IDIOPATHIC SCOLIOSISDR MUHAMMAD ADNANPGMO ORTHO 1

SCOLIOSIS ”Scoliosis is defined as a lateral deviation of

the normal vertical line of the spine. The lateral curvature of the spine also is

associated with rotation of the vertebrae. This produces a three-dimensional deformity

of the spine that occurs in the sagittal, frontal, and coronal planes.

Idiopathic scoliosis is most common type,the exact etiology of which is unknown.

CLASSIFICATION OF IDIOPATHIC SCOLIOSIS Infantile scoliosis

• From birth to 3 years of age; juvenile idiopathic scoliosis,

• between the ages of 4 and 10 years;

adolescent Idiopathic scoliosis• between 10 years of age and skeletal maturity.

INFANTILE IDIOPATHIC SCOLIOSIS Infantile idiopathic scoliosis is a structural,

lateral curvature of the spine occurring in patients younger than age 3 years.

more frequent in boys than in girls, and were primarily thoracic and convex to the left.

Associated findings are mental deficiency,congenital hip dislocation,plagiocephaly,congenital heart defects.

INFANTILE SCOLIOSIS

PROGRESSION OF INFANTILE IDIOPATHIC CURVE Most curves in infantile idiopathic scoliosis are

selflimiting and spontaneously resolve (70% to 90%); however,

some curves may be progressive, usually increasing rapidly, are often difficult to manage, and may result in significant deformity and pulmonary impairment.

Risk of curve progression <6 mo: low and>1 yr: high

rate of curve progression:Gradual progression: 2 to 3 degrees/yr

Malignant progression: 10 degrees/yr

RIB VERTEBRAL ANGLE AND RVAD Mehta developed a method to differentiate resolving from

progressive curves in infantile idiopathic scoliosis based on measurement of the rib-vertebral angle (RVA).

She evaluated the relationship of the convex rib head and vertebral body of the apical vertebra by drawing one line perpendicular to the apical vertebral endplate and another from the midneck to the midhead of the corresponding rib; the angle formed by the intersection of these lines is the RVA .

. The RVA difference (RVAD) is the difference between the values of the RVAs on the concave and convex sides of the curve.

Mehta reported that 83% of the curves resolved if the RVAD measured less than 20 degrees and that

84% of the curves progressed if the RVAD was greater than 20 degrees.

RVA

Construction of rib-vertebral angle (RVA).

RVAD

MRI An increased incidence of neural axis

abnormalities (Chiari malformation, syrinx, low-lying conus, and brainstem tumor) has been noted on MRI in patients with infantile idiopathic scoliosis (21.7%).

MRI evaluation is now recommended for infantile scoliosis for curves measuring more than 20 degrees. These patients usually require sedation for MRI.

TREATMENT Because of the favorable natural history in

70% to 90% of patients with infantile idiopathic scoliosis, active treatment often is not required.

If the initial curve is less than 25 degrees and the RVAD is less than 20 radiographic follow-up every 6 months is recommended.

Most resolving curves correct by 3 years of age; however, follow-up should continue even after resolution because scoliosis may recur in adolescence.

CASTING Once the diagnosis of a progressive curve is

made based on either a progressive Cobb angle or a RVAD of more than 20 degrees, or a double curve treatment is recommended.

In a very young child, serial casting with general anesthesia may be required until the child is large enough for a satisfactory orthosis.

The interval between cast changes is determined by the rate of the child’s growth, but a cast change usually is required every 2 to 3 months.

A, Position on table with traction appliedto halter and pelvis. B, Example of correction maneuver forderotation of left thoracic curve. C, Underarm cast withwindows.

ORTHOSIS An orthotist can make a satisfactory

thoracolumbosacral orthosis (TLSO) or cervicothoracolumbosacral orthosis (CTLSO) for curves that are not too large.

Brace wear is continued full time until the curve stability has been maintained for at least 2 years. At that point, brace wear can be gradually reduced.

McMaster reported control of the curves in 22 children with infantile scoliosis with an average brace time of more than 6 years

TLSO BRACE

OPERATIVE TREATMENT If a curve is severe or increases despite the use

of an orthosis or casting, surgical stabilization is needed.

Ideally, surgery should not only stop progression of the curve but also allow continued growth of the thorax and development of the pulmonary tree.

Growing rods may be used to control curve progression and still allow for growth of the spine

VEPTR vertical expandable prosthetic titanium rib instrumentation has been reported as another alternative to correct the curve and allow for continued growth of the spine

When surgical fusion is necessary, a relatively short anterior and posterior arthrodesis should be considered, including only the structural or primary curve. Combined anterior and posterior arthrodesis is necessary to prevent the “crankshaft” phenomenon.

Because of the deleterious effect on the developing thoracic cage and lung function, fusionless instrumentation techniques are preferred.

SURGICAL FUSION

JUVENILE IDIOPATHIC SCOLIOSIS Juvenile idiopathic scoliosis appears between

the ages of 4 and 10 years. Multiple patterns can occur, but the

convexity of the thoracic curve usually is to the right.

Juvenile idiopathicscoliosis comprises 12% to 21% of idiopathic scoliosis cases.

The female-to-male ratio is 1 : 1 in children between 3 and 6 years of age.

The natural history of juvenile idiopathic scoliosis is usually slow to moderate progression until the pubertal growth spurt.

TREATMENT juvenile idiopathic scoliosis is treated

according to guidelines similar to those for adolescent idiopathic scoliosis.

For curves of less than 20 degrees, observation is indicated, with examination and standing posteroanterior radiographs every 4 to 6 months. Evidence of progression on the radiographs as indicated by a change of at least 5 to 7 degrees warrants brace treatment. If the curve is not progressing, observation is continued until skeletal maturity.

ORTHOTIC TREATMENT Milwaukee brace, a TLSO is used for thoracic

curves with the apex at T8 or below. Initially, the brace is worn full time (22 of 24

hours). If the curve improves after at least 1 year of full-time bracing, the hours per day of brace wear can be decreased gradually to a nighttime-only bracing program, which is much more tolerable, especially when the child reaches puberty.

However, the patient is carefully observed for any sign of curve progression during this weaning process.

If curve progression is noted, a full-time bracing program is resumed.

EVALUATION OF BRACE TREATMENTOF JUVENILE IDIOPATHIC SCOLIOSISBY THE RIB-VERTEBRAL ANGLEDIFFERENCE (RVAD)

If the RVAD values progress above 10 degrees during brace wear, progression can be expected.

■ If the RVAD values decline as treatment continues, parttime brace wear should be adequate.

■ Those patients with curves with RVAD values near or below 0 degrees at the time of diagnosis generally will require only a short period of full-time brace wear before part-time brace wear is begun.

SURGICAL TREATMENT If orthotic treatment fails, operative management of

the curve should be considered. Important considerations in the operative treatment

of patients with juvenile idiopathic scoliosis are the expected loss of spinal height and the limited chest wall growth and lung development after spinal fusion.

Another important consideration is the crankshaft phenomenon.

With a solid posterior fusion, continued anterior growth of the vertebral bodies causes the vertebral body and discs to bulge laterally toward the convexity and to pivot on the posterior fusion, causing loss of correction, increase in vertebral rotation, and recurrence of the rib hump.

Crankshaft phenomenon. A, Spine with scoliosis.B, Despite solid posterior fusion, continued anterior growthcauses increase in deformity.

A B

Fifty-seven-degreecurve (A) was corrected to 39 degreeswith posterior fusion and instrumentation(B). C, Three years aftersurgery, deformity has recurred becauseof crankshaft phenomenon.

SURGERY OPTIONS If the child is younger than 8 years and

small, the ideal treatment is a growing rod system without fusion or growth modulation techniques.

If the child is 9 or 10 years of age or large, growing rods or growth modulation may still be used but instrumentation and fusion may be appropriate. This should be a combined anterior and posterior spinal fusion to avoid the crankshaft phenomenon.

GROWING ROD INSTRUMENTATION Growing rod instrumentation is a technique of

posterior instrumentation that is sequentially lengthened to allow longitudinal growth while still attempting to control progressive spinal deformity.

Moe et al. described the use of a subcutaneous Harrington rod without fusion, followed by a full-time external orthosis, in certain flexible curves in growing children. The authors noted an average length gain in the instrumented area of 3.8 cm that ultimately required fusion.

Complications,most frequently hook dislocation and rod breakage, occurred in 50% of patients.

Technique of dual-rod instrumentation. A, Anteroposteriorview. B, Lateral view showing construct contouredto maintain sagittal alignment. Extended tandem connectorsare placed in thoracolumbar spine to minimize profile.

Growing rod.

A, Model of thoracic chamber. Correct placement of rib anchors (white arrows) lateral to tips of transverse processes(black arrows). B, Dissection of soft tissue anterior to rib.

Postoperative posteroanterior and lateral radiographs after dual growingrods with proximal rib anchors (white arrows). Black arrows indicate connectors and cross-link.

Guided growth and physeal stapling.

ADOLESCENT IDIOPATHIC SCOLIOSIS present when the spinal deformity is

recognized after the child is 10 years of age but before skeletal maturity.

Most idiopathic curves are lordotic or hypokyphotic in the thoracic region.

most common type of idiopathic scoliosis Risk of curve progression is 23% Rate of curve progression is : 1 to 2

degrees/month during puberty Curve resolution is rare

ETIOLOGYThere are many proposed etiological factors,

but these can be divided into six general categories: (1) genetic factors,

(2) neurological disorders,(3) hormonal and metabolic dysfunction, (4) skeletal growth, (5) biomechanical factors, and (6) environmental and lifestyle

FACTORS RELATED TO PROGRESSION OF ADOLESCENT IDIOPATHIC SCOLIOSIS ■ Girls > boys ■ Premenarchal ■ Risser sign of 0 ■ Double curves > single curves ■ Thoracic curves > lumbar curves ■ More severe curve

EFFECTS OF CURVE PROGRESSION The effect of progressive curves on adults

with untreated scoliosis has been studied by several investigators. Five major considerations in the natural history of untreated adolescent idiopathic scoliosis in adults are

(1) back pain, (2) pulmonary function, (3) psychosocial effects, (4) mortality, and (5) curve progression.

PATIENT EVALUATIONA. History

B. Physical examination Serial measurement of height Any dimpling, hair patches, or skin abnormalities,

such as hemangiomas or café au lait spots. Asymmetry of the shoulder, scapula, ribs, and

waistline should be noted by drawing plumb line. Adam forward bending test Limb lengths should be measured because a

discrepancy may cause a pelvic tilt and a compensatory scoliosis.

SIGNS OF SCOLIOSIS

ADAMS TEST

NEUROLOGICAL EXAMINATION

A thorough neurological examination should be done to determine if an intraspinal neoplasm or a neurological disorder is the cause of scoliosis.

Particular attention should be given to the abdominal reflexes, because often they are the only neurological abnormality found with some intraspinal disorders.

RADIOGRAPHIC EVALUATION Posteroanterior and lateral radiographs of the

spine, including the iliac crest distally and most of the cervical spine proximally, should be made with the patient standing.

Assessment of the flexibility of a scoliotic curve pattern is important when the patient is being evaluated for surgery or bracing. This can be assessed by right and left bending films, traction films, fulcrum bending films, or push prone radiographs.

STAGNARA VIEW Stagnara described a

radiographic technique to eliminate this rotational component of the curve. In this technique, an oblique radiograph is made with the cassette parallel to the medial aspect of the rotational rib prominence and the x-raybeam positioned at right angles to the cassette.

A film made at 90 degrees to this provides the true lateral view, allowing a much more accurate measurement of the curve size and better evaluation of vertebral anatomy

Diagram of Stagnara derotation view.

Radiographs at four points during rotational cycle of articulated scoliotic spine show changes in Cobb angle withrotation. On anteroposterior view, apparent Cobb angle of 87 degrees (A) and true Cobb angle of 128 degrees (B). On lateral view,apparent kyphosis of 61 degrees (C) and true apical lordosis of 14 degrees (D).

A, Standard posteroanterior radiograph of large scoliosis. B, Stagnara view showing better detail of curve, size, andvertebral anatomy.

ASSESMENT OF SKELETAL MATURITY1. The Risser sign

is a measurement based on the ossification of the iliac apophysis, which is divided into four quadrants.

.

The Risser sign may not be as useful for predicting curveprogression because grade 1 has been found to begin after theperiod of rapid adolescent growth or peak height velocity.

RISSER SIGN

PHV PHV is calculated from serial height

measurements and is expressed as centimeters of growth per year.

Average values of PHV are 8 cm per year in girls and 9.5 cm per year in boys.

Little et al., in a study of 120 girls with scoliosis, found that PHV reliably predicted cessation of growth (3.6 years after PHV in 90%) and likelihood of curve progression.

MEASUREMENT OF CURVESCobb method:

: (1) locating the superior end vertebra, (2) locating the inferior end vertebra, and (3) drawing intersecting perpendicular lines

from the superior surface of the superior end vertebra and from the inferior surface of the inferior end vertebra. The angle of deviation of these perpendicular lines from a straight line is the angle of the curve.

If the endplates are obscured, the pedicles can be used instead.

COBB ANGLED5

D11

75°

VERTEBRAL ROTATION1. Nash and Moe:

if the pedicles are equidistant from the sides of the vertebral bodies, no vertebral rotation is present (0 rotation).

The grades progress to grade IV rotation, in which the pedicle is past the center of the vertebral body

SAGITAL BALANCE Overall spinal sagittal balance is determined

by a plumb line dropped from the dens. This plumb line usually falls anterior to the

thoracic spine, posterior to the lumbar spine, and through the posterior superior corner of S1 .

On the standing long lateral films generally used in spinal deformity evaluation, the dens is not easily seen. The plumb line therefore usually is dropped from the middle of the C7 vertebral body. This plumb line is called the sagittal vertebral axis.

7 sagittal plumb line is useful measurement ofsagittal balance. Plumb line dropped from middle of C7 vertebralbody falls close to posterior superior corner of S1 vertebral body.

NON OPERATIVE TREATMENTA. Observation: Some degree of scoliosis is frequent in the

general population,but few individuals have curves that require treatment. Unfortunately, no method is reliable for accurately predicting at the initial evaluation which curves will progress; thus, observation is the primary treatment of all curves.

A radiograph of the spine currently is the only definitive documentation of curve size and curve progression

SKELETALLY IMMATURE PTS In general, young patients with mild curves

of less than 20 degrees can be examined every 6 to 12 months.

A curve of more than 20 degrees in a patient who has not reached skeletal maturity will need more frequent examination, usually every 4 to 6 months, with standing posteroanterior radiographs.

If progression of the curve (an increase of 5 degrees during 6 months) beyond 25 degrees is noted, orthotic treatment may be considered.

SKELETALLY MATURE PTS Skeletally mature patients with curves of less

than 20 degrees generally do not require further evaluation

Curves of 30 to 40 degrees in skeletally mature patients generally do not require treatment, but because studies indicate a potential for progression in adult life, these patients should be observed with yearly standing posteroanterior radiographs for 2 to 3 years after skeletal maturity and then every 5 years throughout life.

ORTHOTIC TREATMENT The optimal inclusion criteria consist of age 10 years or older , Risser grades 0 to 2, primary curve angles of 25 to 40 degrees, no

prior treatment, and, if female, either premenarchal or less than 1

year postmenarchal.

The orthoses were originally intended to be worn 23 hours a day, but concern about compliance has led to parttime bracing regimens. Most part-time bracing protocols call for approximately 16 hours or less of brace wear each day.

INDICATIONS FOR OPERATIVETREATMENT OF IDIOPATHIC SCOLIOSIS Increasing curve in growing child■ Severe deformity (>50 degrees) with

asymmetry of trunk in adolescent■ Pain uncontrolled by nonoperative treatment■ Thoracic lordosis■ Significant cosmetic deformity

SURGICAL GOALSThe goals of surgery for spinal deformity are to correct or to improve the deformity, to maintain sagittal balance, to preserve or to improve pulmonary

function, to minimize morbidity or pain, to maximize

postoperative function, and to improve or at least not to harm the

function of the lumbar spine.

POSTERIOR SURGERIES Posterior fusion Posterior spinal instrumentation Multiple hook segmental instrumentation Pedicle fixation

A and B, Hybrid fixation of Lenke 1A (King III)curve with pedicle screws at lower end of construct.

COMPLICATION OF POSTERIOR SURGERIES Early

NEUROLOGICAL INJURY ATELECTASIS PNEUMOTHORAX DURAL TEAR WRONG LEVELS Urinary complication Vision loss

Late Psudoarthrosis Crankshaft phenomenon Superior mesenteric artery syndrome Late infection

ANTERORIOR SURGERIES Anterior spinal fusion

ASF if younger than 11 yrwith open triradiatecartilage

Flexible 43-degree thoracic curve. B, Correction on bending film. C, Correction of fractional curve on bending film.D and E, After anterior fusion with Texas Scottish Rite Hospital (TSRH) instrumentation.