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Knee Injuries and Athletes
'Pp' Goes the ACL

The scene is all too familiar: A young athlete playing a sport involving quick stops and starts suddenly hears a "pop," clutches his knee and falls to the ground in pain. The sideline diagnosis of an anterior cruciate ligament (ACL) injury is later confirmed by a physician.

The ACL is one of four main ligaments that connect the femur (thigh bone) and the tibia (shin bone). It lies in the middle of the knee and prevents the tibia from sliding out in front of the femur. Its function is to provide rotational stability to the knee.

An ACL injury is the extreme stretching or tearing of the ligament. The tear may be partial or complete, but either way affects the knee's stability. These serious knee injuries are increasingly common in young athletes today. Luckily, there are many things athletes can do to reduce their risk of an ACL injury. And if an injury does occur, Alamance Regional Medical Center offers diagnostic imaging, minimally invasive repair treatments and therapy services to help prevent re-injury.

ACL Injury Causes
ACL injuries typically are caused by a sudden twisting motion in the knee when an athlete decelerates, lands or stops. Most ACL injuries occur in team sports; however 70 percent are incurred with little or no contact with another athlete.* Often when a player reacts to a nearby player, the sudden movement causes the ACL tear.

In addition, coming to a quick stop when combined with a direction change, pivoting or landing from a jump also can cause an ACL injury. And although experts aren't sure why, women are two to eight times more likely than their male counterparts to experience an ACL injury.**

Symptoms, Diagnosis and Treatment
An ACL injury often makes a popping sound, and the leg may buckle when weight is applied. Following the initial pain of the rupture or sprain, the knee typically swells for several weeks. When the swelling subsides, athletes may not experience knee pain or buckling in daily activities; however, without treatment, sports activities may result in further knee damage.

A thorough examination is necessary to correctly diagnose an ACL injury. Several tests may be performed to determine if parts of the knee stay in the correct position when pressure is applied in different directions. Magnetic resonance imaging (MRI) can confirm a suspected complete tear. Partial tears can be confirmed by arthroscopy, an outpatient procedure that allows a surgeon to make a small incision to insert pencil-sized instruments and a light to view the knee's structure.

A partial tear may not require surgical treatment. Complete tears may require surgery; however, minimally invasive techniques to repair ACL injuries offer many benefits over traditional open surgery. These benefits include a shorter procedure, smaller incisions and less recovery time. After ACL repair, physical therapists will help you strengthen the muscles surrounding your knee, improve flexibility and learn new ways of moving to reduce risk of re-injury (see "Prevent ACL Injuries" below).

* Source: National Institutes of Health.
** Source: Journal of Bone & Joint Surgery, August 2004.


	Recognized for Top Orthopedic Care Alamance Regional has been recognized as one of the state's best hospitals for orthopedic care and treatment. For six consecutive years, our orthopedics program has been named by Business North Carolina magazine as one of the top 10 in North Carolina. Our comprehensive orthopedic services include minimally invasive surgeries for ACL injuries, rotator cuff injuries, and state-of-the-art hip and knee replacement procedures. These surgical services are backed by a rehabilitation program that provides comprehensive physical therapy for inpatients and outpatients. For more information about our orthopedic services, call (336) 538-7970. Orthopedic Physicians Practicing at Alamance Regional Burlington Orthopedic & Hand Surgery (336) 584-5544 Kernodle Clinic Department of Orthopedics (336) 538-2370

Prevent ACL Injuries

No single exercise can prevent ACL injuries, but developing and maintaining strength in your legs may help.

Thoroughly warm up before playing sports.
Jump and land on the balls of the feet rather than flat-footed.
Train legs with squats and lunges to promote knee stability.
Cross train for cardiovascular activities. For example, use the elliptical, treadmill and stationary bike – not just the elliptical.
Train in the preseason for your sport with at least four weeks of endurance training.

Get out there, and have fun! ACL injuries can be serious, but with proper conditioning you can reduce your risk and stay in the game.

Source: American Council on Exercise.