The cause of most ACL tears is a sudden, abrupt change in force to the knee. This can occur during an unexpected cutting move during sports, or when landing from a jump during basketball. Recent evidence shows that most of these injuries are non-contact and do not involve a collision with another player.

Typically, the knee gives out, and the athlete hears a pop and collapses in agony. Most athletes with an ACL tear cannot resume play and must be helped off the field or court. The knee usually swells very quickly.

At the emergency room, X-rays are taken, which usually come back normal, with swelling on the knee. The diagnosis is typically a knee sprain, and the athlete is placed in a knee brace and instructed to follow-up with a sports medicine specialist in the next few days.

The initial treatment consists of ice during the first 24 to 48 hours, elevation, rest, compression, such as an ACE wrap, and keeping the knee from moving by applying a knee brace. Crutches are usually needed. A pain medication, such as ibuprofen, hydrocodone or oxycodone, is often prescribed. The patient may have to miss a few days of school after the initial injury.

Most young athletes who want to continue playing sports, especially basketball, soccer, volleyball, football and wrestling, choose to have ACL reconstruction surgery. Without surgery, a person with a torn ACL is at risk for repeated knee instability. Each time the knee gives out, there is a risk of increased damage to the cartilage in the knee, which is extremely hard to repair and can cause arthritis later in life.

Because the ACL will not heal even if it is repaired, a nearby tendon is used as a substitute for the torn ACL tendon.  This is why the procedure is called a reconstruction. An adult-style ACL reconstruction will go through the growth plates of the leg bone (tibia) and the thigh bone (femur).  Children and teens who still have a lot of growth remaining in their knees are at some risk for a slowing of growth if standard ACL surgery is performed before they are finished growing. We have co-developed an “All epiphyseal” ACL reconstruction for children that restores normal anatomy and function but does not touch or cross the growth plates. 

The chance of stopping a child’s growth after ACL reconstruction in young patients is a rare complication. Once a teen’s ACL is reconstructed, they can usually return to the prior level of sports competition without any more episodes of instability.

A pre-operative treatment program usually consists of:

• Aggressive rehabilitation with strengthening of the knee muscles
• Regaining range of motion
• Controlling swelling

A brace can help provide support; however, patients awaiting reconstruction should probably avoid basketball, soccer, wrestling, football and volleyball.

After surgery, a patient can usually walk on the affected leg as tolerated, and there are no limits in motion. The patient starts physical therapy the week after surgery and may return to sports when he or she has greater than 90 percent strength in the leg.  This is usually four to six months after surgery.

Neuromuscular training (learning how to land properly from jumps) may reduce ACL injuries in females.

Call your child's pediatrician, family doctor or orthopaedic doctor if:

• Severe pain continues despite pain medication
• Your child develops pain, numbness or coldness in the leg
• The knee keeps giving out