early-onset scoliosis: a review of history, current treatment, and … · 2015-07-09 ·...

Early-Onset Scoliosis: A Review of History, Current Treatment, and Future DirectionsScott Yang, MD,a,b Lindsay M Andras, MD,a Gregory J Redding, MD,c David L Skaggs, MD, MMMa

aChildren’s Orthopaedic Center, Children’s Hospital

Los Angeles, Los Angeles, California; bDepartment of

Orthopaedic Surgery, University of Virginia Health System,

Charlottesville, Virginia; and cDepartment of Pediatrics,

Division of Pulmonary and Sleep Medicine, Seattle

Children’s Hospital, Seattle, Washington

Dr Yang drafted the initial manuscript and edited

the fi nal manuscript; Drs Andras and Redding

provided critical revisions to the manuscript; Dr

Skaggs provided overall supervision and critical

revisions to the manuscript; and all authors

approved the fi nal manuscript as submitted.

The treatment of early-onset scoliosis

(EOS) remains a challenging and

rapidly evolving area of pediatric

orthopedics. EOS is defined as

a curvature of the spine ≥10°

in the frontal plane with onset

before 10 years of age (Fig 1).1,2

The management of EOS requires

consideration of the interrelated

growth of the spine and thorax and

their impact on lung development.

In addition, EOS is often associated

with other comorbid conditions that

increase the complexity of managing

the spinal deformity.

EOS includes an inhomogeneous

grouping of patients, because the

etiology of the spinal deformity

may be idiopathic, associated with

underlying systemic syndromes,

secondary to a neuromuscular

condition, or caused by a structural

congenital spinal deformity (Table

1).3 The true prevalence of EOS is

unknown, although idiopathic EOS

accounts for <1% of all scoliosis

cases.4 Congenital scoliosis results

from abnormalities of vertebral

development in utero and may include

single or multiple hemivertebrae or

segmentation defects with or without

associated rib fusion. Congenital

scoliosis is often progressive and may

necessitate early, more aggressive

treatment. Idiopathic EOS in infants

abstractEarly-onset scoliosis (EOS) is defined as curvature of the spine in children

>10° with onset before age 10 years. Young children with EOS are at risk

for impaired pulmonary function because of the high risk of progressive

spinal deformity and thoracic constraints during a critical time of lung

development. The treatment of EOS is very challenging because the

population is inhomogeneous, often medically complex, and often needs

multiple surgeries. In the past, early spinal fusion was performed in

children with severe progressive EOS, which corrected scoliosis but limited

spine and thoracic growth and resulted in poor pulmonary outcomes.

The current goal in treatment of EOS is to maximize growth of the spine

and thorax by controlling the spinal deformity, with the aim of promoting

normal lung development and pulmonary function. Bracing and casting

may improve on the natural history of progression of spinal deformity

and are often used to delay surgical intervention or in some cases obviate

surgery. Recent advances in surgical implants and techniques have led to

the development of growth-friendly implants, which have replaced early

spine fusion as the surgical treatment of choice. Treatment with growth-

friendly implants usually requires multiple surgeries and is associated with

frequent complications. However, growth-friendly spine surgery has been

shown to correct spinal deformity while allowing growth of the spine and

subsequently lung growth.

STATE-OF-THE-ART REVIEW ARTICLEPEDIATRICS Volume 137 , number 1 , January 2016 :e 20150709

To cite: Yang S, Andras LM, Redding GJ, et al.

Early-Onset Scoliosis: A Review of History, Current

Treatment, and Future Directions. Pediatrics.

2016;137(1):e20150709

by guest on October 30, 2020www.aappublications.org/newsDownloaded from

YANG et al

occurs in children ≤3 years of age

and has a variable course over time.

A unique feature of idiopathic EOS

in infants is that it often improves

spontaneously.5,6 Idiopathic EOS in

juveniles occurs in children aged 4

to 10 years. Among children with

neuromuscular disorders, scoliosis

is common and compounds the

restrictive lung disease produced

by respiratory muscle weakness.

Treatment strategies and duration

differ significantly based on

both etiology and the amount of

anticipated growth remaining. The

younger the child, the greater the

risk that the spinal deformity will

affect pulmonary development and

function.

GROWTH OF THE SPINE AND LUNG DEVELOPMENT

The spine grows most rapidly in

the first 5 years, with an average

T1 to S1 segment length increase

of 10 cm during this time (2 cm/

year). After the first 5 years, there

is a slower T1 to S1 growth from

age 5 to 10 years of ~5 cm until

adolescence (1 cm/year). From

age 10 years to adulthood, T1 to

S1 grows an additional 10 cm; this

includes the adolescent growth spurt

(2 cm/year).7–9 Because growth

can promote the progression of the

deformity, patients with EOS are at

greatest risk for progression of spinal

deformity in the first few years of life

and during the adolescent growth

spurt.

In EOS, the progressive spinal

deformity occurs during a critical

time of lung development. The

number of alveoli and lung volume

increase most rapidly in the first

several years and continue to

increase at a lower rate during

adolescence and adulthood (Fig

2).10–12 Animal models of EOS

produced early in life demonstrate

alveolar simplification and reduced

number, producing an example of

postnatal hypoplasia.13 Autopsies of

children dying of EOS report similar

alveolar features and pulmonary

vascular remodeling associated with

pulmonary hypertension.14 Lung

function studies of children with EOS

demonstrate a variable severity of

restrictive lung disease caused by

small lung volumes, reduced chest

wall compliance, and respiratory

muscle dysfunction.15 The concept

of thoracic insufficiency syndrome

(TIS), popularized by Campbell et

al,16 is defined as the inability of the

thorax to support normal respiratory

function and lung development in

growing children. Because of scoliosis

progression early in life, patients

with severe EOS can potentially

develop TIS. TIS has been associated

with poorer quality of life scores than

those of childhood epilepsy, heart

disease, and cancer.17

The natural history of untreated

EOS is associated with significant

morbidity and often profound

cardiopulmonary compromise,

including respiratory failure and

cor pulmonale. A Swedish study

comparing expected population

death rates demonstrated more than

twice the mortality rate by age 40

in patients with EOS compared with

that of the general population.18

Consequently, the fundamental

principle of treating EOS is to foster

normal respiratory development

and maximize spinal growth while

preventing additional deformity that

can lead to TIS.

HISTORY OF TREATMENT STRATEGIES: WHAT WE HAVE LEARNED

Before the introduction of spinal

implants, the historical treatment of

EOS consisted of casting or bracing

the spine and thorax. Although

casting for scoliosis has been

performed for centuries, it fell out

of favor as the primary treatment

of scoliosis because of concerns

that casting deformed the ribs. Paul

Harrington introduced a spinal

implant for scoliosis in the 1960s

that provided a surgical alternative.

In these cases, the rod was used to

2

FIGURE 1Posteroanterior (A) and lateral (B) radiographs of a 4-year-old boy whose untreated scoliosis had rapidly progressed to 110° and who developed severe kyphosis. Reproduced with permission of Children’s Orthopedic Center, Los Angeles, California.


PEDIATRICS Volume 137 , number 1 , January 2016

surgically correct scoliosis without

fusion by applying distraction

across the concavity of the curve.19

Harrington rods improved curves

in a 2-dimensional plane, although

this technique often led to a flat

back deformity. Implant failure and

dislodgment with this method were

high, and its use was limited.

Early spinal fusion to halt deformity

in EOS then became the preferred

treatment, because a short and

straight spine was thought to

be superior to a progressively

crooked spine. Subsequent studies

demonstrated that early spinal

fusion, which prevents continued

spinal growth of the fused region,

limits intrathoracic volume and

hence lung volume. As a result,

children developed severe restrictive

lung disease with continued growth.

Patients with idiopathic EOS who

underwent spinal fusion at a mean

age of 4.1 years demonstrated mean

forced vital capacity (FVC) of 41% of

normal when evaluated at skeletal

maturity, whereas patients who

underwent fusion at a mean age of

12.9 years demonstrated mean FVC

of 68% of normal.20 In 1 study, the

reduction in FVC ≥5 years after spine

fusion directly correlated with the

number of thoracic spinal segments

fused.21 Early posterior spinal fusion

techniques have often led to the

crankshaft phenomenon, in which

the anterior column of the immature

spine continues to grow, leading to

progressive deformity. Consequently,

new treatment strategies have been

developed that allow or promote

spinal growth, usually referred to

as growth-friendly techniques.22

At worst these techniques may be

thought of as delaying the need

for a spine fusion to allow spinal

growth, and at best they may cure

the scoliosis or avoid the need for a

spinal fusion.

One exception to avoiding early

spinal fusion is congenital scoliosis in

which the spine deformity is limited

to a small number of vertebrae.

The classic example of congenital

scoliosis that requires early fusion is

the case of a hemivertebra causing

progressive scoliosis (Fig 3). In such

cases early fusion (with or without

excision of the hemivertebrae)

can often correct the scoliosis in

1 surgery, with a fusion of only

2 vertebrae. This procedure is

generally performed around the age

of 3 to 6 years.

CURRENT TREATMENT STRATEGIES: NONOPERATIVE

Nonoperative treatment of EOS

consists of bracing or casting.

Bracing can be considered for mild

progressive curves, although its

efficacy remains unproven in EOS,23

and ensuring compliance with brace

wear can be difficult in young children.

Commonly used braces are variants of

a custom-molded thoracolumbosacral

orthosis. Braces are often used to

maintain correction obtained from

serial casting or delay surgical

intervention. Several case series have

shown that 74% to 92% of idiopathic

EOS in infants spontaneously

resolves.6,24 For idiopathic EOS in

3

TABLE 1 Summary of the Different Types of EOS and Their Unique Features

Types of EOS Characteristics Associated Diagnoses Treatment Considerations

Congenital Structural abnormality of

the spine or thorax present

at birth.

Cardiac, renal

abnormalities

Hemivertebrae excision.

Short-segment early

spinal fusion in select

cases in this group

may be the exception to

growth-friendly spine

surgery.

Failure of formation (eg,

hemivertebra).

Other musculoskeletal

abnormalities (upper

limb, club foot)

Failure of segmentation (eg,

fused vertebra or ribs).

Associated with VATER/

VACTERL syndromes

Intraspinal abnormalities

(ie, diastematomyelia,

tethered cord)

Neuromuscular Abnormalities in muscular

tone lead to scoliosis.

Examples: Cerebral palsy,

muscular dystrophies,

myopathies, spinal cord

injuries

Generally higher-risk

surgical patients with

medical comorbidities

(eg, respiratory,

gastrointestinal).

Often a long, sweeping

scoliosis curve.

Syndromic Includes any other syndrome

associated scoliosis

(excluding neuromuscular

or congenital scoliosis

syndromes).

Examples: Connective

tissue disorders,

Marfan syndrome,

neurofi bromatosis,

skeletal dysplasias,

Prader–Willi syndrome

Each syndrome has

unique considerations

(eg, neurofi bromatosis

may have dural ectasia,

making spinal implants

more challenging to

place.

Idiopathic Scoliosis without a known

attributable cause.

Higher incidence

of Arnold–Chiari

malformation and

syringomyelia compared

with adolescent idiopathic

scoliosis

Generally healthier

children.

Infantile (diagnosed <3 y):

Many milder curves will

resolve but need observation.

Casting shown to resolve

some infantile curves.

Juvenile (diagnosed 4–10 y):

Often left sided curves. Slight

male predominance.

Surgery often needed

despite often long-term

casting or brace wear.

Reproduced with permission of Children’s Orthopedic Center, Los Angeles, California.


YANG et al

infants with unresolved progressive

curves, Mehta25 demonstrated that

casting may be effective in completely

resolving some curves, especially

those of lower magnitude. Because

casting has proven to be a safe method

to manage idiopathic EOS, there

has been a resurgence of interest in

expanding traditional cast methods

to treat multiple subtypes of EOS to

avoid the risks of surgery and early

spine fusion (Fig 4). The cast is applied

to the torso under anesthesia while

the child is in traction, elongating

the spine. The cast is molded while

the child’s torso is derotated and

flexed away from the concavity of the

curve. Casts are changed every 8 to

12 weeks. For curves that resolved

or stabilized in a cast, bracing is often

used to help maintain the correction

through skeletal maturity. If there

is progression despite bracing,

additional casting may be used to

attempt to regain the correction.

In other cases, growth-friendly

implants or fusion may be the most

appropriate step depending on the

patient’s age and curve severity.

Serial casting applied to young

children with nonidiopathic EOS has

been shown to be an effective way

to delay surgical treatment.26–28 In 1

study, curve resolution was rare with

serial casting in the nonidiopathic

EOS, but progression of the curve

was controlled sufficiently to delay

spine surgery for at least 2 years.

Normal longitudinal growth of

the spine was observed while the

patient was in the cast.28 Based on

current evidence, a trial of casting in

EOS regardless of curve etiology is

considered a treatment option. The

specific indications for the threshold

to institute cast treatment continue

to vary between institutions but are

generally considered for EOS curves

>25°, with >10° of documented

progression.

CURRENT TREATMENT STRATEGIES: SURGICAL

The surgical treatment strategy for

EOS has evolved significantly over

the past decade with the use of

modern growth-friendly implants.

These implants attempt to maximize

the growth of the spine and thorax

while controlling curve progression

to preserve normal lung volume.

Growth-friendly implants can be

classified into 3 distinct subtypes:

distraction-based, guided growth,

and compression-based strategies.22

Distraction-Based Implants

Distraction-based implants are the

most common devices used in EOS.

They apply traction to the spinal

column between proximal and

distal anchors joined by expandable

rods. The rods are periodically

lengthened as the child grows to

maintain spine curve correction.

Four types of implants have been

used: the traditional growing rod

(TGR), vertical expandable prosthetic

titanium rib (VEPTR) device, hybrid

systems, and magnetically controlled

growing rod (MCGR).

Growing Rod

The TGR incorporates proximal and

distal hook or screw anchors on the

spine, joined by rods with connectors

that allow serial distractions between

the rods (Fig 5). Limited fusion is

performed at the proximal and distal

anchor sites on the spine to provide

4

FIGURE 2Composite plots of total alveolar number, T1–S1 segment growth from birth, and mean lung volume with age. The number of alveoli, mean lung volume, and spinal growth increase rapidly in the fi rst few years of life. Reproduced with permission of Children’s Orthopedic Center, Los Angeles, California.

FIGURE 3Preoperative radiograph (A) and CT scan (B) of a patient with a hemivertebrae (red arrow). Intraoperative images demonstrating correction of the deformity with a hemivertebrectomy (C). Reproduced with permission of Children’s Orthopedic Center, Los Angeles, California.



solid sites for spine distraction.

The area between the anchors is

intentionally not fused, allowing

motion and growth through this

region. Lengthenings are typically

performed at ~6-month intervals.

Akbarnia et al29 reported on the

use of TGRs for EOS in 24 patients,

resulting in improvement of coronal

plane major curves from 82° to

36°, with 1.2 cm growth in T1 to

S1 length per year at mean 4-year

follow-up. Akbarnia et al30 also

demonstrated that patients whose

spines were lengthened at ≤6-month

intervals had significantly higher

annual T1 to S1 growth rate of 1.8

cm/year, compared with 1.0 cm/

year in patients whose spines were

lengthened less frequently. This

finding has led many to believe that

distraction may actually promote

vertebral growth.

VEPTR

Developed by Bob Campbell, VEPTRs

use ribs as anchors, and sometimes

the spine and pelvis as well. VEPTRs

are generally thought of as primarily

providing thoracic expansion,

compared with growing rods,

which primarily provide control

of scoliosis. In reality, thoracic and

spinal deformities are closely linked.

Similar to other distraction-based

systems, these constructs undergo

recurrent surgical expansion (Fig 6).

Original descriptions of the VEPTR

technique recommended incising

between ribs to maximize thoracic

expansion, but concerns of scarring

and stiffening of the chest wall

led most surgeons to cut between

the ribs only in cases of multiple

fused ribs. VEPTR treatment has

demonstrated continued spinal

growth with serial expansions (mean

71 mm over 4 lengthenings) while

improving the coronal curve.31,32

Hybrid

A hybrid distraction-based strategy

incorporates the VEPTR concept of

using ribs as anchor sites but also

uses traditional spinal implants,

as in the TGR system. Traditional

spinal hooks are placed proximally

along the ribs (Fig 7). As in the

TGR strategy, the distal anchor

site is incorporated by a fusion,

5

FIGURE 4A, Radiograph of a 29-month-old girl with idiopathic EOS and a curve of 47°. B, In-cast radiograph shows curve corrected to 18° with the initial cast. C, Like many children she continued to be quite active despite the cast. Reproduced with permission of Children’s Orthopedic Center, Los Angeles, California.


YANG et al

and lengthening is performed at a

connector between the rods. The

advantage of this technique is that

it avoids fusion of the proximal

anchor site of the thoracic spine,

potentially allowing more total

growth of the thorax. Furthermore,

rib anchors without traditional rigid

fusion at the proximal anchor site

allow some motion of the spinal

implant construct. This feature may

reduce the stress and rigidity of the

distraction system across an unfused

mobile spine. Consequently, use of

a hybrid system with proximal rib

anchors has been associated with

a decrease in the incidence of rod

breakage.33

MCGR

Recently the US Food and Drug

Administration cleared the use

of MCGRs, which can lengthen

nonsurgically without anesthesia

after the initial implantation.34,35

This implant is similar to other

growing rod constructs with distal

spine anchors and proximal rib or

spine anchors that are connected by

telescoping rods. This telescoping

portion contains an internal magnet

that can be lengthened from an

external remote control (Fig 8).

Because of the noninvasive nature

of lengthening, it is also possible

to distract at shorter intervals.

Preliminary studies of MCGRs

have been met with optimism

with respect to achieving the same

results of TGRs.34–36 Dannawi et

al34 demonstrated that the mean

coronal Cobb angle improved from

69° to 41° after MCGRs with a mean

of 4.8 distractions per patient were

used over 15 months. The T1 to S1

length increased a mean of 3.5 cm

during this time period. A study

comparing 12 MCGR- and TGR-

treated patients demonstrated no

significant difference in spine length

gains, but there were 57 fewer

surgical procedures in the MCGR

group.37 Although MCGR avoids the

need for repeat surgical intervention

for routine lengthenings, long-term

data are not yet available for this

technique. Similar to growth-friendly

implants, the complication rate is

high: 33% of patients treated with

MCGR within 2 years of follow-up.37

6

FIGURE 5Preoperative (A) and postoperative (B) radiographs of patient with traditional spine-to-spine growing rods. Radiographs obtained 5 years after the initial placement of growing rods (C) show that the scoliosis continues to be well controlled. Reproduced with permission of Children’s Orthopedic Center, Los Angeles, California.

FIGURE 6Postoperative radiograph of an 8-year-old boy with VATER syndrome with congenital scoliosis, multiple rib fusions, and thoracic insuffi ciency syndrome that was treated with a VEPTR construct. Reproduced with permission of Children’s Orthopedic Center, Los Angeles, California.

FIGURE 7A, Preoperative posteroanterior and lateral radiograph of a 4-year-old boy with severe progressive scoliosis and an 85° curve. He was not a casting candidate because of his restrictive lung disease. B, Postoperative radiograph showing a hybrid growing rod construct (rib to spine) with improvement to 37°. Reproduced with permission of Children’s Orthopedic Center, Los Angeles, California.



Complications of Distraction-Based Implants

Regardless of the implant used for

distraction-based treatment of the

growing spine, all strategies are

associated with a high complication

rate.29,30,38–43 Implant complications

such as anchor malfunction (pullout

from the spine, erosion through the

rib) and rod breakage are common

(Fig 9). Distraction-based posterior

implants often produce kyphosis,

which may result in an unfavorable

overall sagittal plane balance. Wound

complications are also common

because of the prominence of

implants under the skin and poor

healing potential in small, thin, and

often chronically malnourished

patients with EOS (Fig 10). At least 1

complication of treatment has been

reported to occur in 58% to 86%

of patients undergoing distraction-

based treatment, leading to multiple

unplanned surgical procedures.38,43,44

Among patients with complications,

1 study demonstrated a mean of

2.2 complications per patient.38

Application of stiff implants on an

unfused spine that continues to have

motion ultimately leads to fatigue

failure of the implants. Risk factors

for implant failures include severe

thoracic kyphosis that produces

proximal anchor pullout and

increased number of lengthening

procedures.40 Implantation

strategies are being critically

evaluated to decrease the incidence

of implant-related complications. A

comparison study of complications

in TGRs, hybrid proximal rib anchor

systems, and VEPTR treatments

in EOS demonstrated a trend

toward decreased implant-related

complications in the hybrid system.43

Hooks are not as rigidly fixed to

the spine compared with screws,

theoretically allowing some motion

and dispersion of stress, decreasing

fatigue-related implant failures.

Yamaguchi et al33 demonstrated

6% rod breakage in proximal rib-

anchored growing rods, compared

with 29% in proximal spine-

anchored growing rods at a mean

56-month follow-up.

The multiple surgeries needed for

treatment with distraction-based

implants are associated with adverse

outcomes. Each lengthening surgery

has been shown to increase the

risk of deep infection 3.3 times in

EOS.41 The length gained from serial

lengthening has also been shown to

follow a law of diminishing returns,

with decreased spinal length gained

after each lengthening because of

increased stiffness of the spine.45,46

Autofusion of the spine has been

also described after repeated

lengthenings.47 Ultimately, the utility

of lengthening may be minimal after

the sixth or seventh lengthening

procedure, limiting the potential

spinal growth to 4 to 5 years after

initial surgery.

In addition to the physical effects

on the spine, there are significant

psychological effects from

distraction-based treatment. Patients

with repeated surgery in EOS

demonstrate abnormal psychosocial

scores, with a positive correlation

between behavioral problems and

the number of repetitive surgeries.42

Repeated general anesthesia in

children may cause detrimental

neurocognitive effects, based on

animal and preclinical studies,

although this remains an area of

controversy.48–50 New technologies,

such as MCGRs that obviate surgical

lengthenings, will probably help

minimize the total number of

exposures to anesthesia in EOS.

Guided Growth Implants

In guided growth techniques, the

spine is straightened with spinal

implants that allow the vertebrae

to grow along the path of the spinal

implants. The original guided growth

system used Luque wires wrapped

around the lamina of each vertebrae,

which were wrapped around straight

rods that corrected scoliosis and then

permitted guided growth as the wires

slid along the rods. This technique

was found to lead to spontaneous

fusion and limited spinal growth. A

more recent type of guided growth

implant, called the Shilla technique,

has been developed by Richard

McCarthy. In this technique, screws

are placed into vertebrae with

minimal dissection in the hopes of

avoiding spontaneous fusion and

allowing 3-dimensional correction of

7

FIGURE 8A, Preoperative anteroposterior radiograph of a 7-year-old girl with spinal muscular atrophy and 100° thoracolumbar curve. B, Postoperative posteroanterior radiograph demonstrating a construct including the MCGR device. C, Model demonstrating an MCGR device. Reproduced with permission of Children’s Orthopedic Center, Los Angeles, California.


YANG et al

the spinal deformity and permitting

growth along the rods (Fig 11).

The major advantage of guided

growth techniques over growing

rods is that children avoid multiple

surgical lengthenings. A recent study

comparing the Shilla technique

with growing rods demonstrated

that patients treated with the Shilla

technique had fewer surgeries (2.8)

compared with growing rods (7.4)

in >4-year mean follow-up. Shilla

resulted in less spinal growth and

less correction of scoliosis, with

similar complication rates to growing

rods.51

Compression-Based Implants

Compression-based implants involve

correcting scoliosis by stopping

the growth of the convex side of

the scoliosis without fusion while

allowing growth of the concave

side of the curve. This correction

is accomplished by placing staples,

tethers, or other devices across the

growth plates of the vertebrae from

an anterior approach on the convex

side of the scoliosis. Although there

is 1 device approved by the US Food

and Drug Administration, tethers

and staples are most commonly

used off label. Several case series on

compression-based implants have

demonstrated curve correction with

growth in patients who underwent

surgery at age <10 years.52,53 There

have been cases of overcorrection

with compression-based implants,

in which the curve corrects and then

develops in the opposite direction.

Therefore, this technique is generally

reserved for patients with limited

growth remaining, such as 9- to

10-year-olds. Additional concerns

include the potential pulmonary

impact of ≥1 transthoracic surgeries.

Serial measures of lung function in

older children with scoliosis treated

with transthoracic spine surgery

have shown greater loss of function

postoperatively when the thorax is

opened.54

PULMONARY OUTCOMES OF RECENT EOS TREATMENT

The study of pulmonary function in

this patient population is extremely

challenging, complicated by the fact

that many of these patients start

treatment of EOS before they are old

enough to undergo formal pulmonary

function tests (PFTs). Much of the

current literature evaluating the

pulmonary outcomes after growth-

friendly spine surgery has been

based on VEPTR in children >6

years old. PFTs have been measured

in both awake and anesthetized

patients. Computed tomography has

also been used to measure thoracic

volumes as a surrogate for PFTs.

Studies of lung function in EOS have

not compared treatment strategies

or different devices and are often

small, descriptive case series. In 1

such series, 10 children with EOS

(median age 4.3 years) demonstrated

increased mean annual absolute

FVC of 27% of predicted norms and

maintenance of FVC as a percentage

of normal after VEPTR treatment at

a mean 22 months of follow-up.55

With longer periods of follow-up

(mean 6 years) during and at the

completion of growing construct

surgery, FVC as a percentage of

normal declined by an average of

28%.56,57 There are no untreated

control groups to assess what loss of

lung function might have occurred in

the natural progression of the spine

deformities. The implication of these

studies is that lung function is not

normalized or predictably improved

after treatments for EOS but that

progressive loss of lung function may

be reduced with treatment.

Surrogate pulmonary outcomes

that do not require voluntary

effort by young children have also

been reported. Several studies

used weight gain as an indirect

marker of improved pulmonary

function and found that up to 50%

of patients with EOS demonstrated

a mean 24- to 26-percentage-

point improvement after VEPTR

or growing rod treatment.58,59

Overnight polysomnography in

children with EOS demonstrates an

increased Apnea–Hypopnea Index

8

FIGURE 9Radiograph demonstrating a broken rod with traditional spine-to-spine growing rods, identifi ed by the red arrow. Reproduced with permission of Children’s Orthopedic Center, Los Angeles, California.

FIGURE 10Clinical photo showing marked hardware prominence in a thin child with EOS. Reproduced with permission of Children’s Orthopedic Center, Los Angeles, California.



and hypoxemia associated with

hypopneic events.60 Serial measures

of breathing during sleep before

and after treatment of EOS may also

prove useful as an indirect measure

of lung function.

Two-dimensional images of the

spine, such as the Cobb angle, do

not correlate with lung function

measures and do not reflect changes

in lung function after spine curvature

has been reduced.61 However,

an encouraging study recently

demonstrated that radiographic

T1 to T12 height and T1 ro S1

height modestly correlate with

improved pulmonary function in

EOS.62 New imaging modalities,

such as diaphragm and thoracic

excursion, measured by dynamic

MRI, hold some promise in improving

assessment of spine structure–

respiratory function relations.

Persistent barriers to a high-quality

literature on the topic include a

lack of control groups, because

untreated progressive EOS is known

to have a poor outcome, and a lack

of standardization and difficulty in

evaluating respiratory function in

young children.

CURRENT TREATMENT RECOMMENDATIONS

Management of EOS involves a

diverse patient population, variable

spinal and thoracic deformities, and

multiple treatment options (Table

2). Optimizing the treatment of each

child is a process in evolution. In

many cases, a trial of serial casting

can help control the scoliosis and

allow growth while delaying surgery.

In some idiopathic cases, these

curves may resolve with casting

alone. Many children may not be able

to tolerate casting or demonstrate

progression of the scoliosis despite

casting necessitating the initiation

of growth-friendly spinal surgery.

There is considerable variation

with regard to the optimal timing

and indication of surgery. A recent

survey of 14 pediatric spine surgeons

found that the majority considered

curves with recent progression and

a magnitude of ≥60° an indication

for distraction-based implants.63 The

indications for any of the distraction-

based implants are similar, although

VEPTR has potential advantages in

cases that require direct expansion

of the thorax, such as cases of

thoracic dystrophy. Compression-

based therapies need more data in

the treatment of EOS, although they

appear to be an option in children

9

FIGURE 11A, Preoperative posteroanterior radiograph of a 7-year-old boy with a 61° curve. B, Initial postoperative radiograph shows correction with a Shilla construct with a fusion at the apex (red arrows) and screws at the upper and lower anchors that can slide along the rod (yellow arrows). C, Images 2.5 years later show how the child’s growth has been guided by the rods, as demonstrated by the shorter distance beyond the anchors that the rods extend (blue arrow). Reproduced with permission of Children’s Orthopedic Center, Los Angeles, California.

TABLE 2 Summary of Treatment Types for EOS and Some of Their Advantages and Disadvantages

Treatment Pros Cons

Bracing May help delay need for surgery in very

young patients.

Standard thoracolumbosacral orthosis

brace cannot control curves with apex

above midthoracic spine (around T7).

Helpful for idiopathic EOS curves in

juvenile patients near adolescent age.

Brace wear compliance may be diffi cult.

Not much literature about bracing in EOS.

Casting Maximizes spinal growth before surgery. Some children may not tolerate full-time

body cast well.

Some idiopathic curves may resolve. Is not a defi nitive treatment in most cases.

Distraction Effective method to correct curve and

lengthen the spine before fi nal spinal

fusion.

Requires multiple periodic lengthening

surgeries (exception: magnetically

controlled rods).

Holds the most clinical experience and

literature in the surgical treatment of

EOS.

High complication rates (eg, implant failure,

infection).

Guided growth Initial apical fusion procedure guides

subsequent spinal growth.

Requires larger anatomy to allow

instrumentation of apex (avoid in very small

children).

No scheduled repeated lengthening

procedures.

Compression Fusionless procedure. Limited data for use in EOS.

Requires a thoracic approach (potentially

detrimental to pulmonary function).

Risk of overcorrection when used for young

children.

Reproduced with permission of Children’s Orthopedic Center, Los Angeles, California.


REFERENCES

1. Akbarnia BA, El-Hawary R. Letter

to the editor, early onset scoliosis:

time for consensus. Spine Deform.

2015;3(2):105–106

2. Skaggs DL, Guillaume T, El-Hawary

R, et al. Early onset scoliosis

consensus statement, SRS Growing

Spine Committee. Spine Deform.

2015;3(2):107

3. Williams BA, Matsumoto H, McCalla DJ,

et al. Development and initial validation

of the classifi cation of early-onset

scoliosis (C-EOS). J Bone Joint Surg

Am. 2014;96(16):1359–1367

4. Riseborough EJ, Wynne-Davies R. A

genetic survey of idiopathic scoliosis

in Boston, Massachusetts. J Bone Joint

Surg Am. 1973;55(5):974–982

5. Lloyd-Roberts GC, Pilcher MF.

Structural idiopathic scoliosis in

infancy: a study of the natural history

YANG et al

nearing adolescence, with less total

growth remaining. After achieving

maximal correction and growth with

growth-friendly spinal implants,

children can have their spine

definitively fused at a later age if

significant deformity remains.

FUTURE DIRECTIONS IN EARLY-ONSET SCOLIOSIS

The basic unanswered question is

how much early and late treatment

strategies for EOS maximize

respiratory function when children

reach maturity. This question

remains difficult to study because

it is unethical to have an untreated

natural history comparison group

in which the scoliosis is allowed to

progress relentlessly. Collaboration

between pediatric pulmonologists

and orthopaedists is essential to

standardize how pulmonary function

evaluations are being performed for

children who are not able to comply

with traditional PFTs.

A better understanding of the

3-dimensional natural growth of

the thorax and how it is affected by

surgical treatment in EOS is crucial.

Distraction-based implants help

decrease the scoliosis, although

how this result correlates with

improved pulmonary function has

not been established. Radiographic

measurements in the 2-dimensional

plane, such as Cobb angles, are

not reliable predictors of severity

of pulmonary disease. Three-

dimensional understanding and

functional imaging of the thorax

warrant additional study to improve

characterization of how the structure

of the thorax relates to function to

predict severity of pulmonary disease

in EOS.

EOS incorporates a multitude of

etiologies and associated diagnoses,

and greater subclassification can

help develop a framework for future

study. Each etiology carries different

implications, because congenital and

idiopathic EOS may behave much

differently with regard to the rate

of curve progression. Williams et

al3 developed a new classification

scheme in EOS that may help

establish the optimal treatment of

each subtype of EOS. Multicenter

groups such as the Growing Spine

Study Group and the Chest Wall

and Spine Deformity Study Group

have been developed to collaborate

in the study of this heterogeneous

population of children.

10

ABBREVIATIONS

EOS: early-onset scoliosis

FVC: forced vital capacity

MCGR: magnetically controlled

growing rod

PFT: pulmonary function test

TGR: traditional growing rod

TIS: thoracic insufficiency

syndrome

VEPTR: vertical expandable

prosthetic titanium rib

DOI: 10.1542/peds.2015-0709

Accepted for publication Jul 28, 2015

Address correspondence to David L. Skaggs, MD, MMM, Children’s Orthopaedic Center, Children’s Hospital Los Angeles, 4650 Sunset Blvd, MS#69, Los Angeles, CA

90027. E-mail: [email protected]

PEDIATRICS (ISSN Numbers: Print, 0031-4005; Online, 1098-4275).

Copyright © 2016 by the American Academy of Pediatrics

FINANCIAL DISCLOSURE: The authors have indicated they have no fi nancial relationships relevant to this article to disclose.

FUNDING: No external funding.

POTENTIAL CONFLICT OF INTEREST: Dr Andras owns stock in Eli Lily, receives publishing royalties from Orthobullets, and is a board or committee member of

the Pediatric Orthopaedic Society of North America and the Scoliosis Research Society. Dr Skaggs has received grants from the Pediatric Orthopaedic Society

of North America & Scoliosis Research Society, paid to Columbia University; has received consulting fees or honoraria from Biomet, Medtronic, Zipline Medical,

Inc, and Orthobullets; is a board member of the Growing Spine Study Group, Scoliosis Research Society, and Growing Spine Foundation; has received payment

for lectures including service on speakers’ bureaus from Biomet, Medtronic, and Johnson & Johnson; is a patent holder for Medtronic and Biomet; has

received royalties from Wolters Kluwer Health–Lippincott Williams & Wilkins and Biomet Spine; and has received payment for the development of educational

presentations from Stryker, Biomet, Medtronic, and Johnson & Johnson. Drs Yang and Redding have indicated they have no potential confl icts of interest to

disclose.


PEDIATRICS Volume 137 , number 1 , January 2016 11

of 100 patients. J Bone Joint Surg Br.

1965;47:520–523

6. Ceballos T, Ferrer-Torrelles M, Castillo

F, Fernandez-Paredes E. Prognosis in

infantile idiopathic scoliosis. J Bone

Joint Surg Am. 1980;62(6):863–875

7. Canavese F, Dimeglio A. Normal

and abnormal spine and thoracic

cage development. World J Orthop.

2013;4(4):167–174

8. Dimeglio A. Growth of the spine before

age 5 years. J Pediatr Orthop B.

1992;1(2):102–107

9. Dimeglio A, Canavese F. The growing

spine: how spinal deformities

infl uence normal spine and

thoracic cage growth. Eur Spine J.

2012;21(1):64–70

10. Dunnill MS. Postnatal growth of the

lung. Thorax. 1962;17(4):329–333

11. Herring MJ, Putney LF, Wyatt G,

Finkbeiner WE, Hyde DM. Growth of

alveoli during postnatal development

in humans based on stereological

estimation. Am J Physiol Lung Cell Mol

Physiol. 2014;307(4):L338–L344

12. Thurlbeck WM. Postnatal human

lung growth. Thorax. 1982;37(8):

564–571

13. Olson JC, Kurek KC, Mehta HP,

Warman ML, Snyder BD. Expansion

thoracoplasty affects lung growth

and morphology in a rabbit model:

a pilot study. Clin Orthop Relat Res.

2011;469(5):1375–1382

14. Davies G, Reid L. Effect of scoliosis

on growth of alveoli and pulmonary

arteries and on right ventricle. Arch

Dis Child. 1971;46(249):623–632

15. Redding GJ. Primary thoraco-spinal

disorders of childhood. Paediatr

Respir Rev. 2015;16(1):25–29. Available

at: www. sciencedirect. com/ science/

article/ pii/ S1526054214001341

16. Campbell RM Jr, Smith MD, Mayes TC,

et al. The characteristics of thoracic

insuffi ciency syndrome associated

with fused ribs and congenital

scoliosis. J Bone Joint Surg Am.

2003;85-A(3):399–408

17. Vitale MG, Matsumoto H, Roye DP Jr,

et al. Health-related quality of life in

children with thoracic insuffi ciency

syndrome. J Pediatr Orthop.

2008;28(2):239–243

18. Pehrsson K, Larsson S, Oden A,

Nachemson A. Long-term follow-up

of patients with untreated scoliosis.

A study of mortality, causes of

death, and symptoms. Spine.

1992;17(9):1091–1096

19. Moe JH, Kharrat K, Winter RB, Cummine

JL. Harrington instrumentation without

fusion plus external orthotic support

for the treatment of diffi cult curvature

problems in young children. Clin

Orthop Relat Res. May 1984;185:35–45

20. Goldberg CJ, Gillic I, Connaughton O, et

al. Respiratory function and cosmesis

at maturity in infantile-onset scoliosis.

Spine. 2003;28(20):2397–2406

21. Karol LA, Johnston C, Mladenov K,

Schochet P, Walters P, Browne RH.

Pulmonary function following early

thoracic fusion in non-neuromuscular

scoliosis. J Bone Joint Surg Am.

2008;90(6):1272–1281

22. Skaggs DL, Akbarnia BA, Flynn JM,

Myung KS, Sponseller PD, Vitale MG;

Chest Wall and Spine Deformity Study

Group; Growing Spine Study Group;

Pediatric Orthopaedic Society of North

America; Scoliosis Research Society

Growing Spine Study Committee.

A classifi cation of growth friendly

spine implants. J Pediatr Orthop.

2014;34(3):260–274

23. Smith JR, Samdani AF, Pahys J, et

al. The role of bracing, casting,

and vertical expandable prosthetic

titanium rib for the treatment of

infantile idiopathic scoliosis: a

single-institution experience with 31

consecutive patients. Clinical article. J

Neurosurg Spine. 2009;11(1):3–8

24. Thompson SK, Bentley G. Prognosis in

infantile idiopathic scoliosis. J Bone

Joint Surg Br. 1980;62-B(2):151–154

25. Mehta MH. Growth as a corrective

force in the early treatment of

progressive infantile scoliosis. J Bone

Joint Surg Br. 2005;87(9):1237–1247

26. Demirkiran HG, Bekmez S, Celilov

R, Ayvaz M, Dede O, Yazici M. Serial

derotational casting in congenital

scoliosis as a time-buying strategy. J

Pediatr Orthop. 2015;35(1)▪▪▪:43–49

27. Waldron SR, Poe-Kochert C, Son-Hing

JP, Thompson GH. Early onset scoliosis:

the value of serial Risser casts. J

Pediatr Orthop. 2013;33(8):775–780

28. Baulesh DM, Huh J, Judkins T, Garg

S, Miller NH, Erickson MA. The role

of serial casting in early-onset

scoliosis (EOS). J Pediatr Orthop.

2012;32(7):658–663

29. Akbarnia BA, Marks DS, Boachie-

Adjei O, Thompson AG, Asher MA.

Dual growing rod technique for

the treatment of progressive early-

onset scoliosis: a multicenter study.

Spine (Phila Pa 1976). 2005;30(17

suppl):S46–57

30. Akbarnia BA, Breakwell LM, Marks DS,

et al; Growing Spine Study Group. Dual

growing rod technique followed for

three to eleven years until fi nal fusion:

the effect of frequency of lengthening.

Spine. 2008;33(9):984–990

31. Schulz JF, Smith J, Cahill PJ, Fine A,

Samdani AF. The role of the vertical

expandable titanium rib in the

treatment of infantile idiopathic

scoliosis: early results from a

single institution. J Pediatr Orthop.

2010;30(7):659–663

32. Hasler CC, Mehrkens A, Hefti F. Effi cacy

and safety of VEPTR instrumentation

for progressive spine deformities in

young children without rib fusions. Eur

Spine J. 2010;19(3):400–408

33. Yamaguchi KT Jr, Skaggs DL, Mansour

S, et al. Are rib versus spine anchors

protective against breakage of

growing rods? Spine Deform.

2014;2(6):489–492

34. Dannawi Z, Altaf F, Harshavardhana NS,

El Sebaie H, Noordeen H. Early results

of a remotely-operated magnetic

growth rod in early-onset scoliosis.

Bone Joint J. 2013;95-B(1):75–80

35. Akbarnia BA, Cheung K, Noordeen H,

et al. Next generation of growth-

sparing techniques: preliminary

clinical results of a magnetically

controlled growing rod in 14 patients

with early-onset scoliosis. Spine.

2013;38(8):665–670

36. Hickey BA, Towriss C, Baxter G, et al.

Early experience of MAGEC magnetic

growing rods in the treatment of

early onset scoliosis. Eur Spine J.

2014;23(suppl 1):S61–S65

37. Akbarnia BA, Pawelek JB, Cheung KMC,

et al. Traditional growing rods versus

magnetically controlled growing

rods for the surgical treatment


YANG et al 12

of early-onset scoliosis: a case-

matched 2-year study. Spine Deform.

2014;2(6):493–497

38. Bess S, Akbarnia BA, Thompson GH,

et al. Complications of growing-rod

treatment for early-onset scoliosis:

analysis of one hundred and forty

patients. J Bone Joint Surg Am.

2010;92(15):2533–2543

39. Flynn JM, Tomlinson LA, Pawelek J,

Thompson GH, McCarthy R, Akbarnia

BA; Growing Spine Study Group.

Growing-rod graduates: lessons

learned from ninety-nine patients who

completed lengthening. J Bone Joint

Surg Am. 2013;95(19):1745–1750

40. Watanabe K, Uno K, Suzuki T, et

al. Risk factors for complications

associated with growing-rod surgery

for early-onset scoliosis. Spine.

2013;38(8):e464–e468

41. Kabirian N, Akbarnia BA, Pawelek JB, et

al Deep surgical site infection following

2344 growing-rod procedures for

early-onset scoliosis: Risk factors and

clinical consequences. J Bone Joint

Surg Am. 2014;96(15):e128

42. Matsumoto H, Williams BA, Corona J,

et al. Psychosocial effects of repetitive

surgeries in children with early-onset

scoliosis: are we putting them at risk?

J Pediatr Orthop. 2014;34(2):172–178

43. Sankar WN, Acevedo DC, Skaggs DL.

Comparison of complications among

growing spinal implants. Spine.

2010;35(23):2091–2096

44. Smith JT, Johnston C, Skaggs D, Flynn J,

Vitale M. A new classifi cation system to

report complications in growing spine

surgery: a multicenter consensus

study [published online ahead of print

January 8, 2015]. J Pediatr Orthop.

10.1097/BPO.0000000000000386

45. Sankar WN, Skaggs DL, Yazici M, et al.

Lengthening of dual growing rods and

the law of diminishing returns. Spine.

2011;36(10):806–809

46. Noordeen HM, Shah SA, Elsebaie

HB, Garrido E, Farooq N, Al-Mukhtar

M. In vivo distraction force and

length measurements of growing

rods: which factors infl uence the

ability to lengthen? [published

correction appears in Spine (Phila

Pa 1976). 2012;37(5):432]. Spine.

2011;36(26):2299–2303

47. Cahill PJ, Marvil S, Cuddihy L, et al.

Autofusion in the immature spine

treated with growing rods. Spine.

2010;35(22):e1199–e1203

48. Loepke AW, Soriano SG. An assessment

of the effects of general anesthetics

on developing brain structure and

neurocognitive function. Anesth Analg.

2008;106(6):1681–1707

49. Lee JH, Zhang J, Wei L, Yu SP.

Neurodevelopmental implications of

the general anesthesia in neonate

and infants [published online ahead

of print April 8, 2015]. Exp Neurol.

10.1016/j.expneurol.2015.03.028

50. McCann ME, Soriano SG. General

anesthetics in pediatric anesthesia:

infl uences on the developing brain.

Curr Drug Targets. 2012;13(7):944–951

51. Andras LM, Joiner ER, McCarthy

RE, et al. Growing rods vs. Shilla

growth guidance: better Cobb angle

correction and T1–S1 length increase

but more surgeries. Spine Deform.

2015;3(3):246–252

52. Betz RR, Ranade A, Samdani AF, et al.

Vertebral body stapling: a fusionless

treatment option for a growing child

with moderate idiopathic scoliosis.

Spine. 2010;35(2):169–176

53. Crawford CH III, Lenke LG. Growth

modulation by means of anterior

tethering resulting in progressive

correction of juvenile idiopathic

scoliosis: a case report. J Bone Joint

Surg Am. 2010;92(1):202–209

54. Lonner BS, Auerbach JD, Estreicher

MB, et al. Pulmonary function changes

after various anterior approaches in

the treatment of adolescent idiopathic

scoliosis. J Spinal Disord Tech.

2009;22(8):551–558

55. Motoyama EK, Deeney VF, Fine GF,

et al. Effects on lung function of

multiple expansion thoracoplasty in

children with thoracic insuffi ciency

syndrome: a longitudinal study. Spine.

2006;31(3):284–290

56. Mayer OH, Redding G. Early changes

in pulmonary function after vertical

expandable prosthetic titanium rib

insertion in children with thoracic

insuffi ciency syndrome. J Pediatr

Orthop. 2009;29(1):35–38

57. Dede O, Motoyama EK, Yang CI, et al

Pulmonary and radiographic outcomes

of VEPTR (vertical expandable

prosthetic titanium rib) treatment in

early-onset scoliosis. J Bone Joint Surg

Am. 2014;96(15):1295–1302

58. Skaggs DL, Sankar WN, Albrektson

J, Wren TA, Campbell RM. Weight

gain following vertical expandable

prosthetic titanium ribs surgery

in children with thoracic

insuffi ciency syndrome. Spine.

2009;34(23):2530–2533

59. Myung KS, Skaggs DL, Thompson GH,

Emans JB, Akbarnia BA; Growing

Spine Study Group. Nutritional

improvement following growing

rod surgery in children with early

onset scoliosis. J Child Orthop.

2014;8(3):251–256

60. Striegl A, Chen ML, Kifl e Y, Song K,

Redding G. Sleep-disordered breathing

in children with thoracic insuffi ciency

syndrome. Pediatr Pulmonol.

2010;45(5):469–474

61. Redding GJ, Mayer OH. Structure-

respiration function relationships

before and after surgical treatment of

early-onset scoliosis. Clin Orthop Relat

Res. 2011;469(5):1330–1334

62. Glotzbecker M, Johnston C, Miller P,

et al. Is there a relationship between

thoracic dimensions and pulmonary

function in early-onset scoliosis?

Spine. 2014;39(19):1590–1595

63. Corona J, Miller DJ, Downs J, et

al. Evaluating the extent of clinical

uncertainty among treatment options

for patients with early-onset scoliosis.

J Bone Joint Surg Am. 2013;95(10):e67


DOI: 10.1542/peds.2015-0709 originally published online December 7, 2015; 2016;137;Pediatrics

Scott Yang, Lindsay M Andras, Gregory J Redding and David L SkaggsDirections

Early-Onset Scoliosis: A Review of History, Current Treatment, and Future

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