Kim loved to ski, but she could not get away from her job too often. When I saw her after one of her ski trips, she was on crutches. She did not break a leg; she tore her anterior cruciate ligament (ACL). She told me that she had been tired on the last day of her skiing vacation, but decided to make one last run down the mountain when she fell. The ACL is a ligament that crosses the middle of the knee and provides rotational stability to the knee by preventing the shinbone (tibia) from sliding out in front of the thighbone (femur). A torn ACL is one of the most common knee injuries. Although anyone can tear their ACL, women, especially women athletes, are more prone to this injury.
Symptoms
Often an ACL injury occurs together with other ligament and cartilage injuries, but an ACL injury has specific symptoms. An MRI (Magnetic Resonance Imaging) can further help to evaluate the knee injury.
1. "Pop" sound
At the time of the injury you may hear a loud popping sound.
2. Pain
You may have trouble walking because of severe pain.
3. Swelling
The knee swells in the hours after the injury. Swelling will also occur if you have a bone fracture.
4. Trick knee
When you try and walk and you feel like the knee is "giving way" and not supporting you, it is an indication that you have an ACL injury.
Causes
Injuries may occur during contact sports or non-contact incidents like twisting your knee. Sports activities can cause injury to your ACL if you suddenly change direction or slow down.
1. Sudden change of movement
Any activity where you overextend or twist your knee can cause an ACL injury.
2. Falling
Falling, while skiing downhill, like my friend Kim did, can cause an ACL injury.
3. Jumping
Landing awkwardly when jumping may cause an ACL injury.
Prevention
The use of proper technique, when engaging in athletic activities like learning to jump correctly, can prevent ACL injuries. So far, studies show that the popular use of knee braces has not prevented knee injuries.
1. Knee muscles
Exercising to strengthen the muscles around the knee and aerobic exercises can help prevent ACL injuries.
2. Hamstring
Strengthening hamstring muscles is important. Women tend to have stronger thigh muscles (quadriceps) and weaker hamstring muscles than men, causing an imbalance.
3. Ski binding
When skiing, make sure that the bindings are adjusted correctly, so that they release when you fall.
Treatment
Surgery is not always necessary. Depending on the extent of the tear and whether you are an athlete, you may do quite well with just physical therapy. My friend Kim chose surgery. Surgery can cause other problems. A year after Kim had surgery; she had to go for treatments to break up scar tissue that had formed in her knee.
1. Ice
Initially, apply ice to the injury to reduce swelling.
2. Compression
You may feel more comfortable by compressing the injured knee with an elastic bandage.
3. Elevation
Lie down with a pillow under your knee so that it is elevated above your heart.
4. Crutches
Use crutches so you don't put weight on the injured knee.
5. Pain killers
Take over-the-counter painkillers and anti-inflammatories like ibuprofen to ease the pain.
6. Physical therapy
Physical therapy is important even if you don't have surgery. Exercises for stability, to strengthen the muscles around the knee, and to regain a full range of motion, will help to rehabilitate the knee.
7. Surgery
The ACL is usually repaired by taking a ligament from another part of the leg to replace the ACL in the knee. For an athlete, reconstructive surgery is often the best option.
Sources
http://www.nlm.nih.gov/medlineplus/ency/article/001074.htm
http://www.mayoclinic.com/health/acl-injury/DS00898
http://www.healthkey.com/health/human-body/knees/hk-torn-acl-harvard-letter,0,1376745.story
