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MCL sprain (Medial ligament sprain) or MCL injury is damage to the ligament on the inside of the knee. It is often caused by twisting or an impact to the outside of the knee.
For a grade 1 MCL injury there may be mild tenderness on the inside of the knee over the ligament. Usually no swelling. When the knee is bent to 30 degrees and an outward force applied to the lower leg to stress the medial ligament, pain is felt but there is no joint laxity (see medial collateral ligament injury assessment).
Significant tenderness on the inside of the knee on the medial ligament. Some swelling seen over the ligament. When the knee is stressed as for grade 1 symptoms, there is pain and mild to moderate laxity in the joint, although there is a definite end point (the knee cannot be bent sideways completely).
This is a complete tear of the ligament. Pain can vary and is sometimes not as bad as that of a grade 2 MCL sprain. When stressing the knee as described above there is significant joint laxity. The athlete may complain of having a very wobbly or unstable knee.
The MCL is tested using a valgus stress test which puts a strain on the ligament by applying force to the outside of the knee, stretching the ligament. If pain or excessive laxity are apparent it is possible that the medial ligament is damaged. If the injury is recent - go easy - don't push too hard (although older injuries may require more pressure)
The Medial Collateral Ligament (MCL) connects the inner (medial) surfaces of the femur (thigh bone) and the tibia (shin bone). Its function is to resist forces applied from the outer surface of the knee and so prevent the medial (inner) portion of the joint from widening under stress.
The medial knee ligament has two parts to it - a deep, inner section that attaches to the cartilage meniscus and joint margins and a superficial band that attaches from higher up on the femur to an area, lower down, on the inner surface of the tibia.
Injury to the MCL often occurs after an impact to the outside of the knee when the knee is slightly bent. The MCL on the inside of the knee becomes stretched and if the force is great enough, some or even all of the fibres will tear. The deep part of ligament is prone to becoming damaged first and this may lead to medial meniscal damage also. See also Medial Cartilage Meniscus Injury.
Whilst repetitive valgus forces can lead to a MCL sprain. A pain in this area which does not occur after a sudden injury, should be considered for Pes Anserine Tendinopathy or Bursitis.
As with all ligament injuries, medial collateral ligament injuries are graded 1, 2 or 3 depending on the degree of damage sustained. A grade one tear consists of fewer than 10% of the fibres being torn. a grade 3 is a complete rupture and grade two sits inbetween! This obviously means grade 2 varies considerably in symptoms and so is sometimes broken down further to grades 2- and 2 .
Torn MCL ligaments of the knee should be taken seriously as they affect the balance and stability of the joint. Without the proper functioning of these ligaments, activities such as running over uneven gound become increasingly difficult with the knee having a tendency to "give way". However, with proper rehabilitation, full recovery can be expected following most MCL tears.