|More about Wilko's knee injury|
|Around the Academy:
Ligament injuries are one of the most common injuries to the knee and very few players fully recover from the problem.
It is usually a twisting or turning action which damages the ligaments.
Direct contact of the knee from opponents can also cause damage to the ligaments.
It can also be simple bad luck - England fast bowler Simon Jones twisted his knee after his studs got caught in the turf as he slid to retrieve the ball in the first Ashes Test in Brisbane in 2003.
How many ligaments are there in the knee?
Gazza's famous knee injury was the Anterior cruciate ligament, which are cross-shaped within the knee-joint.
If it is completely torn you could be out for a year.
The medial ligament is linked to the cartilage so further problems can result.
Physiotherapy is used as the medial ligament, being outside the joint, heals more easily than the internal cruciate ligaments.
Cruciate injuries, however, require surgery to repair the damaged ligament and several hundred such operations are carried out on sports stars each year.
The vast majority of isolated medial ligament injuries heal without an operation
Sports injury consultant