TYPE OF INJURY
The tear of the lateral collateral ligament (LCL) / postero-lateral corner (PCL) is attributed to a great force exerted on the inner surface of the knee that is stretched or slightly flexed, resulting in the tibia being adducted, in relation to the thigh. It is very common in footballers and after road accidents, or falls from a relatively high height.
It is very likely that the injury of the lateral collateral ligament is accompanied by an injury of the common peroneal nerve, or may lead to a disruption of the anterior and / or posterior cruciate ligament, as well as the postero-lateral corner of the knee. The injury is classified into three categories, depending on whether there is a stretch or disruption of very few fibers, or whether it is partial or total. The pain is located on the outer surface of the joint, or at the insertion of the ligament in the head of the fibula, and worsens when the tibia is adducted. In addition, many patients experience knee instability (“Varus Thrust” gait).

DIAGNOSIS
Diagnosis is based on the obtaining of an extensive history and a clinical examination, which includes various tests that will show whether the lesion of the lateral collateral ligament is isolated or not. An MRI will confirm the diagnosis, while the radiological examination will detect any fragmentary fractures.
The treatment is usually surgical, especially in cases where the disruption is total and there are concomitant lesions (disruption of the anterior or posterior cruciate ligament), or if instability is important. It is essential that the surgeon always assesses the knee formation, as well as the possible existence of the “varus thrust” during walking.

SURGICAL PROCEDURE
The main purpose of the surgeon is to repair and reattach each anatomical element onto its original position. If this is not possible - as is usually the case, when the injury is chronic, namely the pain lasts longer than one month - then the surgeon shall proceed to a reconstruction of the lateral collateral ligament or all the posterolateral corner with a tendon autograft.
The selection of autografts on behalf of the surgeon is also crucial, as these knees usually require multiple reconstructions. Postoperatively, it is necessary to use a knee brace and, of course, physical therapies are performed to maintain the knee motion range and exercises for the strengthening of the quadriceps femoris, the biceps femoris and the gastrocnemius muscles.