Scoliosis (: scolioses) is a medical condition in which the spine has an irregular curve in the coronal plane, associated with a rotational component. The curve is usually S- or C-shaped over three dimensions. In some cases, the degree of curvature remains stable, while in others it increases over time. Mild scoliosis does not typically cause problems, but more severe cases can affect breathing and movement. Pain is usually present in adults and can worsen with age. As the condition progresses, it may affect a person's quality of life and, in some cases, may be considered a disability. It can be compared to kyphosis and lordosis, other abnormal curvatures of the spine which are in the sagittal plane (front-back) rather than the coronal (left-right).
The cause of most cases is unknown, but it is believed to involve a combination of genetic and environmental factors. Scoliosis most often occurs during growth spurts right before puberty. Risk factors include other affected family members. It can also occur due to another condition such as muscle spasms, cerebral palsy, Marfan syndrome, and tumors such as neurofibromatosis. Diagnosis is confirmed with X-rays. Scoliosis is typically classified as either structural in which the curve is fixed, or functional in which the underlying spine is normal. Left-right asymmetries, of the vertebrae and their musculature, especially in the thoracic region, may cause mechanical instability of the spinal column.
Treatment depends on the degree of curve, location, and cause. The age of the patient is also important, since some treatments are ineffective in adults, who are no longer growing. Minor curves may simply be watched periodically. Treatments may include bracing, specific exercises, posture checking, and surgery. The brace must be fitted to the person and used daily until growth stops. Specific exercises, such as exercises that focus on the core, may be used to try to decrease the risk of worsening. They may be done alone or along with other treatments such as bracing. Evidence that chiropractic manipulation, dietary supplements, or exercises can prevent the condition from worsening is weak. However, exercise is still recommended due to its other health benefits.
Scoliosis occurs in about 3% of people. It most commonly develops between the ages of ten and twenty. Females typically are more severely affected than males with a ratio of 4:1. The term is . .
Signs and symptoms
Symptoms associated with scoliosis can include: Pain in the back at the site of the curve, which may radiate to the legs. Chest pain at the ribs and sternum location can sometimes be linked to scoliosis of the spine because the ribs wrap around to the chest area which can be misaligned. This can lead to injury, pain and swelling which can turn up on medical imaging (CT scans etc.). Respiratory or cardiac problems in severe cases Constipation due to curvature causing "tightening" of the stomach, intestines, etc. Pain, weakness, or numbness in the lower limbs, difficulty bending forward, and uneven alignment of the pelvis and hips may also be present.
The signs of scoliosis can include: Uneven musculature on one side of the spine Rib prominence or a prominent shoulder blade, caused by rotation of the rib cage in thoracic scoliosis Uneven posture Heart and lung problems in severe cases Calcium deposits in the cartilage endplate and sometimes in the disc itself
Course People who have reached skeletal maturity are less likely to have a worsening case. Some severe cases of scoliosis can lead to diminishing lung capacity, pressure exerted on the heart, and restricted physical activities.
Longitudinal studies have revealed that the most common form of the condition, late-onset idiopathic scoliosis, causes little physical impairment other than back pain and cosmetic concerns, even when untreated, with mortality rates similar to the general population. Older beliefs that untreated idiopathic scoliosis necessarily progressed into severe (cardiopulmonary) disability by old age have been refuted.
Causes
An estimated 65% of scoliosis cases are idiopathic (cause unknown), about 15% are congenital, and about 10% are secondary to a neuromuscular disease.
About 38% of variance in scoliosis risk is due to genetic factors, and 62% is due to the environment. The genetics are likely complex, given the inconsistent inheritance and discordance among monozygotic twins. The specific genes that contribute to the development of scoliosis have not been conclusively identified. Several candidate gene studies have found associations between idiopathic scoliosis and genes mediating bone formation, bone metabolism, and connective tissue structure. Several genome-wide studies have identified several loci as significantly linked to idiopathic scoliosis. In 2006, idiopathic scoliosis was linked with three microsatellite polymorphisms in the MATN1 gene (encoding for matrilin 1, cartilage matrix protein). Fifty-three single nucleotide polymorphism markers in the DNA that are significantly associated with adolescent idiopathic scoliosis were identified through a genome-wide association study. Abnormalities in bone metabolism have also been investigated as potential contributing factors, with studies reporting lower bone mass in adolescents with idiopathic scoliosis compared to controls.
Adolescent idiopathic scoliosis has no clear causal agent and is generally believed to be multifactorial, leading to "progressive functional limitations" for individuals. Research suggests that Posterior Spinal Fusion (PSF) can be used to correct the more severe deformities caused by adolescent idiopathic scoliosis. Such procedures can result in a return to physical activity in about 6 months, which is very promising, although minimal back pain is still to be expected in the most severe cases. The prevalence of scoliosis is 1–2% among adolescents, but the likelihood of progression among adolescents with a Cobb angle less than 20° is about 10–20%.
Congenital scoliosis can be attributed to a malformation of the spine during weeks three to six in utero due to a failure of formation, a failure of segmentation, or a combination of stimuli. Incomplete and abnormal segmentation results in an abnormally shaped vertebra, at times fused to a normal vertebra or unilaterally fused vertebrae, leading to the abnormal lateral curvature of the spine.
Vertebrae of the spine, especially in the thoracic region, are, on average, asymmetric. The mid-axis of these vertebral bodies tends to point systematically to the right of the median body plane. A strong asymmetry of the vertebrae and their musculature, may lead to mechanical instability of the column, especially during phases of rapid growth. The asymmetry is thought to be caused by an embryological twist of the body.
Resulting from other conditions Secondary scoliosis due to neuropathic and myopathic conditions can lead to a loss of muscular support for the spinal column so that the spinal column is pulled in abnormal directions. Some conditions which may cause secondary scoliosis include muscular dystrophy, spinal muscular atrophy, poliomyelitis, cerebral palsy, spinal cord trauma, and myotonia.POSNA. (2014). Neuromuscular Scoliosis. The Pediatric Orthopaedic Society of North America. Scoliosis often presents itself, or worsens, during an adolescent's growth spurt and is more often diagnosed in females than males.
Scoliosis associated with known syndromes is often subclassified as "syndromic scoliosis". Scoliosis can be associated with amniotic band syndrome, Arnold–Chiari malformation, Charcot–Marie–Tooth disease, cerebral palsy, congenital diaphragmatic hernia, connective tissue disorders, muscular dystrophy, familial dysautonomia, CHARGE syndrome, Ehlers–Danlos syndrome (hyperflexibility, "floppy baby" syndrome, and other variants of the condition), fragile X syndrome, Friedreich's ataxia, hemihypertrophy, Loeys–Dietz syndrome, Marfan syndrome, nail–patella syndrome, neurofibromatosis, osteogenesis imperfecta, Prader–Willi syndrome, proteus syndrome, spina bifida, spinal muscular atrophy, syringomyelia, and pectus carinatum.
Another form of secondary scoliosis is degenerative scoliosis, also known as de novo scoliosis, which develops later in life secondary to degenerative (may or may not be associated with aging) changes. This is a type of deformity that starts and progresses because of the collapse of the vertebral column in an asymmetrical manner. As bones start to become weaker and the ligaments and discs located in the spine become worn as a result of age-related changes, the spine begins to curve.
Diagnosis
People who initially present with scoliosis undergo a physical examination to determine whether the deformity has an underlying cause and to exclude the possibility of the more serious underlying condition than simple scoliosis.
The person's gait is assessed, with an exam for signs of other abnormalities (e.g., spina bifida as evidenced by a dimple, hairy patch, lipoma, or hemangioma). A thorough neurological examination is also performed, the skin for café au lait spots, indicative of neurofibromatosis, the feet for cavovarus deformity, abdominal reflexes and muscle tone for spasticity.
When a person can cooperate, they are asked to bend forward as far as possible. This is known as the Adams forward bend test and is often performed on school students. If a prominence is noted, then scoliosis is a possibility, and an X-ray may be done to confirm the diagnosis.
As an alternative, a scoliometer may be used to diagnose the condition.
When scoliosis is suspected, weight-bearing, full-spine AP/coronal (front-back view) and lateral/sagittal (side view) X-rays are usually taken to assess the scoliosis curves and the kyphosis and lordosis, as these can also be affected in individuals with scoliosis. Full-length standing spine X-rays are the standard method for evaluating the severity and progression of scoliosis, and whether it is congenital or idiopathic in nature. In growing individuals, serial radiographs are obtained at 3- to 12-month intervals to follow curve progression, and, in some instances, MRI investigation is warranted to look at the spinal cord. An average scoliosis patient has been in contact with around 50–300 mGy of radiation due to these radiographs during this period.
The standard method for assessing the curvature quantitatively is measuring the Cobb angle, which is the angle between two lines, drawn perpendicular to the upper endplate of the uppermost vertebra involved and the lower endplate of the lowest vertebra involved. For people with two curves, Cobb angles are followed for both curves. In some people, lateral-bending X-rays are obtained to assess the flexibility of the curves or the primary and compensatory curves.
Congenital and idiopathic scoliosis that develops before the age of 10 is referred to as early-onset scoliosis. Progressive idiopathic early-onset scoliosis can be a life-threatening condition with negative effects on pulmonary function.Sponseller PD, Yazici M, Demetracopoulos C, et al. Evidence basis for management of spine and chest wall deformities in children.Spine(Phila Pa 1976). 2007;32(suppl):S81–S90 Scoliosis that develops after 10 is referred to as adolescent idiopathic scoliosis. Screening adolescents without symptoms for scoliosis is of unclear benefit.
Definition Scoliosis is defined as a three-dimensional deviation in the axis of a person's spine. Most instances, including the Scoliosis Research Society, define scoliosis as a Cobb angle of more than 10° to the right or left as the examiner faces the person, i.e. in the coronal plane.
Scoliosis has been described as a biomechanical deformity, the progression of which depends on asymmetric forces otherwise known as the Hueter–Volkmann Law.
Management