Q: My 15-year-old daughter tore her ACL while playing soccer. Her doctor has advised her to wear a brace if she wishes to resume playing. I have heard that surgery is often performed for a torn ACL. Which is better -- surgery or bracing? Will she able to play soccer again? -- Paul.

A: The ACL (anterior cruciate ligament) is one of the more important ligament in the knee. The ACL runs in the knee from the tibia up and backward to the femur and helps to stabilize the knee during walking and running. The ACL is usually injured from a twisting injury to the knee. Other structures which can be injured at the same time are the menisci, other ligaments in the knee or the knee cartilage.

For reasons which are not clear, young women who play soccer have an increase incidence of ACL injuries. Other athletic activities which involve running and changing of direction such as football, basketball, skiing have an increased chance of an ACL tear.

The symptoms of a torn ACL are usually sudden pain, pain with walking and swelling in the knee. Due to the swelling and the pain the patient will usually lose the ability to move the knee and will have difficulty walking or running.

In a knee where the ACL is torn the dynamics of the knee is affected which can lead to further damage to the knee's internal structures such as the menisci, cartilage or other ligaments. These damages can lead to early osteoarthritis.

For young patients and those patients who are very physically active it is recommended that the ACL be reconstructed. The timing of the reconstruction is usually as soon as the swelling in the knee has gone down and when the patient has regained range of motion of the knee.

There is a debate whether to reconstruct ACl in patients who growth plates are open. Since the ACl reconstruction would cross the growth, it is felt that it would damage the plate and might cause growth disturbances. Since your daughter is 15 years old, it is likely that she has completed her growth spurt but you can discuss this with your surgeon.

There are different ways of reconstructing the ACL; each with its own pluses and minuses.

The most common way is to use a portion of the patella tendon as the graft material for the ACL; another technique is to use tendons from two of the thigh muscles. If the patella tendon is used anterior knee pain or possible fracture of the patella can result in the recovery period. If the two tendons are used from the thigh muscle the reconstructed ACL can stretch over time leading to knee instability.

As important as the surgery for reconstructing the ACL is, the rehabilitation is equally important. If rehabilitation isn't performed well the patient can end up with a stiff and at times a painful knee. The rehabilitation usually takes about 12 weeks and is focused on regaining range of motion of the knee and then strengthening the muscles around the knee.

Lastly, rehab is focused on resuming regular sporting activities. Most patients are able to resume normal sporting activities after an ACL reconstruction although it is sometimes recommended that a special ACL brace be used during strenuous physical activities to prevent a repeat ACL tear.

The opinions expressed are solely those of the writer. Dr. Dwight Tyndall is a practicing Spine Surgeon. He can be reached at dstyndall@yahoo.com (use the subject line "bone doctor column"), www.spinecarespecialists.com or at Dr. Dwight Tyndall, 730 45th St., Munster, IN 46321. This column is intended for informational purposes only. Readers should seek specific medical advice from their own physician.