Cruciate ligament injuries are common amongst sports stars and can affect anyone. What are they?

The knee joint lies between the thigh bone (femur) and the shin bone (tibia). The joint is kept in place and the two bones maintained in their appropriate places by four ligaments, like elastic straps. Two of these are cruciate ligaments.

The anterior (forward) cruciate passes from the rear of the thigh bone to the front of the shin bone. The posterior (rear) cruciate passes the opposite way. The two entwine in the knee joint, forming a cross, hence the description of cruciate.

A tear in either of these cruciate ligaments is possible. Those in the forward ligament are most common. They are often suffered by people involved in sports. The tear will allow the shin bone to move forward as against the thigh bone.

A direct blow to the knee can have this effect, as can the force caused by a twist of the knee or an unusual action of the leg. For example, if the weight is on the leg and the top of the leg forced forwards, a tear could take place. Any unusual movement against the normal position of the knee may also cause a tear.

Less common are tears to the rear cruciate ligament. They are more often the result of heavier accidents such as car crashes. The result here is to allow the shin bone to move backwards as against the thigh bone.

The symptom to the sufferer is likely to be immediate pain and swelling in the joint, difficulty in movement and pain when under pressure. Sporting injuries are often accompanied by a sound as the tear takes place.

These tears will immobilise the sufferer and require expert medical assistance from an Orthopedic Doctor to recover.