Scoliosis
From Wikipedia, the free encyclopedia
| ICD-10 | M41.0, Q67.5, Q76.3 |
|---|---|
| ICD-9 | 737.3 |
Scoliosis is a condition that involves complex lateral and rotational curvature and deformity of the spine. It is typically classified as congenital (caused by vertebral anomalies present at birth), idiopathic (sub-classified as infantile, juvenile, adolescent, or adult according to when onset occurred) or as having developed as a secondary symptom of another condition, such as cerebral palsy or spinal muscular atrophy.
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[edit] Cause
The cause of scoliosis is poorly understood. In the case of the most common form of scoliosis, Adolescent Idiopathic Scoliosis, there is a clear Mendelian inheritance but with incomplete penetrance. Various causes have been implicated, but none have consensus among scientists as the cause of scoliosis. Scoliosis is more common in females and is often seen in patients with cerebral palsy or spina bifida, although this form of scoliosis is different than that seen in children without these conditions. In some cases, scoliosis exists at birth due to a congenital vertebral anomaly. Occasionally development of scoliosis during adolescence is due to an underlying anomaly such as a tethered spinal cord, but most often the cause is unknown or idiopathic. Contrary to common belief, scoliosis does not come from slouching, sitting in awkward positions, or sleeping on an old mattress.
[edit] Prevalence
Scoliotic curves greater than 10° affect 2-3% of the population [citation needed]. The prevalence of curves less than 20° is about equal in males and females. Curves greater than 20° affect about 1 in 2500 people. Curves convex to the right are more common than those to the left, and single or 'C' curves are slightly more common than double or 'S' curve patterns. Males are more likely to have infantile or juvenile scoliosis, but there is a high female predominance of adolescent scoliosis. Young females are seven times more likely than young males to develop a significant, progressive curvature. Females are nine times more likely to require treatment than males as they tend to have larger, more progressive curves.
[edit] Symptoms
Those with scoliosis often do not have pain as adolescents and young adults. Pain is common in adulthood if left untreated. The most common complaint from parents and patients is cosmetic deformity.
The symptoms of scoliosis are:
- Uneven musculature on one side of the spine
- A rib "hump" and/or a prominent shoulder blade, caused by rotation of the ribcage in thoracic scoliosis
- Uneven hip and shoulder levels
- Asymmetric size or location of breast in females
- Unequal distance between arms and body
- Clothes that do not "hang right", ie. with uneven hemlines
[edit] Associated conditions
Scoliosis is sometimes associated with other conditions such as cerebral palsy, spinal muscular atrophy, familial dysautonomia, Friedreich's ataxia, skeletal dysplasias, Marfan's syndrome, neurofibromatosis, connective tissue disorders, and craniospinal axis disorders (e.g., syringomyelia).
However, the majority of patients with scoliosis have no other abnormalities.
[edit] Investigation
Patients who are initially present with scoliosis are examined to determine if there is an underlying cause of the deformity. During a physical examination, the following is assessed:
- Skin for café au lait spots indicative of neurofibromatosis
- The feet for cavovarus deformity
- Abdominal reflexes
- Muscle tone for spasticity
During the exam, the patient's gait is assessed, and there is an exam for signs of other abnormalities (e.g., dysraphism as evidenced by a dimple, hairy patch, lipoma, or hemangioma). A thorough neurological examination is also performed..
Full-length standing spine X rays are the standard method for evaluating the severity and progression of the scoliosis, and whether it is congenital or idiopathic in nature. In growing individuals, serial radiographs are obtained at 3-12 month intervals to follow curve progression. In some instances, MRI investigation is warranted.
The standard method for assessing the curvature quantitatively is measurement of the Cobb angle, which is the angle between two lines, drawn perpendicular to the upper endplate of the uppermost vertebrae involved and the lower endplate of the lowest vertebrae involved. For patients who have two curves, Cobb angles are followed for both curves. In some patients, lateral bending xrays are obtained to assess the flexibility of the curves or the primary and compensatory curves.
[edit] Prognosis
The prognosis of scoliosis depends on the likelihood of progression. The general rules of progression are that larger curves carry a higher risk of progression than smaller curves, and that thoracic and double primary curves carry a higher risk of progression than single lumbar or thoracolumbar curves. In addition, patients who have not yet reached skeletal maturity have a higher likelihood of progression.
[edit] Management
The traditional medical management of scoliosis is complex and is determined by the severity of the curvature, skeletal maturity, and likelihood of progression.
The conventional options are, in order:
- Observation
- Bracing
- Surgery
Bracing is only done when the patient has bone growth remaining, and is generally implemented in order to hold the curve and prevent it from progressing to the point where surgery is necessary. Bracing involves fitting the patient with a device that covers the torso and in some cases it extends to the neck. The most commonly used brace is a TLSO, a corset-like appliance that fits from armpits to hips and is custom-made from plastic. It is usually worn 23 hours a day and applies pressure on the curves in the spine. Bracing is only mildly effective as compliance is typically low, although some of the newer braces (such as the Charleston back brace) are touting better compliance rates and outcomes. Typically braces are only used for idiopathic curves that are not grave enough to warrant surgery, but they may also be used to prevent the progression of more severe curves in young children, in order to buy the child time to grow before performing surgery which would prevent further growth in the part of the spine affected.
In infantile and sometimes juvenile scoliosis a body cast or plaster jacket may be used instead of a brace. It has been proven possible to permanently correct some cases of infantile idiopathic scoliosis by using a series of plaster body casts applied under corrective traction, which help to "mould" the infant's soft bones and work with their infantile growth spurts. This method was pioneered by UK scoliosis specialist Min Mehta.
Chiropractic and physical therapy have some degree of anecdotal success in treating scoliosis that is primarily neuromuscular in nature, however non-surgical approaches will not address severe bony deformities associated with many cases of scoliosis. Chiropractors and physical therapists utilize joint mobilization techniques and therapeutic exercise to increase a scoliosis patient's flexibility and strength, theorizing that this better enables the brace to influence the curvature of the spine. Electronic Muscle Stimulation (EMS) is another therapeutic modality commonly utilized by chiropractors and physical therapists to reduce muscle spasms and strengthen atrophied muscles.
There is limited published scientific research to evaluate the efficacy of treatment programmes that include a combination of bracing along with physical therapy. While much debate remains in the scientific community about whether or not chiropractic and physical therapy can influence scoliotic curvature, there is less dispute about their palliative benefit in scoliosis patients who experience back pain either directly as a result of their deformity or indirectly from wearing an uncomfortable brace for the vast majority of the day.
[edit] Surgery
Surgery is usually indicated for curves that have a high likelihood of progression, curves that would be cosmetically unacceptable as an adult, curves in patients with spina bifida and cerebral palsy that interfere with sitting and care, and curves that affect physiological functions such as breathing.
Surgery for scoliosis is usually done by an orthopaedic surgeon or by a specialized spine surgeon. For various reasons it is usually impossible to completely straighten a scoliotic spine, but in most cases very good corrections are achieved.
[edit] Spinal fusion with instrumentation
Spinal fusion is the most widely performed surgery for scoliosis. In this procedure bone (either harvested from elsewhere on the body, or donor bone) is grafted to the vertebrae so that when it heals, they will form one solid bone mass and the vertebral column becomes rigid. This prevents worsening of the curve at the expense of spinal movement. This can be performed from the anterior (front) aspect of the spine by entering the thoracic or abdominal cavity, or performed from the back (posterior). A combination of both is used on more severe cases.
Originally, spinal fusions were done without metal implants. A cast was applied after the surgery, usually under traction to pull the curve as straight as possible and then hold it there while fusion took place. Unfortunately, there was a relatively high risk of pseudarthrosis (fusion failure) at one or more levels and significant correction could not always be achieved. In 1962 Paul Harrington introduced a metal spinal system of instrumentation which assisted with straightening the spine, as well as holding it rigid while fusion took place. The original, now obsolete Harrington rod operated on a ratchet system, attached by hooks to the spine at the top and bottom of the curvature that when cranked would distract, or straighten, the curve. Modern spinal systems involve a combination of rods, screws, hooks and wires fixing the spine and can apply stronger, safer forces to the spine than the Harrington rod. Spinal fusion is rarely performed without this instrumentation.
Modern spinal fusions generally have good outcomes with high degrees of correction and low rates of failure and infection. Patients with fused spines and permanent implants tend to have normal lives with unrestricted activities. They are able to participate in recreational athletics, have natural childbirth and are generally satisfied with their treatment. The most notable limitation of spinal fusions is that patients who have undergone surgery for scoliosis are ineligible for military service in the United States.
In cases where scoliosis has caused a significant deformity resulting in a rib hump, it is often possible to perform a surgery called a "costoplasty" (also called "thorocoplasty") in order to achieve a more pleasing cosmetic result. This procedure may be performed at any time after a fusion surgery, whether as part of the same operation or several years afterwards. As stated before, it is usually impossible to completely straighten and untwist a scoliotic spine, and it should be noted that the level of cosmetic success will depend on the extent to which the fused spine still rotates out into the ribcage.
[edit] Alternatives
Recently, new implants have been developed that aim to delay spinal fusion and to allow more spinal growth in young children. These include rods that are extendable and allow growth while still applying corrective forces, ribcage implants that push apart the ribs on the concave side of the curve, and vertebral stapling which is a method of retarding normal growth on the convex side of a curve, allowing the concave side to 'catch up'. Although these methods are novel and promising, these treatments are only suitable for growing patients. Spinal fusion remains the 'gold-standard' of surgical treatment for scoliosis.
[edit] References
- Gylys, Barbara A. and Mary Ellen Wedding, Medical Terminology Systems, F.A. Davis Company, 2005.
- Canale: Campbell's Operative Orthopaedics, 10th ed., Copyright © 2003 Mosby, Inc.
[edit] See also
[edit] External links
- National Scoliosis Foundation of America
- Scoliosis Support - forums for people with Scoliosis, Kyphosis and Lordosis
- SpineKIDS - dedicated to children and parents dealing with scoliosis and other spinal disorders
- Keeping Kids Healthy: Scoliosis-What It Is and What to Do
- Resource for those with scoliosis, featuring many articles, patient stories and exercises
