Anterior Cruciate Ligament Injury

ACL injuries are commonly divided into two categories:

• Partial tears occur when only some fibres of the ligament are damaged.
• Complete tears occurs when the ligament is torn through entirely and no longer supports knee stability.

The signs of an ACL injury may include:

• A popping sound in the knee at the time of injury.
• Severe pain in the knee.
• Difficulty moving the knee or walking normally.
• Swelling that appears within a few hours of injury.
• Reduced range of knee movement.
• Instability or the knee “giving way” when putting weight on it.

ACL injuries may be triggered by different risk factors and activities:

• Females are more prone to ACL injuries because of anatomical and hormonal differences.
• Playing intensely physical sports such as soccer, football, basketball, gymnastics, or skiing.
• Weak muscles and poor conditioning, which reduce knee support.
• Wearing ill-fitting shoes or poorly maintained sports equipment.
• Playing on artificial turf, which can strain the knee during sudden stops or twists.

Doctors use a combination of clinical examinations and imaging tests to confirm an ACL injury:

• Clinical tests such as the Drawer test, Lachman test, or Pivot shift test assess ACL stability, while McMurrays’s test checks for meniscus injury.
• Magnetic resonance imaging (MRI) is the gold standard for diagnosis. It provides a clear picture of the ligament and can reveal other damage inside the knee.
   

Treatment depends on the severity of the condition, the patient’s age, and how physically active the patient is.

• Non-surgical treatment is often used for partial ACL tears or for people with lower activity demands. It may include:
  • Rest and keeping the leg raised to reduce swelling.
  • Applying ice packs to decrease pain and inflammation.
  • Using a knee immobiliser to support the joint and limit painful movement.
  • Following a rehabilitation programme focused on strengthening the thigh muscles.
• Surgical treatment is usually recommended for complete ACL tears, especially in young or active patients, or when the injury is combined with meniscus damage. The standard procedure is arthroscopic ACL reconstruction. This involves:
  • An autograft, where the patient’s own tendon (taken from the hamstring, thigh, or ankle area) is used to replace the torn ACL.
  • During surgery, the doctor makes a few small opening in the knee, places a camera and special tools inside, and repairs the ligament while viewing the procedure on a screen.
• After surgery:
  • Patient are encouraged to bear weight on the leg with the help of a walker and a knee brace.
  • A physiotherapy programme aimed at restoring strength and mobility is initiated soon after surgery. This aims to help the patient regain full range of motion by around 6 weeks, with continued exercises for muscle strengthening.
     

Patients are advised to visit a doctor if they experience sudden knee pain with a popping sound, swelling within a few hours of injury, persistent knee instability, or difficulty bearing weight on the affected leg.

You can reduce the risk of ACL injuries by:

• Strengthening core and leg muscles, particularly the hips, lower abdomen, and hamstrings.
• Practising correct techniques for jumping and landing to protect the knees.
• Improving movement patterns and learning safe techniques during sports.

If you suspect an ACL injury, you should see an orthopaedic surgeon, particularly one who specialises in sports injuries. A physiotherapist also plays a key role in both rehabilitation and prevention after treatment.