ACL vs MCL Tear: Differences, Causes and Treatments

Which is Worse Torn ACL or MCL

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 ACL is located in the interior of the knee joint and connects the bottom, back of the thigh bone (femur) to the front, top of the shin bone (tibia). 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.

While not always the case, an ACL tear is in most cases going to be the more severe injury. It is considered worse than tearing the MCL because ACL tears are in general more complex to treat and require a longer recovery time after surgery. A medial collateral ligament (MCL) tear can even at times heal on its own without the need for surgery.

What Causes ACL and MCL Tears

The causes of ACL and MCL tears are similar, and they will also exhibit similar symptoms. However, there are key differences that might be able to let you know which ligament may be damaged. Both injuries can occur as a result of a hard blow to the knee, or a twisting or pivoting motion where the foot is planted on the ground but the body continues moving.

In both cases, at the time of injury you may hear a popping sound and feel as though you have immediately lost stability in the leg. This is where the main difference lies. 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.

The ACL is intended to prevent hyperextension of the knee. Think of your knee bending the wrong way. It is an excessive straightening of the knee, and when the force that causes the knee to hyperextend is greater than the ACL can withstand, it tears.

You may continue to be able to walk after a tear of the ACL but you may not. After a MCL tear, you most likely will still be able to walk. It all depends on the severity of the injury. But in both cases, you will feel significant instability of the injured knee.

A meniscus tear in the knee is often accompanied with a ligament tear. By itself however, a tear to a meniscus will not cause the same amount of instability as with a ligament tear, but the symptoms will be similar as far as pain, swelling, and redness.

How Long to Recover from ACL and MCL Tear?

Recovery from these injuries is very different. ACL tears almost always require surgical intervention to fix, and proper recovery can take 6 months to a year.

MCL tears, on the other hand, sometimes have the ability to heal without surgery requiring just a course of physical therapy. If surgery is required to repair your MCL, the recovery process will not be as long as for an ACL repair recovery and will usually only last a few weeks or months.

Treatments at Dr. Burke Orthopedics

An accurate diagnosis is the critical first step in determining how to treat your knee. The specialists at Dr. Burke Orthopedics are quite experienced with treating ligament disorders of the knee and will be able to determine exactly what is injured, how severely, and figure out the best course of treatment.