The goal of ACL surgery is to stabilize the knee joint, return it to normal mechanical function, and permit the athlete to resume sports without a deficit. Here are the most common reasons I see failures and what can be done about it.

When college-age people come to see me with severely damaged joints, it’s a challenge. High school kids with the same issues are depressing. There are solutions, but they simply are not being applied widely enough.

The ACL Study Group meets every two years to update the latest knowledge on ACL injuries and treatments. This year’s meeting was at the base of the Hahnenkamm ski race in Kitzbuhel Austria—the most famous downhill ski race on the World Cup circuit. One hundred and fifty of the world’s top ACL surgeons watched 30 of the world’s bravest ski racers hurtle down the ice-crusted hill at 140 km/h (84 mph). The outcome of the race was predictable: The Austrians dominated. The outcome of the scientific meeting, however, was less conclusive; the ACL is still a tough problem to solve.

For decades there have been unsuccessful efforts to repair the anterior cruciate ligament (ACL) after rupture. Why? Because the forces required to tear the complex weave of the ACL’s collagen fibers involve both tearing and pulling apart. Think of a climbing rope: When overstretched the rope fails within its sheath, not just at a single clean edge. Here is why the ruptured anterior cruciate ligament is most often replaced (reconstructed) rather than repaired.

“Doc, my knee popped, it now catches and gives way.” Whether it is the knee, the ankle, the hip, or the shoulder, catching and giving way—especially after hearing a pop—is bad news.

The ACL is the key stabilizer of the knee and is torn 300,000 times a year in the U.S. alone. The treatment of these torn ligaments has evolved in some ways, but not so much in others. Here is what we know today.

Red is the color. So much depends on red. Healthy red blood is the essence of all tissues and even the determinant of the health of bone. I look at life through this prism and notice the shades suggestive of this injury or that disease. I read those signals to predict outcomes.

To cut, or not to cut? To repair, or to let heal? To rehab without fixing? To live with imperfect parts? Each of these questions is faced every day by surgeons and their patients. Here are a few decisions about incisions.

A recent study documented that 40% of people who undergo ACL surgery experience clinically diagnosable depression. Life disruptions are a drag—especially when they put the brakes on your active lifestyle.

ACL injuries may not be as notorious as concussions, but they’re a wider threat.

Arthritis is preventable. Yet until recently most people thought it was inevitable. Here are some examples of how to best treat your injured knee.

Standardized care is not always the best care. What we really need is an agile medical system that values innovation.

ACL injuries are more devastating to the knee then previously thought—and the tools for replacing the ACL produce their own problems. But there is hope. Here is an update from the leading ACL surgeons’ conference, just held in Sweden.

The Golden State Warriors, and star Steph Curry, may seem like superheroes—but they’re human beings with human parts. He’s what their knees endure during each game, and why (barring injury) they're able to handle it with such finesse.

When a professional dancer hears the dreaded “pop” of an anterior cruciate ligament (ACL) tear, he or she might imagine that they’ll never perform again. However, modern treatment and healing techniques can make what seems like miraculous recoveries.