A fracture is a crack or break in a bone, usually accompanied by injury to the surrounding tissues.
Fractures vary greatly in size, severity, and the treatment needed. They can range from a small, easily missed crack in a foot bone to a massive, life-threatening break of the pelvis. Serious injuries, including injuries to the skin, nerves, blood vessels, muscles, and organs, may occur at the same time as the fracture. These injuries can complicate treatment of the fracture, cause temporary or permanent problems, or both.
Trauma is the most common cause of fractures. Low-energy trauma, such as a fall on level ground, usually causes minor fractures. High-energy trauma, such as high-speed motor vehicle collisions and falls from buildings, can cause severe fractures that involve several bones.
Certain underlying disorders can weaken parts of the skeleton so that breaks are more likely to occur. Such disorders include certain infections, benign bone tumors, cancer, and osteoporosis.
Pain is the most obvious symptom. Fractures hurt, especially when force is applied, such as when a person tries to put weight on an injured limb. The area around the broken bone is also tender to touch. Swelling of soft tissue around the fracture begins within a few hours. The limb may not function properly, so that an arm or a leg, hand, finger, or toe may move in only a limited range or in an abnormal direction. Moving is very painful. For a person who cannot speak (for example, a very young child, a person with a head injury, or an older person with dementia), refusal to move an extremity may be the only sign of a fracture. However, some fractures do not keep people from moving an injured extremity. Just because an extremity can move does not mean there is no fracture.
Internal bleeding may occur with a closed fracture (one in which the skin is not torn). The bleeding may occur from the bone itself or from surrounding soft tissues. The blood eventually works its way to the surface, forming a bruise (ecchymosis). At first, the bruise is purplish black, but it then slowly turns to green and yellow as the blood is broken down and reabsorbed back into the body. The blood can move quite a distance from the fracture, and it can take a few weeks for blood to be reabsorbed. The blood can cause temporary pain and stiffness in surrounding structures. Shoulder fractures, for instance, can bruise the entire arm and cause pain in the elbow and wrist. Some fractures, especially pelvic and femur fractures, can cause a person to lose quite a lot of blood into the surrounding tissues, resulting in low blood pressure.
Injury to an artery, vein, or nerve may occur. An open fracture (in which the skin is torn) can lead to a bone infection (osteomyelitis), which may be very difficult to cure. Fractures of long bones may release enough fat (and other substances in bone marrow) to travel through the veins, lodge in the lungs, and block a blood vessel there. Respiratory complications can result. Fractures that extend into joints usually damage cartilage (a smooth, tough, protective tissue that reduces friction as joints move). Damaged cartilage tends to scar, causing osteoarthritis and impairing motion in the joints.
The person usually feels some discomfort with activities even after fractures have healed sufficiently to allow full weight bearing. For example, a fractured wrist may be strong enough to allow some use in about 2 months, but the bone is still being rebuilt (remodeled). Forceful gripping with the wrist will be painful for up to 1 year. The person may also notice increased pain and stiffness when the weather is damp, cold, or stormy.
Most fractures heal with few problems. However, some do not heal despite appropriate diagnosis and treatment. This failure to heal is called nonunion. Fractures may also heal very slowly (called delayed union) or incompletely (called malunion). Certain bones, such as the scaphoid bone of the hand and some parts of the hip, are prone to poor healing because the blood supply is often damaged when these areas are fractured.
Compartment syndrome is a very rare but serious limb-threatening condition caused by excessive swelling of injured muscles, such as may occur as a result of a fracture or crush injury to a limb. Certain muscle groups, such as those of the lower leg, are surrounded by a tight fibrous covering. This covering forms a closed space (compartment) that cannot expand to accommodate the normal swelling that occurs when muscles or bones inside that compartment are damaged. Instead, the swelling causes the pressure within the muscle tissue to increase. This increase in pressure decreases the blood flow that provides oxygen to the muscle. When the muscle is deprived of oxygen for too long, further injury to the muscle occurs, which leads to further swelling and higher tissue pressures. After only a few hours, irreversible injury and death of muscle and nearby soft tissues may result. A similar increase in muscle pressure and tissue damage can occur when a damaged limb is confined by a cast. Compartment syndrome is most common with fractures of the lower leg.
A doctor becomes concerned about compartment syndrome when people who have a fracture feel
The diagnosis of compartment syndrome can be confirmed by using a device that measures pressure in the muscles.
Pulmonary embolism is the sudden blocking of blood flow in the lung when a blood clot that has formed in a vein breaks off (becoming an embolus) and travels to the lung. Most of these clots come from the deep veins of the legs (see Pulmonary Embolism (PE)). In the lung, these clots cause many problems, including limiting blood flow to the heart, decreasing the lung's ability to put oxygen in the blood, and damaging lung tissue. Pulmonary embolism is the most common fatal complication of serious hip and pelvic fractures. People with hip fractures are at high risk of pulmonary embolism because of the combination of trauma to the leg, forced immobilization for hours or days, and swelling around the fracture site blocking blood flow in the veins. Of people with a hip fracture who die, about one third die of pulmonary embolism. Pulmonary embolism occurs much less commonly with fractures of the lower leg and very rarely with fractures of the arm.
Doctors may suspect pulmonary embolism based on a range of symptoms, including chest pain, cough, shortness of breath, extreme weakness, and fainting. An electrocardiogram (ECG), ultrasound scan, chest x-ray, or various other tests may suggest the presence of a blood clot in the lung. Confirmation usually involves computed tomography (CT) of the chest or lung scanning.
Pulmonary embolism may be prevented with drugs that reduce the tendency of the blood to clot. Such drugs include heparin, low-molecular-weight heparin, warfarin, and newer anticoagulants such as hirudin, danaparoid, and fondaparinux (a new drug similar to heparin). They are given to people with fractures that put them at risk of forming a pulmonary embolism. However, blood clots may form despite efforts to stop them.
X-rays are the most important tool for diagnosing a fracture. X-rays are taken from several different angles to show how the fragments of bone are aligned. However, some small, nondisplaced fractures (called occult or hairline fractures) can be difficult or impossible to see on routine x-rays. Sometimes, additional x-rays taken at special angles reveal the fracture. Occasionally, such small fractures become visible on x-rays only days or weeks later, when the fracture begins to heal, revealing callus (new bone) formation. This course is particularly common with rib fractures. Stress fractures also may be undetectable on initial x-rays and visible only after callus formation begins. Fractures caused by disease (pathologic fractures) are diagnosed when x-rays show fractures in bones that have certain abnormalities, such as punched-out (lytic) areas caused by infection, noncancerous (benign) tumors, or cancer.
X-rays are usually the only test done to diagnose fractures. However, when findings strongly suggest a fracture but x-rays do not show one, doctors may do CT or magnetic resonance imaging (MRI). Alternatively, the doctor may apply a splint and re-examine the person days later and take another x-ray if symptoms are still significant. CT and MRI also are used to show details of fractures not seen on routine x-rays. CT can show the fine details of a fractured joint surface or can reveal areas of a fracture hidden by overlying bone. MRI shows the soft tissue around the bone, which helps to detect injury to nearby tendons and ligaments and joint structures, and can show evidence of cancer. MRI also shows injury (swelling or bruising) within the bone and can thus detect hidden or less visible (occult) fractures before they appear on x-rays.
Bone scanning (see Diagnosis of Musculoskeletal Disorders: Bone Scanning) is an imaging procedure that involves use of a radioactive substance (technetium-99m–labeled pyrophosphate) that is taken up by any healing bone. Occult fractures can be detected on bone scans 3 to 5 days after the injury. However, if doctors suspect an occult fracture, they usually order an MRI or CT scan rather than a bone scan.
Fractures require immediate attention because they cause pain and loss of function. After initial emergency care, fractures usually require further treatment, such as immobilization with casts or fixation with surgery.
Fractures in children are often treated differently from those in adults because bones in children are smaller, more flexible and less brittle, and most importantly, still growing. Children's fractures heal much faster and more perfectly than adult fractures do. Several years after most fractures in children, the bone can look almost normal on x-ray. In addition, children develop less stiffness with cast treatment and are more likely to regain normal motion if a fracture involves a joint. Because of these factors and because surgery near a joint often risks damage to the part of the bone responsible for bone growth (the growth plate), treatment with casts is often preferred over surgery.
When a fracture is suspected, people typically should go to a hospital emergency department. Those who are unable to walk or who have multiple injuries must be transported by ambulance. Until they see the doctor, people can do the following:
Aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) usually are no better than acetaminophen and in some people may worsen bleeding (see Pain: Nonsteroidal Anti-Inflammatory Drugs).
Open fractures need to be treated immediately with surgery to carefully clean and close the wound. Massive open fractures with great losses of the skin, muscle, and blood supply to the bone are the most serious and difficult to treat.
For most closed fractures, treatment can be delayed up to 1 week without affecting the long-term result. However, there is usually no advantage to waiting, because until they are treated, people are troubled by pain and loss of function. People should keep an injured arm or leg elevated to control pain and swelling. For arm fractures, pillows are used for elevation. For leg fractures, people should lie flat with the leg on a pillow. The doctor compares the swelling of the injured limb with the normal appearance of the uninjured limb to help determine how long or often elevation is needed. During the later stages of healing, elastic stockings may be used during the daytime to help control swelling when the person is sitting or standing.
Fractures are immobilized with a splint, sling, or cast until they heal. Allowing the broken ends to move prevents healing and results in nonunion. Displaced fractures must be aligned (reduced) before being immobilized. Alignment without surgery is called closed reduction. Alignment with surgery is called open reduction. When minor fractures (such as those of the fingers or wrist) are reduced, people may need an injection of a local anesthetic, such as lidocaine, to prevent pain. When major fractures (such as those of the arm, shoulder, or lower leg) are reduced, people may need sedation and pain relievers given by vein, or general or spinal anesthesia.
A splint is a long, narrow slab of plaster, fiberglass, or aluminum applied with elastic wrap or tape. The slab does not completely encircle the limb, which allows for some expansion due to tissue swelling. For this reason, splints are often used for initial treatment of fractures. For finger fractures, aluminum splints lined with foam are commonly used.
A sling by itself provides sufficient support for many shoulder and elbow fractures. The weight of the arm pulling downward helps to keep many shoulder fractures well aligned. Cloth or a strap passing around behind the back can be added to keep the arm from swinging outward, especially at night. Slings permit some use of the hand.
A cast is made by wrapping rolls of plaster or fiberglass strips that harden once wetted. Plaster is often chosen for the initial cast when a displaced fracture is being treated. It molds well and has less of a tendency to cause painful contact points between the body and cast. Otherwise, fiberglass has the advantage of being stronger, lighter, and more durable. In either case, the cast is applied over a layer of soft cottony material to protect the skin from pressure and rubbing. If the cast becomes wet, it is often impossible to completely dry the lining. As a result, the skin can soften and break down (macerate). For partially healed fractures, a special, more expensive and less protective waterproof lining is sometimes substituted.
After a cast is applied (especially for the first 24 to 48 hours), it should be kept elevated as much as possible at or above the level of the heart to combat swelling. Regularly flexing and extending the fingers or wiggling the toes helps the blood to drain from the limb and also helps to prevent swelling. Pain, pressure, or numbness that remains constant or worsens over time should be reported to a doctor immediately. These conditions may be due to a developing pressure sore or compartment syndrome.
The combination of rest, ice, compression (for example, with a splint, cast, or sometimes an elastic bandage), and elevation is often called RICE therapy.
Fractures sometimes require surgical treatment, as for the following:
Surgery may also be needed to repair injury to ligaments, nerves, tendons, or major arteries.
Surgical stabilization involves first accurately reducing the fracture to restore the bone's original shape and length. The surgeon uses anesthesia to relax the muscles and x-ray equipment to help align the bones. A surgeon exposes the fracture to see and manipulate the fragments with special instruments. Then, the bone fragments are securely fixed using some combination of metal wires, pins, screws, rods, and plates. This procedure is called open reduction and internal fixation (ORIF). Metal plates are contoured and fixed to the outside of the bone with screws. Metal rods are inserted from one end of the bone into the marrow cavity. These implants are made of stainless steel, high-strength alloy metal, or titanium. All such implants made in the last 20 years are compatible with the strong magnets that are used for MRI. Most will not set off security devices at airports. Some of the hardware used to repair a fracture is permanently left in place, and some is removed after healing has taken place.
A joint replacement procedure (arthroplasty) may need to be done when fractures severely damage the upper end of the femur, which is part of the hip joint, or humerus, which is part of the shoulder joint.
Bone grafting, using chips of bone harvested from another part of the body such as the pelvis, may be done initially, if the gap between fragments is too large, or later, if the healing process has slowed (delayed union) or stopped (nonunion).
Treatment of Compartment Syndrome:
Anything confining the limb, such as a splint or a cast, is removed immediately. If this does not relieve pressure in the muscle compartment, an emergency surgical procedure called fasciotomy must be done. In fasciotomy, the doctor makes an incision along the entire length of the thick fibrous tissue (fascia) that makes up the compartment. This incision relieves pressure and allows blood flow to return to the muscles. Otherwise, the muscles and nerves could die because of a lack of oxygen, and then the limb may need to be amputated. If left untreated, complications of compartment syndrome can cause death.
Rehabilitation and Prognosis
Healing time varies from weeks to months. The outcome depends on the nature and location of the fracture. For many fractures, people eventually recover full function and have few or no symptoms. Some fractures, particularly those that involve a joint, can leave residual pain, stiffness, or both.
Stiffness and loss of strength are natural consequences of immobilization. A joint of a fractured limb immobilized in a cast becomes progressively stiffer each week, eventually losing its ability to fully extend and flex. Wasting away of muscle (atrophy) also can be severe. For instance, after wearing a long leg cast for a few weeks, most people can insert their hand into the formerly tight space between the cast and their thigh. When the cast is removed, the weakness resulting from muscle atrophy is very apparent.
Daily exercise using range-of-motion and muscle-strengthening exercises (see Rehabilitation: Muscle-strengthening exercises) helps people combat stiffness and regain strength. While the fracture is healing, the joints outside the cast can be exercised. The joints within the cast cannot be exercised until the fracture has healed sufficiently and the cast can be removed. When exercising, the person should pay attention to how the injured limb feels and avoid exercising too forcefully. Passive exercises in which a therapist applies external force (see Rehabilitation: Increasing the Shoulder's Range of Motion) must be used when muscles are too weak for effective motion and when strong muscle contractions might displace a fracture. Ultimately, active exercise (in which the person uses his own muscle force) against gravity or weight resistance is necessary to regain full strength of an injured limb.
Last full review/revision December 2008 by James R. Roberts, MD