MCL Tears and Repairs
The medial collateral ligament (MCL), located on the inside portion of the knee, is one of the more common sporting injuries to the lower extremity. It is usually an “acute” injury, meaning that it happens suddenly due to trauma. In sports, the athlete may take a sudden blow to the outside of the knee, creating excessive tensile force to the MCL, such as being tackled in football. This injury also occurs commonly in sports where the ankle is immobilized such as hockey and downhill skiing, where the ankle is stabilized in a skate or boot. This immobilization leaves the knee to absorb the full impact of a collision or fall and increases the risk of knee injury.
Functional Anatomy
The skeletal anatomy of the knee consists of three bones. The thigh bone, medically termed the femur connects with the shin bone, called the tibia. In the front of the knee is the knee cap, or the patella. Holding these bones together are the four major knee ligaments. Two are located deep within the joint and are called cruciate ligaments. They prevent excessive forward and backward motion, as well as rotation. The remaining two are the collateral ligaments, and are located on the sides of the knee. Their job is to prevent lateral, or sideways, motion of the knee. The MCL is located on the inside of the knee joint and prevents the knee from collapsing inward. In addition to the bones and ligaments, the knee has two cartilage pads called the medial meniscus and lateral meniscus. These pads act as shock absorbers within the knee.
Types of MCL Injury
Tears to the MCL are usually a result of direct trauma, either from a blow to the outside of the knee, such as with a football tackle, or a fall that pushes the lower leg sideways. Partial tears will cause varying degrees of instability within the knee, and are often treated successfully with conservative interventions including bracing and physical therapy to strengthen the surrounding musculature. Complete tears may cause significant instability in the knee, especially if in combination with other ligament injuries such as the ACL.
If isolated, even high-grade MCL tears can still often be treated with bracing alone. However, such tears often occur in conjunction with other structures such as the medial meniscus or the anterior cruciate ligament (ACL). The medial meniscus has a direct connection to the MCL, making it particularly susceptible to injury during an acute MCL sprain. Should this be the case, surgical intervention may be required to restore full function due to the degree of instability caused by multiple injuries.
Non-operative Treatment
MCL tears are most often treated successfully without surgery. With significant tears there may be an initial degree if instability following injury. A hinged knee brace may be prescribed to limit control of this aberrant movement. As the ligament heals, your orthopedic surgeon may refer you to physical therapy to strengthen the leg musculature surrounding the knee, and also to restore normal movement patterns that may have been disrupted following injury and immobilization. Patients are able to perform most of their normal daily activities during this process, with the possible exception of high intensity athletics, and generally have very good outcomes following four to eight weeks of rehabilitation.
Surgical Treatment
In cases where non-operative treatment has failed or in some multiple ligament injuries, the surgeon will recommend repair or reconstruction surgery. This means that the damaged MCL will be repaired with sutures if possible. If that is not possible, then a new ligament can be fashioned from a soft-tissue “graft,” a piece of tendon taken from either the patient or a cadaver. A small incision is made to gain access to the area, and the repair made, or the tendon graft is anchored in place with surgical screws.
Following surgery, there will be a period of immobilization, followed by physical therapy. The duration and intensity of the rehabilitation process is dependent on the type of MCL repair or reconstruction, and the other injuries present. In most cases, patients can return to full function including athletics at the conclusion of treatment.