fracture

Definition

A fracture is a complete or incomplete break in a bone resulting from the application of excessive force.

Description

A fracture usually results from traumatic injury to bones causing the continuity of bone tissues or bony cartilage to be disrupted or broken. Fracture classifications include simple, compound, incomplete and complete. Simple fractures (more recently called "closed") are not obvious as the skin has not been ruptured and remains intact. Compound fractures (now commonly called "open") break the skin, exposing bone and causing additional soft tissue injury and possible infection. A single fracture means that one fracture only has occurred and multiple fractures refer to more than one fracture occurring in the same bone. Fractures are termed complete if the break is completely through the bone and described as incomplete or "greenstick" if the fracture occurs partly across a bone shaft. This latter type of fracture is often the result of bending or crushing forces applied to a bone.

Fractures are also named according to the specific part of the bone involved and the nature of the break. Identification of a fracture line can further classify fractures. Types include linear, oblique, transverse, longitudinal, and spiral fractures. Fractures can be further subdivided by the positions of bony fragments and are described as comminuted, non-displaced, impacted, overriding, angulated, displaced, avulsed, and segmental. Additionally, an injury may be classified as a fracture-dislocation when a fracture involves the bony structures of any joint with associated dislocation of the same joint.

Linear fractures have a break that runs parallel to the bone's main axis or in the direction of the bone's shaft. For example, a linear fracture of the arm bone could extend the entire length of the bone. Oblique and transverse fractures differ in that an oblique fracture crosses a bone at approximately a 45° angle to the bone's axis. In contrast, a transverse fracture crosses a bone's axis at a 90° angle. A longitudinal fracture is similar to a linear fracture. Its fracture line extends along the shaft but is more irregular in shape and does not run parallel to the bone's axis. Spiral fractures are described as crossing a bone at an oblique angle, creating a spiral pattern. This break usually occurs in the long bones of the body such as the upper arm bone (humerus) or the thigh bone (femur).

Comminuted fractures have two or more fragments broken into small pieces, in addition to the upper and lower halves of a fractured bone. Fragments of bone that maintain their normal alignment following a fracture are described as being non-displaced. An impacted fracture is characterized as a bone fragment forced into or onto

another fragment resulting from a compressive force. Overriding is a term used to describe bony fragments that overlap and shorten the total length of a bone. Angulated fragments result in pieces of bone being at angles to each other. A displaced bony fragment occurs from disruption of normal bone alignment with deformity of these segments separate from one another. An avulsed fragment occurs when bone fragments are pulled from their normal position by forceful muscle contractions or resistance from ligaments. Segmental fragmented positioning occurs if fractures in two adjacent areas occur, leaving an isolated central segment. An example of segmental alignment is when the arm bone fractures in two separate places, with displacement of the middle section of bone.

— L. Fleming Fallon, Jr., MD, DrPH

1. 1. The act or process of breaking.
   2. The condition of having been broken or ruptured: "a sudden and irreparable fracture of the established order" (W. Bruce Lincoln).
2. A break, rupture, or crack, especially in bone or cartilage.
3. Mineralogy.
   1. The characteristic manner in which a mineral breaks.
   2. The characteristic appearance of the surface of a broken mineral.
4. Geology. A crack or fault in a rock.

1. 1. To cause to break: The impact fractured a bone.
   2. To undergo a break in (a bone): He fractured his ankle in the fall.
2. To disrupt or destroy as if by breaking: fractured the delicate balance of power.
3. To abuse or misuse flagrantly, as by violating rules: ignorant writers who fracture the language.
4. Slang. To cause to laugh heartily: "Jack Benny fractured audiences . . . for more than 50 years" (Newsweek).

[Middle English, from Old French, from Latin frāctūra, from frāctus, past participle of frangere, to break.]

For more information on fracture, visit Britannica.com.

verb

1. To crack or split into two or more fragments by means of or as a result of force, a blow, or strain: break, rift, rive, shatter, shiver², smash, splinter, sunder. See help/harm/harmless.
2. To undergo partial breaking: crack, fissure, rupture, split. See help/harm/harmless.

Definition

A fracture is a crack or break in a bone. It results from the application of excessive force through injuries, such as a fall or a hard blow.

Description

Up to the age of 50, more men suffer from fractures than women because of occupational hazards. However, after the age of 50, more women suffer fractures than men because of osteoperosis. Simple, or closed, fractures are not obvious on the surface because the skin remains intact. Compound, or open, fractures break through the skin, exposing bone. They are generally more serious than closed fractures. When bones are broken, there may be an accompanying soft tissue injury or an infection either in the surrounding tissue or the bone itself. If an artery is damaged, there can be a significant loss of blood. Single and multiple fractures refer to the number of breaks in the same bone. Fractures are termed complete if the break is completely through the bone, and described as incomplete, or green-stick, if the fracture occurs partly across a bone shaft. This latter type of fracture is often the result of bending or crushing on the bone. A stress fracture is usually a small break in the bone due to repeated or prolonged force.

Causes & Symptoms

Fractures usually result from an injury to a bone that causes the bone tissue or cartilage to be disrupted or broken. Bones weakened by disease or misuse will be more likely to break. In some women who have gone through menopause, the bones fracture easily due to osteoperosis. This is because the body produces less estrogen at that time of life, and estrogen is a major regulator of bone density through its effects on calcium in the body. Moderate exercise and weight training is helpful in building and maintaining strong bones; so, the bones of an inactive person may also tend to fracture easier than those who are moderately active. However, individuals with a very high activity level have a greater risk of fractures. This group includes children and athletes participating in contact sports. Because bones start to thin out with the aging process, the elderly are also at a high risk of sustaining a fracture. Diseases that may lead to an increased risk of fractures include Paget's disease, rickets, osteogenesis imperfecta, osteoporosis, tumors, deficiencies of vitamins A or D, and stroke induced paralysis.

Fractures usually begin with intense pain and swelling at the site of injury. Obvious deformities, such as a crooked or otherwise misshapen limb, point to a possible fracture. Pain that prevents the use of a limb may also indicate a break. In severe fractures, there may be a loss of pulses below the fracture site and a resultant numbness, tingling, or paralysis in the feet, hands, fingers, or toes below the site. An open fracture is often accompanied by bleeding or bruising. If a leg is fractured, there will usually be difficulty bearing weight on it. If there is dizziness, sweating, disorientation, or thirst, the onset of shock may be indicated.

Diagnosis

Diagnosis begins immediately with the individual's own observation of symptoms. A thorough medical history and physical exam completed by a physician often provides enough information to determine if further testing is necessary. An x ray of the injured area is most commonly used to determine the presence of a bone fracture. However, it is important to note that not all fractures are apparent on an initial x ray. Rib fractures are often difficult to diagnose and may require several views at different angles. If the fracture is open and occurs in conjunction with soft tissue injury, further laboratory studies may have to be done.

In the event of stress fractures, a tuning fork can provide a simple, inexpensive test. The tuning fork is a metal instrument with a stem and two prongs that vibrate when struck. If a patient has increased pain when the tuning fork is placed on the bone, such as the lower leg bone or shinbone, the likelihood of a stress fracture is high. Bone scans also are helpful in detecting stress fractures or other difficult-to-detect fractures.

Treatment

Prevention is the most effective way to avoid fractures. Wearing protective gear, such as a helmet, or using protective equipment, such as safety gear, while playing sports may greatly reduce the risk of a fracture.

A daily multivitamin and mineral supplement (for instance, containing calcium, magnesium, boron, strontium) is recommended to help build and maintain a healthy, resilient skeleton. These, together with an adequate protein intake, will also help rebuild the bone and surrounding tissue. Some physical therapists use electro-stimulation over a fractured site to promote and expedite healing. Chinese traditional medicine seeks to reconnect the qi through the meridian lines along the line of a fracture. Homeopathy can enhance the body's healing process. A particularly useful homeopathic remedy for soft tissue is Arnica 12c, taken every 10 minutes for the first two hours after injury, and then once every eight hours for two to three days. Symphytum officinalis is also a good remedy to help heal the fractured bone.

Calming herbs are often useful for relief of pain and tension. Cups of chamomile (Matricaria recutitca), catnip (Nepeta cataria), or lemon balm (Melissa officinalis) tea can be given freely for a calming effect. Fifteen drops of skullcap (Scutellaria lateriflora), St. John's wort (Hypericum perforatum), or valerian (Valeriana officinalis) tincture can be given every half hour as needed. A tea to encourage the bone tissue to knit and heal can be made by mixing together one ounce each of comfrey leaves (Symphytum officinale), nettles (Urtica dioica), and oatstraw (Avena sativa), plus half an ounce each of horsetail, skullcap, and marsh mallow root (Althaea officinalis). One quarter ounce each of fennel seeds (Foeniculum officinalis) and peppermint leaves (Mentha piperita) should also be added. A strong tea should be made of one ounce of the mixture in one quart of boiling water, which should steep for at least a half hour. The dosage is two cups taken daily. Frequent soaks or compresses with comfrey root in the water is recommended if there is no broken skin. Arnica montana, Calendula officinalis, St. John's wort, or comfrey salves or ointments can improve healing when applied externally, as well.

After initial treatments, the application of contrast hydrotherapy to a hand or foot below the area of the fracture can be used to assist healing by enhancing circulation. Contrast hydrotherapy uses an alternating series of hot and cold water applications. Either compresses or basins of water may be used. First, hot compress is applied for three minutes. It is followed by cold water for 30 seconds. These applications are repeated three times each, ending with the cold water.

Allopathic Treatment

Broken bones need to be treated as soon as possible by a physician. Temporary measures include applying ice packs to injured areas, and the use of aspirin or nonsteroidal anti-inflammatories (NSAIDS) to reduce pain and swelling. Initial first aid for a fracture may include splinting, control of blood loss, and monitoring of vital signs, such as breathing and circulation. Medical treatment will depend on the location of the fracture, its type and severity, and the individual's age and general health status. If an open fracture is accompanied by serious soft tissue injury, it may be necessary to control bleeding and the shock that can accompany it.

Immobilization of the fracture site can be done internally or externally. The primary goal of immobilization is to maintain the realignment of the bone long enough for healing to start and progress. Immobilization by external fixation uses splints, casts, or braces; this may be the primary and only procedure for fracture treatment. Splinting to immobilize a fracture can be done with or without traction. In emergency situations, splinting is a useful form of fracture management, if medical care is not immediately available. It should be done without causing additional pain and without moving the bone segments. In a clinical environment, plaster of Paris casts are used for immobilization. Braces are useful as they often allow movement above and below the fracture site.

Open reduction is surgery that is usually performed by an orthopedist. It allows the surgeon to examine and correct soft tissue damage while the bones are being repositioned into their normal alignment. Internal fixation devices, such as metal screws, plates, and pins, hold the bones in place as they heal. Fragments are often held together with metal rods. Later, the physician may or may not elect to remove these devices when healing is complete. Open reduction is most often used for open, severe, or comminuted fractures. Fractures with little or no displacement of the bones do not usually require such surgery.

Closed reduction refers to realigning the bones without using surgery. It is accomplished by manually adjusting the bones or using traction, and often requires the use of an anesthetic. Traction is a form of closed reduction that works by applying a steady force to the bones, pulling on them with weights until the proper alignment is achieved. The traction device can also be used to immobilize the affected area while the bone heals. Since traction restricts movement, this treatment means that the patient will be confined to bed rest for an extended period of time.

In external fixation, pins or screws are attached to the bone directly above and below the site of the fracture. They are then connected to a device of metal bars fixed over the skin. These act as a frame, keeping the bones aligned so they can heal properly. With any type of treatment for a fracture, muscle and joint strength and flexibility should be maintained through proper exercises done as the bone tissue heals.

Healing time for fractures varies from person to person, with the elderly generally needing more time to heal completely. Recovery is complete when there is no bone motion at the fracture site, and x rays indicate complete healing.

Expected Results

Fractures can normally be cured with proper first aid and after care. Proper realignment of the bones is much more difficult if the break has occurred more than six hours in the past. If broken bones are not properly treated, deformities may occur as the bones heal, and strength and flexibility may be affected.

Prevention

Adequate calcium intake, as well as intakes of other minerals like magnesium, boron, strontium, and others, is necessary for strong bones and can help decrease the risk of fractures. Foods rich in calcium should be eaten. These include fish, dairy products, sardines, broccoli, enriched soymilk, seaweed, tahini, and other sesame seed foods, nuts, molasses, and dark leafy green vegetables. Calcium supplements may be also be useful; however, those with bone meal or oyster shell have been found to often contain toxic heavy metals. Adequate stores of vitamin D are needed to help use calcium, therefore, some time should be spent in the sun, as this will activate vitamin D and help decrease fractures. Safety measures to avoid accidents that may bring on fractures include wearing seat belts and protective sports gear, when appropriate. Estrogen replacement combined with exercise and weight training for women past the age of 50 has been shown to help prevent osteoporosis and the fractures that may result from this condition.

Resources

Books

American Red Cross Editors. First Aid and Safety. St. Louis: Mosby, 1993.

The Editors of Time-Life Books. The Medical Advisor: The Complete Guide to Alternative and Conventional Treatments. Alexandria, VA: Time-Life, Inc., 1996.

Romm, Aviva Jill. Natural Healing for Babies and Children. Freedom, CA: The Crossing Press, 1996.

Other

American Academy of Orthopedic Surgeons. http://orthoinfo.aaos.org/brochure/.

drkoop.com. http://www.drkoop.com/conditions/ency/article/000001.htm.

[Article by: Patience Paradox]

Definition

A fracture is a complete or incomplete break in a bone resulting from the application of excessive force.

Description

A fracture usually results from traumatic injury to a bone, causing the continuity of bone tissues or bony cartilage to be disrupted or broken. Fracture classifications include simple or compound and incomplete or complete. Simple fractures (often called "closed") are not obvious as the skin has not been ruptured and remains intact. Compound fractures (commonly called "open") break the skin, exposing bone and causing additional soft tissue injury and possible infection. A single fracture means that one fracture has occurred, and multiple fractures refer to more than one fracture occurring in the same bone. Fractures are termed complete if the break is completely through the bone and described as incomplete or "greenstick" if the fracture occurs partly across a bone shaft. This latter type of fracture is often the result of bending or crushing forces applied to a bone.

Fractures are also named according to the specific part of the bone involved and the nature of the break. Identification of a fracture line can further classify fractures. Types include linear, oblique, transverse, longitudinal, and spiral fractures. Fractures can be further subdivided by the positions of bony fragments and are described as comminuted, non-displaced, impacted, overriding, angulated, displaced, avulsed, and segmental. Additionally, an injury may be classified as a fracture-dislocation when a fracture involves the bony structures of any joint with associated dislocation of the same joint.

Fractures Line Identification

Linear fractures have a break that runs parallel to the bone's main axis or in the direction of the bone's shaft. For example, a linear fracture of the arm bone could extend the entire length of the bone. Oblique and transverse fractures differ in that an oblique fracture crosses a bone at approximately a 45° angle to the bone's axis. In contrast, a transverse fracture crosses a bone's axis at a 90° angle. A longitudinal fracture is similar to a linear fracture. Its fracture line extends along the shaft but is more irregular in shape and does not run parallel to the bone's axis. Spiral fractures are described as crossing a bone at an oblique angle, creating a spiral pattern. This break usually occurs in the long bones of the body such as the upper arm bone (humerus) or the thigh bone (femur).

Bony Fragment Position Identification

Comminuted fractures have two or more fragments broken into small pieces, in addition to the upper and lower halves of a fractured bone. Fragments of bone that maintain their normal alignment following a fracture are described as being non-displaced. An impacted fracture is characterized as a bone fragment forced into or onto another fragment resulting from a compressive force. Overriding is a term used to describe bony fragments that overlap and shorten the total length of a bone. Angulated fragments result in pieces of bone being at angles to each other. A displaced bony fragment occurs from disruption of normal bone alignment with deformity of these segments separate from one another. An avulsed fragment occurs when bone fragments are pulled from their normal position by forceful muscle contractions or resistance from ligaments. Segmental fragmented positioning occurs if fractures in two adjacent areas occur, leaving an isolated central segment. An example of segmental alignment occurs when the arm bone fractures in two separate places, with displacement of the middle section of bone.

Demographics

The exact number of fractures sustained in the United States each year is not known as many are not treated. Experts estimate the number of fractures at between 10 and 20 million. People of all ages and races experience fractures. Broken bones are slightly more common among children due to their increased level of activity and among older people due to their lack of exercise and inadequate intake of calcium.

Causes and Symptoms

Individuals with high activity levels appear to be at greater risk for fractures. This group includes children and athletes participating in contact sports. Because of an increase in bone brittleness with aging, elderly persons are also included in this high-risk population. Up to the age of 50, more men suffer from fractures than women due to occupational hazards. However, after the age of 50, women are more prone to fractures than men. Specific diseases causing an increased risk for fractures include Paget's disease, rickets, osteogenesis imperfecta, osteoporosis, bone cancer and tumors, and prolonged disuse of a nonfunctional body part such as after a stroke.

Symptoms of fractures usually begin with pain that increases with attempted movement or use of the area and swelling at the involved site. The skin in the area may be pale and an obvious deformity may be present. In more severe cases, there may be a loss of pulse below the fracture site, such as in the extremities, accompanied by numbness, tingling, or paralysis below the fracture. An open or compound fracture is often accompanied by bleeding or bruising. If the lower limbs or pelvis are fractured, pain and resistance to movement usually accompany the injury causing difficulty with weight bearing.

When to Call the Doctor

A physician should be called when a child complains of bone pain. This is a deep pain that may be exquisitely tender to the touch.

Diagnosis

Diagnosis begins immediately with an individual's own observation of symptoms. A thorough medical history and physical exam by a physician often reveals the presence of a fracture. An x ray of the injured area is the most common test used to determine the presence of a bone fracture. Any x-ray series performed involves at least two views of the area to confirm the presence of the fracture because not all fractures are apparent on a single x ray. Some fractures are often difficult to see and may require several views at different angles to see clear fracture lines. In some cases, CT, MRI, or other imaging tests are required to demonstrate fracture. Sometimes, especially with children, the initial x ray may not show any fractures, but if it is repeated seven to 14 days later, the x ray may show changes in the bone(s) of the affected area. If a fracture is open and occurs in conjunction with soft tissue injury, further laboratory studies are often conducted to determine if blood loss has occurred.

In the event of exercise-related stress fractures (micro-fractures due to excessive stress), a tuning fork can provide a simple, inexpensive test. The tuning fork is a metal instrument with a stem and two prongs that vibrate when struck. If an individual has increased pain when the tuning fork is placed on a bone, such as the tibia or shinbone, the likelihood of a stress fracture is high. Bone scans also are helpful in detecting stress fractures. In this diagnostic procedure, a radioactive tracer is injected into the bloodstream and images are taken of specific areas or the entire skeleton by CT or MRI.

Treatment

Treatment depends on the type of fracture, its severity, the individual's age, and the person's general health. The first priority in treating any fracture is to address the entire medical status of the patient. Medical personnel are trained not to allow a painful, deformed limb to distract them from potentially life-threatening injury elsewhere or shock. If an open fracture is accompanied by serious soft tissue injury, it may be necessary to control bleeding and the shock that can accompany loss of blood.

First aid is the appropriate initial treatment in emergency situations. It includes proper splinting, control of blood loss, and monitoring vital signs such as breathing and circulation.

Immobilization

Immobilization of a fracture site can be done internally or externally. The primary goal of immobilization is to maintain the realignment of a bone long enough for healing to start and progress. Immobilization by external fixation uses splints, casts, or braces. This may be the primary and only procedure for fracture treatment. Splinting to immobilize a fracture can be done with or without traction. In emergency situations if the injured individual must be moved by someone other than a trained medical person, splinting is a useful form of fracture management. It should be done without causing additional pain and without moving the bone segments. In a clinical environment, plaster of Paris casts are used for immobilization. Braces are useful as they often allow movement above and below a fracture site. Treatments for stress fractures include rest and decreasing or stopping any activity that causes or increases pain.

Fracture Reduction

Fracture reduction is the procedure by which a fractured bone is realigned in normal position. It can be either closed or open. Closed reduction refers to realigning bones without breaking the skin. It is performed with manual manipulation and/or traction and is commonly done with some kind of anesthetic. Open reduction primarily refers to surgery that is performed to realign bones or fragments. Fractures with little or no displacement may not require any form of reduction.

Traction is used to help reposition a broken bone. It works by applying pressure to restore proper alignment. The traction device immobilizes the area and maintains realignment as the bone heals. A fractured bone is immobilized by applying opposing force at both ends of the injured area, using an equal amount of traction and countertraction. Weights provide the traction pull needed or the pull is achieved by positioning the individual's body weight appropriately. Traction is a form of closed reduction and is sometimes used as an alternative to surgery. Since it restricts movement of the affected limb or body part, it may confine a person to bed rest for an extended period of time.

A person may need open reduction if there is an open, severe, or comminuted fracture. This procedure allows a physician to examine and surgically correct associated soft tissue damage while reducing the fracture and, if necessary, applying internal or external devices. Internal fixation involves the use of metallic devices inserted into or through bone to hold the fracture in a set position and alignment while it heals. Devices include plates, nails, screws, and rods. When healing is complete, the surgeon may or may not remove these devices. Virtually any hip fracture requires open reduction and internal fixation so that the bone will be able to support the patient's weight.

Alternative Treatment

In addition to the importance of calcium for strong bones, many alternative treatment approaches recommend use of mineral supplements to help build and maintain a healthy, resilient skeleton. Some physical therapists use electro-stimulation over a fractured site to promote and expedite healing. Chinese traditional medicine may be helpful by working to reconnect chi (life energy) through the meridian lines along the line of a fracture. Homeopathy can enhance the body's healing process. Two particularly useful homeopathic remedies are arnica (Arnica montana) and symphytum (Symphytum officinalis). If possible, applying contrast hydrotherapy to an extremity (e.g., a hand or foot) of a fractured area can assist healing by enhancing circulation.

Prognosis

Fractures involving joint surfaces almost always lead to some degree of arthritis of the joint. Fractures can normally be cured with proper first aid and appropriate aftercare. If determined necessary by a physician, the fractured site should be manipulated, realigned, and immobilized as soon as possible. Realignment has been shown to be much more difficult after six hours. Healing time varies from person to person with the elderly generally needing more time to heal completely. A non-union fracture may result when a fracture does not heal, such as in the case of an elderly person or an individual with medical complications. Recovery is complete when there is no bone motion at the fracture site, and x-rays indicate complete healing. Open fractures may lead to bone infections, which delay the healing process. Another possible complication is compartment syndrome, a painful condition resulting from the expansion of enclosed tissue and that may occur when a body part is immobilized in a cast.

Prevention

Fractures can be prevented if safety measures are taken seriously. These measures include using seat belts in cars and encouraging children to wear protective sports gear. Weight-bearing exercise also helps to strengthen bones.

Nutritional Concerns

Persons who consume diets that are rich in calcium are less likely to experience a fracture than those who have diets that are deficient in calcium. Good dietary sources of calcium are milk, cheese, and other dairy products.

Parental Concerns

Parents should ensure that their children drink milk to provide an adequate intake of calcium. Children should also participate in regular physical exercise.

Resources

Books

Burr, David B. Musculoskeletal Fatigue and Stress Fracture. Boca Raton, FL: CRC Press, 2001.

Eiff, M. Patrice, et al. Fracture Management for Primary Care, 2nd ed. New York: Elsevier, 2002.

Jupiter, J. Fractures and Dislocations of the Hand. St. Louis: Mosby, 2001.

Koval, Kenneth J., and Joseph D. Zuckerman. Handbook of Fractures, 2nd ed. Philadelphia: Lippincott, 2001.

Moehring, H. David, and Adam Greenspan. Fractures:Diagnosis and Treatment. New York: McGraw Hill, 2000.

Ogden, John A. Skeletal Injury in the Child. New York: Springer Verlag, 2000.

Periodicals

Cameron, I. D. "How to manage musculoskeletal conditions: when is 'Rehabilitation" appropriate?" Best Practice and Research in Clinical Rheumatology 18, no. 4 (2004): 573–86.

Lindsay, R. "Perspectives on osteoporosis prevention: How far have we come?" Journal of Family Practice 53, no. 8 (2004): S3–9.

Minns, J., et al. "Can flooring and underlay materials reduce hip fractures in older people?" Nursing Older People 16, no. 5 (2004): 16–20.

Smith-Adaline, E. A., et al. "Mechanical environment alters tissue formation patterns during fracture repair." Journal of Orthopedic Research 22, no. 5 (2004): 1079–85.

Organizations

American Academy of Emergency Medicine. 611 East Wells Street, Milwaukee, WI 53202. Web site: www.aaem.org/.

American Academy of Family Physicians. 11400 Tomahawk Creek Parkway, Leawood, KS 66211–2672. Web site: www.aafp.org/.

American Academy of Orthopedic Surgeons. 6300 North River Road, Rosemont, Illinois 60018–4262. Web site: www.aaos.org/.

American Academy of Pediatrics. 141 Northwest Point Boulevard, Elk Grove Village, IL 60007–1098. Web site: www.aap.org/default.htm.

American Academy of Physical Medicine and Rehabilitation. One IBM Plaza, Suite 2500, Chicago, IL 60611–3604. Web site: www.aapmr.org/.

American College of Foot and Ankle Surgeons. 515 Busse Highway, Park Ridge, Illinois 60068–3150. Web site: www.acfas.org/index.html.

American College of Sports Medicine. 401 W. Michigan St., Indianapolis, IN 46202–3233. Web site: www.acsm.org/.

American College of Surgeons. 633 North St. Clair Street, Chicago, IL 60611–32311. Web site: www.facs.org/.

Web Sites

American Academy of Orthopaedic Surgeons. "Fractures." Your Orthopedic Connection. Available online at (accessed November 19, 2004).

"Falls and Hip Fractures among Older Adults." National Center for Injury Prevention and Control. Available online at www.cdc.gov/ncipc/factsheets/falls.htm accessed November 19, 2004).

"Fracture Information." About. Available online at (accessed November 19, 2004).

"Fractures." National Library of Medicine, October 21, 2004. Available online at www.nlm.nih.gov/medlineplus/fractures.html (accessed November 19, 2004).

[Article by: L. Fleming Fallon, Jr., MD, DrPH]

1. the breaking of a part, especially a bone.
2. a break in the continuity of bone. Fractures may be caused by trauma, by twisting due to muscle spasm, or indirect loss of leverage or by disease that results in decalcification of the bone.

• avulsion f. — separation of a small fragment of bone cortex at the site of attachment of a ligament or tendon.
• blow-out f. — fracture of the orbital floor caused by a sudden increase of intraorbital pressure due to traumatic force; the orbital contents herniate into the maxillary sinus so that the inferior rectus or inferior oblique muscle may become incarcerated in the fracture site, producing diplopia on looking up.
• capillary f. — one that appears on a radiograph as a fine, hairlike line, the segments of bone not being separated; sometimes seen in fractures of the skull.
• closed f. — one that does not produce an open wound.
• comminuted f. — one in which the bone is splintered or crushed.
• complete f. — one involving the entire cross-section of the bone.
• compound f. — see open fracture (below).
• compression f. — one produced by compression.
• contaminated f. — see open fracture (below).
• depressed f. — fracture of the skull in which a fragment is depressed. See also depression fracture.
• direct f. — one at the site of injury.
• dislocation f. — fracture of a bone near an articulation with concomitant dislocation of that joint.
• double f. — fracture of a bone in two places.
• fissure f. — a crack extending from a surface into, but not through, a long bone.
• greenstick f. — one in which one side of a bone is broken, the other being bent.
• impacted f. — fracture in which one fragment is firmly driven into the other.
• incomplete f. — one that does not involve the complete cross-section of the bone.
• indirect f. — one at a point distant from the site of injury.
• interperiosteal f. — greenstick or incomplete fracture.
• intrauterine f. — fracture of a fetal bone incurred in utero.
• lead pipe f. — one in which the bone cortex is slightly compressed and bulged on one side with a slight crack on the other side of the bone.
• malunion f. — a large space between the displaced ends of the bone has been filled by new bone.
• nonunion f. — there is still a wide translucent space between the ends of the broken bone.
• oblique f. — a common type, usually seen in the shaft of a long bone, such as the femur, tibia or humerus.

  Oblique fractures of the radius and ulna. By permission from Lamb CR, Diagnostic Imaging of the Dog and Cat, Mosby, 1993

• open f. — one in which a wound through the adjacent or overlying soft tissues communicates with the site of the break; called also compound fracture. A classification system has been used which is based on the mechanism of injury and the extent of tissue damage. In type I, a bone fragment was briefly forced through the skin leaving a communicating wound; type II fractures are caused by impact and there is damage to overlying tissues and exposure of the bone; in type III, there is extensive damage and loss of overlying tissues, including shearing and degloving wounds, with loss of vascular supply.
• pathological f. — one due to weakening of the bone structure by pathological processes, such as neoplasia, osteomalacia or osteomyelitis.
• pertrochanteric f. — fracture of the femur passing through the greater trochanter.
• Salter f. — see salter classification.
• saucer f. — creates a saucer-shaped fragment; caused usually by direct trauma at midshaft in a long bone. Likely to create a sequestrum.
• simple f. — closed fracture.
• slab f. — one in which a flat piece of underlying bone or tooth is separated or lost. Common in carpal bones of horses and in teeth.
• spiral f. — one in which the bone has been twisted apart.
• spontaneous f. — pathological fracture.
• sprain f. — the separation of a tendon from its insertion, taking with it a piece of bone. See also avulsion fracture (above).
• stellate f. — one with a central point of injury, from which radiate numerous fissures.
• stress f. — fracture produced by the stress created by the pull of muscles without the intervention of trauma or extreme weight-bearing.
• trabecular f. — there is no discontinuity of the bone as a whole but microscopic examination shows fractured trabeculae.
• transverse f. — one at right angles to the axis of the bone.
• trophic f. — one due to a nutritional (trophic) disturbance.

For other uses, see Fracture (disambiguation).

Mechanical failure modes
Buckling
Corrosion
Creep
Fatigue
Fracture
Impact
Mechanical overload
Rupture
Thermal shock
Wear
Yielding
This box: view • talk • edit

This article includes a list of references, related reading or external links, but its sources remain unclear because it lacks inline citations. Please improve this article by introducing more precise citations where appropriate. (February 2009)

A fracture is the (local) separation of an object or material into two, or more, pieces under the action of stress.

The word fracture is often applied to bones of living creatures, or to crystals or crystalline materials, such as gemstones or metal. Sometimes, in crystalline materials, individual crystals fracture without the body actually separating into two or more pieces. Depending on the substance which is fractured, a fracture reduces strength (most substances) or inhibits transmission of light (optical crystals).

A detailed understanding of how fracture occurs in materials may be assisted by the study of fracture mechanics.

Contents 1 Types of fracture 1.1 Brittle fracture 1.2 Ductile fracture 2 Crack separation modes 3 See also 4 Bibliography 5 External links

Types of fracture

Brittle fracture

Brittle fracture in glass.

Fracture of an Aluminum Crank Arm. Bright: Brittle fracture. Dark: Fatigue fracture.

In brittle fracture, no apparent plastic deformation takes place before fracture. In brittle crystalline materials, fracture can occur by cleavage as the result of tensile stress acting normal to crystallographic planes with low bonding (cleavage planes). In amorphous solids, by contrast, the lack of a crystalline structure results in a conchoidal fracture, with cracks proceeding normal to the applied tension.

The theoretical strength of a crystalline material is (roughly)

where: -

E is the Young's modulus of the material,

γ is the surface energy, and

r_o is the equilibrium distance between atomic centers.

On the other hand, a crack introduces a stress concentration modeled by

(For sharp cracks)

where: -

σ_applied is the loading stress,

a is half the length of the crack, and

ρ is the radius of curvature at the crack tip.

Putting these two equations together, we get

Looking closely, we can see that sharp cracks (small ρ) and large defects (large a) both lower the fracture strength of the material.

Recently, scientists have discovered supersonic fracture, the phenomenon of crack motion faster than the speed of sound in a material.^{[citation needed]} This phenomenon was recently also verified by experiment of fracture in rubber-like materials.

Ductile fracture

Ductile failure of a specimen strained axially.

Schematic representation of the steps in ductile fracture.

In ductile fracture, extensive plastic deformation takes place before fracture. Many ductile metals, especially materials with high purity, can sustain very large deformation of 50–100% or more strain before fracture under favorable loading condition and environmental condition. The strain at which the fracture happens is controlled by the purity of the materials. At room temperature, pure iron can undergo deformation up to 100% strain before breaking, while cast iron or high-carbon steels can barely sustain 3% of strain.^{[citation needed]}.

Because ductile rupture involves a high degree of plastic deformation, the fracture behavior of a propagating crack as modeled above changes fundamentally. Some of the energy from stress concentrations at the crack tips is dissipated by plastic deformation before the crack actually propagates.

The basic steps sample of smallest cross-sectional area), void formation, void coalescence (also known as crack formation), crack propagation, and failure, often resulting in a cup-and-cone shaped failure surface.

Crack separation modes

The three fracture modes.

There are three ways of applying a force to enable a crack to propagate:

• Mode I crack – Opening mode (a tensile stress normal to the plane of the crack)
• Mode II crack – Sliding mode (a shear stress acting parallel to the plane of the crack and perpendicular to the crack front)
• Mode III crack – Tearing mode (a shear stress acting parallel to the plane of the crack and parallel to the crack front)

For more information, see fracture mechanics.

See also

• Bone fracture
• Brittle-ductile transition zone
• Environmental stress fracture
• Fracture mechanics
• Fracture (mineralogy)
• Fracture (geology)
• Fracture toughness
• Fractography
• Forensic engineering
• Forensic materials engineering
• Rupture (engineering)
• Structural failure

Bibliography

• Dieter, G. E. (1988) Mechanical Metallurgy ISBN 0-07-100406-8
• A. Garcimartin, A. Guarino, L. Bellon and S. Cilberto (1997) " Statistical Properties of Fracture Precursors ". Physical Review Letters, 79, 3202 (1997)
• Callister, Jr., William D. (2002) Materials Science and Engineering: An Introduction. ISBN 0-471-13576-3
• Peter Rhys Lewis, Colin Gagg, Ken Reynolds, CRC Press (2004), Forensic Materials Engineering: Case Studies.

External links

• Web postings at http://www.jwave.vt.edu/crcd/farkas/lectures/Fract1/tsld006.htm
• Virtual museum of failed products at http://materials.open.ac.uk/mem/index.html
• Fracture and Reconstruction of a Clay Bowl
• Ductile fracture

This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)

Dansk (Danish)
n. - brud, fraktur
v. tr. - brække, imponere, genere
v. intr. - blive brækket

Nederlands (Dutch)
fractuur, breuk, breukvlak, scheur, vervanging van twee klinkers door een, (ver) breken, (ver)scheuren, verdelen, schenden, door de war maken, gebroken/ gescheurd worden

Français (French)
n. - (gén, Méd) fracture
v. tr. - fracturer, (fig) se fissurer
v. intr. - se fracturer, se fissurer

Deutsch (German)
n. - Bruch, Fraktur
v. - brechen

Ελληνική (Greek)
n. - (ιατρ.) κάταγμα, θλάση
v. - σπάζω, θρυμματίζω/-ομαι, κατακερματίζω/-ομαι, θραύω, τσακίζω, υφίσταμαι ή προξενώ κάταγμα ή θλάση, ραγίζω

Italiano (Italian)
frattura

Português (Portuguese)
n. - fratura (f)
v. - fraturar

Русский (Russian)
трещина, излом, перелом, раскалываться

Español (Spanish)
n. - fractura
v. tr. - fracturar
v. intr. - fracturarse

Svenska (Swedish)
n. - brytning, fraktur (kir.)
v. - bryta(s)

中文（简体）(Chinese (Simplified))
破碎, 骨折, 使破裂, 使折断, 使断裂, 使骨折, 破裂, 折断, 断裂

中文（繁體）(Chinese (Traditional))
n. - 破碎, 骨折
v. tr. - 使破裂, 使折斷, 使斷裂, 使骨折
v. intr. - 破裂, 折斷, 斷裂

한국어 (Korean)
n. - 부서짐, 분열, 골절
v. tr. - 부수다, 무시하다
v. intr. - 부서지다, 삐다

日本語 (Japanese)
n. - 割れ目, 骨折
v. - 割る, 砕く, 折る

العربيه (Arabic)
‏(الاسم) كسر العظم (فعل) يكسر , يمزق‏

עברית (Hebrew)
n. - ‮סדק (בעצם), שבר, הפיכת תנועה כפולה לרגילה (בלשנות)‬
v. tr. - ‮שבר‬
v. intr. - ‮נסדק‬

If you are unable to view some languages clearly, click here.

To select your translation preferences click here.