Ankle sprains are tears in the ligaments that hold the ankle in place.
Usually, ankle sprains occur when people walk or run on uneven ground and the foot turns in, stretching the ligaments of the ankle beyond their limits and tearing them.
Typically, the ankle is swollen, and walking is painful.
Doctors can usually diagnose ankle sprains based on the physical examination and sometimes x-rays.
Treatment usually includes PRICE (protection, rest, ice, compression with a bandage, and elevation of the leg) for mild sprains, immobilization and physical therapy for moderate and severe sprains, and sometimes surgery for very severe sprains.
(See also Overview of Sprains and Other Soft-Tissue Injuries.)
In the United States, ankle sprains are very common.
The ankle joint consists of the shinbone (tibia), smaller leg bone (fibula), ankle bone (talus), and several ligaments, which hold the bones of the ankle in place (see figure Ligaments: Holding the Ankle Together).
The severity of the sprain depends on which ligaments are injured and how badly they are stretched or torn. Based on severity, doctors classify sprains as
1st-degree: Mild
2nd-degree: Moderate to severe
3rd-degree: Very severe
Most ankle sprains are mild.
Ligaments: Holding the Ankle Together
Sprains usually occur when the foot turns in, causing the sole of the foot to face the other foot (called inversion). This injury usually damages the ligaments on the outside of the ankle. Inversion can occur when people walk on uneven ground, especially when they step on a rock or off the edge of a curb.
Spraining an Ankle
The foot turns in, tearing a ligament on the outside of the ankle. |
Less commonly, the ankle is sprained when the foot turns out (called eversion).
When the foot turns out, several other injuries may occur:
An avulsion fracture: The ligament that attaches the shinbone (tibia) to one of the foot bones on the inside of the ankle may pull a small piece of bone off the shinbone. Turning the foot out tends to cause an avulsion fracture rather than a sprain because this ligament is so strong.
A high ankle sprain: The ligaments that hold the shinbone and the other lower leg bone (fibula) together at their lower ends may be torn.
Fracture of the fibula: The fibula may be broken at the ankle or sometimes near the knee.
When the ankle is sprained, nerves may also be damaged.
Certain conditions tend to cause the foot to turn (or ankle to roll) out and thus increase the risk of a sprain:
Having had a previous sprain that made the ligaments in the ankle loose
Having weak leg muscles or nerve damage in the legs
Wearing certain types of shoes, such as spiked heels
Symptoms of Ankle Sprains
In general, the area over the injured ligament is painful and swollen. Sometimes people with a sprained ankle have muscle spasms—unintended contraction of muscles around the ankle.
How severe symptoms are depend on the severity of the tear. If nerves are damaged, people may have problems sensing where their foot and ankle are without looking at them (a sense called proprioception).
Mild
Ligaments stretch and tear, but the tears are so small that they can be seen only with a microscope. The ankle usually does not hurt or swell very much, but it is weakened and more likely to be injured again. Recovery can take hours to days.
Moderate to severe
Ligaments tear partially. The ankle is often swollen and bruised, and walking is usually painful and difficult. Healing takes days to weeks.
If the ankle is sprained again, nerves may be damaged.
Very severe
Ligaments tear completely. The whole ankle may be swollen and bruised. The ankle is unstable, and people cannot put any weight on it.
Healing usually takes 6 to 8 weeks. If people do not wait until their ankle is healed completely before they resume their usual activities, they increase their risk of future injuries, and the ankle may not heal well.
Nerves may also be damaged.
Very severe ankle sprains may fracture the cartilage at the ends of the bones in the ankle joint. This injury can result in long-term pain, swelling, and occasionally problems walking. The joint may catch (stick) or give way (involuntarily buckle). Sometimes arthritis develops in the ankle at a young age.
Diagnosis of Ankle Sprains
A doctor's evaluation
Sometimes x-rays to check for fractures
Doctors ask how the injury occurred and do a physical examination.
Doctors also move the ankle joint in various ways to determine how severe the sprain is. However, if a person has a lot of pain and swelling or muscle spasms, the examination is usually postponed until x-rays are done to check for fractures.
To evaluate the ankle, doctors gently touch the ankle to determine where the pain is most intense. If touching the skin over a ligament causes intense pain, the ligament is probably torn. If touching the skin over a bone causes pain, the bone may be fractured. Swelling and spasms make evaluating the ankle difficult. In such cases, doctors may immobilize the joint with a splint and examine the joint again several days later.
Doctors can usually diagnose sprains based on results of the examination. However, doctors sometimes take x-rays to check for a fracture when
The ankle or foot is very painful in certain areas.
People cannot bear weight without assistance, both immediately after the injury AND in the emergency department or doctor's office (for 4 steps), with or without limping
Did You Know...
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Magnetic resonance imaging (MRI) may be done to check for other injuries, particularly if the ankle is still painful after 6 weeks of treatment with protection, rest, ice, compression, and elevation (PRICE).
Treatment of Ankle Sprains
Protection, rest, ice, compression, and elevation (PRICE)
A bandage, splint, specially designed boot, or cast
Physical therapy
Treatment may include PRICE
Mild sprains
Most ankle sprains are mild, require no special treatment, and heal well.
PRICE is recommended. It involves the following:
Protection: Support of the ankle with an elastic bandage, a splint, a specially designed boot, or a cast depending on how severe the sprain is
Rest: Not walking on the injured ankle and using a crutch to walk when necessary
Ice: Putting ice packs on the injured ankle
Compression: Compressing the ankle by wrapping it and the foot with an elastic bandage or tape
Elevation: Elevating the ankle as much as possible
Most people can begin to walk and exercise immediately as long as they wear supportive footwear.
Did You Know...
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Moderate sprains
Moderate sprains may be treated with PRICE. If walking is extremely difficult, a splint or boot can be worn for support. Most people can begin to walk and exercise within a few days.
Physical therapy is needed to help minimize swelling, maintain the joint's range of motion, and gradually strengthen the muscles around the ankle (and thus prevent future sprains).
Severe sprains
Severe sprains require immediate medical attention. Without treatment, the ankle may remain unstable and painful.
The ankle is immobilized, sometimes with a cast. Most people are referred to a specialist.
Whether surgery should be done is controversial. Most experts believe that surgically reconstructing torn ligaments is no better than treatment without surgery.
Physical therapy to restore movement, strengthen muscles, and improve balance is necessary before people resume strenuous activity. Physical therapy can also speed recovery.
High ankle sprains
High ankle sprains usually require a cast for several weeks.
