Idiopathic Scoliosis – Types, Presentation and Treatment

Last Updated on July 15, 2019

Idiopathic scoliosis is the lateral deviation deformity of the spine where the cause is not known. Because there is also a vertebral rotation and not just deviation, the term rotoscoliosis is also used to describe the deformity.

Idiopathic signifies that it is not secondary or due to some deformity and other secondary causes.
On plain radiographs, scoliosis is defined as greater than 10 degrees of deviation.

Females are more commonly affected than males.

Frequently used terms in Scoliosis

Apical vertebra 

The apical vertebra is the vertebra that is displaced and rotated the most. Its end plates are least tilted.

End Vertebra

The most superior and inferior vertebrae of the curve are called end vertebrae. These vertebrae are least displaced and rotated.

These vertebrae appear laterally wedged, longer in the convex side, and compress

There is the maximal tilting of the endplates towards the curve.ed on the concave side. [This aspect is not visible in the above image]

Neutral Vertebra

The neutral vertebra is the first vertebra after end vertebra which is not rotated on the anteroposterior image.

Curves

• Primary curve
  • Structural curve, with wedging, angulation, rotation
  • Vertebrae are displaced to the convexity of the curve.
  • Structural means the curve does not correct with spontaneously or bending
  • If 3 curves are present, the middle one is usually the primary curve
  • If 4 curves are present, the middle 2 are the primary ones
  • The primary curve may be the greatest curve.
• Secondary curve
  • Nonstructural curve
  • Develops in response to the primary curve
  • Structural changes occur slowly [compare with primary where structural changes are present along with deformity]
  • Can be corrected spontaneously
  • Vertebrae are displaced to the concavity of the curve.

Causes

The precise etiology of idiopathic scoliosis remains unknown but the following possibilities have been suggested.

• A primary muscle disorder
• An elastic fiber system defect
• Disorganized skeletal growth due to some genetic reason
• X-linked inheritance pattern

Types of Idiopathic Scoliosis

Infantile Idiopathic Scoliosis

A scoliotic curve in patients younger than 3 years is termed as infantile idiopathic scoliosis. Infantile idiopathic scoliosis is more frequent in boys than in girls, the curves are primarily in the thoracic spine and generally convex to the left.

Infantile idiopathic scoliosis may be progressive, usually increasing rapidly, or resolve spontaneously within a few years with or without treatment. The resolving type occurs in 70% to 90% of patients.

Infantile idiopathic scoliosis is unique being

• Only idiopathic scoliosis type with most common curve pattern is left thoracic.
• Only type that is more common in boys.
• Only type with a significant chance of spontaneous resolution.

Prediction of curve progression can be gauged by calculating the rib vertebral angle difference (RVAD). The angle was originally described by Dr Mehta in 1972

Juvenile idiopathic scoliosis

The curve appears between the ages of 4 and 10 years. Usually, the convexity of the curve is towards the right in the thoracic region. Juvenile idiopathic scoliosis is considered to be more progressive than adolescent idiopathic scoliosis. The risk of progression increases if the curve has an angle greater than 20 degrees.

There is a high incidence of neural abnormalities in children of juvenile idiopathic scoliosis.

Juvenile idiopathic scoliosis is more common in females.. Some authors consider it to be an aggressive subtype of adolescent idiopathic scoliosis as demography,  and rate of progression and need for surgery are similar.

Adolescent Idiopathic Scoliosis

Adolescent idiopathic scoliosis is the most common type of idiopathic scoliosis and also the most common type of scoliosis overall.

Age of presentation is 10 to 20 years and females are affected six times more as compared to boys. In adolescent idiopathic scoliosis, right thoracic curve is more predominant. There is a low risk of cardiovascular compromise and overall risk of progression is around 25%.

The characteristics of adolescent idiopathic scoliosis is a three-dimensional deformity of the spine with lateral curvature plus rotation of the vertebral bodies.

Less than 10% of children with curves of 10 degrees or more require treatment. What is more important is the probability of curve progression. Progression is defined as an increase of 5 degrees or more measured by the Cobb angle over two or more visits.

Following factors have been found to be related to curve progression in idiopathic adolescent scoliosis

• Female gender
• Rapid adolescent growth spurt before the onset of menses.
• Double curves
• Single thoracic curves
• More severe curves

The effect of progressive curves on adults are back pain, decreased lung function, and psychosocial effects.

Clinical Presentation

Deformity either noticed by relatives or patient herself is the major reason to seek the advice. The pain is not present in most of the cases.

Do ask for the presence of spinal deformity in other family members.

Physical examination involves a baseline assessment of posture and body contour.

Note if shoulders are not in level and there is protrusion of scapulae.

In a normal spine,  a straight line can be drawn through the cervicothoracic, dorsolumbar, and lumbosacral junctions.

A deviation reveals the deformity.

The deformity should be assessed in detail.

A rib hump can be present as the posterior ribs are pushed posteriorly on the convex side of the curve.

Moreover, the ribs are closely approximated on the concave side and separated on the convex side.

A detailed neural examination should be done. Some patients have limb-length discrepancy and leg lengths should be measured.

Four patterns are seen in idiopathic scoliosis

• Thoracic curve
• Lumbar curve
• The thoracolumbar curve on the same side
• Thoracic and lumbar curves on opposite sides

An assessment of the extent and vertebral involvement should be made.

Lab Studies

Lab workup is not required for diagnosis. Labwork is needed for preoperative assessment and includes routine blood tests and testing for pulmonary functions in case of severe scoliosis.

Imaging

X-rays

X-rays are main imaging investigation in idiopathic scoliosis and is used to

• Identify the presence of a curve
• Curve features
  • Number and location curves
  • Curve length and measurement
  • Vertebral rotation.

• Special measurements like the rib-vertebral angle in infantile idiopathic scoliosis.
• Skeletal maturity
  • progression of the curve stops after the growth stops when the curve is mild to moderate.
• Monitor curve progression
• Evaluate associated cardiac and pulmonary anomalies
• Evaluate complications after surgery
• Measurement of associated kyphosis could be less, normal or more than normal]

X-ray Views for evaluation of scoliosis are as follows:

• Posteroanterior (PA) erect view of the entire spine from cervical to sacral spine and including the iliac crest
• AP recumbent view of the entire spine, cervical to sacral.
• Lateral view of the thoracolumbar spine
• Lateral profile at the apex of scoliosis
  • to eliminate kyphosis and show the true extent of scoliosis.
• Stagnara view
  • Perpendicular to the true coronal plane of the apical vertebra.
• Leeds view
  • True lateral view 90° perpendicular to the Stagnara view.
• Left and right lateral bending views
  • To exclude postural scoliosis
  • To assess asymmetry and loss of normal mobility of the primary curve
  • Gauge wedging rotation of the individual vertebra
• AP view of the left hand to assess bone age
• Ferguson view
  • perpendicular to the L5-S1 discs
• Coned views of focal vertebral anomalies.

However, routinely, full-length frontal and lateral views, as well as right and lateral bending views, are enough. All the x-rays are not required.

In followup after surgery, the frontal posteroanterior view is sufficient. Lateral views are required only if there is a superimposed kyphosis.

Xray Findings

A straight line can be drawn through the cervicothoracic, dorsolumbar, and lumbosacral junctions in a normal spine. A deviation is observed in the scoliotic deformity.

The apical vertebrae is noted to have increased anterior height and decreased posterior height.

Vertebral bodies and intervertebral disk spaces are wider on the convex side than on the concave side.

A rib hump is seen on the convex side. The ribs are closely approximated on the concave side and separated on the convex side.

Disc spaces may be widened on the concave side. The vertebrae and neural arches are thick on the concave side.

The spinous process is shifted toward the concave side whereas and the pedicle and vertebral body are shifted toward the convex side.

Apical vertebra is most rotated and there is no or neutral rotation at the end vertebrae.

Both intersegmental (between vertebrae) or intrasegmental (between elements of one vertebra) rotations can be seen. The intrasegental rotation when present is not correctable.

The psoas shadow is absent on the concave side of the curve.

Computed Tomography

CT scan with 3D reconstructions provides all the info that x-rays provide. CT scan is useful in

• Assessing segmentation abnormalities
• Assess the true extent of rotation
• Rib deformities
  • Rib cage deformity
  • Rib hump index
• Shows associated lesions like osteoid osteoma, osteoblastoma, infection or tumors etc.

Postoperative CT scanning can assess the complications.

MRI

MRI can show neural tissue and other soft tissue lesions.

MRI should be done if there is a neural deficit after the procedure,

MRI is not used for diagnosing scoliosis but is indicated when atypical features are present.

However, it is useful for assessing spinal cord anomalies, spinal cord tumors, dysraphism and other conditions. 

Ultrasonography

It is useful for post-surgery evaluation of collection [hematoma, abscess].

It is useful in young children for evaluating spina bifida, cord tethering can be evaluated along with associated lesions if present.

Bone Scans

These can be helpful in identification of tumors or infections but are not performed routinely.

Classification of Scoliotic Curves

Many classification systems are used to describe the types of scoliotic curves. Classification helps surgeons determine appropriate management as the treatment depends on type and extent of the curve.

King classification of curves was published in the early 1980s. But this classification is more of historical interest.

The Lenke classification has become more commonly used for adolescent idiopathic scoliosis.

Ponseti Friedman classification is another classification that is often used.

Radiographic Measurements and Indices

Cobb’s Angle

Cobb’s angle measures the severity of scoliosis. Its value is helpful in determining the management and predicting prognosis.

Cobb’s angle is calculated by identifying upper and lower end vertebrae and drawing lines tangential to the superior endplate of these vertebrae.

The angle formed at the intersection of the lines is Cobb’s angle or also called Cobb Webb angle.

Sometimes, the lines do not intersect and the angle is calculated by drawing a perpendicular line and then measuring the intersection angle. [both values are same.]

For making a diagnosis of scoliosis, Cobb angle of at least 10° is essential

Ferguson technique or Risser Ferguson Technique

 

A line is drawn from the center of the apical vertebra to the center of the upper-end vertebra. Another line is drawn from the center of the apical vertebra to the center of the inferior end vertebra.

The angle between these lines is used to assess the severity of the deformity.

Greenspan index

It is claimed to be a more comprehensive method of measurement.

A vertical spinal line is drawn between the midpoint of the vertebra above the upper-end vertebra and the midpoint of the vertebra below the lower end vertebra.

Now, from center of each vertebra in the curve, draw a line to the vertical spinal line.

Now sum of these lines is divided by the length of the vertical spinal line.

A correction factor can be adjusted for magnification.

In a healthy person, the value is zero.

This method is also more valuable in measuring short-segment or small curvatures.

Measurement of Vertebral Rotation

Vertebral rotation is measured by the following methods

• Nash and Moe
• Perdriolle and Vidal.

Nash and Moe

In this method, the distance of the pedicle is noted from the sides of vertebral bodies. The vertebral body is divided into six segments and grades 0 to 4+ are assigned, depending on the location of pedicle within segments. Because pedicle on concave side disappears early in the rotation, pedicle on the convex side, easily visible through a wide range of rotation, is used as standard.

The rotation by this method is calculated by analyzing the AP radiograph.

• Stage 0 Rotation – Both the pedicles are at equidistant and there is no asymmetry
• Stage I Rotation – The pedicle on the convex side migrates within the first segment and the pedicle on the concave side may start disappearing.
• Stage II Rotation – The pedicle on the convex side moves to the second segment and the other pedicle disappears.
• Stage III Rotation – The pedicle on the convex side migrates to the third segment and other pedicle is not visible
• Stage IV Rotation – The pedicle on the convex side moves past the midline

Perdriolle Method

Perdriolle method uses a template called torsion meter that measures the amount of vertebral rotation on a spinal radiograph.

CT scan is also a good and reliable method to measure rotation but is not don on a routine basis.

Cobb method of assessing vertebral rotation

It uses the position of the spinous process for rotational assessment of the degree of vertebral rotation. The vertebra is divided into 6 equal segments by drawing 5 vertical lines.

The spinous process is normally situated in the midpart of the vertebra overlying the third line. With increasing rotation, the spinous process is rotated toward the convex side of the curve.

Sagittal Balance

If a plumb line is dropped from the dens, it usually falls anterior to the thoracic spine, posterior to the lumbar spine, and through the posterior superior corner of S1. However, because on the standing long lateral films, the dens is not easily seen and therefore, the plumb line is dropped from the middle of the C7 vertebral body. This plumb line is called the sagittal vertebral axis.

A positive sagittal vertebral axis is considered present when the plumb line is anterior to the anterior aspect of S1. A negative sagittal vertebral axis occurs when this plumb line passes posterior to the anterior body of S1.

For sagittal balance to be maintained, lumbar lordosis should measure 20 to 30 degrees more than the kyphosis.

In the thoracic spine, the normal sagittal curvature is kyphotic and the normal regional lumbar sagittal alignment is lordotic.

The thoracolumbar junction is the transition area from a relatively rigid kyphotic thoracic spine to a relatively mobile lordotic lumbar spine. Bernhardt and Bridwell showed that the thoracolumbar junction is nearly straight. This relationship must be maintained during reconstructive procedures to prevent a junctional kyphosis.

If there exists sagittal plane imbalance, it must also be corrected so that there is no undue stress on unfused vertebrae when the segments are fused.

 

Risser index

The Risser index (see the image below) is used to measure ossification of the iliac apophysis

Rib-vertebral angle

This parameter is useful in predicting the progression of the curve in the idiopathic infantile type of scoliosis (see the images below).

Skeletal maturity

Ossification and maturation of the epiphysis of the left hand and wrist are compared with standards. Two main methods are used. The first is the Greulich-Pyle method, in which the radiograph of the hand and wrist is compared with standard radiographs in the atlas. The second is the Tanner-Whitehouse method, in which the epiphyses of the hand and wrist are compared with those of the atlas. A score is assigned to each of them, and the sum is compared with values on standard tables. Thus, bone age is assessed.

Treatment of Idiopathic Scoliosis

Treatment for idiopathic scoliosis has the following options

• Observation
• Orthosis
• Surgery

The choice of treatment depends on many factors such as the severity of the curve, age of the child and progression potential of the curve among other factors.

Again, the risk of curve progression varies with the group to which the patient belongs (ie, infantile, juvenile, adolescent).

Infantile Idiopathic Scoliosis

Based on the measurement of the rib vertebral angle, Mehta developed a method to differentiate resolving from progressive curves and this is quite helpful in predicting curve progression.

For treatment, it is important to identify the progressive type from resolving type. If the rib vertebral angle difference (RVAD)  is more than 20 degrees and the curve is not flexible on clinical examination, it is considered progressive until proved otherwise.

A treatment outline for infantile idiopathic scoliosis may be as follows:

• Curves less than 25 degrees with an RVAD less than 20 degrees
  • Observation
  • X-rays at every 4-6 months interval
  • If there is a progression of 5-7 degrees – bracing
  • If the curve is not progressing, observation is continued until skeletal maturity.
• Curves more than 25 degrees and RVAD less than 20 degrees
  • Bracing or casting [young child till brace can be worn]
  • Brace  – Cervico-thoracolumbosacral orthosis** or thoracolumbosacral orthosis
  • Brace is worn full time***
  • Till two years after the curve has become stable or has started reducing
• Curves not adequately controlled with nonoperative measures
  • Surgery

** Milwaukee brace is an example of cervicothoracolumbosacral brace

***Initially, the brace is worn at least 22 hours of 24 hours [called full time bracing]. If the curve shows improvement after one year of full time bracing, the time of wearing of brace is decreased gradually to only night time bracing.  However, if the progression is noted after decreasing the bracing time, a full-time brace program is resumed. However, some studies have reported success with the part-time wearing program too.

Significant improvement can be obtained with the use of a well-fitting orthosis during the early period of skeletal growth.

Surgery

If a curve is severe or increases despite the use of an orthosis, surgical stabilization is needed. Effort should be made to delay surgical procedures as long as possible to optimize spinal growth, but if the curve progression is substantial, it would need to be operated.

Ideally, surgery should not only stop the progression of the curve but also allow continued growth of the thorax. But if fusion is necessary, it should be done spanning short length so as to preserve a maximum number of motion segments and growth plates.

Anterior release and fusion followed by posterior spinal fusion with instrumentation is considered to be the functional treatment but subcutaneous growth rods should be preferred.

• If the child is younger than 8 years and small, the ideal treatment is subcutaneous rod insertion, also termed as growing rod instrumentation.
• If the child is larger and 9 or 10 years of age, instrumentation, and fusion may be done, but combined anterior and posterior spinal fusions should be considered to avoid a crankshaft phenomenon.

Juvenile Idiopathic Scoliosis

The treatment of juvenile idiopathic scoliosis is

• Observation
  • Curves less than 25 degrees
  • Follow-up x-rays at regular intervals
• Bracing
  • Curves that range from 25 degrees to 40 degrees
  • Curves between 40 degrees to 50 degrees which are flexible
  • Curves that were small to begin with but make the rapid progression to the 20-25° range
• Surgery
  • Inflexible curves over 40 degrees
  • Any curve [felxible o rinflexible] greater than 50 degrees

There are two kinds of surgeries for Juvenile idiopathic scoliosis.

• Growing rod instrumentation
• Instrumentation with fusion

Growing rod instrumentation allows the growth of the vertebral column as the vertebrae are not fused.

Fusion is done older children or when the requirements of growing rod instrumentation cannot be met with.

Growing Rod Instrumentation

This technique is considered in a cooperative patient and whose family is able to understand the procedure and its demands.

A multihook segmental instrumentation system is used.

Surgery is required every 6 months to lengthen the construct.  A thoracolumbosacral orthosis [TLSO] is needed for at least the first 6 months to provide protection to instrumentation.

The orthosis can be discontinued if the hook sites are solidly fused. The rods are lengthened every 6 months. At a point where no further distraction can be achieved, final arthrodesis is done and usually, the instrumentation is removed.

Instrumentation with Fusion

Instrumentation and spinal fusion is considered for children older than 9 or 10 years or are noncooperative.

A combined anterior and posterior procedure should be considered if the patient is deemed at risk for the crankshaft phenomenon.

A multi hook segmental system is used or pedicle screw fixation can be considered if it is feasible.

Adolescent Idiopathic Scoliosis

Observation

Observation is the primary treatment of all curves. Few degrees of scoliosis is frequent in the population and most of these do not require treatment. Periodic evaluation of the spine with radiographs still is necessary.

• Young patients with less than 20 degrees-  examined every 6 to 12 months.
• Adolescents with larger degrees of curvature-  examined every 3 to 4 months.
• Skeletally mature patients with curves of less than 20 degrees generally do not require further evaluation.

Depending on the type of curve and age of the patient, further treatment options are considered

• If progression of the curve (an increase of 5 degrees during 6 months) beyond 25 degrees is noted –  orthotic treatment is considered.
• For curves of 30 to 40 degrees in a skeletally immature patient, orthotic treatment is recommended at the initial evaluation.
• Curves of 30 to 40 degrees in skeletally mature patients generally do not require treatment, but there is a potential for progression,  these patients should be observed with yearly for  2-3 years after skeletal maturity, then every 5 years for life.

A rapidly progressive curve in near puberty child say, 17 degrees to 27 degrees is also a candidate for bracing.

Bracing as treatment is indicated in the following situations

• A flexible curve of 20 to 30 degrees in a growing child with the documented progression of 5 degrees or more.
• Curves in children between the 30 to 40-degree range at the initial evaluation.
• Orthotic treatment is not used in patients with curves of more than 50 degrees.

The Charleston and  Boston braces are frequently used braces.

Beyond 45 degrees in a skeletally immature patient, surgery is considered.

For surgery, the patients may be divided into

• Those with significant anterior spinal growth
• Those with not

The one with significant possible growth has the risk of running a crankshaft phenomenon after surgery.

Simply put, this means that after posterior fusion, these kids with significant growth potential would cause the anterior spine to grow whereas fused posterior part acts as tether leading to curving of spine and rotation.

Therefore, these children would require an anterior spinal fusion procedure.

Presence of a radiographic Risser sign and indicators of puberty may menarche are somewhat predictive but less so than the closure of the triradiate cartilage, and reaching one’s peak height velocity is perhaps the most powerful predictor of being at rather low risk for the crankshaft phenomenon.

Surgery involves correction of the curve using pedicle screws connected with rods.

Implants serve the purpose of correction and hold the spine until the fusion fructifies.

Both posterior and anterior approaches are used, based on previously discussed factors.

For assessing the skeletal maturity,  the most common is the assessment of bone age at the hand and wrist or Risser sign.

MRI of the whole spine is required for assessment if there is an unusual curve, a very rapid progression and a very large curve at presentation.

Surgery for Idiopathic Scoliosis

Important points

Proper preparation of the patient is very necessary for the scoliosis surgery.  If the patient is on any nonsteroidal anti-inflammatory agent, it should be discontinued before surgery. In case of females, birth control pills should be discontinued 1 month before surgery [Increase the possibility of thrombophlebitis in the postoperative period].

The patient should be evaluated with x-rays, computed tomography, magnetic resonance imaging, and myelography for evaluation of spinal levels and to rule out conditions such as syringomyelia, diastematomyelia, and tethered cord.

In patients with severe curves, pulmonary function studies usually are indicated.

Autologous blood donation in the preoperative period in patients who are fit for autodonation is a good option. Autologous donation reduces the risks of homologous blood transfusion. Erythropoietin is another good but costly option.

Somatosensory evoked potentials and Stagnara wake-up tests can be done intraoperatively to check neural injuries.

SSEP

Somatosensory evoked potentials involve stimulation of distal sensory proximal to the surgical area and can alert the surgeon to possible alteration of spinal cord transmission. The preoperative baseline can be compared with one during the surgery. As it measures only the integrity of the sensory system, the use of motor evoked potentials has increased. The combination of motor evoked potentials and somatosensory evoked potentials can provide important information regarding the primary motor and sensory tracts within the spinal cord.

Stagnara wake-up test

Stagnara wake-up test, the anesthesia is decreased or reversed after correction of the spinal deformity. The patient is brought to a conscious level and asked to move both lower extremities. Once voluntary movement is noted, anesthesia is returned to the appropriate level, and the surgical procedure is completed.

Posterior Scoliosis Surgery

Posterior approach to the spinal column is the most commonly used for surgeries of idiopathic scoliosis. [Posterior means that incision is put on the back]

The technique involves putting the patient on a Jackson table in the prone position. Some surgeons also use special frames on routine OT tables.

Following types of surgeries are performed on the scoliotic spine.

Posterior Fusion

The long-term success of any operative procedure for scoliosis depends on a good arthrodesis.

The success of spinal arthrodesis depends on the ability of the graft material to stimulate a healing process.

Autografts provide the best chances of the union as it combines the osteogenic, osteoinductive and osteoconductive properties. Autograft taken from the iliac crest is considered as “Gold Standard”. Another excellent source is rib obtained from a thoracoplasty.

There are several graft substitutes like tricalcium phosphate, hydroxyapatite, and demineralized bone matrix but they are still under investigation

Posterior Spinal Instrumentation

The goals of instrumentation in scoliosis surgery are to correct the deformity as much as possible and to stabilize the spine in the corrected position while the fusion mass becomes solid.

The fusion mass in a well-corrected spine is subjected to lower bending and tensile forces than the fusion mass in an uncorrected spine.

Spinal Instrumentation System

No Single device is the best choice for every surgeon or every patient.

Harrington instrumentation system for scoliosis and had been standard of scoliosis correction surgery for long.

Due to its disadvantages of need for distraction, laminar fractures, and loss of sagittal contour, other instrumentation systems have replaced it.

Multi hook or posterior segmental instrumentation system with screws are more commonly used now.

Posterior segmental spinal instrumentation systems have the following advantages

• Multiple points of fixation to the spine
• Apply compression, distraction, and rotation forces through the same rod.
• Do not require any postoperative immobilization in most of the cases
• Better coronal plane correction and better control in the sagittal plane.
• Preserves normal contours of the spine to a good extent

The systems have, however, a potential disadvantage of being bulky and complex and not many surgeons have much experience with them.

 Posterior Thoracoplasty For Rib Hump In Scoliosis

Posterior thoracoplasty is surgery for correction of rib hump in scoliosis though with newer surgical techniques and newer instrumentation, it is now done rarely.

The procedure is performed in a prone position and the approach used is midline posterior. The procedure involves cutting of the ribs at the site of deformity.

Anterior thoracoplasty also aims at the same correction.

Anterior Surgery

Anterior instrumentation and fusion is used in thoracolumbar and lumbar curves. It provides excellent derotation and correction of the curve in the coronal plane.

At some occasions, the deformity correction requires lesser number of motion segments to be fused than if done posteriorly.

For treatment to be effective the thoracolumbar or lumbar curve should be flexible. The thoracic curve should be nonstructural and reducible to 25 degrees or less on the bending films.

The child should be around 9 years of age.

Anterior instrumentation and fusion in thoracic curves is controversial.

In the case of the thoracolumbar curve, a thoracoabdominal approach is required. However, in lumbar curves, a lumbar extraperitoneal approach can be used. Pedicle screws are used to instrument the spine.

Video-Assisted Thoracoscopic Surgery

In this, the surgery is done with the help of thoracoscope [An endoscope that is inserted in the thorax from a portal and its  imaging is used to guide the surgeon.

The Advantages of thoracoscopic surgery over open thoracotomy are

• Better illumination and magnification
• Lesser injury to the anatomical structures
• Decreased blood loss
• Better cosmesis
• Shorter recovery time
• Improved postoperative pulmonary function
• Shorter hospital stays.

The disadvantages are –  technically demanding procedure, steep learning curve, and requirement of the specialized equipment.

Video-assisted thoracoscopic surgery is indicated in

• Patients with a compromised pulmonary function requiring anterior release
• Rigid curves requiring anterior release and posterior fusion
• When surgery is needed in young children to prevent crankshaft phenomenon
•  and skeletal immaturity in patients in whom anterior surgery is needed to prevent the crankshaft phenomenon.
• Rigid thoracic idiopathic curves

Video-assisted thoracoscopic surgery is contraindicated in

• Inability to tolerate single-lung ventilation
• Respiratory insufficiency
• High airway pressures with positive-pressure ventilation
• Emphysema
• Previous thoracotomy

Complications of video-assisted thoracoscopic surgery are

• Damage to lung tissue
• Dural tear
• Lymphatic injury [ Injury to thoracic duct]

Endoscopic Anterior Instrumentation

This technique allows anterior instrumentation of the thoracic spine using a thoracoscopic approach. These techniques are still being developed for getting results comparable to that of open thoracotomy.

Postoperative Care

Use of postoperative bracing varies with the surgeon and the stability of fixation.

The patient is not advised to go to school for six weeks.

It may take up to 6 months before normal activities are resumed.

Strenuous may be restricted for at least a year. Some cases may have to stop playing.

Complications

• Intraoperative coagulopathy
• Chylothorax in anterior surgeries
• Infections.
• crankshaft phenomenon
• Interscapular pain
• Pseudarthrosis – failure of fusion

Prognosis

The magnitude of the curve is the main defining factor of the prognosis.

Irrespective of the treatment offered,  patients with scoliosis were found to have a higher self-reported rate of arthritis and poorer perceptions of their overall health, ability and, body image.

References

• James JI. Idiopathic scoliosis; the prognosis, diagnosis, and operative indications related to curve patterns and the age at onset. J Bone Joint Surg Br. 1954 Feb. 36-B (1):36-49.
• Morrissy RT, Goldsmith GS, Hall EC, et al. Measurement of the Cobb angle on radiographs of patients who have scoliosis. Evaluation of intrinsic error. J Bone Joint Surg Am. 1990 Mar. 72(3):320-7.
• Carman DL, Browne RH, Birch JG. Measurement of scoliosis and kyphosis radiographs. Intraobserver and interobserver variation. J Bone Joint Surg Am. 1990 Mar. 72(3):328-33. .
• Schwend RM, Hennrikus W, Hall JE, Emans JB. Childhood scoliosis: clinical indications for magnetic resonance imaging. J Bone Joint Surg Am. 1995 Jan. 77(1):46-53.
• Ozturk C, Karadereler S, Ornek I, Enercan M, Ganiyusufoglu K, Hamzaoglu A. The role of routine magnetic resonance imaging in the preoperative evaluation of adolescent idiopathic scoliosis. Int Orthop. 2010 Apr. 34 (4):543-6.
• Gagnon S, Jodoin A, Martin R. Pulmonary function test study and after spinal fusion in young idiopathic scoliosis. Spine (Phila Pa 1976). 1989 May. 14 (5):486-90.
• Mehta MH. The rib-vertebra angle in the early diagnosis between resolving and progressive infantile scoliosis. J Bone Joint Surg Br. 1972 May. 54(2):230-4
• Figueiredo UM, James JI. Juvenile idiopathic scoliosis. J Bone Joint Surg Br. 1981 Feb. 63-B(1):61-6.
• Gupta P, Lenke LG, Bridwell KH. Incidence of neural axis abnormalities in infantile and juvenile patients with spinal deformity. Is a magnetic resonance image screening necessary?. Spine (Phila Pa 1976). 1998 Jan 15. 23 (2):206-10.
• Molina A, Martin C, Muñoz I, Aguilar L, Serrano S, Ballester J. Spinal intraosseous arteriovenous malformation as a cause of juvenile scoliosis. A case report. Spine (Phila Pa 1976). 1997 Jan 15. 22 (2):221-4.
• Lenke LG, Betz RR, Harms J, Bridwell KH, Clements DH, Lowe TG, et al. Adolescent idiopathic scoliosis: a new classification to determine the extent of spinal arthrodesis. J Bone Joint Surg Am. 2001 Aug. 83-A(8):1169-81.
• Roberto RF, Lonstein JE, Winter RB, Denis F. Curve progression in Risser stage 0 or 1 patients after posterior spinal fusion for idiopathic scoliosis. J Pediatr Orthop. 1997 Nov-Dec. 17(6):718-25
• Kostuik JP. Operative treatment of idiopathic scoliosis. J Bone Joint Surg Am. 1990 Aug. 72(7):1108-13.