Stan Kolby leads a very active life--skiing, mountain biking, hunting, running and golf. He even owns a company that caters to people, like himself, who enjoy river sports such as canoeing, kayaking and rafting.

A few years ago, a skiing injury to his left knee brought all of Stan's activities to a halt. Stan had torn his anterior cruciate ligament, or ACL. The ACL, which runs down the middle of the knee, is one of the most commonly injured ligaments of the knee. This injury occurs when a person suddenly pivots and places excessive stress on the ligament. When the ACL tears or ruptures, bleeding occurs and the knee becomes unstable.

After the initial swelling and pain subside, surgery is often required to get the patient back to former activity levels. Stan's injury required surgery because a torn ACL cannot be repaired, only replaced. His orthopaedic surgeon replaced the ligament using tissue from a tissue bank. This surgery was done using arthroscopic techniques, which use specialized surgical instruments that enable the surgeon to implant the new tendon while viewing video images of the inside of the knee. Arthroscopic surgical techniques are often preferred over "open" surgical techniques because they require smaller incisions, less blood loss, less swelling and less pain. As a result, the patient can get into physical therapy and back to their normal daily activities much faster.

Today Stan can participate in the many activities that he enjoys without pain or instability in his knee. "I'm still as active as I used to be," says Stan, "although I don't ski off cliffs anymore!"

More than 50 million people in the United States suffer trauma and injuries to the musculoskeletal system each year. While many of these injuries are minor, more than half result in activity restrictions, with 20 percent resulting in restricted bed days. Ongoing research for new and better ways to treat musculoskeletal injuries is critical to getting injured patients back to former levels of productivity quickly and with the least amount of pain. Improved materials such as biological replacements for ligaments and tendons, better surgical techniques to reduce the impact of invasive surgeries, and understanding of trauma injuries are all important areas of orthopedic research to help injured patients return to normal, pain-free lives.

"The surgery helped me get back to doing the things I like to do," Stan says. "After all, isn't that what medicine is all about?"