ANTERIOR CRUCIATE LIGAMENT INJURY

WHAT IS IT?

The anterior cruciate ligament is located in the middle of the knee and it connects the thighbone with the shin. Its main mechanical function is to prevent the shin bone shifting forward against the thighbone. When it tears this shift can occur resulting in subjective feeling of instability, a giving way sensation. If the knee is unstable other structures such as the meniscus and the joint cartilage are more at risk of damage themselves.

HOW DOES IT HAPPEN?

ACL rupture is usually a result of a sporting injury when you suddenly stop or try to change direction. The foot stays in one place while the body moves resulting in forceful twisting of the knee. It can also happen if you land badly or when you collide with another player such as a rugby tackle.

WHAT ARE THE RISK FACTORS?

Certain anatomical features, in other words how your knee is designed.
Age. This injury mainly affects people between 14-45 as they tend to be more active.
Female sex. Female athletes are 3 times more likely to suffer an ACL injury than males.
You are more likely to suffer an ACL tear if you are overweight. You can check your BMI here.
Sport. Football, rugby, tennis, skiing, squash, basketball, handball are the highest risk sports for an ACL injury. Some of this is related to the use of studded boots or increased friction between the shoe and the floor.
Poor conditioning. This means that your are not used to doing a kind of activity and your technique is below par. This is common in recreational athletes.
Previous ACL rupture. You are about 15% more likely to suffer an ACL tear if you had one before.

WHAT ARE THE SYMPTOMS?

Pain and swelling. When the ACL tears you can often feel a pop and have sharp pain and swelling in the knee. Most people cannot weight bear. Things settle down in a few weeks and patients start walking normally again, but some people have a degree of ongoing pain.
Locked knee. Some people will also sustain a meniscus tear and a few of these cause the knee to lock.
Chronic instability. About a fifth of people can continue with normal activities following an ACL tear. However, most will develop chronic instability (buckling or giving way) especially when engaging in activities involving twisting on the knee.

HOW IS AN ACL TEAR DIAGNOSED?

A history of the injury and the symptoms are usually fairly typical.
The clinical examination confirms the pattern of instability, limited movement and swelling. The acutely injured, painful knee is difficult to examine properly. Examination of the healthy other knee is useful for comparison.
An x-ray is useful to see if there is bone damage and to exclude other conditions.
Mr Kordas will request an MRI scan to confirm the diagnosis and assess the rest of the structures in and around the knee such as the meniscus, ligaments and joint cartilage.

WHAT TREATMENTS CAN I HAVE?

Non-surgical treatment. Immediately after the injury you will need treatment to reduce the swelling and inflammation in your knee so you can regain full movement and get rid of the pain. Our physiotherapist will advise you on using ice, rest and gentle exercises. Once your knee has settled down you will go through an ACL rehab program which may take a few months. If your knee feels stable enough for the activities you are doing you may not need any further treatment.
If your knee is locked you will need a keyhole operation to remove any mechanical cause before you can start the exercises. Depending on the circumstances you may or may not be able to have ACL surgery at the same time.
Surgery. If your knee keeps giving way during everyday activities, stops you taking part in sport, or interferes with your work you may need an ACL reconstruction.