Idiopathic Scoliosis

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Dear Patient
The following information was put together to help in the decision-making process. The graphs show the answers of the members of EuroSpine, the Spine Society of Europe, considered to be the European experts in the field of treatment of spine pathology. This information should help you to learn and understand what most of the experts in the field would do in each specific situation. The information reflects a “common sense” approach to treatment of the members of EuroSpine, yet does not replace a careful evaluation of your individual situation. Therefore, if you find a significant difference between the answers below and you doctor’s opinion, ask your doctor what made him/her reach this decision.

Each specific situation has to be evaluated on an individual basis. EuroSpine and its members cannot be held responsible for any misunderstandings (or misdiagnosis) based on the information provided here, which in no way attempts to replace a targeted evaluation.

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MORPHOLOGY OF THE NORMAL SPINE
The vertebral column, also known as the spine, forms the skeleton of the neck and the posterior aspect of the trunk (thorax and abdomen). It comprises 33 vertebrae (7 cervical, 12 thoracic, 5 lumbar and 9 sacro-coccygeal) which are joined and run from the head to the pelvis. The region of the spine that forms the neck and unites the head with the trunk includes seven cervical vertebrae, designated C1 to C7. C1 is in contact with the cranium and C7 is closest to the thorax. The region of the vertebral column that occupies the posterior aspect of the thorax is called the thoracic spine and is comprised of 12 vertebrae, designated T1 to T12. Each of the thoracic vertebrae is associated with a pair of ribs (right and left). T1 is the closest to the neck and articulates (forms a joint) with C7, whereas T12 is the closest to the abdomen. The region of the vertebral column that constitutes the abdominal skeleton is called the lumbar spine and is comprised of five vertebrae, designated L1 to L5. L1 is the closest to the thorax and articulates with T12, L5 is the closest to the pelvis. The sacrum and coccyx are two rigid regions of the vertebral column, which comprise a part of the pelvic skeleton. There are five sacral vertebrae, designated S1 to S5, and four coccygeal vertebrae. S1 is the closest to the abdomen and articulates with L5, S5 forms a part of the pelvic end of the spine and articulates with the coccyx. The cervical, thoracic and lumbar spines are mobile. In these regions, the vertebrae are held together by joints, discs and ligaments.

The vertebral column is straight when seen from the front or back (frontal plane). When viewed in profile (sagittal plane), the normal column is seen to have four curves, two with posterior convexity (concave forward), termed kyphosis, and two with anterior convexity (convex forward), termed lordosis. The cervical and lumbar regions are in lordosis and the thoracic and sacral regions in kyphosis. Commonly we refer to cervical lordosis, thoracic kyphosis and lumbar lordosis.

SCOLIOSIS is an alteration of the normal morphology of the spinal column.
Normal spine from front/back
Fig 1
Normal spine from the side
Fig 2

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DEFINITION
Scoliosis is a lateral curvature or deviation (right or left) of the spine greater than 10º and associated with vertebral rotation. In scoliosis, the vertebral column seen from the front or back is no longer straight. Although the most evident anomaly is in the frontal plane, vertebral rotation makes scoliosis a three-dimensional deformity. Therefore, in addition to the lateral curve, alterations in the sagittal plane may also be evident as well as the development of a back prominence or hump.
Scoliosis
Fig 3
Rib hump in scoliosis
Fig 4

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ETIOLOGY
Scoliosis may have an unknown cause or be secondary to an underlying disease. Scoliosis due to an unknown etiology is known as idiopathic scoliosis. Idiopathic scoliosis mainly affects healthy adolescent women, although it can occur in men (1:7) (adolescent idiopathic scoliosis) and at earlier ages: infantile idiopathic scoliosis (before the age of three) and juvenile idiopathic scoliosis (between three years of age and puberty). Although the cause of this spinal deformity remains unknown, it may have a multifactorial origin with genetic and hereditary factors playing an important role. The development of scoliosis has not been related to nutritional or postural factors, the practice of sports, use of backpacks or carrying a heavy book bag. Around 2 or 3% of adolescents have scoliosis, but only 0.3 to 0.5% have curves exceeding 20º.

Secondary scoliosis is usually associated with neuromuscular (cerebral palsy, poliomyelitis, myelomeningocele, myopathy, etc.) or connective tissue diseases (Marfan syndrome, Ehler-Danlos syndrome, etc.). When scoliosis is secondary to a vertebral malformation it is known as congenital scoliosis.


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NATURAL HISTORY
The most important problem related to scoliosis is the progression of the deformity and the resulting collateral effects. The risk of progression is not constant in scoliosis, but instead varies according to a series of parameters. The factors that can have an influence on the risk of progression in idiopathic scoliosis include the following:

1. The growth potential of the patient
2. The magnitude of the curve
3. The type of curve
4. The sex of the patient

Growth potential can be assessed on the basis of the patient’s age, skeletal maturity and the appearance of secondary sex characteristics or menarche (first menstruation). Younger patients with a less mature skeleton and an absence of secondary sex characteristics and menstruation have a higher potential for growth and a greater risk of scoliosis progression. By contrast, the lower the growth potential, the smaller the risk of progression.
Skeletal maturity is usually assessed by determining the ossification of the iliac crest, which is divided into five stages. The appearance of secondary sex characteristics has also been classified into five stages according to breast and genital development and the distribution of pubic hair.
Skeletal maturity
Fig 5
The magnitude of the curve is generally evaluated using a radiograph and a goniometer. The greater the magnitude, the higher the risk of progression, and vice-versa.
Size and magnitude of the curve
Fig 6
The type of curve depends on the affected region of the vertebral column. Scoliosis is termed thoracic when located in the thoracic spine and lumbar when located in the lumbar spine. Thoracolumbar scoliosis refers to curves located at the junction of the thoracic and lumbar spines. The term double curve is used when there is a concurrent thoracic curve and lumbar curve.

The risk of progression is higher in scoliosis involving double curves than single curves. Lumbar scoliosis carries a lower risk of progression than thoracic scoliosis.
Types of scoliosis
Fig 7
Sex: The risk of progression is greater in women than in men.

The factors that best define the risk of progression in scoliosis are the growth potential and the magnitude of the curve. The theoretical risk of progression has been established on the basis of these two factors.

Table Peterson, Nachemson JBJS 1995; 77A:823-7

Nevertheless, it should be emphasized that it is impossible to predict with complete accuracy which curves will progress and which will not.

* In the adult (in adults): Once growth has stopped, the risk of progression is minimal or null in patients with thoracic scoliosis less than 50º or lumbar/thoracolumbar scoliosis less than 30º. Adult idiopathic scoliosis with curves greater than 50º may progress slowly at a rate of 0.5–1º/year.

* Progression of scoliosis can involve an aesthetic problem and lead to functional problems. Respiratory disorders may develop in large curves greater than 80º. Nonetheless, the mortality rates and vital prognosis in individuals with scoliosis are comparable to those of the general population.

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DIAGNOSIS
Scoliosis is usually diagnosed by radiological methods, but the physical examination can give a good indication of the condition.

Characteristics of the physical examination

Individuals with scoliosis often display some type of trunk asymmetry. One shoulder may appear to be higher than the other, there may be a tilt at the waistline, or one scapula may be more prominent. Probably the most effective way to detect scoliosis is to have the patient bend forward with the knees straight and flexing the waist (forward-bending test). It is quite easy to detect trunk asymmetries by viewing the patient from behind while he/she is in this posture, and scoliosis should be suspected when asymmetry is evident.
Rib hump in scoliosis
Fig 8

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TREATMENT
Treatment should be individualized and should take into account the risk of progression of the deformity. Only 10% of adolescents with curves greater than 10º require active treatment. Of these, 85–90% can be treated with non-surgical methods.

Exercise and physiotherapy do not reduce the magnitude of the curve or the risk of progression, but these options can be used as coadjuvant therapy to improve posture and strengthen the muscles.

Orthotic treatment (corset/brace) modifies the natural history of adolescent idiopathic scoliosis, reducing the risk of progression. However, as long-term studies have demonstrated, the initial correction achieved with bracing may be lost over time. Braces are most effective in curves of less than 40º and are one of the treatments of choice for growing patients with curves of 20–40º. Only a small number of patients with curves of less than 20º progress.

Bracing does not impede the progression of scoliosis in patients who have stopped growing.

Specialist's opinion:
1) Preferred treatment for a 30º adolescent idiopathic scoliosis in a growing girl
No treatment

0 votes
Observation and control

13 votes
Brace

32 votes
Surgery

1 votes
Total: 46 Specialists answered
2) Preferred treatment for a 30º idiopathic scoliosis in a 25-year-old woman
No treatment

31 votes
Observation and control

11 votes
Brace

1 votes
Surgery

2 votes
Total: 45 Specialists answered

Surgery may be necessary in the case of very large curves, in those with persistent progression, or on the patient’s request to improve his/her physical appearance (cosmetic reasons). Surgery can prevent progression and correct the deformity. Generally, the surgeon uses metal implants to correct and sustain the region of the deformity until the operated vertebrae have joined (fused).

Surgical treatment is usually proposed for curves of more than 60º, or 40–60º in growing patients with documented progression despite bracing. Curves of more than 40º that the patient considers an unacceptable deformity may also undergo surgery.

Specialist's opinion:
3) Preferred treatment for a 65º adolescent idiopathic scoliosis in a skeletally mature patient
No treatment

2 votes
Observation and control

3 votes
Brace

1 votes
Surgery

39 votes
Total: 45 Specialists answered
4) Preferred treatment for a 45º adolescent idiopathic scoliosis, affecting self-body image in a skeletally mature patient
No treatment

1 votes
Observation and control

9 votes
Brace

3 votes
Surgery

32 votes
Total: 45 Specialists answered
5) Preferred treatment for a 50º progressing curve in a growing adolescent treated with a brace
No treatment

0 votes
Observation and control

0 votes
Brace

3 votes
Surgery

42 votes
Total: 45 Specialists answered

Observation and periodic control without active treatment are advisable for patients with growth potential and scoliosis of 10–20º.

Specialist's opinion:
6) Preferred treatment for a 15º scoliosis in a 10-year-old, pre-menarchal girl
No treatment

0 votes
Observation and control

41 votes
Brace

4 votes
Surgery

0 votes
Total: 45 Specialists answered

Surgical principles in scoliosis
The goal of surgery in deformities of the spine is to straighten the curve and prevent progression. With metallic implants (usually rods and screws/hooks/wires) correction and fixation can be achieved. The bony fusion guarantees permanent stability.
Surgery in scoliosis
Fig 9
Fig 10
The rods are pre-bent into the desired position and fixed to the spine. By applying forces to the flexible spine, correction of the curve is achieved.
Principles of surgical corrections
Fig 11
Operative correction of rigid scoliosis
Fig 12
In cases with rigid curves that resist the corrective forces (e.g. adult scoliosis), the spine first has to be mobilized to facilitate the correction. It is important to balance the spine so as to optimize the result and avoid muscle overload.
Balance of the spine
Fig 13
Imbalance of the spine
Fig 14
Safety during spinal surgery
Corrections of spinal deformities include a considerable risk of neural damage. Changing the bone-spinal cord relation may lead to irreversible damage of neural structures by compression or lengthening. Multimodal intraoperative monitoring allows online registration of the function of spinal cord and nerves. This technique represents a considerable advance in safety measures and risk-reduction during spinal surgery.
Fig 15
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EuroSpine, April 2007