what was the injury darren bent had last season

one of these ?...The medial collateral ligament is located on the inside of the knee and is taut when the leg is straightened. It is a strong ligament but can be sprained or completely torn (ruptured) when the straightened leg is twisted at the same time as being knocked sidewards. This can be during a contact sport, as with a football tackle, or without contact, as can happen in a fall while skiing.

The injured knee is painful and swollen, especially on the medial (inner) side. By examining the knee and seeing how much the lower leg can be moved outwards, while the upper leg is held still, doctors can usually establish how badly the ligament is sprained. Grade I (a sprain) and grade II (partial tear) injuries of the ligament, are more painful than a complete (grade III) tear. Many grade I or II sprains will heal by themselves. A grade III tear usually requires surgery.
Knee injuries