Orthopaedic Surgery - Spina Bifida

Basics

Spina bifida is a congenital condition caused by:

Incomplete closure of the posterior elements of the spine.

It is present at birth but may not be recognized until:

Later in life.

The defect may occur at:

Any spinal level

or at multiple levels, although it most commonly affects the:

Caudal spine.

When associated with a neurologic deficit, spina bifida may lead to secondary problems involving the:

Genitourinary system

and

Lower extremities.

Spina Bifida Occulta

Spina bifida occulta is a small, skin-covered defect involving the posterior arch, most often at:

L5

or

S1.

It is generally a:

Benign incidental finding

without neurologic consequences.

Patients may have a slightly increased risk of:

Spondylolisthesis.

Myelomeningocele

Myelomeningocele consists of:

Multiple absent laminae

with exposed:

Meninges

and usually abnormal neural tissue.

A neurologic deficit is commonly present at the level of the defect.

Patients have a high risk of:

Hydrocephalus

and associated:

Chiari malformation.

Lipomeningocele

A lipomeningocele is a:

Fat-containing mass

arising from the caudal spinal canal and palpable beneath the skin.

It is associated with:

Neurologic dysfunction

but generally carries no substantial risk of:

Hydrocephalus.

Motor-Level Classification

All patients with spina bifida should be classified according to their:

Motor level.

The motor level is defined as the lowest spinal level with:

Antigravity muscle strength.

The motor level should be recorded separately for:

Each limb.

Synonyms

Other terms include:

Spinal dysraphism

Neural tube defect

and

Myelomeningocele.

Prevention

Periconceptional folate supplementation may reduce the risk of:

Neural tube defects.

A commonly recommended dose is:

0.4 mg of folic acid daily

during the early months of pregnancy, particularly before conception and during the first trimester.

Epidemiology

Spina bifida affects:

Males and females equally.

Incidence

Spina bifida occulta is found in approximately:

2–3% of the general population.

The overall incidence of neural tube defects in the United States is approximately:

1 per 1,000 births.

Rates vary considerably among:

Countries and geographic regions.

The risk is increased when a:

First-degree relative

has been affected.

Prevalence

The prevalence is reported to be:

Slightly higher in White populations

and

Lower in African American populations

than in the general population.

The frequency varies substantially between:

Different countries.

Risk Factors

Recognized risk factors include:

An affected first-degree relative

and

Poor maternal or perinatal nutrition.

Genetics

Spina bifida is not inherited in a simple:

Mendelian pattern.

It is thought to follow a:

Polygenic and multifactorial pattern.

No single causative genetic abnormality has been identified in most cases.

Etiology

The underlying mechanism is failure of:

Neural tube closure

or later:

Rupture of the neural tube.

The precise cause of this failure remains:

Unknown.

Associated Conditions

Spina bifida may be associated with:

Hydrocephalus

Chiari malformation

Syringomyelia

Kyphosis

Scoliosis

Renal dysfunction

Latex allergy

Sprengel deformity

and increased risk of:

Pathologic fracture.

Diagnosis

Diagnosis is based on:

Physical examination

Neurologic assessment

and appropriate:

Prenatal or postnatal imaging.

Signs and Symptoms

Local findings depend on the type of defect.

The skin overlying the lesion may show:

A small dimple

Hair growth

Vascular markings

or other abnormal pigmentation.

Lipomeningocele

A lipomeningocele may appear as a:

Subcutaneous fatty mass.

Myelomeningocele

A myelomeningocele may present with:

Exposed meninges

and neural tissue at birth.

Spina Bifida Occulta

Spina bifida occulta usually has:

No visible physical abnormality.

Neurologic Findings

General neurologic findings may include:

Motor weakness

Calf or thigh atrophy

and a corresponding:

Sensory deficit.

Bladder Dysfunction

A:

Neurogenic bladder

is common in patients with clinically significant spina bifida.

This may lead to:

Recurrent urinary tract infections

Urinary incontinence

or progressive:

Renal damage.

Symptoms

Spina bifida itself is often:

Asymptomatic.

Back pain is not usually caused directly by the bony defect.

However, patients may develop pain or neurologic deterioration from associated:

Tethered cord

or

Spondylolisthesis.

Physical Examination

The examination should include assessment of:

Spinal alignment

Skin coverage

Motor function

Sensation

Joint motion

Contractures

Gait

and signs of associated:

Hydrocephalus or Chiari malformation.

Spinal Deformity

Evaluate for:

Scoliosis

and

Kyphosis.

These deformities may progress during growth and can interfere with:

Sitting balance

or

Mobility.

Skin Examination

The quality of the skin covering the defect is important because poor skin coverage increases the risk of later:

Skin breakdown

and

Ulceration.

Motor Examination

Record the strength of the major muscle groups.

The motor level is the lowest level demonstrating:

Contraction against resistance.

This baseline should be documented for future comparison.

Sensory Examination

Record the lowest level of preserved sensation.

The sensory level helps predict the risk of:

Pressure sores

in areas of insensate skin.

Joint Examination

Assess each joint for:

Contractures

Dislocations

Deformities

and limitations in:

Range of motion.

Gait

If the patient is ambulatory, observe:

Gait pattern

Balance

Bracing requirements

and the efficiency of:

Walking.

Hydrocephalus and Chiari Malformation

Look for clinical signs of:

Hydrocephalus

or

Chiari malformation.

These may include:

Head enlargement

Headache

Vomiting

Abnormal eye movements

Swallowing difficulty

or other:

Brainstem symptoms.

Laboratory and Prenatal Testing

For pregnancies at increased risk, prenatal evaluation may include:

Amniocentesis

with measurement of:

Alpha-fetoprotein

and

Acetylcholinesterase.

Prenatal Ultrasound

Prenatal ultrasonography can detect many neural tube defects and may identify associated:

Cranial

Spinal

and

Limb abnormalities.

Imaging

Plain Radiographs

Baseline spinal radiographs are often obtained early in infancy to identify associated congenital abnormalities such as:

Hemivertebrae

and

Congenital vertebral fusion.

These abnormalities may occur in up to:

20% of children with true spina bifida.

Pelvic Radiographs

A baseline:

Anteroposterior pelvis radiograph

may be obtained to evaluate:

Hip development

and identify associated:

Subluxation or dislocation.

MRI

MRI of the:

Neuraxis

is obtained when needed to evaluate for:

Syringomyelia

Chiari malformation

Tethered spinal cord

or other spinal cord abnormalities.

Pathological Findings

A typical myelomeningocele may contain a:

Flattened spinal cord

with:

Scarring

and

Abnormally developed neural tissue.

Hydrocephalus and Chiari Malformation

Associated findings may include:

Hydrocephalus

and

Chiari malformation

with herniation of the:

Cerebellar tonsils

through the:

Foramen magnum.

Differential Diagnosis

The differential diagnosis includes:

A defect from previous laminectomy

and

Delayed ossification of an otherwise intact posterior arch.

Treatment

Management should be:

Multidisciplinary

and individualized according to:

Motor level

Sensory function

Spinal deformity

Bladder function

Ambulatory potential

and associated:

Neurologic abnormalities.

General Measures

An experienced:

Neurologist

Neurosurgeon

Orthopaedic surgeon

and

Urologist

should evaluate the child early, ideally:

At birth.

Latex Avoidance

Patients with spina bifida should avoid:

Latex exposure

because latex allergy is common and may become severe.

Genetic Counseling

Families should be offered:

Genetic counseling

regarding recurrence risk and preventive:

Folate supplementation.

Urinary Tract Infection Prevention

Patients with recurrent urinary tract infections may require:

Long-term, low-dose prophylactic antibiotics

under the supervision of a:

Urologist.

Bladder management should be individualized and may include:

Clean intermittent catheterization.

Neurologic Monitoring

Motor strength and sensory levels should be documented throughout life to detect:

Tethered cord

or other progressive neurologic complications.

Foot Deformities

Clubfoot should initially be treated with:

Serial casting

using a method such as:

Ponseti treatment.

Other Deformities

Additional deformities may be managed with:

Stretching

Bracing

or

Surgery

depending on severity and functional impact.

Skin Protection

Families and patients should be taught to protect areas of:

Insensate skin

from:

Pressure

Heat

Friction

and

Trauma.

Daily skin inspection is important.

Support Services

Families should be connected with appropriate support organizations, such as:

The Spina Bifida Association

and other community-based resources.

Hip Subluxation

Most cases of hip subluxation do not require surgery, particularly when the condition is:

High

Bilateral

and present in a:

Nonambulatory patient.

Treatment should focus on:

Comfort

Positioning

and

Function.

Activity

Patients should be encouraged to maximize activity using the most efficient and safe method, including:

Wheelchair mobility

or

Walking with braces.

Adaptive Sports

Wheelchair sports and other adaptive activities should be offered to interested patients.

These activities can improve:

Physical fitness

Social development

and

Self-image.

Physical Therapy

Patients should receive ongoing physical therapy throughout growth to:

Maximize mobility

Monitor muscle strength

Maintain joint motion

and

Optimize the use of braces and wheelchairs.

Weight Management

A physical therapist and nutritionist may help prevent:

Excessive weight gain

which can impair:

Mobility

and increase the difficulty of transfers and self-care.

Surgery

Clubfoot Surgery

Casting is the initial treatment for clubfoot.

If residual deformity persists, surgery may be required to:

Lengthen contracted tendons

and

Realign the bones

to create a plantigrade foot that can rest:

Flat on the ground.

Other Lower-Extremity Surgery

Additional foot or leg procedures may be performed when necessary to improve:

Alignment

Brace tolerance

Standing

or

Walking.

Spine Surgery

Spinal surgery may be indicated for progressive:

Scoliosis

or

Kyphosis

that causes:

Unbalanced sitting

or significant functional impairment.

Treatment may involve:

Spinal correction and fusion

with implanted:

Growing rods

or other spinal instrumentation.

Fetal Surgery

Prenatal repair of the neural tube defect may reduce the later risk of:

Hydrocephalus

and possibly decrease the need for shunt placement.

However, fetal surgery increases the risk of:

Premature birth

and requires careful maternal-fetal evaluation.

Prognosis

With modern neonatal and multidisciplinary care, infant mortality is only:

Slightly higher than in the general population.

The prognosis is worse in patients with severe:

Spina bifida cystica

and extensive:

Central nervous system involvement.

Functional Independence

Some patients may not achieve long-term independence because of:

Neurologic impairment

Hydrocephalus

Cognitive complications

Bladder dysfunction

or severe:

Lower-extremity weakness.

Complications

Potential complications include:

Shunt failure

Tethered cord

Progressive weakness

Syringomyelia

Chiari-related symptoms

Pressure sores

Fractures

and

Renal failure.

Shunt Failure

Patients with hydrocephalus may develop:

Ventriculoperitoneal shunt failure.

This can cause:

Headache

Vomiting

Altered mental status

or new:

Neurologic deterioration.

Tethered Cord

The spinal cord may become tethered at the site of the original defect.

As the child grows, tethering may cause progressive:

Weakness

Sensory loss

Pain

or worsening:

Bladder dysfunction.

Fracture

The risk of fracture is increased in patients with a more severe:

Neurologic deficit.

Fractures may occur with minimal trauma because of:

Insensate limbs

Muscle imbalance

Osteopenia

and impaired protective responses.

Fracture Presentation

Signs of fracture may be subtle and include:

Low-grade fever

Swelling

Warmth

and little or no:

Pain.

Radiographs may show:

Exuberant callus formation.

Pressure Sores

Pressure sores may develop over:

The ischium

The foot

or

The greater trochanter.

They are especially likely in areas of:

Insensate skin.

Renal Failure

Poor bladder care and recurrent urinary tract infections may eventually lead to:

Renal impairment

or

Renal failure.

Patient Monitoring

Patients with myelomeningocele should generally be followed every:

6–12 months.

Follow-up is intended to:

Identify new problems

Monitor neurologic function

Assess spinal alignment

and

Check the fit of braces and equipment.

Neurologic Deterioration

New neurologic deficits may result from:

Shunt failure

Syringomyelia

Tethered cord

or

Chiari malformation.

Any new weakness, sensory change, pain, gait deterioration, or bladder dysfunction requires prompt evaluation.

Equipment Monitoring

Regular assessment should ensure that:

Wheelchairs

Braces

Standing devices

and other adaptive equipment remain properly fitted and functional.

Key Principle

Spina bifida is a congenital neural tube defect caused by incomplete closure of the posterior spinal elements. Its clinical severity ranges from asymptomatic spina bifida occulta to myelomeningocele with major neurologic, bladder, and lower-extremity dysfunction.

Patients should be classified by their:

Motor level

and monitored for:

Tethered cord

Hydrocephalus

Chiari malformation

Syringomyelia

Spinal deformity

Pressure sores

and

Renal complications.

Successful care requires coordinated management by:

Neurology

Neurosurgery

Orthopaedics

Urology

Physical therapy

and

Rehabilitation services.

The goals are to preserve:

Neurologic function

Skin integrity

Bladder and renal health

Mobility

and

Long-term independence.