Outer collateral ligament rupture


The bones in the knee joint comprise the thigh bone (femur), shin bone (tibia) and the kneecap (patella). There is furthermore a small joint between the shin bone and the calf bone (fibula). The knee joint is strengthened by a joint capsule which is in turn strengthened on the sides by an outer and an inner collateral ligament (ligamentum collaterale laterale (LCL) and ligamentum collaterale mediale (MCL)). Inside the knee there are two ligaments, the anterior and posterior cruciate ligaments (ligamentum cruciatum anterius (ACL) and ligamentum cruciatum posterius (PCL)).


  1. Ligamentum cruciatum posterius
  2. Ligamentum collaterale mediale/tibiale
  3. Meniscus medialis
  4. Insertio anterior menisci medialis
  5. Ligamentum transversum genus
  6. Tibiae
  7. Fibulae
  8. Ligamentum cruciatum anterius
  9. Ligamentum collaterale laterale/fibulare
  10. Meniscus lateralis
  11. Femur



  1. M. gastrocnemius
  2. Caput fibulae
  3. B. subtendinea m. bicipitis femoris inferior
  4. M. biceps femoris
  5. Ligamentum collaterale laterale/fibulare
  6. M. plantaris


Cause: When the shin bone is pressed inwards in relation to the thigh bone the outer side-ligament is stretched. If the load becomes sufficiently powerful (as is the case when the load is sudden, so that the thigh muscles do not have time to tighten and stabilize the joint) the ligament can rupture.

Symptoms: Sudden pain on the outside of the knee. Occasionally a snap is felt when the ligament ruptures. In severe cases the athlete complains about a sense of looseness in the knee

Acute treatment: Click here.

Examination: If a total or partial rupture of the ligaments in the knee is suspected, you should seek medical attention for a diagnosis. An x-ray examination is recommended as many ligament injuries in children and adolescents can be accompanied by damage to the bone at the point of attachment of the ligaments (article). The doctor can perform various knee tests to examine the stability of the knee (external side-instability-test). If the knee is stable the injury is called a “sprain” of the outer side-ligament. If the knee is loose the injury is called a “rupture” of the ligament. The diagnosis is usually made from a normal medical examination. If there are any doubts surrounding the diagnosis, an ultrasoundexamination scan can be performed which will reveal the rupture and the bleeding along the ligaments (Ultrasonic image)

Treatment: The treatment of a partial or total rupture of the outer side-ligament involves relief and rehabilitation (article). If the knee is markedly loose, you can, for a short period, use a support splint (Don Joy). With pronounced sideways looseness surgery can be considered (article). (However if the rupture of the outer side-ligament is combined with other ligament ruptures, as is often the case, surgery is recommended).

Rehabilitation of children and adolescents: INSTRUCTION

Bandage: Hinge bandages can be used initially (Don Joy). Tape treatment of ligament ruptures in the knee have no sure effect.

Complications: If smooth progress is not achieved, it should be considered whether the diagnosis is correct or whether complications have arisen. Supplementary examinations (X-ray, ultrasound, MR scan or arthroscopy) will often be required. The following should be considered:

An inflammation by the ligament fastening is sometimes seen later in the course of the injury, and in some cases bursitis at the ligament fastening is seen (article).

Special: Since there is a risk that the injury can cause permanent disability, the injury should be reported to your insurance company.