Overview of Sprains and Other Soft-Tissue Injuries

Significant soft-tissue injuries cause bleeding under the skin (bruises).

If a person is taking a medication to prevent blood clots from forming (an anticoagulant), relatively minor injuries can cause substantial bleeding.

Rarely, what appears to be a severe sprain (for example, of the knee) may be a dislocation that has slipped back in place on its own. These dislocations may damage an artery and disrupt the blood supply to the injured limb. A disrupted blood supply may not cause any symptoms until several hours after the injury. Untreated, such damage can lead to loss of the limb.

Sometimes nerves are stretched, bruised, crushed, or torn. A direct blow can bruise or crush a nerve. Crushing causes more damage than bruising. Nerve damage causes numbness and sometimes tingling in the area past where the nerve is damaged. These injuries usually heal on their own over weeks to months to years, depending on the severity of the injury. Torn nerves do not heal spontaneously and may have to be repaired surgically. Some nerve injuries never heal completely.

Joints can become stiff if they must be kept from moving (immobilized) for a long time—for example, by a splint or cast. The knee, elbow, and shoulder are particularly likely to become stiff after an injury, especially in older people.

Physical therapy is usually needed to prevent stiffness and help the joint move as normally as possible.

Severe sprains can make a joint unstable. Having unstable joints can be disabling and increases the risk of osteoarthritis. Appropriate treatment can help prevent permanent problems.

Rarely, swelling (usually under a cast) is severe enough to contribute to compartment syndrome. Because the swelling puts pressure on nearby blood vessels, blood flow to the injured limb is reduced or blocked. As a result, tissues in the limb may be damaged or die, and the limb may have to be amputated.

Doctors ask the person (or a witness) to describe what happened. The person may not remember how an injury occurred or cannot describe it accurately. Knowing how the injury occurred can help doctors determine the type of injury. For example, if a person reports that a snap or pop occurred, the cause may be an injury to a ligament or tendon (or a fracture). Also, doctors ask in which direction the joint was stressed during the injury. This information can help doctors determine which ligaments and/or bones may be damaged.

Doctors also ask when the pain started. If it started immediately after the injury, the cause may be a severe sprain. If the pain began hours to days later, the injury is usually minor. If the pain is more severe than expected for the injury or if the pain steadily worsens during the first hours after the injury, compartment syndrome may have developed or blood flow may be disrupted.

The physical examination includes the following (in order of priority):

• Checking for damage to blood vessels near the injured body part

• Checking for damage to nerves near the injured part

• Examining and moving the injured part

• Examining the joints above and below the injured part

To check for signs of blood vessel damage and disrupted blood flow, doctors check pulses and skin color and temperature. When blood flow is disrupted (as can occur in compartment syndrome), pulses may be absent or weak and the skin may be pale and cool. Doctors measure blood pressure, which is usually low in people who have lost a lot of blood.

To check for nerve damage, doctors evaluate sensation in the skin—whether the person can feel normally—and ask whether the person has abnormal sensations, such as a pins-and-needles sensation, tingling, or numbness. Abnormal sensations suggest that nerves have been damaged.

Doctors gently feel the injured part to determine whether the area is tender and whether tendons or muscles feel abnormal. If a fracture or dislocation is present, doctors may feel that bones are in pieces or out of place. Doctors also check for swelling and bruising. They ask whether the person can use, put weight on, and move the injured part.

Doctors test the stability of a joint by gently moving it in a way that puts stress on the joint (called stress testing). If the joint feels very unstable, doctors suspect a severe ligament injury (or a dislocation). However, if a fracture is possible, x-rays are done first to determine whether moving the joint is safe. Sometimes, stress testing is delayed until pain lessens.

Moving the affected joint can also help doctors determine the severity of an injury. For example, they can determine how severe a sprain (a torn ligament) is based on how far they can move the joint and how painful the movement is. When a ligament is partially torn, moving the joint is very painful. When a ligament is completely torn, moving the joint is less painful because the torn ligament is not being stretched as the joint is moved. A joint can usually be moved more freely when a ligament is torn than when it is not and can be moved more freely when a ligament is completely torn than when it is partially torn.

Because tendons connect muscles to bone, doctors can often determine the severity of a tendon injury by moving the muscle that the tendon is attached to. When a tendon is completely torn, moving the muscle attached to the tendon may not move the bone. For example, if the Achilles tendon (which attaches the calf muscles to the heel bone) is completely torn, the foot may not move. Partial tears may be hard to detect because the joint may seem to move normally.

If the physical examination does not detect a problem in the joint identified as painful, the injury may be elsewhere. This type of pain is called referred pain. For example, if the joint between the breastbone and collar bone is injured, people may feel pain in their shoulder. Thus, doctors always examine the joint above and below the painful joint to check for injury.

If pain or muscle spasms interfere with the examination, doctors may give the person a pain reliever and/or muscle relaxant by mouth or injection, or a local anesthetic may be injected into the injured area to make the examination easier. Or the injured part may be immobilized until the spasms stop, usually for a few days, and then examined.

Imaging tests are done to check for possible fractures and dislocations and to identify soft-tissue injuries. These tests include

• X-rays if needed

• Magnetic resonance imaging (MRI)

• Sometimes computed tomography (CT)

X-rays are not always needed. They do not show injuries to ligaments, tendons, or muscles. They show only bones (and the fluid that collects around an injured joint). However, x-rays may be done to check for fractures and dislocations, which may also be present. In addition, x-rays can show abnormalities in the position of bones that may suggest a sprain or other soft-tissue injury.

X-rays, if needed, are usually taken from at least two angles. If a fracture is present, two x-rays can show how the fragments of bone are aligned.

MRI can show soft tissues, which are not usually visible on x-rays. MRI thus helps detect injury to tendons, ligaments, cartilage, and muscle.

CT or MRI may be done to check for subtle fractures, which may accompany a soft-tissue injury.

Other tests may be done to check for injuries that can accompany a soft-tissue injury:

• Angiography (x-rays or CT scans taken after a contrast agent is injected into arteries) to check for damaged blood vessels

• Nerve conduction studies to check for damaged nerves

In the emergency department, doctors check for any injuries that require immediate treatment or may cause serious complications, such as compartment syndrome. Without treatment, complications may get worse, becoming more painful and making loss of function more likely.

To make sure the injured part is not deprived of blood, doctors surgically repair damaged arteries unless the arteries are small and blood flow is not affected.

Severed nerves are also repaired surgically, but this surgery can be delayed until several days after the injury if necessary. If nerves are bruised or damaged, they may heal on their own.

If the skin is torn, the wound is covered with a sterile dressing, and the injured person is given a vaccine to prevent tetanus and antibiotics to help prevent infection. Also, the wound is cleansed, usually after a local anesthetic is used to numb the area.

After serious injuries are treated, doctors focus on relieving symptoms and immobilizing soft-tissue injuries as needed.

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PRICE refers to the combination of protection, rest, ice, compression (pressure), and elevation. This treatment is used to treat injured muscles, ligaments, and tendons.

Protection helps prevent further injury that could worsen the original one. Typically, a splint or other device is applied.

Rest prevents further injury and may speed healing. People should limit their activity and avoid putting weight on and/or using the injured body part. For example, they should not participate in contact sports, and they should use crutches if needed.

Ice and compression minimize swelling and pain. Ice is enclosed in a plastic bag, towel, or cloth and applied for 15 to 20 minutes at a time, as often as possible during the first 24 to 48 hours. Usually, compression is applied to the injury with an elastic bandage.

Elevating the injured limb helps drain fluid away from the injury and thus reduce swelling. The injured limb is elevated above heart level for the first 2 days.

After 48 hours, people can periodically apply heat (for example, with a heating pad) for 15 to 20 minutes at a time. Heat may relieve pain and speed healing. However, whether heat or ice is best is unclear, and what works best may vary from one person to another.

How To Fit and Use Crutches

Keeping a limb from moving (immobilization) reduces pain and helps with healing by preventing further injury to surrounding tissues. Joints on both sides of the injury are immobilized.

If immobilization lasts too long (for example, for more than a few weeks in young adults), the joint may become stiff, sometimes permanently, and muscles may shorten (causing contractures) or shrink (waste away, or atrophy). Blood clots may develop. Such problems can develop quickly, and contractures can become permanent, usually in older people. Consequently, doctors encourage movement as soon as the injury heals. They also tend to use treatments that enable older people to walk as soon as possible, rather than ones that require them to be immobilized for a long time (such as bed rest or a cast).

Whether immobilization is required and which technique is used depend on the type of injury.

If a partial tear in a tendon is suspected or if the diagnosis is uncertain, doctors may apply a splint to immobilize the injured part so that the tendon can heal. Some severe tendon tears are immobilized for days or weeks, sometimes with a cast.

Mild sprains are immobilized briefly if at all. Moving the injured part as soon as possible is usually the best treatment. Moderate sprains are often immobilized with a sling or splint for a few days. Some severe sprains and tendon tears are immobilized for days or weeks, sometimes with a cast. However, many severe sprains must be surgically repaired and are not always immobilized.

Casts are usually used for injuries that must be kept immobilized for weeks.

To apply a cast, doctors wrap the injured part in cloth, then apply a layer of soft cottony material to protect the skin from pressure and rubbing. Over this padding, doctors wrap dampened plaster-filled cotton bandages or fiberglass strips, which harden when they dry. Plaster is often used to immobilize broken bones that have been separated because it molds well and is less likely to rub against the body. Fiberglass casts are stronger, lighter, and longer-lasting. After a week or so, the swelling goes down. Then, the plaster cast can sometimes be replaced with a fiberglass cast to fit the limb more snugly.

People who require a cast are given special instructions for its care. If a cast is not correctly cared for, problems can develop. For example, if the cast becomes wet, the protective padding under the cast may become wet, and drying it completely may be impossible. As a result, the skin can soften and break down, and sores may form. Also, if a plaster cast gets wet, it can fall apart and thus no longer protect and immobilize the injured area.

People are instructed to keep the cast elevated as much as possible at or above heart level, especially for the first 24 to 48 hours. Ideally, elevation is in a position that provides an uninterrupted downward path, allowing gravity to help drain swelling. People should also regularly flex and extend their fingers or wiggle their toes.

Rarely, casts cause pain, pressure, or numbness that remains constant or worsens over time. Such symptoms must be reported to a doctor immediately. These symptoms may be due to a developing pressure sore or compartment syndrome. In such cases, doctors may have to remove the cast and apply another one.

Commercial Cast Cover

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Image courtesy of Danielle Campagne, MD.

A splint can be used to immobilize some sprains and other injuries, particularly if they need to be kept immobile for only a few days or less. Splints allow people to apply ice and to move more than a cast does.

A splint is a long, narrow slab of plaster, fiberglass, or aluminum applied with elastic wrap or tape. Because the slab does not completely encircle the limb, there is room for some expansion due to swelling. Thus, a splint does not increase the risk of developing compartment syndrome. Some injuries that eventually require a cast are first immobilized with a splint until most of the swelling resolves.

A sling by itself can provide some support. Slings can be useful when complete immobilization has undesirable effects. For example, if a shoulder is completely immobilized, the tissues around the joint may become stiff, sometimes within days, preventing the shoulder from moving (called frozen shoulder). Slings limit movement of the shoulder and elbow but allow movement of the hand.

A swathe, which is a piece of cloth or a strap, may be used with a sling to prevent the arm from swinging outward, especially at night. The swathe is wrapped around the person's back and over the injured part.

Commonly Used Techniques for Immobilizing a Joint

Many 3rd-degree sprains and tendon tears require surgical repair.

Arthroscopic surgery is sometimes used. For this procedure, a pencil-sized viewing tube is inserted in the joint through a tiny incision. This procedure is done most often to repair ligaments in the knee (knee sprains) or pads of cartilage (menisci) in the knee.