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1

Review Arthrogryposis Syndrome

Overview

Nonprogressive disorder with multiple joints that are congenitally rigid (Fig. 3.36)

Can be myopathic, neuropathic, or both

Associated with a decrease in anterior horn cells and other neural elements of the spinal cord

Intelligence is normal.

Evaluation

Evaluation should include neurologic studies, enzyme tests, and muscle biopsy (at 3–4 months of age).

Affected patients typically have normal facies, normal intelligence, multiple joint contractures, and no visceral abnormalities.

Upper extremity involvement

Adduction and internal rotation of the shoulder

Extension of the elbow—no appreciable elbow crease

Flexion and ulnar deviation of the wrist

Lower extremity involvement

Teratologic hip dislocations

Knee contractures (extended is classic, flexed is more common)

Resistant clubfoot

Vertical talus

The spine may be involved, with characteristic C-shaped (neuromuscular) scoliosis (33% of cases).

Treatment

Upper extremity

Passive manipulation and serial casting to achieve some motion

Posterior elbow release with tricepsplasty to improve motion

Active elbow flexion achieved through:

Anterior transfer of long head of triceps or

Bipolar transfer of latissimus or pectoralis major

Steindler flexorplasty—transfers origin of flexor pronator to the anterior humerus (rarely indicated because unopposed wrist flexion produces deformity in patients without active extension)

Osteotomies are also considered after 4 years of age to allow independent eating.

One upper extremity should be left in extension at the elbow for positioning and perineal care and the other elbow in flexion for feeding.

Lower extremity

Hip dislocation

Unilateral: medial open reduction with possible femoral shortening

Bilateral: typically left unreduced because ambulation is often preserved

Pavlik harness contraindicated

Knee contractures are treated with early (age 6–9 months) soft tissue releases (especially hamstrings).

Foot deformities (clubfoot and vertical talus) are initially treated with a soft tissue release, but later recurrences may necessitate bone procedures (talectomy).

The goal is for the foot to be stiff and plantigrade to enable the patient to wear shoes and possibly ambulate.

Knee contractures should be corrected before hip reduction to maintain the reduction.

Spine

Fusion if curve is large (>50 degrees) or progressive

Large curve magnitude may impede function and ambulatory ability

Distal arthrogryposis syndrome

Evaluation

Autosomal dominant disorder that affects predominantly hands and feet

Ulnarly deviated fingers (at metacarpal joints), metacarpal and proximal interphalangeal flexion contractures, and adducted thumbs with web space thickening are common.

Clubfoot and vertical talus deformities are also common.

Treatment

Comprehensive releases are more often required, combined with bony surgery.

2

Review Larson Syndrome

Evaluation

Similar to arthrogryposis in clinical appearance, but joints are less rigid

Characterized primarily by multiple joint dislocations (including bilateral congenital knee dislocations), flattened facies, scoliosis, and clubfeet

Cervical kyphosis (late myelopathy should be watched for) is important to recognize early.

Affected patients have normal intelligence.

Autosomal dominant form linked to mutation of gene encoding filamin B

Autosomal recessive form linked to carbohydrate sulfotransferase 3 deficiency

Treatment

Posterior cervical fusion for progressive cervical kyphosis

Knee reduction may necessitate femoral shortening and excision of collateral ligaments; closed reduction often unsuccessful.

Open hip reduction is required; closed reduction unsuccessful.

3

General overview of Spina Bifida

Disorder of incomplete spinal cord closure or rupture of the developing cord secondary to hydrocephalus

Classification

Spina bifida occulta: defect in the vertebral arch, with confined cord and meninges

Meningocele: sac without neural elements protruding through the defect

Myelomeningocele: in spina bifida, sac with neural elements protrudes through the skin

Rachischisis: neural elements exposed, with no covering

Function is related primarily to the level of the defect and the associated congenital abnormalities.

Myelodysplasia level based on lowest functional level (Table 3.12)

 

L4 is a key level because the quadriceps can function and allow household ambulation.

L5 function is a good prognostic indicator of independent ambulation.

Evaluation

Diagnosis

Can be diagnosed in utero (increased levels of alpha fetoprotein)

Related to a folate deficiency in utero

Type II Arnold-Chiari malformation is the most common comorbid condition.

Central axis

Sudden changes in function (rapid increase of scoliotic curvature, spasticity, new neurologic deficit, or increase in urinary tract infections) can be associated with tethered cord, hydrocephalus (most common), or syringomyelia.

Head CT (70% of myelodysplastic patients have hydrocephalus) and myelography or spinal MRI are required.

Fractures

Fractures are also common in myelodysplasia, most often about the knee and hip in children 3 to 7 years of age, and can frequently be diagnosed only if redness, warmth, and swelling are noted.

Fractures are commonly misdiagnosed as infection in these patients.

Fractures are treated conservatively with well-padded splints.

Fractures usually heal with abundant callus.

Treatment principles

Careful observation of patients with myelodysplasia is important. Several myelodysplasia “milestones” have been developed to assess progress (Table 3.13).

Treatment involves a team approach (urologist, orthopaedist, neurosurgeon, and developmental pediatrician) to allow maximal function consistent with the myelodysplasia level and other abnormalities.

Proper use of orthoses is essential in patients with myelodysplasia.

Determination of ambulation potential is based on the level of the deficit and motivation of the child.

Surgery for myelodysplasia focuses on balancing of muscles and correction of deformities.

Increased attention has been focused on latex sensitivity in myelodysplastic patients (immunoglobulin E–mediated allergy).

A latex-free environment is necessary to prevent life-threatening allergic reactions.

4

Review the levels of Spina Bifida

5

Review the lower extremity problems with Spina Bifida

Hip pathology

Wide spectrum of hip disease

Flexion contractures

Hip subluxation and dislocation

DDH

Abduction or external rotation contracture

Management of the hip in patients with myelomeningocele is controversial.

Flexion contractures

Occur in patients with thoracic/high lumbar myelomeningocele as a result of unopposed hip flexors or in patients who sit most of the time

Treatment

Anterior hip release with tenotomy of the iliopsoas, sartorius, rectus femoris, and tensor fasciae latae

For patients with lesions at the low lumbar level, the psoas should be preserved for independent ambulation.

Hip abduction contracture can cause pelvic obliquity and scoliosis; it is treated with proximal division of the tensor fasciae latae and distal iliotibial band release (Ober-Yount procedure).

Adduction contractures are treated with adductor myotomy

Hip dislocation

Caused by paralysis of the hip abductors and extensors with unopposed hip flexors and adductors

Hip dislocation is most common at the level of L3–4.

Treatment

Containment is controversial, but in general, it is considered for low lumbar levels.

Redislocation may occur no matter what treatment is used to maintain the reduction.

Principles of treatment should follow those for any paralytic hip dislocation.

Late dislocation at the low lumbar level may be caused by a tethered cord, which must be released before the hip is reduced.

The functional outcome of thoracic-level myelomeningocele is independent of whether the hips are in proper position or dislocated.

Management should focus on limiting soft tissue contractures.

Knee problems

Usually include quadriceps weakness (usually treated with knee-ankle-foot orthoses [KAFOs])

Flexion deformities are not problematic in patients who use wheelchairs but can be treated with hamstring release and posterior capsular release.

Recurvatum is rarely a problem and can be treated early with serial casting and KAFO.

Tenotomies (quadriceps lengthening) are sometimes required.

Valgus deformities are usually not a problem.

Occasionally, iliotibial band release, guided growth, or osteotomies are needed.

Ankle and foot deformities

Objectives: (1) braceable and plantigrade feet and (2) muscle balance

Calcaneal deformity

Often caused by unopposed action of the tibialis anterior in patients with paralysis at the lower lumbar level

Predisposes to heel ulcers that can result in osteomyelitis of the calcaneus

Passive stretching is initial treatment, but tibialis anterior transfer to calcaneus often required

At time of transfer, should not be fixed in equinus position, which would predispose to distal tibial metaphyseal fracture.

Valgus foot and ankle

Valgus ankle deformity is common in ambulatory patients with the deformity in the distal tibia or subtalar joint (or both).

Surgical correction is warranted when pressure sores are present and orthotics fail to hold correction.

For skeletally immature patients: distal tibial hemiepiphysiodesis or Achilles tendon–fibular tenodesis

For skeletally mature patients: distal tibial osteotomy

In subtalar region valgus, AFOs are often helpful, but tendon release (anterior tibialis, Achilles), posterior tibialis lengthening, and other procedures may be required.

Triple arthrodesis should be avoided in most patients with myelodysplasia; it is used only for severe deformities with sensate feet.

Rigid clubfoot

Secondary to retained activity or contracture of the tibialis posterior and tibialis anterior; common in patients with L4-level lesions

Treatment consists of complete subtalar release through a transverse (Cincinnati) incision, lengthening of the tibialis posterior and Achilles tendons, and transfer of the tibialis anterior tendon to the dorsal midfoot.

Talectomy may be appropriate for refractory clubfoot.

Spine problems

Lumbar kyphosis or other congenital malformation of the spine as a result of a lack of segmentation or formation (i.e., hemivertebrae, diastematomyelia, unsegmented bars)

Treatment of kyphosis is based on problems with skin breakdown or the necessity of using upper extremities to hold up the torso.

Resection of the kyphosis (kyphectomy) with local fusion or fusion to the pelvis with instrumentation is required in severe cases.

Scoliosis can also occur with severe lordosis as a result of muscular imbalance that is caused by thoracic-level paraplegia.

Scoliosis develops in nearly all patients with thoracic-level paraplegia.

Bracing is generally unsuccessful in treating these spinal deformities.

Rapid curve progression can be associated with hydrocephalus or a tethered cord, which may manifest as lower extremity spasticity or an increase in urinary tract infections.

Severe progressive curves necessitate surgical treatment.

Infection rates are high because of frequent septicemia and poor skin quality over the lumbar spine.

Pelvic obliquity

Result of prolonged unilateral hip contractures or scoliosis

Treatment

Custom seat cushions, thoracolumbosacral orthosis, spinal fusion, and ultimately pelvic osteotomies may be required.

6

Review Duchene's Muscular Dystrophy

Caused by absence of dystrophin protein

Markedly elevated creatine phosphokinase (CPK) level and absence of dystrophin protein on muscle biopsy and DNA testing

A muscle biopsy sample shows foci of necrosis and connective tissue infiltration.

Dystrophin absence leads to poor muscle fiber regeneration and progressive replacement of muscle tissue with fibrofatty tissue.

X-linked recessive inheritance (Xp21.2 dystrophin gene mutation; one-third of cases are from spontaneous mutation)

Occurs in young boys

Physical findings

Manifests as muscle weakness (proximal groups weaker than distal)

Clumsy walking

Decreased motor skills

Lumbar lordosis

Calf pseudohypertrophy

Presence of Gowers sign (patient rises by walking the hands up the legs to compensate for gluteus maximus and quadriceps weakness) (Fig. 3.37)

Hip extensors are typically the first muscle group affected.

Also associated with low IQ, megacolon, volvulus, malabsorption

Treatment

Goal is to keep patients ambulatory as long as possible.

Patients lose independent ambulation by age 10 years.

Although controversial, the use of KAFOs and release of contractures can extend walking ability for 2–3 years.

Patients are usually wheelchair dependent by age 15 years.

Patients usually die of cardiorespiratory complications before age 20 years.

Newer medical treatment includes high-dose steroids, which have been shown to prevent scoliosis formation and prolong walking ability.

Foot deformities

Treat with tendo Achilles lengthening (TAL), split posterior tibialis tendon transfer into peroneus brevis (if tibialis posterior active in both stance and swing phase).

Rancho procedure: TAL, tibialis posterior lengthening, split anterior tibialis transfer into dorsal cuboid

Scoliosis

With no muscle support, scoliosis rapidly progresses in virtually all patients by age 14 years.

Patients can become bedridden by age 16 years as a result of spinal deformity and are unable to sit for more than 8 hours.

FVC decreases by 4% each year and by another 4% for every 10 degrees of thoracic scoliosis.

Scoliosis should be treated early (at 20 to 30 degrees of curvature), before pulmonary and cardiac function deteriorate.

Surgical approach includes posterior spinal fusion with segmental instrumentation to include the pelvis.

Differential diagnosis

Becker muscular dystrophy (also sex-linked recessive with a decrease in dystrophin)

Found in boys with red/green color blindness, with a similar but less severe picture

Diagnosis of Becker muscular dystrophy applies to patients with the same examination findings but who live beyond 22 years without respiratory support.

7

Diffence between Becker's and DMD

Becker muscular dystrophy (also sex-linked recessive with a decrease in dystrophin)

Found in boys with red/green color blindness, with a similar but less severe picture

Diagnosis of Becker muscular dystrophy applies to patients with the same examination findings but who live beyond 22 years without respiratory support.

8

Scoliosis treatment in muscular dystrophy

With no muscle support, scoliosis rapidly progresses in virtually all patients by age 14 years.

Patients can become bedridden by age 16 years as a result of spinal deformity and are unable to sit for more than 8 hours.

FVC decreases by 4% each year and by another 4% for every 10 degrees of thoracic scoliosis.

Scoliosis should be treated early (at 20 to 30 degrees of curvature), before pulmonary and cardiac function deteriorate.

Surgical approach includes posterior spinal fusion with segmental instrumentation to include the pelvis.

9

Fascioscapuluhumeral muscular dystrophy

Causes and findings

Autosomal dominant disorder typically observed in patients 6 to 20 years of age

Slow progression of muscle weakness involving muscles of facial expression and proximal upper extremity

Normal CPK level

Winging of the scapula

Inability to whistle

Treated with stabilization by means of scapulothoracic fusion

WNT DUCT?

10

Friedrich Ataxia

 

Autosomal recessive with the frataxin gene

GAA repeat at 9q13

Causes and findings

Autosomal recessive disorder with problems with the frataxin gene (GAA repeat at 9q13)

Spinocerebellar degenerative disease with mean onset between 7 and 15 years of age

Manifests as staggering wide-based gait, nystagmus, cardiomyopathy, a cavus foot, and scoliosis

Involves motor and sensory defects, with an increase in polyphasic potentials on electromyograms

Use of a wheelchair is needed by age 15 years; death occurs between ages 40 and 50 years, usually from cardiomyopathy.

Treatment

Foot deformities treated with plantar release with or without metatarsal and calcaneal osteotomies early, and triple arthrodesis later

Spinal fusion when curves progress to 50 degrees; number of levels should be determined as for a neuromuscular curve.

Bracing ineffective for treatment of scoliosis

11

Review list of Major Sensory/Heriditary peripheral nerve neuropathies

12

What is Riley Day syndrome?

Causes and findings

One of five inherited (autosomal recessive) sensory and autonomic neuropathies

This disease is found only in patients of Ashkenazi Jewish ancestry.

Clinical presentation includes dysphagia, alacrima, pneumonia, excessive sweating, postural hypotension, and sensory loss.

13

Review Charcot Marie Tooth Disease

Charcot-Marie-Tooth disease (peroneal muscular atrophy)

Causes and findings

Autosomal dominant sensory motor demyelinating neuropathy

Two forms are described: a hypertrophic form with onset during the second decade of life, and a neuronal form with onset during the third or fourth decade but with more extensive foot involvement.

Orthopaedic manifestations include pes cavus, hammer toes with frequent corns and calluses, peroneal weakness, and muscular atrophy usually distal to the knees (“stork legs”).

Involves motor defects much more than sensory defects

Low nerve conduction velocities with prolonged distal latencies are noted in peroneal, ulnar, and median nerves.

Diagnosis is made most reliably by DNA testing for a duplication of a genomic fragment that encompasses the peripheral myelin protein-22 (PMP22) gene on chromosome 17.

Intrinsic wasting is noted in the hands.

Most common cause of pes cavus

The most severely affected muscles are the tibialis anterior, peroneus longus, and peroneus brevis.

Plantar flexion of the first ray is the foot deformity that occurs first, as a result of a weakened tibialis anterior muscle.

Treatment for feet

Plantar release, posterior tibial tendon transfer (if hindfoot varus is flexible); hindfoot flexibility tested via Coleman block test

The Coleman block test—block placed under lateral rays, allowing first ray to plantar flex (see Fig. 3.20)

Flexible hindfoot will correct to neutral.

Rigid hindfoot will not correct to neutral.

Triple arthrodesis (poor long-term results) versus calcaneal and metatarsal osteotomies (if heel varus is fixed and the foot not too short)

The Jones procedure for hammer toes, and intrinsic procedures for hand deformity

14

CMT review orthobullets

Deformity characterized by    

cavus (elevated longitudinal arch) 

plantarflexion of the 1st ray and forefoot pronation

hindfoot varus

forefoot adduction

Epidemiology 

seen in both pediatric and adult populations

67% due to a neurologic condition 

when bilateral often hereditary or congenital

Pathophysiology neurologic 

diagnosis of neurologic condition is critical to render appropriate treatment 

unilateral - rule out tethered spinal cord or spinal cord tumor

bilateral - most commonly Charcot-Marie-Tooth (CMT) disease

muscle imbalances generate deformity   

weak tibialis anterior and peroneus brevis overpowered by strong peroneus longus and posterior tibialis   

results in plantarflexed 1st ray and forefoot pronation with compensatory hindfoot varus

with the 1st metatarsal plantflexed and forefoot pronated, the medial forefoot strikes ground first

the subtalar joint supinates to bring the lateral forefoot to the ground and maintain three-point contact, resulting in hindfoot varus

while initially flexible, hindfoot varus can become rigid with time

idiopathic 

usually subtle and bilateral

traumatic  

talus fracture malunion

compartment syndrome

crush injury

Associated conditions conditions which present with cavovarus foot

Charcot-Marie-Tooth disease  

Cerebral palsy

Freidreich's ataxia 

Spinal cord lesions

Polio 

conditions caused by the presense of cavovarus foot 

see complications below

Prognosis depends on 

deformity severity

etiology

patient age

Presentation

History
recurrent ankle sprains and lateral ankle pain

peroneal tendon pathology

lateral foot pain 

excessive weight bearing by the lateral foot due to deformity

can result in 5th metatarsal stress fractures

painful plantar calluses under 1st metatarsal head and 5th metatarsal head or base

plantar fasciitis

elevated medial arch, forefoot pronation and tight gastronemius lead to contracture of the plantar fascia

Physical exam Coleman block test 

evaluates flexibility of hindfoot deformity  

technique 

place 1" block under the lateral foot

eliminates contribution of the plantarflexed 1st ray and forefoot pronation to the hindfoot deformity 

findings 

flexible hindfoot will correct to neutral or valgus when block placed under lateral aspect of foot 

rigid hindfoot will not correct to neutral

guides surgical treatment 

flexible hindfoot deformities resolve with forefoot corrective procedures

rigid hindfoot deformities require corrective hindfoot osteotomy in addition to forefoot procedures

peek-a-boo heel  

anterior standing examination shows varus heel "peeking" around the ankle 

prominent first metatarsal fat pads

Silfverskiold testcheck dorsiflexion with both knee flexion and knee extension 

if tight only with knee extension, then gastrocnemius is tight

if tight also with knee flexion, then soleus is also tight

gastronemius tightness often present with cavovarus foot 

altered gait 

unstable base of support

increased double limb stance and decreased single limb stance

wasting of 1st dorsal interosseous muscle of the hand

suggestive of CMT

spine exam 

scoliosis is suggestive of CMT

spinal dysraphism 

Imaging

Radiographs recommended views 

standing anteroposterior (AP), lateral radiographs of the ankle

standing AP, lateral and oblique radiographs of the foot

findings AP foot talocalcaneal angle < 20° (nl 20-45°)  

hindfoot varus

talonavicular overcoverage  

talonavicular angle > 7° indicates forefoot adduction

metatarsal overlap  

forefoot pronation

lateral foot lateral talo-first metatarsal angle (Meary's angle) > 4° apex dorsal  

break in Meary's line caused by plantarflexion of the 1st ray

calcaneal pitch or inclination angle > 30°  

sinus tarsi see-through sign and double talar dome sign  

due to external rotation of the ankle and hindfoot relative to the xray cassette, which is placed along the medial border of the adducted forefoot

bell-shaped cuboid

increased distance between base of 5th metatarsal and medial cuneiform

oblique foot 

metatarsal stress fractures

calcaneonavicular coalitions

Studies

Electrodiagnostic Studies (EMG/NCS) diagnostic algorithm for CMT generally dictates 

a neurologic physical exam

electrodiagnostic studies

genetic testing

Genetic studies 

used to confirm diagnosis after physical exam and electrodiagnostic studies

Treatment

Nonoperativeaccomodative shoe wearindications

rarely sufficient except in mild deformity

full-length semi-rigid insole orthotic with a depression for the first ray and a lateral wedge  indications

mild cavus foot deformity in adult (not indicated in children)

supramalleolar orthosis (SMO) indications

more severe cavovarus deformity recalcitrant to shoewear accomodations

ankle foot orthosis (AFO)indications

may be needed if equinus also present, resulting in equinocavovarus foot deformity

works best if equinus is a dynamic defomrity (not rigid)

lace-up ankle brace and/or high-top shoe or bootsindications

may consider in moderate deformities when patient does not tolerate the more rigid bracing with an SMO or AFO

Operativesoft tissue reconstructionindications

failure of nonoperative treatment

performed with a combination of the following procedures
plantar releaseindications  

cavus deformity

technique  

plantar fascia release

Steindler stripping (release short flexors off the calcaneus)

peroneus longus to brevis transfer indications  

plantar flexed first ray

technique  

decreases plantarflexion force on first ray without weakening eversion

posterior tibial tendon transferindications  muscle imbalance  

posterior tibialis typically is markedly stronger than evertors and maintains strength for a long time in most cavovarus feet

may consider transfer of posterior tibialis to dorsum of foot if severe dorsiflexion weakness of anterior tibialis

lengthening of gastrocnemius or tendoachilles (TAL) indication  

true ankle equinus

gastrocnemius recession produces less calf weakness and can be combined with plantar release simultaneously

TAL should be staged several weeks after plantar release

1st metatarsal dorsiflexion osteotomy indications  flexible hindfoot varus deformities (normal Coleman block test)  

corrects the forefoot pronation driving the hindfoot deformity

lateral ankle ligament reconstruction (e.g. Broström ligament reconstruction) indications  

chronic ankle instability due to lignamentous incompetence following long-standing cavovarus

Jones transfer(s) of EHL to neck of 1st MT and lesser toe extensors to 2nd-5th MT necks indication  

toe clawing combined with cavus foot  

performed if the indication is met and time permits

the modified Jones transfer for the hallux includes an IP joint fusion 

lateralizing calcaneal valgus-producing osteotomyindications  

rigid hindfoot varus deformity (abnormal Coleman block test) 

triple arthrodesisindication  

almost never indicated due to very poor long-term results

Complications

Ankle instability 

standard lateral ankle ligament reconstruction will fail if cavovarus deformity is not concomitantly addressed

untreated can lead to varus ankle arthritis

Stress fractures 

5th metatarsal base (Jones fracture)

4th metatarsal

navicular

medial malleolus 

Hallux sesamoiditis

overload from plantarflexed 1st metatarsal head

Peroneal tendon pathology

tendonitis, tears, subluxation or dislocation 

peroneus brevis most commonly involved

Plantar fasciitis

contracture of the plantar fascia results from elevated medial arch, forefoot pronation and tight gastronemius

 

15

Review  myathenenia Gravis

Causes and findings

Chronic disease with insidious development of easy muscle fatigability after exercise

Caused by competitive inhibition of acetylcholine receptors at the motor end plate by antibodies produced in the thymus gland

Treatment consists of cyclosporine, antiacetylcholinesterase agents, or thymectomy.

16

Review Spinal Muscular Atrophy

Anterior Horn Disorder

Autosomal recessive

loss of survival motor neuron gene

A disease of progressive motor weakness 

significant variability in severity of disease

Epidemiology incidence 

most common genetic disease resulting in death during childhood

1 in 10,000 live births

location

progressive weakness starts proximally and moves distally

Pathophysiology 

caused by progressive loss of alpha-motor neurons in anterior horn of spinal cord  

Genetics inheritance

autosomal recessive

mutationsurvival motor neuron (SMN) gene mutation  

present in 90% of cases of SMA

a telomeric gene deletion 

SMN critical to RNA metabolism and is a mediator of apoptosis

there are two SMN genes

all patients with SMA lack SMN-I protein  

severity of disease based on number of functional copies of SMN-II

Associated conditions orthopaedic manifestations of SMA 

hip dislocation and subluxation (see below)

scoliosis 

lower extremity contractures

Prognosis

see classification 

Classification

 

Type

Name

Presentation

Prognosis

Type IAcute Werdnig-Hoffman disease
• Present at < 6 months
• Absent DTR
• Tongue fasciculationsPoor, usually die by 2 yrs.

Type IIChronic Werdnig-Hoffman disease• Present at 6-12 months 
• Muscle weakness worse in LE
• Can sit but cant walkMay live to 5th decade

Type IIIKugelberg-Welander disease• Present at 2-15 years 
• Proximal weakness
• Walk as children, wheelchair as adultNormal life expectancy - may need respiratory support

 

Presentation

Symptoms symmetric progressive weakness that is 

more profound in lower-extremity than upper extremity

more profound proximally than distally

Physical examabsent deep tendon reflexes

distinguishes from Duchenne's muscular dystrophy where DTR are present

fasciculations present 

Imaging

Radiographs 

scoliosis series

pelvis

Evaluation

Diagnosis based on 

DNA analysis

muscle biopsy

prenatal diagnosis is possible

Treatment

Nonoperative 

Nusinersen has been FDA approved for treatment of SMA. It is administered intra-thecally.

Operative treat associated orthopaedic disorders (details below) 

hip dislocation

scoliosis 

lower extremity contractures

Hip Dislocation

Overview 

hip  subluxation and dislocation occur in 62% with type II SMA, and less frequently in Type III.

Treatment nonoperative observation alone (leave dislocated)indications

standard of care as dislocations typically remain painless and high recurrence rate if open reduction attempted

Scoliosis

Overview 

the development of scoliosis is almost universal 

usually occurs by age 2 to 3 years

often progressive

Treatment nonoperative bracingindications 

devices may delay but not prevent surgery in children younger than ten years

operative PSF with fusion to pelvisindications 

progressive curve 

technique 

address hip contractures and any other lower extremity contractures before PSF to ensure seating balance

to allow for intrathecal Nusinersen to be given after spine surgery,  perfrom a laminectomy in the lower lumbar spine that is kept free of fusion.  perform fusion of spine around this laminectomy

outcomes 

for improved wheelchair sitting

may lead to temporary loss of upper extremity function 

Combined PSF with anterior releases/fusion  indications 

curves >100 degrees

very young child with high risk of crankshaft phenomenon

contraindications 

pulmonary compromise

typically not necessary due to the high flexibility of SMA curves 

 Hip, knee, and ankle contractures

Overview 

Common in the hip and knee

Nonambulators also develop ankle equinus

Treatment

Physical therapy

Surgical release is controversial as function in nonwalkers is rarely improved and recurrence is common