The upper back bone (thoracic region), is normally curved forward. If the curve exceeds 50° it is considered abnormal (kyphotic).
Causes and symptoms
Kyphosis can be divided into three ages of acquisition—birth, old age, and the time in between.
- Spinal birth defects can result in a fixed, exaggerated curve. Vertebrae can be fused together, shaped wrong, extraneous, or partially missing. Congenital and hereditary defects in bone growth weaken bone and result in exaggerated curves wherever gravity or muscles pull on them. Dwarfism is such a defect.
- During life, several events can distort the spine. Because the natural tendency of the thoracic spine is to curve forward, any weakness of the supporting structures will tend in that direction. A diseased thoracic vertebra (a spine bone) will ordinarily crumble its forward edge first, increasing the kyphotic curve. Conditions that can do this include cancer, tuberculosis, Scheuermann's disease, and certain kinds of arthritis. Healthy vertebrae will fracture forward with rapid deceleration injuries, such as in car crashes when the victim is not wearing a seat belt.
- Later in life, kyphosis is caused from osteoporosis, bone weakness, and crumbling forward.
The stress caused by kyphosis produces such symptoms as an increase in musculoskeletal pains, tension headaches, back aches, and joint pains.
A quick look at the back will usually identify kyphosis. X rays of the spine will confirm the diagnosis and identify its cause.
Congenital defects have to be repaired surgically. The procedures are delicate, complicated, and lengthy. Often orthopedic hardware must be placed to stabilize the back bone. At other times, a device called a Milwaukee brace can hold the back in place from the outside. Fitting Milwaukee braces comfortably is difficult because they tend to rub and cause sores.
Kyphosis acquired during the younger years requires treatment directed at the cause, such as medications for tuberculosis. Surgical reconstruction or bracing may also be necessary.
Kyphosis induced by osteoporosis is generally not treated except to prevent further bone softening.
Congenital kyphosis may be alleviated to some extent by surgery and bracing. Kyphosis occurring later in life may worsen over time.
Preventing osteoporosis is within the grasp of modern medicine. Menopausal women must start early with estrogen replacement, calcium supplementation, and appropriate exercise. The treatment must continue through the remainder of life. Evidence suggests that a high calcium intake even during younger years delays the onset of symptomatic osteoporosis. Dairy products are the major dietary sources of calcium.
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Arthritis Foundation.1300 W. Peachtree St., Atlanta, GA 30309. (800) 283-7800. <http://www.arthritis.org>.
National Osteoporosis Foundation. 1150 17th St., Suite 500 NW, Washington, DC 20036-4603. (800) 223-9994. <http://www.nof.org>.
Osteoporosis and Related Bone Diseases-National Resource Center. 1150 17th S. NW, Ste. 500, Washington, DC20036. (800) 624-2663.
J. Ricker Polsdorfer, MD
Congenital—Present at birth.
Dwarfism—A congenital disease of bone growth that results in short stature and weak bones.
Orthopedic—Refers to surgery on the supporting structures of the body—bones, joints, ligaments, muscles.
Osteoporosis—A weakening of bones due to calcium loss that affects post-menopausal women.
Scheuermann's disease—Juvenile kyphosis due to damaged bone in the spinal vertebrae.