ACL Tears

What are ACL Tears?

The anterior cruciate ligament (ACL) is one of the four main ligaments of the knee. The ACL runs diagonally through the middle of the knee joint and prevents the tibia (shin bone) from sliding out in front of the femur (thighbone) and prevents the knee from rotating out of joint.

Although the ligaments of knee are strong, they are frequently injured. Injuries tend to occur by:

  • changing direction rapidly
  • stopping suddenly
  • landing incorrectly
  • direct contact

During the injury, the ligament is stretched and tears occur in the fibres. Because of the forces involved, the ACL is nearly always fully torn.

Unfortunately, when the ACL is torn there is very little healing potential. Lack of a functioning ACL can lead to long-term instability.

ACL injuries are very common in people who play ‘pivoting’ sports such as football, netball and basketball. Women are 2–10 times more likely to injure their ACL than men. ACL injury is also more common in younger people, with 50% of ACL injuries occurring in 15-25 year olds. Unfortunately there has been a recent increase in ACL injuires in children under the age of 15.

What are the symptoms of an ACL tear?

The symptoms of an ACL tear include:

  • a popping sound or a feeling of the knee giving way at the time of the injury
  • swelling
  • pain
  • reduced range of motion
  • tenderness when the knee is touched
  • a feeling like your knee is unstable when you stand or walk on it or try to change direction

What does your doctor look for?

Your doctor will ask you about how the injury happened, about your symptoms and about your general medical history (eg pre-existing conditions or previous injuries).

You doctor will examine your knee looking for swelling, tenderness and move your leg into different positions to check your knee ligaments.

What investigations are needed?

If your doctor is concerned about a serious injury, you may need to have an MRI scan to gain information about the ACL and other important structures within the knee. If a fracture needs to be ruled out, an x-ray will be ordered.

How is an ACL tear treated?

Straight after the injury, you should consider:

  • Paying the PRICE – Protect (use crutches and/or a knee brace), Rest, Ice, Compression, Elevation
  • Do no HARM – no Heat, Alcohol, Running or Massage.

Depending on the severity of your injury and on your specific needs (eg you are a professional footballer), treatment options include:

  • therapy (eg physiotherapy, knee braces)
  • medications (eg anti-inflammatories and other pain medication such as paracetamol)
  • surgery

Our specialists at Orthopaedic Clinics Gold Coast will work with you to create the best treatment plan for your particular situation.

ACL surgery

Based on the Gold Coast, the lower limb surgeons at Orthopaedic Clinics Gold Coast specialise in surgery to fix ACL injuries. The aim of ACL reconstructive surgery is to return stability to the knee. Unfortunately, a torn ACL does not heal by itself and in most cases cannot be directly repaired with stitches, therefore the ligament must be reconstructed. This involves surgery to place a tissue graft where the old ACL was to allow a new ligament togrow onto. There are several graft sources for an ACL reconstruction including the patellabone and the patellar and hamstring tendons.


Physiotherapy is an import part of the treatment for an ACL injury. Not only is it beneficial after surgery, it is also very important to restore strength and motion to the knee before surgery (sometimes called pre-habilitation).

Return to Sport

After extensive physiotherapy most peple return to sport between 9 and 12 months after surgery.  It is important to achieve full strength and motion before return and your surgeon will guide you in this regard.  Recent research suggests that in spite of a good surgical outcome and appropriate rehabilitation, a proportion of people never return to participating in sport at the same level as before their injury.