Acute knee ligament injuries

Understanding this condition

The knee is stabilised by four main ligaments: the two cruciate ligaments (ACL and PCL) at the centre, and the two collateral ligaments (medial and lateral) on the sides. A violent trauma can injure one or more ligaments in isolation or in combination.

Multi-ligament injuries (two or more) are rare but serious. Knee dislocation (complete loss of contact between femur and tibia) is an absolute emergency as it may be accompanied by vascular injury (popliteal artery) threatening limb viability.

Symptoms

Immediate pain, sometimes rapid swelling (a sign of a serious injury), major instability, and sometimes inability to mobilise the knee. A dislocation may reduce spontaneously, but the knee remains very unstable and painful.

A precise clinical examination (often performed under anaesthesia in the emergency setting) and early MRI provide a full assessment.

How can it progress?

An untreated multi-ligament injury leaves major knee instability, severe loss of function, and predisposes to early osteoarthritis. For dislocations, failure to manage the emergency may compromise the limb.

Treatment options

As an emergency: immobilisation, systematic vascular and neurological assessment for dislocations, and specialist management.

Subsequently: surgical ligament reconstruction, sometimes in several stages depending on the injuries. Outcomes depend greatly on the promptness and quality of management. A specialist consultation is essential.