Anterior and Posterior Cruciate Ligament Injury

What Are the Causes of Injury to the Cruciate Ligaments?

Injury to the cruciate ligaments of the knee is sometimes referred to as a "sprain." The anterior cruciate ligament is most often stretched, torn, or both by a sudden twisting motion (for example, when the feet are planted one way and the knees are turned another way). The posterior cruciate ligament is most often injured by a direct impact, such as in an automobile accident or football tackle.

What Are the Symptoms of Cruciate Ligament Injury? How Is Injury Diagnosed?

Injury to a cruciate ligament may not cause pain. Rather, the person may hear a popping sound, and the leg may buckle when he or she tries to stand on it. To diagnose an injury, the doctor may perform several tests to see if the parts of the knee stay in proper position when pressure is applied in different directions. A thorough examination is essential to the diagnosis. An MRI is very accurate in detecting a complete tear, but arthroscopy may be the only reliable means of detecting a partial tear.

How Are Cruciate Ligament Tears Treated?

For an incomplete tear, the doctor may recommend that the patient begin an exercise program to strengthen surrounding muscles. The doctor may also prescribe a protective knee brace for the patient to wear during activity. For a completely torn anterior cruciate ligament

in an active athlete and motivated patient, the doctor is likely to recommend surgery. The surgeon may reattach the torn ends of the ligament or reconstruct the torn ligament by using a piece (graft) of healthy ligament from the patient (autograft) or from a cadaver (allograft). Although repair using synthetic ligaments has been tried experimentally, the procedure has not yielded as good results as use of human tissue. One of the most important elements in a patient's successful recovery after cruciate ligament surgery is following an exercise and rehabilitation program for 4 to 6 months that may involve the use of special exercise equipment at a rehabilitation or sports center. Successful surgery and rehabilitation will allow the patient to return to a normal full lifestyle.

Each year, Medical College of Wisconsin physicians care for more than 180,000 patients, representing nearly 500,000 patient visits. Medical College physicians practice at Children's Hospital of Wisconsin, Froedtert Memorial Lutheran Hospital, the Milwaukee VA Medical Center, and many other hospitals and clinics in Milwaukee and southeastern Wisconsin.