What is a knee ligament injury?

A ligament tear of the knee occurs when an excessive strain is placed across the knee overloading the supporting ligament, resulting in damage and pain.

Ligaments are the names given to strong bands of connective tissue which run through our joints to help provide strength and stability. The knee has four main ligaments:

  • The anterior cruciate ligament (ACL) helps to prevent the knee from over-rotating and helps to limit forward movement of the tibia on the femur
  • The posterior cruciate ligament (PCL) helps to prevent the knee from over-rotating and helps to limit backwards movement of the tibia on the femur
  • The medial collateral ligament (MCL) supports the inner side of the knee
  • The lateral collateral ligament (LCL) supports the outer side of the knee

Knee ligament injuries most commonly occur from trauma such as when playing sports requiring rapid changes of direction such as football, rugby and netball or during tackling.

Knee ligament injury

Common symptoms

At the time of injury: Symptoms may vary depending on the ligament affected.

For a cruciate ligament tear, pain and a rapid onset of swelling are most common. A pop may be experienced in up to 70% of these cases.

If you experience any knee swelling it is recommended to seek the advice of a suitably qualified clinician to obtain appropriate clinical guidance. 

The location and extent of pain and swelling will depend on the ligament injured and the severity of the injury.

First few weeks after injury: Pain and any swelling should begin to reduce. The main symptom are usually stiffness and weakness to the knee joint. Early and regular movements and rehabilitative exercises are vital, reducing the stiffness and maintaining power, as quickly as possible.

Ongoing symptoms: Some individuals may experience ongoing knee joint instability, giving way and pain.

It is very difficult to predict who may experience these symptoms as there is little correlation between the severity of knee ligament injury and ongoing knee instability.

Adhering to a supervised knee joint strengthening and co-ordination rehabilitation routine will significantly reduce the chances of developing ongoing knee pain and instability.

How are knee ligament injuries diagnosed?

Knee ligament injuries can be reliably diagnosed by your doctor or physiotherapist by taking a history of your condition and by conducting a physical examination.

The main feature on examination is laxity into specific movements of the knee designed to stress each ligament.

X-rays or other scans may be requested to exclude any associated fracture or cartilage injury or to plan surgery if needed.

How are knee ligament injuries treated?

Acute phase management

MICE = Movement, Ice, Compression, Elevation

Acute phase management is aimed at reducing swelling and alleviating pain to allow rehabilitation to commence as early as possible following injury. The following self-help videos explain how to safely follow a MICE routine after an injury:

Ongoing non-surgical management

Ongoing management requires a supervised rehabilitation program of exercises to ensure the knee restores its full range of motion and to ensure appropriate grading of strengthening and coordination exercises are undertaken. The exercises below are a guide to the type of rehabilitation indicated. In significant ligament injuries it is important to seek professional advice to ensure the correct exercises are being performed at the right stage of rehabilitation.

Exercises. Regular exercises to maintain flexibility and strength to the affected knee joint:

5×30 second holds, 2x per day

3×10 repetitions 3-4x per week

3×10 repetitions 3-4x per week

Surgical management

Surgery is rarely required to repair the medial and lateral collateral ligaments which normally respond well to rehabilitation. For anterior cruciate ligament injuries, ligament reconstruction is an effective option if instability or a “giving way” of the knee continues in spite of undergoing a supervised rehabilitation regime.