A tear or rupture of the anterior cruciate knee ligament (ACL) is an increasingly common injury in today's youth sports, especially among female athletes playing sports that involve jumping and pivoting such as basketball, soccer, volleyball, and lacrosse.

In the best case scenario, reconstructive surgery of the ACL would allow an athlete to return to his previous level of function with respect to performance/quality, frequency and intensity of sports participation, without an increased risk of further injury or permanent degenerative changes to the knee such as osteoarthritis.

The bad news

While treatment advances in surgery and physical rehabilitation over the past 30 years have allowed many athletes to return to the playing field or court, the hard truth (which some parents and athletes don't want to, but need, to hear) is sobering:

• Even with intensive rehabilitation, a reconstructed knee is usually not going to be even close to normal until at least 1 year after surgery;

• Coming back too early is a real problem and puts the athlete at a higher risk for re-injury.

• Only 60% to 70% of athletes are ultimately able to return to play, often with a decreased level of performance. A recent National Football League study revealed that 20% of players never returned to play after ACL reconstruction; among those who did return, a drop in performance level was the norm.

• It is not unusual for an athlete to have had two ACLs replaced by the time she enters high school. It is very unlikely in such circumstances that the athlete's knees will ever be normal;

• Athletes who have had reconstructive ACL surgery "retire" at a much higher rate than their peers.

• Early retirement is a critical problem among female athletes participating at an elite level in soccer, basketball, gymnastics, cheerleading and volleyball;

• Surgical and rehabilitation advances have done little or nothing to prevent the future development of osteoarthritis in young athletes; degenerative changes are the rule rather than the exception.

Hope for the future?

A new surgical technique (anatomic double-bundle ACL reconstruction) holds out the promise of better clinical outcomes in terms of return to play, re-injury rate, retirement date, and, most importantly, in delaying or preventing osteoarthritis in the repaired knee.

In the meantime, it is critically important that the return to play decision be individualized to the athlete and the sport; that both parents and young athletes understand that a slow, phased-in approach be taken during the rehabilitation process; and that they hear not just the stories about players who come all the way back from ACL surgery after only four months, but about those that don't.