The ACL, or anterior cruciate ligament, is a ligament located inside the knee joint. It is a major connector of the femur and the tibia and one of the key parts of the joint for maintaining a stable, yet flexible knee.
What Causes an ACL Injury
ACL injuries are caused by several factors. The most common is a traumatic force being applied to the knee in a twisting moment, causing forceful hyperextension. Skiers are particularly susceptible to these types of strains when landing jumps, skiing moguls or during twisting falls. The injury can also occur due to a contact force such as being hit from the front or side. Finally, ACL injuries can happen during a fall by a novice skier, when the bindings do not release.
What Does it Sound and Feel Like?
The most common sound heard when there is a severe ACL injury is an audible "pop" at the moment of impact immediately followed by brief, acute pain. Swelling, pain, and instability of the knee are common. You will experience difficultly supporting your weight when standing, and the knee feels as though it will 'give out'. If you experience any of these symptoms, you should have a friend flag down the ski patrol and head to a doctor's office immediately. An MRI is usually used to diagnose an ACL tear, but arthroscopy may be the only reliable means of detecting a partial tear.
What is the Prognosis?
It is possible to function with even a complete tear, however, it will limit mobility and, even after the pain has subsided, expose one to the risk of the knee collapsing during any exercise. The injury is serious and usually requires surgical repair or reconstruction in an athletic person. Fortunately, the state-of-the-art in the 1990's is that a skier, after a properly done cruciate repair or reconstruction, can return to skiing within the year.
What is the Treatment?
Depending on the severity of the injury, recovery can involve exercise, a brace, or surgical reconstruction of the ligament. If it is even a relatively moderate ACL tear, your season is over and daily therapy will become a routine. The initial treatment of an acute ACL injury often includes ice, anti-inflammatory medication, and physical therapy which is directed at restoring the range of motion of the injured knee.
A complete tear will most likely require surgical reconstruction of the ACL. This is a common procedure with an extremely high success rate. most common type of ACL reconstruction involves harvesting the central third of the patellar tendon with a bone block at each end of the tendon graft.
Nevertheless, surgery is never an appealing thought. There is some disagreement among doctors as to when surgery is necessary so get multiple opinions and do your own research on the subject before committing to surgery.
There is generally a long recovery period. Therapy will begin in a few days and progress over the months until low impact exercises can be done with any intensity. It could take a year before you are back on skis.
Can I Prevent an ACL Injury?
There are several things you can do in the preseason and off season to decrease your risk of an ACL injury.
- Do conditioning and strengthening exercises of the quadriceps and hamstring before ski season starts. This is the number one protection.
- Ski easier at the end of the day, when you are typically fatigued. Avoid difficult trails, big air, lots of moguls, and speed skiing on ice. Take it easy in the late afternoon.
- Do regular stretching exercises for the hamstrings, quadriceps, hip, back, shoulder. The more you stretch, the less likely you are to snap.
- Use gear that is fit to you and is tuned up.
- Check your bindings for release tension. Do not set them too tight!