Orthopaedic Surgery - Cerebral Palsy

Basics

Cerebral palsy is an umbrella term describing a broad group of permanent disorders of movement and posture caused by a static injury or abnormality of the developing central nervous system.

Although the underlying neurologic lesion itself is nonprogressive, its clinical consequences can change considerably as the child grows.

Muscle imbalance, contracture, skeletal deformity, altered gait, and functional limitations may therefore become more or less apparent over time even though the cerebral injury remains unchanged.

Classification

Cerebral palsy can be classified according to both the anatomic distribution of involvement and the physiologic pattern of motor abnormality.

A complete description should ideally include both components.

Anatomic Classification

Monoplegia affects one limb.

Hemiplegia involves the arm and leg on the same side of the body.

Diplegia predominantly affects both lower extremities.

Triplegia involves three extremities.

Quadriplegia involves all four extremities, with relatively preserved head control.

The term totally involved cerebral palsy is used for extensive involvement of all extremities accompanied by poor head and trunk control.

Physiologic Classification

The major physiologic patterns include spastic, athetoid, dystonic, and mixed cerebral palsy.

Spasticity is the most common motor abnormality.

Some patients demonstrate more than one movement pattern and are therefore classified as having mixed cerebral palsy.

Gross Motor Function Classification

The Gross Motor Function Classification System (GMFCS) is frequently used to describe functional mobility.

It assists with prognosis, communication among clinicians, and decision-making regarding operative and nonoperative treatment.

Functional classification is particularly useful because children with the same anatomic distribution of cerebral palsy may have very different levels of independence.

Epidemiology

Cerebral palsy affects approximately 2 per 1,000 live births.

Despite advances in obstetric and neonatal care, the overall prevalence has not shown a major decline.

Risk Factors

Important risk factors include prematurity, difficult delivery, multiple gestation, and postnatal injury to the central nervous system.

Several prenatal, perinatal, and postnatal events can ultimately produce the static cerebral lesion responsible for cerebral palsy.

Pathophysiology

Cerebral palsy produces predominantly upper motor neuron findings.

Peripheral nerves are generally anatomically normal.

The exact regions of the brain affected depend on the underlying cause and timing of the insult.

Muscle Changes

Although the primary lesion is neurologic, muscles in affected limbs can undergo secondary structural changes.

These include varying degrees of fibrosis, reduced muscle growth, shortening, and loss of normal excursion.

Such changes contribute to fixed contractures and progressive orthopaedic deformity.

Muscle biopsy is not routinely required.

Etiology

Potential causes include prenatal brain dysplasia, maternal infection, fetal hypoxia, vascular events, encephalitis, meningitis, trauma, and kernicterus.

In many patients, the precise causal event cannot be identified.

Associated Conditions

Cerebral palsy may coexist with a number of neurologic, developmental, and systemic conditions.

These include learning difficulties, behavioral disorders, abnormalities of sensory processing, visual impairment, hearing loss, seizures, and osteoporosis.

Respiratory and Gastrointestinal Disease

Children with severe cerebral palsy may also develop chronic respiratory and gastrointestinal problems.

Swallowing dysfunction, aspiration, gastroesophageal reflux, impaired cough, reduced mobility, and poor nutrition can contribute to these complications.

Diagnosis

Signs and Symptoms

One common early pattern is initial hypotonia followed later by increasing spasticity.

Developmental motor milestones may be delayed, and abnormal gait may become evident as walking begins.

Asymmetry of posture, limb use, strength, or gait may also be present.

Reflex Abnormalities

Deep tendon reflexes are often increased after the first year of life.

Clonus may develop in involved muscle groups.

Persistent primitive reflexes beyond the expected developmental period may also be observed.

Contractures

As children grow, contractures commonly develop in muscle groups exposed to persistent spasticity and reduced excursion.

The Achilles tendon, hamstrings, and hip adductors are especially prone to shortening.

Physical Examination

The examination should assess the child globally rather than focusing on a single joint or extremity.

Neurologic findings, muscle tone, mobility, joint motion, skeletal alignment, function, and independence in activities of daily living should all be considered.

Upper-Extremity Examination

The upper extremities should be examined for deformity, motor function, sensation, selective control, and practical use of the hands.

The ability to integrate sensation with motor function is especially important when considering reconstructive procedures.

Spine Examination

The spine should be examined for scoliosis, pelvic obliquity, and signs of spinal dysraphism.

Progressive spinal deformity is especially common in children with severe motor impairment.

Limb-Length Assessment

Limb lengths should be measured and compared.

Asymmetric growth may occur, especially in hemiplegic cerebral palsy.

Leg-length discrepancy can influence gait and pelvic alignment.

Joint Contractures

Range of motion should be measured systematically at all major joints.

Important measurements include ankle dorsiflexion, popliteal angle, and hip abduction.

These measurements help distinguish dynamic spasticity from established contracture.

Muscle Excursion

Muscle length and excursion should be documented.

Particular attention should be paid to the gastrocnemius-soleus complex, hamstrings, hip adductors, hip flexors, and rectus femoris.

Loss of excursion may indicate developing fixed deformity.

Dynamic Versus Fixed Deformity

The examiner should distinguish between dynamic spasticity, fixed soft-tissue contracture, bony torsional deformity, and joint instability.

This distinction is essential because each problem requires a different treatment strategy.

Gait Analysis

Instrumented and video gait analysis can provide detailed information about abnormal walking patterns.

It is particularly useful in ambulatory children with complex gait abnormalities.

Role of Instrumented Gait Analysis

Three-dimensional gait analysis may assist with planning single-event multilevel surgery (SEMLS).

It can identify the contribution of individual joints and muscle groups to the gait abnormality and can also help assess postoperative outcomes.

Imaging

Brain MRI

Most children clinically suspected of having cerebral palsy demonstrate abnormalities on brain imaging.

MRI is useful for identifying evidence of prior cerebral injury, malformation, hypoxic-ischemic damage, or other structural abnormalities.

However, a minority of children who meet clinical criteria for cerebral palsy may have a normal MRI.

Cervical Spine Imaging

Cervical spine radiographs may be indicated in selected patients with severe athetoid or dystonic movements.

Repeated involuntary neck motion can predispose some patients to cervical degeneration or instability.

Hip Radiographs

Routine surveillance radiographs of the hips are important in children with severe diplegia, quadriplegia, or total-body involvement.

These patients are at increased risk of progressive hip subluxation and dislocation.

Scoliosis Imaging

When clinical spinal deformity is present, standing or sitting scoliosis radiographs should be obtained as appropriate.

Children with severe motor impairment are particularly susceptible to progressive spinal curvature.

Differential Diagnosis

Conditions that may mimic cerebral palsy include brain or upper spinal cord tumors, upper cervical instability, neurodegenerative disorders, muscular dystrophies, metabolic disease, familial spastic paraparesis, early myopathy or neuropathy, and Rett syndrome.

Unlike cerebral palsy, many of these disorders are progressive.

Treatment

General Principles

Treatment does not correct the original cerebral lesion.

Management is therefore directed toward maximizing function, encouraging development, reducing spasticity, preventing contracture, and correcting secondary musculoskeletal deformity.

Early Stimulation

In infancy, stimulation and encouragement of movement are among the most important interventions.

Children should be given opportunities to develop motor skills, postural control, reaching, sitting, standing, and mobility according to their abilities.

Stretching

Muscle groups at risk of contracture should be stretched regularly.

The hamstrings and gastrocnemius-soleus complex commonly require particular attention.

Stretching is most useful for preserving existing range of motion rather than reversing a mature fixed contracture.

Physical Therapy

Physical therapy is most effective when directed toward specific and achievable short-term goals.

It can address gait training, mobility, stretching, strengthening, positioning, transfers, and use of adaptive equipment.

Therapists also help monitor changes in function over time.

Orthotics and Bracing

Orthoses may improve positioning, maintain range of motion, support standing or walking, and reduce deforming forces.

Ankle-foot orthoses are frequently used to improve foot position and assist gait.

Bracing should be individualized to functional goals.

Botulinum Toxin

Botulinum toxin injections can temporarily reduce focal spasticity.

They are particularly useful in younger children who are not yet appropriate candidates for definitive orthopaedic surgery.

Botulinum toxin may facilitate therapy, improve gait or positioning, and delay development of fixed contracture.

Intrathecal Baclofen

Intrathecal baclofen can reduce severe generalized spasticity by delivering medication directly into the spinal fluid.

It is used particularly in patients with widespread tone abnormalities, often in those who are nonambulatory.

Diazepam

Diazepam may reduce muscle spasm in selected circumstances but generally has limited long-term benefit.

It may occasionally be used around the time of surgery when temporary control of postoperative spasm is needed.

Multidisciplinary Care

Optimal management requires a multidisciplinary approach.

The treatment team may include physical therapists, occupational therapists, speech and language therapists, orthotists, dietitians, social workers, pediatricians, neurologists, rehabilitation specialists, and orthopaedic surgeons.

Occupational Therapy

Occupational therapy focuses on upper-extremity function, self-care, positioning, adaptive equipment, and activities of daily living.

Therapists may also assist with seating systems, communication strategies, and environmental adaptations.

Speech and Feeding Therapy

Speech and language specialists may address communication difficulties and swallowing dysfunction.

Feeding assessment is particularly important in children with severe cerebral palsy who are at risk of aspiration or inadequate nutrition.

Surgery

Surgical management is directed toward secondary effects of cerebral palsy rather than the original brain injury.

Procedures may include soft-tissue releases, tendon lengthening, selective dorsal rhizotomy, intrathecal baclofen pump placement, osteotomy, hip reconstruction, and scoliosis surgery.

Single-Event Multilevel Surgery

Single-event multilevel surgery (SEMLS) involves correcting several lower-extremity deformities during one operative episode.

Soft-tissue and bony procedures are combined according to the patient’s gait abnormalities.

The goal is to reduce the number of separate operations and consolidate rehabilitation into a single major recovery period.

Selective Dorsal Rhizotomy

Selective dorsal rhizotomy (SDR) is a neurosurgical procedure designed to reduce spasticity at the spinal cord level.

Individual dorsal sensory rootlets are electrically tested, and those producing the most abnormal spastic responses are selectively divided.

Candidates for Selective Dorsal Rhizotomy

SDR is most commonly considered in younger ambulatory children with spastic diplegia, particularly those under approximately 10 years of age who have good underlying strength and selective motor control.

Only a small proportion of children improve by an entire GMFCS level after the procedure.

The primary goal is reduction of spasticity rather than transformation of baseline neurologic function.

Intrathecal Baclofen Pump

An intrathecal baclofen pump provides continuous medication to the spinal canal.

It is particularly useful for severe generalized spasticity or dystonia and is used more commonly in nonambulatory patients.

The pump requires long-term surveillance and periodic refilling.

Muscle Lengthening

Lengthening of contracted muscles can reduce abnormal triggering and allow improved joint positioning during gait.

Commonly treated structures include the Achilles tendon, hamstrings, hip adductors, and occasionally the rectus femoris.

Overlengthening should be avoided because it may create weakness.

Foot Deformities

Significant foot deformity should generally be corrected when it interferes with standing, shoe wear, bracing, or walking.

Even children with limited ambulatory potential may benefit from a plantigrade, braceable, and pain-free foot.

Upper-Extremity Surgery

Surgery for upper-extremity muscle imbalance is undertaken selectively.

Outcomes may be less predictable when sensory integration and selective motor control are poor.

For this reason, hand surgery is less commonly beneficial than lower-extremity reconstruction in severely involved patients.

Hip Subluxation

Progressive hip displacement should ideally be treated before degenerative changes and severe pain develop.

Hip surveillance is therefore a critical component of long-term management.

Adductor Lengthening

Early hip migration caused partly by adductor contracture may be treated with adductor muscle lengthening in selected children.

The goal is to reduce deforming forces and maintain hip containment.

Femoral and Pelvic Osteotomy

More advanced hip subluxation may require a femoral osteotomy, often combined with a pelvic osteotomy.

These procedures restore alignment and improve containment of the femoral head within the acetabulum.

Salvage Hip Procedures

When severe chronic hip dislocation has already produced major pain and joint destruction, reconstructive surgery may no longer be possible.

Rarely, salvage procedures such as femoral head resection may be considered to relieve pain and improve sitting or hygiene.

Scoliosis

Progressive scoliosis can interfere with sitting balance, comfort, pulmonary function, skin care, and mobility.

Treatment depends on curve severity, growth, functional status, and symptoms.

Bracing for Scoliosis

A spinal brace may improve sitting comfort and support in selected patients.

However, bracing generally does not reliably prevent progression of neuromuscular scoliosis.

Scoliosis Surgery

Children with severe progressive curves causing poor sitting balance, pain, or functional difficulty may benefit from spinal correction and fusion.

The aim is to create a stable, balanced trunk and improve comfort and care.

Follow-Up

Children with cerebral palsy should generally be reviewed by an orthopaedic team at least once each year during growth.

Those with more severe involvement or known progressive deformity may require more frequent assessment.

Importance of Surveillance

Regular monitoring allows early detection of hip dysplasia, contracture, scoliosis, foot deformity, and declining function.

Treatment is often more effective when abnormalities are identified before they become fixed or painful.

Prognosis

Prognosis depends primarily on the severity and distribution of cerebral palsy and associated medical conditions.

Patients with extensive total-body involvement may have reduced life expectancy because of respiratory, nutritional, and other systemic complications.

Individuals with less severe forms may have a life expectancy close to that of the general population.

Walking Ability

Many ambulatory children experience some decline in walking efficiency near skeletal maturity.

Walking with cerebral palsy often requires substantially more energy than normal gait.

As body size and weight increase, this energy demand can make community ambulation more difficult.

Complications

Potential complications include progressive joint contracture, hip displacement, scoliosis, foot deformity, reduced mobility, osteoporosis, fractures, obesity, respiratory disease, and gastrointestinal dysfunction.

The pattern varies considerably according to GMFCS level and overall severity.

Weight Gain

Excessive weight gain can further impair mobility and increase the energy cost of walking or transfers.

At the same time, some severely affected patients may have poor nutritional intake.

Nutrition therefore requires careful individualized monitoring.

Fractures and Osteoporosis

Nonambulatory patients are at increased risk of low bone mineral density and fractures.

Reduced weight-bearing, nutritional deficiencies, anticonvulsant use, and limited mobility may all contribute.

Respiratory Complications

Children with severe total-body involvement are more prone to chronic respiratory problems.

Aspiration, weak cough, recurrent infection, scoliosis, and reduced mobility can impair pulmonary function.

Gastrointestinal Complications

Gastroesophageal reflux, constipation, swallowing dysfunction, and feeding difficulties are common in more severely affected children.

These problems can contribute to poor growth and recurrent respiratory illness.

Patient Monitoring

Children should be assessed periodically for functional mobility, gait, joint range of motion, muscle tone, hip stability, spinal alignment, and independence in activities of daily living.

At minimum, yearly review during growth is appropriate, with closer surveillance when progressive deformity or functional decline is present.