Anterior Cruciate Ligament Sprain

Home > Top Conditions > Knee > Anterior Cruciate Ligament Sprain

About

Picture a football player making his way to the end zone. To get there, he must dodge and weave around opposing players, turning quickly in the process. If one of his feet stays planted while he makes such a turn, his body goes one way and his leg goes the other. If he's unlucky, that will cause the popping sound and knee pain that indicate an anterior cruciate ligament (ACL) sprain -- one of the most common sports injuries.

Swelling will begin almost immediately and certainly within the first 12 hours, and this will help the football player's trainer to distinguish the injury from an injury to another knee structure called the meniscus, which would involve swelling that developed gradually over a number of hours or days. If the ACL is stretched, the injury will qualify as a strain, but if it's torn it will obviously qualify as a tear. To determine if the ACL is torn, the trainer may ask the football player to straighten his leg. Like some people with an ACL tear, he may not be able to.

About one in 3,000 people in the United States injure an ACL each year, and research shows that 70% of these injuries are sports-related. Any activity that involves abrupt twisting and pivoting or sudden stopping and starting can cause the injury. Alpine skiers, gymnasts, basketball players, soccer players and, obviously, football players are most commonly affected. Female athletes are also more at risk, because their muscles, ligaments and joints are not as strong as male athletes and therefore cannot withstand as much pressure.

For most mild sprains or tears, noninvasive care is effective. If, however, someone has a severe ACL tear, he or she may require surgery. In addition, athletes or people who rely heavily on the stabilizing properties of the ACL, and who have previously injured their ligament, may need surgery to ensure the ligament is strong enough to withstand additional stress.

If surgery isn't necessary, proper care can be helpful for restoring and maintaining the knee joint's function. If you have an ACL sprain or tear, your healthcare practitioner can relieve pain, decrease swelling and improve knee joint stability and motion. Combined with your commitment to rehabilitative exercises, this will quickly get you back in the game.

Anatomy

To find out where the anterior cruciate ligament (ACL) is and how it works, examine the knee joint. There are two main bones that make up the joint, the femur (thighbone) and the tibia (shinbone). Between them sits a round bone called the patella, commonly called the kneecap.

The ACL attaches to the back of the femur and the front of the tibia, running through the space behind where the patella sits. If you looked at the structure from the side, the ACL and its opposing ligament, the posterior cruciate ligament (PCL), which attaches to the front of the femur and the back of the tibia, would form an X.

Normally, the ACL prevents the tibia from moving too far forward, and the PCL prevents the tibia from moving too far backward. But the ACL is relatively weak, and can rupture during activities that involve abrupt movements. Direct contact to the knee can also damage the ligament, as can sudden contraction of the quadriceps muscle in the thigh.

Depending on the severity of the injury, the ligament will either be partially or completely torn. If you have an injury to the ACL your chiropractor will assess its severity. While in some cases a medical referral is necessary, in most cases conservative chiropractic care is effective.

Chiropractic Care

If you have an anterior cruciate ligament (ACL) sprain or tear, your chiropractor's first step is determining whether the injury will respond to conservative chiropractic care or whether a referral is necessary.

To make that decision, he or she will probably use a three-grade system of classification. If you complain of tenderness behind your knee, but there isn't severe damage to the ACL, your chiropractor will probably classify the injury as a grade one sprain. If, however, the pain is more severe and the knee joint feels loose, your chiropractor will probably classify the injury as a grade two sprain. Grade three injuries are the most severe, as they refer to full tears of the ACL that make the joint extremely unstable.

After grading your sprain and comparing your knees to determine the extent of swelling and discoloration, your chiropractor will manage your condition according to the specifics of the injury.

Within the first 24 to 72 hours of all grades of injury, your chiropractor will probably suggest you remember the acronym RICE, which stands for rest, ice, compression and elevation. Rest ensures you don't cause additional damage to the knee joint, ice constricts blood vessels to decrease swelling and numbs pain receptors to decrease pain, compression prevents blood vessels from releasing additional inflammatory fluid and elevation drains any inflammatory fluid that is already present.

With a grade one or two sprain, your chiropractor may perform an adjustment to the knee joint, which involves a quick, strategic hand thrust that helps restore normal joint motion, relax tight muscles, increase blood flow and decrease inflammation.

Physiotherapeutic tools like ultrasound and interferential current (IFC) are also helpful for grade one and two sprains. Ultrasound refers to any sound wave that has a frequency above the range the human ear can perceive. To produce these waves, chiropractors use a machine that channels electricity through a crystal located at the end of an applicator. The crystal vibrates in response to electricity, and the machine allows users to alter the electrical current to affect the waves' frequency. Depending on the frequency, this can increase blood flow, decrease pain, reduce muscle spasm, lessen nerve root irritation, break down scar tissue and speed healing.

IFC is very similar, but instead of sound waves involves a painless electrical current that penetrates the skin into nerve fibers below, which causes the body to produce endorphins, its natural painkillers. By targeting the knee joint with such mild electrical currents, your chiropractor can cause endorphins to interrupt the flow of pain signals from the affected tissues to the brain, as well as decrease inflammation.

If you have a grade one or two sprain, your chiropractor will probably also recommend that you avoid activities that endanger the joint. Patients who don't choose surgery for a grade one or two tear will have to endure some instability in the knee, and should avoid any activity that involves sudden starting and stopping. If you don't want to give up your favorite sport you should at least lower your level of participation, and consider wearing a knee brace to reinforce weak structures and enhance stability.

Rehabilitative exercises, including strengthening, stretching, proprioceptive and aerobic activities, are also important for enhancing stability in the knee joint. By strengthening your quadriceps and hamstrings, which are in your thigh, you can help restore proper knee motion, improve walking patterns and allow muscles to perform some of the stabilizing function of a healthy ACL. Stretching exercises for the same muscles will help decrease stress on the knee joint, as tight muscles that move the leg can pull the joint off track. Proprioceptive exercises are also essential, as they promote balance, improve communication between the brain and the body and enhance stability. Finally, aerobic exercises don't target the knee joint directly, but promote healing by getting blood flowing to muscles and joints.

While conservative care like this is often sufficient for grade one and two sprains, grade three sprains involve a complete tearing of the ACL and are so severe that your chiropractor will probably refer you to a medical doctor for surgery, especially if you are committed to returning to a particular sport.

Anterior Cruciate Ligament Sprain

About

Anatomy

Chiropractic Care

Newsletter Sign Up

3D Spine Simulator

Wellness Topics

Member Wellness