Congenital Spinal Deformity

Harminder S Gosal

Embryology

• Developmental defect in formation of

mesenchymal structures during 4th to 6th

weeks of gestation

Epidemiology

• Incidence - 1:1000 for congenital vertebral

anomalies- Wynne-Davies 1975

• Solitary anomaly - non-familial

• Multiple anomalies - famial, related to

anencephaly & spina bifida cystica, 5-10%

risk to siblings

• ? Incidence of congenital spinal deformity

• 13/1250- affected relatives - Winter 1983

Classification

• Type

• Location

• Direction

• Extent

• Magnitude of deformity

• Anatomic malformation

Classification by Type

• Scoliosis

• Kyphosis

• Lordosis

Scoliosis

• Lateral deviation of the spine

• Structural - lateral curve with rotation

• Non-structural - 2º to other factors, e.g. Leg

length inequality

Kyphosis

• Posterior angulation of the spine

• Normal [thoracic spine]

• Abnormal kyphosis = kyphos

• Kyphos - rounded or angular

• Angular kyphos = gibbus

• Kyphosis in cervical, thoracolumbar, or

lumbar spine is always abnormal

Kyphosis

• Normal range - 15º to 49º in midthoracic

region

• Thoracic hypokyphosis - 1º to 14º in

midthoracic region

• Hyperkyphosis - thoracic kyphosis >50º

Winter 1983

Lordosis

• Anteriorly directed curve in cervical and

lumbar spine

• ? Normal range

• Winter - abnormal if 60º or more

Classification by Location

• Location of a curve identified by its apex

regardless of where the ends of the curve lie

Curve Location

• Occipitocervical-Apex at C1 or the occiput & C1

junction

• Cervical- Apex from C2 to C6

• Cervicothoracic- Apex at C7, T1, or C7-T1

interspace

• Thoracic- Apex between T2 & T11

• Thoracolumbar- Apex at T12, L1, or T12-L1

interspace

• Lumbar- Apex between L2 & L4

• Lumbosacral- Apex at L5, S1, or L5-S1 interspace

Classification by Direction

• All scolioses are classified as to whether the

apex is directed to the right of left

Classification by Extent

• All curvatures are classified by the end

vertebrae e.g. T5 to T12

Classification by Magnitude

• Cobb-Lippman angle

Classification by Anatomic

Malformation

• 3 types

• Defects of segmentation

• Defects of formation

• Mixed

Defects of Segmentation

• Anterior

• Posterior

• Lateral

• Posterolateral

• Anterolateral

• Total

Anterior Failure of Segmentation

• Anterior unsegmented

bar

• Leads to kyphosis

Posterior Failure of Segmentation

• Usually involves both

laminae & facet joints

• ‘Laminar Synostosis’

• Lordosis

Lateral Failure of Segmentation

• Unilateral Unsegmented

Bar

• Produces a Scoliosis

which may be severe

Posterolateral Failure of

Segmentation

• In facet joints and adjacent laminae

• Continued growth anteriorly and on

opposite side

• Lordoscoliosis

Anterolateral Failure of

Segmentation

• Very rare

• Kyphoscoliosis

Total Failure of Segmentation

• ‘Block Vertebra’

• Shortened Spine

Defects of Formation

• Anterior

• Posterior

• Lateral

• Anterolateral

• Anterior central

Anterior Failure of Formation

• Minimal failure of one

vertebra to absence of

several adjacent

vertebrae

• Kyphosis produced

tends to be angular

Posterior Failure of Formation

• Extremely rare

• Results in Lordosis

Lateral Failure of Formation

• Hemivertebra

• Common

• Mild Wedging

• Total Absence except

a pedicle & a facet

joint

• Multiple,adjacent or

scattered

Incarcerated Hemivertebra

• Vertebrae above &

below compensate

• No spinal distortion

• Pedicle line intact

Nonincarcerated Hemivertebra

• Pedicle line disturbed

• Distorted vertebral

column

Segmented Hemivertebra

• Normal disc space

above & below

Unsegmented Hemivertebra

• Defect of segmentation

both above & below

Anterolateral Defect of

Formation

• ‘Corner’ vertebra

• Angular Kyphoscoliosis

Anterior Central Defect of

Formation

• Midline defect of

fusion

• ‘Butterfly’ vertebra

• Associated with

Kyphosis

Mixed Failures

• Defects of segmentation + formation

• Unilateral unsegmented bar with

hemivertebrae

• Nonsegmented Hemivertebrae

Unilateral Unsegmented Bar with

Hemivertebrae

• Rapidly progressive

deformity

Nonsegmented Hemivertebrae

• Little/slow

progression of

deformity

Patient Evaluation-History

• Appearance of curve/progression/symptoms

• Family history/pregnancy/diabetes

• Other systems/GU/CVS/GIT/CNS

• Growth/Gait

Patient Evaluation-Examination

• Asymmetry- head tilt/ shoulders/ribs/pelvic

obliquity

• Pattern of deformity

• Stiffness

• Respiratory/Cardiac-Murmurs

• Development

• Neurological

Patient Evaluation-Radiology

• AP/lateral/Oblique-Standing/Sitting

• Standing films in new walkers may be

misleading

• Serial for comparison

• CT/MRI-Spinal Dysraphism[40%]

• IVP/Renal US - 20-30% GU anomalies

• Cobb-Lippman angle

Natural History of Congenital

Spinal Deformity

• 25% Nonprogressive

• 25% Mild progression

• 50% Significant progression

• Depends on defect

Natural History of Congenital

Spinal Deformity

• Females do worse

• Most curve progression in adolescence

• Kyphosis[paraparesis]>Lordosis>Scoliosis

• Thoracic Scoliosis more severe progression

• ‘Free’ hemivertebrae>semisegmented

• Unilateral unsegmented bars always

progress

Natural History-Defects of

Segmentation

• Unilateral unsegmented bar - ‘malignantly’

progressive - 50º at birth & 100º at 10yrs,

die of cor pulmonale at 25-30yrs

• Longer bar- worse prognosis

• Most common in thoracic spine

Natural History-Defects of

Formation

• Nonincarcerated

hemivertebra- worst

growth potential

Management of Congenital

Spinal Deformity

• Evaluate patient

• Monitor for progress of deformity

• Prompt action when progress observed

• Nonoperative - Bracing

• Operative - Spinal fusion

Treatment Goal

• Stop progression of the congenital spinal

deformity

• Before corrective surgery is needed

Nonoperative Treatment

• Exercise/physiotherapy - No effect on curvature

• Serial casts for a small child

• Brace - Milwaukee - Limited but definite role

• In longer, more flexible primary & secondary

curves

• Short rigid curves do not respond to bracing

Bracing in Congenital Spinal

Deformity

• Congenital Kyphosis & Lordosis do not

respond

• Congenital Scoliosis - May benefit long

flexible curves

• Discontinue if not controlling progression

of curve

Operative Treatment

• Spinal fusion is the mainstay of treatment

• Four main operative procedures :

1. Posterior fusion

2. Combined anterior and posterior fusion

3. Epiphysiodesis [convex growth arrest]

4. Hemivertebra excision

Congenital Spinal Deformity

• Scoliosis

• Kyphosis

• Lordosis

• [Lordoscoliosis, Kyphoscoliosis]

• Spinal Dysraphism

• Cervical spine deformity

• Associated Anomalies & Syndromes

Congenital Scoliosis

• Defect of Segmentation

• Defect of Formation

• Combined defects commonest

• Any area of spine

• Most common congenital spinal deformity

Congenital Scoliosis-Natural

History

• 25% Nonprogressive

• 25% Slowly progressive

• 50% Very progressive

• Type of anomaly

• Rate of growth of patient

Congenital Scoliosis - Treatment

• Brace - Long, flexible curves

• Posterior fusion for most progressive curves

• In girls<10yrs, boys<12yrs, ‘crankshaft’

phenomenon may occur because of

continued anterior spinal growth

• In these cases ant/post fusion may be

required

Unilateral Unsegmented Bar with

a Contralateral Hemivertebra

• Most progressive

[rapid & relentless]

scoliosis

• 10º to 20º per year

• Posterior fusion [add

anterior fusion for

girls<10, boys<12]

Unilateral Unsegmented Bar

• 2nd most progressive

[rapid] scoliosis

• Posterior fusion [add

anterior fusion for

girls<10, boys<12]

Fully Segmented Hemivertebra

• Steadily progressive

scoliosis

• Anterior fusion

• Ant/post convex

hemiepiphysiodesis

[age<5, curve<70, no

kyphosis]

• Hemivertebra excision

Semisegmented Hemivertebra

• Less rapid progression

of scoliosis

• Curve usually<40° at

maturity

• Observe

• Hemivertebra excision

Incarcerated hemivertebra

• May progress slowly

• Observe

Nonsegmented Hemivertebra

• Little progression of

scoliosis

• Observe

Congenital Kyphosis

• More common than lordosis, but less than

congenital scoliosis

• Defects of formation [Type1] most common

& worst prognosis

• Defects of segmentation [Type2] -

midthoracic or thoracolumbar regions

• Treatment is surgical

Type 1 - Congenital Kyphosis

• 1 or multiple level formation

defects

• 95% progress

• Paraplegia - Growth spurt

• Posterior fusion [<5yrs,<50°]

• Ant/Post fusion [older child,

more severe curve]-2 stage

Type 2 - Congenital Kyphosis

• Midthoracic/Thoracolumbar

• Slow progression / Round kyphosis

• Paraplegia - rare

• Low-back pain due to 2º lumbar

hyperlordosis

• Observe

• Posterior fusion-prevent progression

• Ant/Post fusion-correct deformity

Congenital Lordosis

• Defect of segmentation posteriorly in

presence of anterior growth

• Most patients have some degree of scoliosis

• Usually progressive

• In thoracic spine - respiratory compromise

• Early death can result

Treatment of congenital Lordosis

• Purely surgical

• Anterior fusion to prevent progression

• Ant/Post fusion for correction of

deformity

Timing of Surgery in Congenital

Spinal deformity

• Aim of treatment is to stop progression of

deformity

• Never postpone fusion until end of growth

• Early fusion - child will be taller &

straighter than if curve allowed to progress

• If curve progression detected - Take action!

Dysraphism

• Failure of two halves of an organism to fuse

• Abnormal midline structure in the neural

axis

• e.g. Myelomeningocoele

Spinal Dysraphism

• Faulty development in the midline of the

dorsal aspect of the embryo

• Resulting in bony and neural abnormalities

• Ranging from lethal rachischisis to

asymptomatic spina bifida occulta

• 10% of patients with congenital spinal

deformity have spinal dysraphism

Spinal Dysraphism

• Myelomeningocoele

• Meningocoele

• Diastematomyelia

• Tight filum terminale

• Fibrous Bands

• Intra- and extradural lipomas,

• Dermoids etc

Myelomeningocoele

• Spina bifida + protrusion of the dural sac

with neural elements

• In one study 20% patients also had

congenital scoliosis

• Bilateral lower limb paralysis

• Absence of sphincter control

• Anterolateral epiphysiodesis

• Diastematomyelia associated

Diastematomyelia

• Splitting of the spinal cord with a bony,

cartilagenous, or a fibrous band

• 5% patients with spine deformity

• Abnormal skin - a hair patch, a dimple, a

sinus, a naevus

• Lower limb atrophy, shortening, muscle

weakness, sensory deficit, a short/club foot

• Multiple spurs can occur

Cervical Spine Deformity

• Lateral defects - torticollis

• Defects of segmentation - Klippel-Feil

Syndrome[1912]

• Hemivertebra - Congenital scoliosis of

cervical spine - treat like other congenital

scoliosis - brace/posterior fusion

• Unsegmented bars rare

Klippel-Feil Syndrome

• Failure of segmentation of 2 or more

cervical vertebrae

• Neck Shortening/Neck webbing

• Loss of neck motion

• Low-set hairline

• May also have angular deformity

• Sprengel’s deformity

Anomalies associated with

Congenital spinal deformity

• GU malformations- 25%

• Cardiac [defects]- 10%

• VATER - V -vertebral, A -anal, T -tracheal,

E -oesophageal, R -renal

• Malformation of ears/hearing deficit

• Rib malformations /Tracheoesophageal

fistula

• Sprengel’s deformity/Club feet

Congenital Spinal Deformity

• Defects of Segmentation/Formation/Mixed

• 3 major deformities - Scoliosis, Kyphosis,

Lordosis

• Aim to prevent progression of deformity

• Mainstay of treatment is surgery