What are the cruciate ligaments?

Ligaments are strong bands of tissue that connect the bones in your body.

The anterior and posterior cruciate ligaments connect the shin bone (tibia) and the thigh bone (femur). They help stabilise the knee and keep the knee joint together during twisting or pivoting movements.


The anterior cruciate ligament (ACL) is the most commonly injured knee ligament. You can stretch or tear your ACL if you make a sudden change of speed or direction or a movement that twists the knee.

The posterior cruciate ligament (PCL) is stronger and so less commonly injured. PCL injury is seen most commonly following car accidents.


  • Popping sensation – may be felt or heard in the knee at the time of injury. This doesn’t happen to everyone
  • Pain – often felt suddenly after injury. Pain may be absent in stretches or small tears
  • Swelling – usually occurs in the first 24 hours following injury
  • Joint instability – may give trouble weight baring or walking on affected leg
  • Loss of joint mobility – inability to bend or extend your knee as you would normally.

What is the treatment?
In the first 48 – 72 hours after injury think of:

Paying the PRICE

  • Protect your injured knee
  • Rest: using a crutch may help keep weight off your knee
  • Ice: applied for 10-30 minutes at a time. Wrap ice in a plastic bag or towel to prevent ice-burn
  • Compression: a tubular bandage may be helpful. Should not be too tight or worn at night. Only to be used in first 48 hours
  • Elevation: reduces swelling. Prop up legs using a pillow when sitting or lying in bed. Aim to keep above the level of the heart.

Do no HARM – no Heat, Alcohol, Running or Massage

Further treatment depends on the severity of ligament damage. Non-surgical management of minor injuries includes:

  • Physiotherapy – to strengthen the muscles supporting the knee
  • Knee supports and braces
  • Painkillers: paracetamol and non-steroidal anti-inflammatory medicines should be used with guidance from your general practitioner or pharmacist.

Surgery may be necessary to reconstruct the damaged ligament if it is torn badly, if your knee gives way when walking despite physiotherapy, or if your ACL tear is associated with other injuries such as cartlage or other ligaments.