Scoliosis and Kyphosis

See also the separate article Back Examination (Thoraco-lumbar).

Spinal deformity rarely occurs in a single plane and is usually in 3 dimensions. Combined kyphosis and scoliosis is called kyphoscoliosis.

• Kyphosis is excessive curvature of the spine in the sagittal (A-P) plane. The normal back has 20° to 45° of curvature in the upper back and anything in excess of 45° is called kyphosis.
• Scoliosis is abnormal curvature of the spine in the coronal (lateral) plane. Scoliosis of between 10° and 20° is called mild. Less than 10° is postural variation.
• Lordosis or hyperlordosis is excessive curving of the lower spine and is often associated with scoliosis or kyphosis. It can be exaggerated by poor posture.

• The prevalence of these conditions varies considerably according to the precise definition that is used.
• In early childhood about 60% are boys but in the adolescent variety girls represent 90%. Some varieties of spinal deformity seem to be inherited as multifactorial autosomal dominants.¹
• Using a Cobb's angle² of 10° as the cut-off point to define idiopathic scoliosis, the point prevalence in a study from Leeds was 0.5% between 6 and 14 years old with a maximum of 1.2% between 12 and 14 years old.³
• Screening should be directed at girls at the maximum age of incidence. Boys should be screened at a slightly later age but girls outnumber boys by 9 to 1.
• Scoliosis to the right is very much more common than to the left except in the infantile type where a left-sided curve is commoner. A right thoracic scoliosis has the thoracic spine convex to the right.

Risk factors

• Abnormal curvature of the spine can result from disease of the vertebral column, including trauma or imbalance of the neuromuscular system. It may be congenital. It can be produced by legs of different lengths.
• In adults, kyphosis is often related to osteoporosis but in children it more often results from injury, a tumour on the spine, or a genetic disorder, such as Hunter's syndrome, or spina bifida.
• Scoliosis may be more rapidly progressive in children of older mothers but not older fathers.⁴
• About 80% of scoliosis is idiopathic.

Symptoms

• Mild disease is usually painless but, as deformity grows, pain will increase.
• Scoliosis in children or adolescents is often detected on routine screening.
• Ask about family history of scoliosis.

Signs

• Physical examination should include a baseline assessment of posture and body contour.
• Inspect the back from behind with the patient standing upright with the whole back bared and the patient wearing no shoes:
  • Note any curvature and difference in muscle mass between the two sides.
  • Often it is helpful to run a finger down the dorsal spines of the vertebral column as it is easier to feel than to see a curve.
  • Shoulder unlevelling and protruding scapulae are common. The scapula normally protrudes on the convex side.
  • In the commonest type (right thoracic), the right shoulder is consistently rotated forward and the medial border of the right scapula protrudes posteriorly.
• Ask the patient to bend forwards. Does the curvature become more or less with this manoeuvre? A fixed scoliosis becomes more obvious on flexion.
• Ask the patient to bend sideways. Note the range of movement and if there is lack of symmetry between the two sides. An instrument called a scoliometer can be used.
  Assessment of tendon reflexes should be performed in all 4 limbs. Tightness of hamstrings should be assessed. Check for ataxia, poor balance and proprioception.
• The hip normally protrudes on the concave side.
• If there is just a mild scoliosis, try placing a small wedge under one foot (this might be a pad of paper about 1 cm thick):
  • Does it improve the condition? If it makes it worse, try the wedge under the other foot.
  • Adjust the size of the wedge to remove the curvature. If this can be achieved, the problem is due to shortening of one leg and a built-up shoe will correct it.
  • Legs may be shorter after severe trauma with fractures or if there is neuromuscular imbalance before maturity, as with poliomyelitis, but shortening of 1 cm or 2 cm often occurs with no apparent cause.

• Congenital malformations of the vertebrae can cause deformity.
• Neuromuscular conditions include cerebral palsy, spina bifida and poliomyelitis.
• Metabolic problems such as Hunter's syndrome.
• Crush fracture from trauma, osteoporosis, tuberculosis or malignancy.
• Idiopathic (80%).

• PA and lateral X-rays of the spine are fundamental. The radiologist will use a full spine X-ray to measure and evaluate the curve. This measurement can well have an inaccuracy of 10°.⁵ A commonly used parameter is the Cobb's angle. As a general rule, a Cobb's angle of 10° is regarded as the minimum angulation to define scoliosis.
• Lateral bending view can assess the degree to which it can be corrected.
• A radionucleotide bone scan shows the metabolic activity in the bone.
• CT and MRI can be used to assess the spinal canal, the structure of the vertebral column and threat to the spinal cord. CT is better at showing bone. MRI is better for assessing soft tissue including nerves and fat.
• Depending upon the age of the patient and other findings, other investigations may be indicated to check for osteoporosis, tuberculosis or malignancy. Pott's disease of the spine is discussed elsewhere.
• Particularly in children, where deformity is more than mild, monitoring of respiratory function is advised.⁶

• There may be a spinal tumour causing musculoskeletal dysfunction.
• There may be malformations of the nervous system with Arnold Chiari malformation or syringomyelia.
• Congenital malformations of the vertebrae may be associated with abnormalities of the kidneys or urinary tract in up to 20% and congenital heart defects in 10% to 15%.⁷

• Infantile scoliosis occurs before age 3 and is seen more frequently in boys. Although neurological involvement is possible, many resolve spontaneously but some may progress to severe deformity.
• Juvenile scoliosis is found more frequently in girls between the ages of 3 and 10. These curves are at a high risk for progression and often require surgical intervention.
• Adolescent scoliosis, also termed adolescent idiopathic scoliosis (AIS), occurs between age 10 and maturity. AIS may start at the onset of puberty or become apparent during an adolescent growth spurt. Females are at higher risk, often requiring surgical treatment, if non-operative treatment fails to halt curvature.
• Adult scoliosis occurs after maturity.
• A degree of thoracic vertebral collapse is relatively common in aging women and is called the "dowager's hump".

Management depends upon the type of condition, the severity, the prognosis and the patient's tolerance for various interventions. Early diagnosis and intervention are beneficial. Management may be divided into:

• Observation
• Orthosis
• Operation

Infantile idiopathic scoliosis

• This has a much better chance of spontaneous recovery than the others, at about 90%. Double curves have a worse prognosis.
• If the condition worsens, conventional thoracolumbosacral orthosis (TLSO) type braces or Milwaukee braces can be employed.
• Casts are sometimes used but their value is debated.
• If surgery is required, a balance must be drawn between improving prognosis as the child gets older and bigger and worsening prognosis as the condition deteriorates.

Juvenile idiopathic scoliosis

• This is very similar to the adolescent version form and might be considered to be a more severe type of AIS.
• A study from Scotland⁸ found that 95% (104 of 109 patients) demonstrated curve progression and 64% (70 of 109 patients) required spinal fusion.

Adolescent idiopathic scoliosis

• AIS is the most common type of idiopathic scoliosis and the most common type of scoliosis overall.
• Small curves in more mature patients have a low risk of progression at about 2%.
• Larger curves in more immature patients, have a much higher risk at around 70%.
• Treatment for AIS depends on the extent of the curve.
• Brace treatment is thought to be effective only in patients who are still growing.
• A rapid change in the degree of curvature is likely to demand bracing or even surgery.

Adult idiopathic scoliosis

• This form is likely to be associated with cardio-pulmonary problems if the angle exceeds 60° to 65° and myelopathy if it exceeds 90°.
• They may progress at about 1° a year even after growth is complete.
• Operative treatment has more complications than with juveniles.

Postural

• Postural "round back" is an increase in thoracic kyphosis while standing.
• Curve flexibility is seen when the patient "stands tall" or, when prone or supine, it disappears.
• This condition is commonly seen in middle school children, especially girls.
• It does not progress and resolves spontaneously.

Scheuermann's disease

• This disease produces a thoracic kyphosis of more than 40° with true structural changes within the thoracic vertebra with 5° of wedging in each of 3 adjacent vertebrae measured on side-view films. It is usually painless.
• Observation is enough for angles of less than 60° and brace treatment for curves between 60° and 80° if the patient is skeletally immature. Surgery is rarely required.
• A subtype of Scheuermann's disease occurs in the lumbar spine, usually in males in late adolescence who are involved in heavy lifting. The changes of the vertebra and disc reflect the physical stress effects. Treatment is to eliminate the offending activity. It has a strong familial trend and may be an autosomal dominant. Scoliosis also occurs in 25%.

Non-operative treatment

• Exercising and stretching of back and hamstrings may prevent excessive lordosis or contractures.
• In scoliosis, braces are effective only until maturity but in kyphosis they can be effective at all ages.
• They are worn continuously for 1 year, then just at night for 2 years.
• A Milwaukee brace is required for thoracic deformity but a TLSO is needed from T8 down.
• A longitudinal study of over 1,000 patients over 26 years suggests that the Milwaukee brace is effective⁹ in preventing deterioration.

Operative treatment

• Orthopaedic surgeons will have different criteria for the various types of deformity and the age and progress of the patient.
• Operative fixation is required if deformity is very marked but at a lesser level if the deformity is rigid. Rapid deterioration also requires action.

• Distortion of the spinal column can cause restriction of the chest with impairment of lung function. The relationship between the angle of scoliosis and the degree of impairment is complex.¹⁰
• Compression of abdominal contents can occur.
• Severe deformity may impinge on the spinal cord and cause paraplegia.
• Treatment of scoliosis without recognition of Arnold Chiari malformation or syringomyelia may result in paraplegia.
• The disease is associated with psychological problems, especially in adolescents.^11,12

• The younger the child and the greater the curvature, the worse the prognosis, with the exception of infantile scoliosis.
• Skeletal maturity is important as scoliosis can progress during skeletal growth.
• Once a deformity has proved to be progressive, surgical intervention will probably be necessary because orthotic treatment is less effective in these cases.¹³

There is little that can be done to prevent scoliosis or kyphosis except that the adult type is often related to osteoporosis, especially the dowager's hump. Prevention of osteoporosis is discussed in the osteoporosis article.