Fracture and dislocation
Causes and Symptoms (Magill’s Medical Guide, Sixth Edition)
A fracture is a linear deformation or discontinuity of a bone produced by the application of a force that exceeds the modulus of elasticity (ability to bend) of a bone. Normal bones require excessive force to fracture. Bones may be weakened by disease or other pathology such as a tumor or tumor-related disease that reduces their ability to withstand an impact. Bones respond to stresses made upon them and can thus be strengthened through physical conditioning and made more resistant to fracture. This is a normal part of training in many athletic activities.
Fractures are classified according to the type of break or, more correctly, by the plane or surface that is fractured. A break that is at a right angle to the axis of the bone is called transverse. A fracture that is similar but at an angle, rather than perpendicular to the main axis of the bone, is called oblique. If a twisting force is applied, the break may be spiral, or twisted. A comminuted fracture is a break that results in two or more fragments of bone. If the pieces of bone remain in their original positions, the fracture is undisplaced. In a displaced fracture, the portions of bone are not properly aligned.
If bones do not penetrate the skin, the fracture is called closed, or simple. When bones protrude through the skin, the result is an open, or compound, fracture. Other types of fractures are associated with pathologic or disease processes. A stress...
(The entire section is 1320 words.)
Treatment and Therapy (Magill’s Medical Guide, Sixth Edition)
Fractures are usually treated by reduction and immobilization. Reduction, which refers to the process of returning the fractured bones to normal position, may be either closed or open. Closed reduction is accomplished without surgery by manipulating the broken bone through overlying skin and muscles. Open reduction requires surgical intervention in which the broken pieces are exposed and returned to normal position. Orthopedic appliances may be used to hold the bones in correct position. The most common of these appliances are pins and screws, but metal plates and wires may also be employed. Orthopedic appliances are usually made of stainless steel. These may be left in the body indefinitely or may be surgically removed after healing is complete. Local anesthesia is usually used with closed reductions; open reductions are performed in an operating room, under sterile conditions using general anesthesia.
Immobilization is generally accomplished by the use of a cast. Casts are often made of plaster, but they may be constructed of inflatable plastic. It is important to hold bones in a rigid, fixed position for a sufficient length of time for the broken ends to unite and heal. The cast must be loose enough, however, to allow blood to circulate. Padding is usually put in place before plaster is applied to form a cast. Whenever possible, the newly immobilized body part is elevated to reduce the chance of swelling in the cast,...
(The entire section is 1209 words.)
Perspective and Prospects (Magill’s Medical Guide, Sixth Edition)
Fractures rarely threaten a patient’s life directly, and injuries to the brain, heart, circulatory system, and abdominal cavity must receive priority of treatment. It is imperative, however, not to move a patient in whom a fracture is suspected without first immobilizing the potential fracture site. This is especially true with suspected fractures of the spine. Instability may not be apparent when a patient is lying down but can become catastrophic if the person is moved without proper preparation and immobilization.
Crush injuries of the spinal cord are relatively common among victims of osteoporosis. Osteoporosis is a pathological syndrome defined by a decrease in the density of a bone below the level required for mechanical support and is frequently associated with a deficiency of calcium, problems related to calcium in the body, or a rate of bone cell breakdown that is greater than the rate of bone cell remodeling. Crush fractures occur when the bones become so weak that the weight of the upper portion of the body is greater than the ability of the vertebrae to support it. These crush injuries may occur slowly over time and cause no serious injury to the underlying spinal cord. The resulting deformity of the spine, however, impairs movement. There is no treatment for osteoporotic crush fractures of the vertebrae.
Occupational exposures may lead to fractures and dislocations. Professional athletes are...
(The entire section is 479 words.)
For Further Information: (Magill’s Medical Guide, Sixth Edition)
Brunicardi, F. Charles, et al., eds. Schwartz’s Principles of Surgery. 9th ed. New York: McGraw-Hill, 2010. A standard textbook of surgery containing sections on fractures and dislocations. Its intended audience is practicing surgeons, and thus the language is sometimes technical. Nevertheless, the serious reader can obtain much useful detail from this work.
Currey, John D. Bones: Structures and Mechanics. Princeton, N.J.: Princeton University Press, 2002. Very accessible overview of a range of information related to whole bones, bone tissue, and dentin and enamel. Topics include stiffness, strength, viscoelasticity, fatigue, fracture mechanics properties, buckling, impact fracture, and properties of cancellous bone.
Doherty, Gerard M., and Lawrence W. Way, eds. Current Surgical Diagnosis and Treatment. 12th ed. New York: Lange Medical Books/McGraw-Hill, 2006. The diagnosis and treatment of fractures and dislocations is discussed in a brief and concise format emphasizing treatment modalities. The different section authors are recognized experts in their fields. The material is accessible to the general reader, but the sections are brief.
Marieb, Elaine N., and Katja Hoehn. Human Anatomy and Physiology. 9th ed. San Francisco: Pearson/Benjamin Cummings, 2010. Nonscientists at the advanced high school level or above will be able to understand this fine textbook. The...
(The entire section is 310 words.)