with a camera

Treatment of Anterior Knee Ligament Injury

Treatment of anterior knee ligament injuries is tailored to the symptoms experienced and the severity of the injury. Treatments that can be done include:

First aid

The first aid that can be done when an anterior knee ligament injury occurs is with the RICE method, namely:

  • Rest : Resting the knees
  • Ice : Compress the knee with ice wrapped in a clean cloth for 15-20 minutes
  • Compression : Wrapping the knee with an elastic bandage
  • Elevation : Lying down and positioning the knee higher by supporting it with a pillow


The doctor can give medicine to reduce inflammation and pain. These drugs include  ibuprofen , ketorolac, or  paracetamol . If necessary, the doctor can inject  corticosteroid medicine into the patient's knee to reduce inflammation.

Knee braces and crutches

The patient will be given a knee brace to provide extra protection to the knee. In addition, the patient will also be advised to use a support stick to reduce pressure on the knee.


Physical therapy ( physiotherapy ) aims to restore muscle strength and knee movement function. Physiotherapy should be done several times a week to strengthen the muscles around the knee, while restoring the ability to move the knee.

Physiotherapy can also be done to strengthen the muscles of the front thigh and the muscles of the back thigh before undergoing knee surgery.


The operation will be performed if the patient has some of the following conditions:

  • The anterior knee ligament is severely torn (avulsion)
  • There is more than one torn ligament
  • The knee pads were also damaged
  • Knees cannot support the weight of the body when walking
  • Injuries happen to athletes who want to stay active

Surgery is usually only performed if there is no improvement in knee function within a period of 5 months. The length of this waiting time is also intended to reduce the risk of scar tissue forming around the knee ( arthrofibrosis ) after surgery.

This operation is performed by the doctor by removing the damaged knee ligament and replacing it with a new muscle ligament ( graft ). The graft can be taken from the knee ( hamstring ) or kneecap tendon ( patellar tendon ) from the patient's own muscle or from a donor. After the operation, the patient needs to undergo rehabilitation.

The length of rehabilitation time required to restore muscle function after surgery can vary. However, in general, patients who have been operated on and undergoing rehabilitation can return to sports within 6-9 months.

Complications of Anterior Knee Ligament Injury

Patients with anterior knee ligament injuries are at risk of developing  knee osteoarthritis  , even after undergoing ligament reconstruction surgery. In addition, the knee joint can be damaged when the sufferer experiences blood accumulation ( hemarthrosis ) in the knee joint.

Surgery to treat anterior cruciate ligament injuries also carries the risk of causing the following complications:

  • Pain around the kneecap
  • Infection of the graft used to replace the damaged ligament
  • Damage to the graft used to replace the damaged ligament
  • Stiff knees due to lack of active movement after surgery
  • Deep vein thrombosis

Prevention of Anterior Knee Ligament Injury

Anterior knee ligament injuries are difficult to prevent. However, there are several things that can be done to reduce the risk of knee ligament injury, namely:

  • Do sports to strengthen leg muscles and knee muscles routinely to maintain balance and leg strength.
  • Do routine exercises to strengthen the hips, pelvis, and lower abdomen.
  • Do exercises to determine the position of the feet when landing after jumping.
  • Use appropriate footwear and protective equipment when exercising.
  • Be sure to  warm up before exercising .
  • Change the intensity of the exercise slowly and gradually, and do not suddenly change the exercise to be more intense.
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