Within the knee joint, there are four essential ligaments that provide stability to the knee. A ligament connects bone to bone and protects against movements of hypermobility in the joint. The four ligaments in the knee are the anterior cruciate ligament (ACL), the posterior cruciate ligament (PCL), the lateral collateral ligament (LCL), and the medial collateral ligament (MCL). The topic of this article will be the fourth ligament mentioned above, the medial collateral ligament. The MCL is located on the inner side of the knee, connecting the bottom of the thigh bone to the top of the shin bone, the tibia. The medial collateral ligament protects against extreme valgus stresses on the knee. A valgus stress is one that causes the lower leg to be in a more lateral position than is normal relative to the upper leg. Think of your knee collapsing inward from the side, this is a valgus stress on the knee and this is what the MCL is intended to prevent. In a healthy knee, when the knee is sustaining a valgus force, the MCL gets pulled taut and prevents the leg from being overstressed in the valgus position. If the force is great enough or if the MCL is weak or compromised, it may tear, either partially or completely. All ligament sprains are graded according to the severity of injury. These grades are:

● Grade I: mild injury, an overstretching of the ligament, but no tear
● Grade II: moderate injury and partial tear, not completely torn, still able to provide some stability to the joint
● Grade III: complete tear, unable to provide any stability

The symptom of an MCL sprain will be very similar to other symptoms of an acute orthopedic injury, particularly a ligament sprain. The location of the pain, however, will differ and be a key indicator as to the nature of your injury. The symptoms you experience with an MCL sprain may be any or all of the following:

● Severe pain at the site of injury
● Pain located on the inner side of your knee
● A ‘popping’ sound may have been heard at the time of injury
● Swelling, erythema (reddening of skin), and warmth around the knee joint
● Bruising may be noticed
● A feeling of instability or looseness in the knee joint when attempting to walk or bear any weight on the affected knee

Symptoms may wane and wax over time. You may experience some symptoms immediately after injury while some may not appear until days later.



If You Are Experiencing Symptoms, Schedule an Appointment Dr. Burke Orthopedics Immediately.

The causes of a sprain to the MCL are almost always sports-related. However, any force that places valgus stress on the knee and causes your leg to collapse inward can cause an MCL sprain. High impact, contact sports are a likely cause. A direct hit to the knee from the side, or landing incorrectly can cause an MCL tear. A strong twisting motion can also be a cause. Planting of the foot while rotating the body while running can cause this. This may sound similar to a mechanism of injury you have read for a tear of the ACL. These two ligaments are often torn simultaneously. When the ACL, MCL, and medial meniscus are all injured together, this is known as the unhappy triad and while an MCL sprain alone has the possibility of healing with conservative treatment, an unhappy triad injury will almost always require surgical intervention.

Treatment of any ligament injury depends on the severity of trauma. If you experience a mild or even moderate sprain, grades I or II, conservative treatment may be all that is necessary in order to allow the injury to heal. This will require a course of physical therapy possibly along with walking with crutches as well as wearing a knee brace for some time in order to eliminate weight being placed on the joint for a while. In the case of a complete tear or Grade III sprain, surgical intervention will most likely be necessary. In the case of an acute injury, an immediate intervention that you should put into effect is the RICE protocol. This stands for:

● Rest
● Ice
● Compression
● Elevation, when elevating the leg, be sure to lie back and elevate the leg so that the injury is above the level of the heart in order to help facilitate blood flow

Other treatment for an MCL sprain will include:

● Restoring range of motion through stretching
● Strengthening the muscles
Decreasing swelling
● Focusing on restoring stability of the leg
● Reducing pain with pain relieving modalities