A multi ligament injury is when 2 or more knee ligaments are damaged following an injury potentially rendering the knee joint very unstable indeed.
Classically they occur following sporting injury or high-energy motor vehicle accidents. In addition to ligament injury there may also be nerve or vessel damage requiring surgery.
The injury is accompanied by significant pain and swelling. In addition, the knee may feel very unstable patients may struggle to weight-bear at all.
The vast majority of multi-ligament injuries will require an operation, preferably within 10-14 days of the injury unless there has been a vascular injury which requires immediate surgery.