The signs of scoliosis can include:
- Uneven musculature on one side of the spine
- A rib prominence and/or a prominent shoulder blade, caused by rotation of the ribcage in thoracic scoliosis
- Uneven hips / leg lengths
- Asymmetric size or location of breast in females
- Slow nerve action (in some cases)
Associated conditionsScoliosis is sometimes associated with other conditions such as Ehler-Danlos syndrome (hyperflexibility, 'floppy baby' syndrome, and other variants of the condition), Charcot-Marie-Tooth, Prader-Willi syndrome, kyphosis, cerebral palsy, spinal muscular atrophy, muscular dystrophy, familial dysautonomia, CHARGE syndrome, Friedreich's ataxia, proteus syndrome, spina bifida, Marfan's syndrome, neurofibromatosis, connective tissue disorders, congenital diaphragmatic hernia, and craniospinal axis disorders (e.g., syringomyelia, mitral valve prolapse, Arnold-Chiari malformation).
CauseIn the case of the most common form of scoliosis, adolescent idiopathic scoliosis, there is no clear causal agent and it is generally believed to be multifactorial. Genetics are believed to play a role. Various causes have been implicated, but none have consensus among scientists as the cause of scoliosis, though the role of genetic factors in the development of this condition is widely accepted.
Scoliosis is more often diagnosed in females. 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, having been inherited through multiple factors, including genetics. Scoliosis often presents itself, or worsens, during the adolescence growth spurt.
In April 2007, researchers at Texas Scottish Rite Hospital for Children identified the first gene associated with idiopathic scoliosis, CHD7. The medical breakthrough was the result of a 10-year study and is outlined in the May 2007 issue of the American Journal of Human Genetics. and is often performed on school students.) If a prominence is noted, then scoliosis is a possibility and the patient should be sent for an X-ray to confirm the diagnosis. Alternatively, a scoliometer may be used to diagnose the condition. The patient's gait is assessed, and there is 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.
It is usual, when scoliosis is suspected, to arrange for weight-bearing full-spine AP/coronal (front-back view) and lateral/sagittal (side view) X-rays to be 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 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 to look at the spinal cord.
The standard method for assessing the curvature quantitatively is measurement of the Cobb angle. The Cobb angle 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 X-rays are obtained to assess the flexibility of the curves or the primary and compensatory curves.
Genetic testingGenetic testing for AIS, which has become available in 2009 and is still under investigation, attempts to gauge the likelihood of curve progression.
Through a genome-wide association study, geneticists have identified single nucleotide polymorphism markers in the DNA that are significantly associated with adolescent idiopathic scoliosis. Fifty-three genetic markers have been identified. Scoliosis has been described as a biomechanical deformity, the progression of which is dependent on asymmetric forces otherwise known as the Heuter-Volkmann law.