What is the ACL?

The Anterior Cruciate Ligament (ACL) is one of the main stabilizing ligaments in the knee. It connects the thigh bone (femur) to the shin bone (tibia) and helps prevent abnormal movement. The ACL is especially important for rotational stability, allowing safe movements such as pivoting, twisting, or changing direction quickly without the knee giving way.

Why are ACL injuries so common?

The knee is vulnerable because it supports the body’s entire weight while also allowing a wide range of motion. Stability decreases when the knee bends, making it more prone to injury. Sports that involve jumping, cutting, or pivoting increase the risk of ACL tears.

Inside the Knee: Where is the ACL?

The knee joint contains bones, ligaments, tendons, cartilage, nerves, and blood vessels. The ACL runs diagonally through the center of the knee inside a fibrous capsule that provides stability.

Signs and Symptoms of an ACL Injury

• Pop: Many patients hear or feel a “pop” at the time of injury.
• Swelling: Rapid swelling from bleeding within the joint.
• Pain: Usually significant after the injury.
• Instability: A feeling that the knee may buckle or give way.

Diagnosis

Doctors diagnose ACL injuries through:

• Physical examination – Special tests such as the Lachman Test, Anterior Drawer Test, and Pivot Shift Test.
• Imaging:
  
  • X-rays: Rule out bone injury.
  • MRI: Shows soft tissue damage, including ligaments, cartilage, and menisci.

Watch video of ACL Reconstruction Hamstring Method

Treatment Options

Immediate Care (RICE)

• Rest – Use crutches, avoid weight-bearing.
• Ice – Reduce pain and swelling.
• Compression – Wrap with bandages.
• Elevation – Keep the leg raised.

Non-Operative Treatment

Best suited for:

• Older or less active patients.
• Those willing to avoid pivoting sports.
• Partial tears or low-demand activities.

These patients may do well with bracing and rehabilitation.

Surgical Treatment (ACL Reconstruction)

Recommended for:

• Younger or athletic patients.
• Those with persistent instability.
• Multiple ligament injuries.

ACL surgery involves replacing the torn ligament with a graft (tissue from your own body). Direct stitching (“repair”) of the ACL is generally unreliable. In patients with high risk of re-rupture an additional procedure is undertaken in addition to the ACL reconstruction. This is a lateral extra-articular tenodesis (LET) where a strip of tissue from the iliotibial band on the outer side of the knee is used as an extra reinforcement of the ACL reconstruction. The LET significantly reduces re-rupture in higher risk patients such as patients under 25 years, soccer players and patients with loose ligaments.

Recovery and Rehabilitation

An individualised rehabilitation programme is provided to each patient.

Bracing and Follow-Up

• A brace is usually not needed after isolated ACL reconstruction.
• Doctors and rehabilitation therapists evaluate motion, stability, pain, and return to function at 6–12 months post-surgery.