Unfortunately, ACL injuries are difficult to avoid, short of being in good condition and not getting over-fatigued. Derotational braces are a possible option, but are cumbersome and expensive, says Simonian.

Injuries can also occur from increased traction in footwear. If the foot is being anchored when the body goes off balance, the body spins around the knee joint, tearing or stretching the ligament. This is followed immediately by swelling, severe pain and limited motion.

There is no way to tell who is predisposed to ACL injury unless the other knee has already been injured, says Simonian. For instance, someone who has skied for 10 years may have had the same fall 100 times before tearing a ligament. Also, the injuries are not age-related, although they most commonly occur among those between 18 to 30.

Unlike tears to other parts of the knee, the ACL does not mend by itself. Surgery is the only means to a full recovery, although some patients can manage without a fully functional ACL if they limit themselves to straight-ahead exercise, such as bicycling, swimming or weight training, says Simonian.

The ACL can be replaced by grafting a tendon from the patient’s own knee. Surgical procedures have improved vastly over the past decade and are minimally invasive. A fiber-optic microscope, called an arthroscope, allows the surgeon to view the inside of the joint with minimal incisions. After surgery, patients can expect to be on crutches for at least two weeks and to wear a brace for four weeks. Normal walking can resume in five to six weeks but patients must refrain from high-risk sports for approximately nine months and undergo extensive physical therapy.

Patients with any knee injury need to begin range-of-motion exercises as soon as possible after seeing a doctor to prevent stiffness, stresses Simonian. ¶

Ellen Liang