Transcript poliomyelitis A

Poliomyelitis
Dr.Farzad Ravari
M.D
Specialist Orthopedic Surgeon
Cedars J.A. Int.l Hospital
POLIOMYELITIS
• Acute anterior poliomyelitis is a viral infection localized in the anterior
horn cells of the spinal cord and certain brainstem motor nuclei.
• One of three types of poliomyelitis viruses usually is the cause of
infection, but other members of the enteroviral group can cause a
condition clinically and pathologically indistinguishable from
poliomyelitis. Viral transmission is primarily fecal-oral, and initial
invasion by the virus occurs through the gastrointestinal and respiratory
tracts and spreads to the central nervous system through a
hematogenous route. Although most individuals in an endemic area are
infected with poliovirus, only 0.5% of infected individuals
• develop paralytic poliomyelitis. The host and viral factors responsible for
the penetration of the central nervous system are areas of active
investigation.
• In 1988, the World Health Organization
initiated the Global Polio Eradication Initiative
to eradicate poliomyelitis; at the time, it was
endemic in 125 countries. As of 2006, only 6
countries were endemic for polio; however,
the worldwide campaign to eradicate polio
continues today, as do efforts to prevent
transmission of the disease into polio-free
areas.
• Acute poliomyelitis has a worldwide distribution, with the
peak season being from July to September and the
concentration being in tropical areas of the Northern
Hemisphere. As of 2006, 6 countries were endemic to
polio: Afghanistan, Egypt, India, Niger, Nigeria, and
Pakistan. The condition continues to occur epidemically in
nonimmunized populations in developing regions. Poor
sanitation and crowded circumstances are 2 additional
factors associated with dissemination. Internationally,
importation of polio continues to occur into polio-free
countries. From 2002-2005, 21 previously polio-free
countries experienced a resurgence of wild-type polio.[6] In
8 of those countries, the cases were limited and no further
spread was observed. In the remaining 13 countries,
multiple cases were observed, with the outbreak lasting
less than 6 months.[7, 8]
Pathophysiology
• Acute poliomyelitis is caused by small ribonucleic
acid (RNA) viruses of the enterovirus group of the
picornavirus family. The single-stranded RNA core
is surrounded by a protein capsid without a lipid
envelope, which makes poliovirus resistant to
lipid solvents and stable at low pH. Three
antigenically distinct strains are known, with type
I accounting for 85% of cases of paralytic
illnesses. Infection with one type does not
protect from the other types; however, immunity
to each of the 3 strains is lifelong.
•. enteroviruses of poliomyelitis infect the human intestinal
The
tract mainly through the fecal-oral route (hand to mouth).
The viruses multiply in oropharyngeal and lower
gastrointestinal tract mucosa during the first 1-3 weeks of the
incubation period. Virus may be secreted in saliva and feces
during this period, causing most host-to-host transmission.
After the initial alimentary phase, the virus drains into the
cervical and mesenteric lymph nodes and then into the blood
stream. Only 5% of infected patients have selective nervous
system involvement after viremia. It is believed that
replication in extraneural sites maintains the viremia and
increases the likelihood that the virus will enter the nervous
system
• The poliovirus enters the nervous system by either crossing
the blood-brain barrier or by axonal transportation from a
peripheral nerve. It can cause nervous system infection by
involving the precentral gyrus, thalamus, hypothalamus,
motor nuclei of the brainstem and surrounding reticular
formation, vestibular and cerebellar nuclei, and neurons of
the anterior and intermediate columns of the spinal cord. The
nerve cells undergo central chromatolysis along with an
inflammatory reaction while multiplication of the virus
precedes onset of paralysis. As the chromatolysis process goes
on further, muscle paralysis or even atrophy appears when
fewer than 10% of neurons survive in the corresponding cord
segments. Gliosis develops when the inflammatory infiltrate
has subsided, but most surviving neurons show full recovery
• Mortality/Morbidity
• Of acute poliovirus infections, 4-8% show only nonspecific illness, and 12% of infections finally result in neurologic symptoms. The incidence of
paralytic diseases increases with young age, advanced age, recent hard
exercise, tonsillectomy, pregnancy, and impairment of B-lymphocyte
defenses. The mortality from acute paralytic poliomyelitis is 5-10%, but it
can reach 20-60% in cases of bulbar involvement.
• Race
• Acute poliomyelitis has no racial predilection.
• Sex
• The male-to-female ratio for acute poliomyelitis is 1:1.
• Age
• Most cases of acute poliomyelitis occur in the pediatric population.
Infection or immunization against poliovirus provides lifelong protection
History
• Most patients (95%) with poliomyelitis virus infections are
asymptomatic or have only mild systemic symptoms, such as
pharyngitis or gastroenteritis. These cases are referred to as minor
illness or abortive poliomyelitis. The mild symptoms are related to
viremia and immune response against dissemination of the virus.
Only 5% of patients exhibit different severities of nervous system
involvement, from nonparalytic poliomyelitis to the most severe
form of paralytic poliomyelitis.[4]
• Nonparalytic poliomyelitis or preparalytic poliomyelitisThe
prodromal symptoms include generalized, nonthrobbing headache;
fever of 38-40 º C; sore throat; anorexia; nausea; vomiting; and
muscle aches. These symptoms may or may not subside in 1-2
weeks.
• Headache and fever, as well as signs and symptoms of nervous
system involvement (eg, irritability, restlessness, apprehensiveness,
emotional instability, stiffness of the neck and back) and Kernig and
Brudzinski signs because of meningitis, then may follow.
• Children generally exhibit milder systemic symptoms than do
adults.
Paralytic poliomyelitis
• Preparalytic symptoms also may develop into paralytic ones.
• Paralytic poliomyelitisThe incubation period from virus exposure
to the neurologic phase can last 4-10 days but may extend to 4-5 weeks.
• Severe muscle pain and spasms, followed by weakness, develop. Muscle
weakness tends to become maximal within 48 hours but may develop for
longer than a week. No progression of weakness should be noted after
the temperature drops to normal for 48 hours. Weakness is asymmetric,
with the lower limbs affected more than upper limbs.
• Muscle tone is flaccid, and the reflexes initially are brisk but
then become absent. The transient or occasionally persistent
coarse fasciculations also are observed frequently in patients
with paralytic poliomyelitis.
• Patients also complain of paresthesias in the affected limbs
without real sensation loss.
• Paralysis remains for days or weeks before slow recovery
occurs over months or years. Which factors favor
development of paralytic disease remains unclear, but some
evidence exists that physical activity and intramuscular
injections during the prodrome may be important
exacerbating factors.[4]
Paralytic poliomyelitis with bulbar involvement
• The purely bulbar form of poliomyelitis without limb weakness may occur
in children, particularly in those whose tonsils and adenoids have been
removed.
• Bulbar paralysis with spinal involvement is more common in adults, most
frequently involving the medulla and leading to dysphagia, dysphonia,
respiratory failure, and vasomotor disturbance.
• Patients may have symptoms and signs, such as hiccough, shallowness
and slowing of respiration, cyanosis, restlessness, and anxiety.
• When paralysis of diaphragmatic and intercostal musculature also occurs,
patients need immediate respiratory assistance and intensive care
because of life-threatening respiratory failure. Cranial nerve and bulbar
involvement can cause obstruction, due to decreased respiratory drive
and associated problems with mucus plugging or actual pharyngeal
weakness-induced direct airway obstruction. The loss of vasomotor
control with circulatory collapse also contributes to high mortality.
The encephalitic form of poliomyelitis
– This form is very rare and manifests as agitation,
confusion, stupor, and coma.
– Autonomic dysfunction is common, and it has a
high mortality.
Physical
• Vital signs are the key to monitoring patients with
poliovirus infection.
• Muscle weakness can be assessed by muscle strength
testing.Usually asymmetric proximal weakness is
present with more involvement of lumbar than cervical
segments and more spinal cord than brainstem
segments.
• The trunk muscles are affected least.
• Sensation should be within normal limits objectively.
• Deep tendon reflexes are diminished or absent.
• Atrophy of muscle may be detected 3 weeks after
onset of paralysis, which becomes maximal at 12-15
weeks and remains permanent.
• Fifty percent of adult patients with poliomyelitis experience transient
acute urinary retention.
• Stiffness and pain in the neck and back because of meningeal irritation,
as well as abnormalities of autonomic function, also can be seen in some
patients.
• Cranial nerve involvementApproximately 10-15% of cases affect the
lower brainstem motor nuclei.
• When the ninth and tenth cranial nerve nuclei are involved, patients
develop paralysis of pharyngeal and laryngeal musculature. Unilateral or
bilateral facial muscles, as well as the tongue and mastication muscles,
may become paralyzed.
• External oculomotor weakness with pupil sparing may occur in rare
cases.
• Direct infection of the brainstem reticular formation can cause breathing
and swallowing disruption, as well as loss of control of the cardiovascular
system.
Causes
• The carrier with poliomyelitis virus infection is
one major source of virus spread from person
to person. The major route is oral-fecal
transmission. The greatest dissemination of
virus occurs within families with poor
sanitation and hygiene or crowded
circumstances.
Differential Diagnoses
• Guillain-Barre Syndrome
• West Nile Virus
Laboratory Studies
• Order lumbar puncture test.Cerebrospinal fluid (CSF) pressure
may be increased.
• Pleocytosis (neutrophils in the first few days, then lymphocytes)
may be noted in the CSF during the period before onset of paralysis
in acute poliomyelitis.
• The CSF protein content may be elevated slightly with a normal
glucose, except in patients with severe paralysis, who may
demonstrate protein elevations to 100-300 mg/dL for several weeks.
• Order a complete blood count (CBC), because leukocytosis may
be present.
• Perform virus recovery from throat washing, stool culture, blood
culture, and CSF culture. Viral studies in stool specimens are
essential for the diagnosis of poliomyelitis.Recover virus from
throat washing during the first week and stool culture from the
first 2-5 weeks.
• In rare cases, the virus may be isolated from CSF or serum, in
contrast to the paralytic illnesses caused by other enteroviruses.
• These tests require additional demonstration of a 4-fold rise in the
virus antibody titer to make a specific diagnosis.
• Polymerase chain reaction is routinely used to differentiate
wild-type strains from vaccine strains.
• Magnetic resonance imaging (MRI) may show
localization of inflammation to the spinal cord
anterior horns.
Electromyography
• The earliest electromyographic finding in poliomyelitis is a reduction
in the recruitment pattern and a diminished interference pattern
due to acute motor axon fiber involvement.
• Fibrillations develop in 2-4 weeks and persist indefinitely;
fasciculations also may be observed.
• Motor unit action potentials initially have decreased amplitude and
then become large in amplitude with increased duration. Later,
polyphasic motor units are observed because of nerve reinnervation.
• The motor nerve conduction velocities remain within normal limits;
however, the compound muscle action potential (CMAP) is reduced
in direct proportion to the number of motor axons that are affected.
Sensory nerve conduction studies remain within normal
parameters, due to sparing of the dorsal root ganglion
Under microscopy
• , the spinal anterior horn cells are surrounded
by inflammatory cells. Spongiosis of the gray
matter, containing many scattered
inflammatory cells, also is noted. Most
inflammatory cells are neutrophil leukocytes.
Rehabilitation Program
• Physical Therapy
• Physical therapy plays an important role in rehabilitation for
patients with poliomyelitis. Patients with muscle paralysis benefit
from frequent passive range of motion (PROM) and splinting of
joints to prevent contracture and joint ankylosis. Chest physical
therapy (CPT) helps patients with bulbar involvement prevent any
pulmonary complications, such as atelectasis. Frequent
repositioning of paralyzed patients helps to prevent bedsores (see
image below).
• Orthotic treatment for deformities around the knee in
poliomyelitis.Occupational Therapy
• Patients with paralysis of the extremities may benefit from hand or
arm splints, knee or trochanter rolls, a footboard, or Multi-Podus
boots to prevent foot drop, ulcers, and other deformities. Hot
packs also are helpful to relieve the muscle pain.
• Speech Therapy
• Patients with cranial nerve involvement may develop
swallowing dysfunction. To protect the airway and prevent
aspiration pneumonia, a speech therapist needs to be
involved early to perform an evaluation of the safety of
swallowing. Decisions on the appropriate consistency of oral
foods and use of various strategies/techniques greatly reduce
the risk of aspiration. Periodic follow up of patient status can
be performed with serial video swallow testing.
• Recreational Therapy
• Patients may attend leisure activities to reduce stress and
learn how to get involved in group activities.
• All patients should be placed on bed rest in an
isolation unit. Monitor patients' vital signs
carefully; focus especially on the swallowing
function, vital capacity, pulse, and blood
pressure, in anticipation of respiratory or
circulatory complications. Patients who develop
respiratory failure because of depression of the
brainstem respiratory center, in addition to
paralysis of the intercostal and diaphragmatic
muscles, may require immediate positive
pressure ventilation and/or tracheotomy in the
respiratory intensive care unit.
Prevention
• Prevention has been proven to be the key to
treatment for poliomyelitis. Development of
effective vaccines from cultures of human
embryonic tissues and monkey kidney cells
represent significant achievements. As a result of
the introduction of inactivated poliovirus vaccine
in the 1950s, followed by oral poliovirus vaccine
in the 1960s, cases of poliomyelitis in the United
States have become rare following vaccination.
Inadequate use of the vaccine in areas with low
standards for public health still may increase the
risk of outbreaks of poliomyelitis because of lack
of immunity.
Class Summary
• Provide active immunity against poliovirus
• Salk vaccine (inactivated poliovirus vaccine [IPV])
• Two IPV products are licensed in the United States, although only 1
of these (IPOL) is distributed there. IPV contains formalin-inactivated
poliovirus strains of the 3 different serotypes (Mahoney, MEF-1,
Saukett). Administered through injection, stimulates serum IgM, IgG,
and IgA. Data have confirmed that 90-100% of children develop
protective antibodies to all 3 types of poliovirus after administration
of 2 doses of currently available IPV, and 99-100% develop
protective antibodies after 3 doses. Routine poliovirus vaccination of
adults residing in the United States is not necessary.
• High-risk adults (eg, travelers to epidemic areas, members of
community with poliovirus disease, health care workers with close
contact of patients who might excrete wild poliovirus, unvaccinated
adults whose children will receive oral polio vaccine) should be
vaccinated.
• IPV is the only vaccine recommended for vaccination of immuno
deficient persons and their household contacts.
Sabin vaccine (Orimune)
• Consists of attenuated live poliovirus. Sabin vaccine is very
effective in providing local gastrointestinal immunity and
circulating antibodies.
• Routine immunization using oral polio vaccine (OPV) in the
United States has been discontinued to eliminate the risk for
vaccine-associated paralytic poliomyelitis (VAPP) according to
the 2000 ACIP new recommendations. However, an
emergency stockpile of OPV for polio outbreak control is
maintained.
• Continue physical therapy on an outpatient
basis to help muscle reeducation. Specific
exercise programs for strengthening lower
extremities are helpful to avoid contracture
and muscle atrophy. Individuals with bowel
and bladder problems need ongoing follow-up
as outpatients.
• Poliovirus vaccines have been recommended for all
pediatric populations in the United States. Vaccination
is the most powerful means of prevention, and it has
helped to bring about dramatic reduction in the
incidence of poliomyelitis. The Western Hemisphere
was certified as free of indigenous wild poliovirus in
1994. The recommendation for routine childhood
poliovirus vaccination has been changed from an allOPV schedule to a sequential IPV-OPV vaccination
schedule. As of January 1, 2000, the ACIP has
recommended exclusive use of IPV for routine
childhood polio vaccination in the United States based
on the continued occurrence of VAPP, the absence of
indigenous disease, and the sharply decreased risk for
wild poliovirus importation into the United States.
• Urinary tract infection usually is transient during
acute phase poliomyelitis. Other complications
(eg, atelectasis, pneumonia, pulmonary edema,
myocarditis) also may occur. Respiratory failure
may be the result of respiratory muscle paralysis
or airway obstruction from lesions of the cranial
nerve nuclei or respiratory center. Related
problems caused by central and spinal loss of
respiratory drive with mucus plugging or actual
pharyngeal weakness may induce direct airway
obstruction.
prognosis
• The overall prognosis for patients with poliomyelitis is
good. Only 5-10% mortality (slightly higher in pediatric
and elderly populations) results from acute paralytic
poliomyelitis because of respiratory and cardiovascular
impairments. Most patients recover from respiratory
failure, and only a small percentage of patients need
chronic respirator care. Muscle strength from paralyzed
muscles may achieve approximately 60% recovery in
the first 3-4 months, probably because of reinnervation
of the denervated muscle fibers. Slow recovery may
continue for about a year because of hypertrophy of
the undamaged muscle.
• 9]
Postpolio syndrome
• The diagnosis of postpolio syndrome (PPS) can be made when a new
history of decreased muscle strength, weakness, and atrophy in an
asymmetric distribution compatible with previous polio is noted, along
with electrophysiologic features of acute denervation superimposed on
chronic denervation-reinnervation in the absence of another
neuromuscular cause.
• Slow but gradual progressive weakness occurs decades after the acute
attack of poliomyelitis. The weakness could develop in already affected
muscles or muscles previously thought to be unaffected. The new
symptoms often are accompanied by fasciculations or additional atrophy.
Patients also may report fatigue, muscle and joint pain, and intolerance to
cold.
• PPS is not infectious in origin; rather, it is associated with increasing
dysfunction in surviving motor neurons, which has been demonstrated
through muscle biopsy showing active denervation and reinnervation. The
overall prognosis is good with slow progression of weakness, rarely
causing further disability or death.
Key to the treatment of PPS
• , other than the active involvement of multidisciplinary rehabilitation
team members, is energy conservation. Patients should brace their weak
muscles, perform only nonfatiguing exercises, simplify their work duties,
learn effective time management, take adequate rest breaks, and
correlate activity with their symptoms. Modification of their diet and sleep
patterns is also essential to improve function.
• A prospective, randomized, controlled study from Turkey looked at the
effects of home- and hospital-based exercise programs on functional
capacity, fatigue, and quality of life in patients with PPS.[10] The results
indicated that such programs, whether carried out at home or in a
hospital, can improve fatigue problems and quality of life in these
patients. The study's hospital exercise group also demonstrated
improvement in functional capacity.
The etiology of PPS
• is unclear. A number of possible mechanisms have been
suggested to account for the condition. The development of
PPS depends on the severity of the acute illness rather than
on the age of the patient. Immunologic mechanisms also are
suggested, because of the presence of mild inflammatory
changes in muscle biopsy. PPS may primarily be caused by a
process of attrition and premature neuronal exhaustion. The
dysfunction of the muscles results from the loss of motor
neurons and reduced neuromuscular reserve capacity, in
combination with a disturbed balance between the ongoing
reinnervation and denervation, at the expense of
reinnervation.
complications
• Orthopedic complications result from prolonged, abnormal
stresses from skeletal deformity and muscle weakness. These
complications include osteoporosis, fractures, instability of
joints, osteoarthritis, and scoliosis.
• Neurologic complications tend to result from skeletal
deformity and the subsequent lifelong use of adaptive
equipment. Peripheral nerve entrapments are common with
the use of crutches, wheelchairs, and other adaptive devices.[
• As poliomyelitis became a rare disease following the
development of the poliovirus vaccine, postpolio
syndrome (PPS) began to attract more attention. Public
education on the importance of mass vaccination
programs for poliovirus — not only in the United
States, but also around the world — is helping to
eradicate this debilitating paralytic illness.
• Education on PPS, especially among individuals with a
history of poliomyelitis, helps patients understand their
own disease and contribute to its management
PATHOLOGICAL FINDINGS
• When the poliomyelitis virus invades the body through the
• oropharyngeal route, it multiplies in the alimentary tract
• lymph nodes and spreads through the blood, acutely
attacking
• the anterior horn ganglion cells of the spinal cord, especially
• in the lumbar and cervical enlargements. How the virus
• penetrates the blood-brain barrier and why the virus has a
• predilection for the anterior horn cell is under investigation.
• The incubation period is 6 to 20 days. The anterior horn
• motor cells may be damaged directly by viral multiplication
• or toxic by-products of the virus or indirectly by ischemia,
• edema, and hemorrhage in the glial tissues surrounding
• them.
•
Destruction of the spinal cord occurs focally and randomly,and within 3
days, wallerian degeneration is evident throughout the length of the
individual nerve fiber. Macrophages and neutrophils surround and
partially remove
• necrotic ganglion cells, and the inflammatory response gradually subsides.
Within the muscle, axonal “sprouting” occurs when nerve cells from
surviving motor units develop new axons, which innervate muscle cells
that have lost their lower motor neuron, thus expanding the size of the
motor unit.
• After 4 months, residual areas of gliosis and lymphocytic cells fill the area
of destroyed motor cells in the spine. Reparative neuroglial cells
proliferate. Continuous disease activity has been reported in spinal cord
segments 20 years after disease onset.
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The number of individual muscles affected by the resultant flaccid paralysis and
the severity of paralysis vary; the clinical weakness is proportional to the number
of lost motor units. Weakness is clinically detectable only when more than
60% of the nerve cells supplying the muscle have been destroyed. Muscles
innervated by the cervical and lumbar spinal segments are most often affected,
and paralysis occurs twice as often in the lower extremity muscles as in upper
extremity muscles. In the lower extremity, the most commonly affected muscles
are the quadriceps, glutei, anterior tibial, medial hamstrings, and hip flexors; in the
upper extremity, the deltoid, triceps, and pectoralis major are most
often affected.
The potential for recovery of muscle function depends on the recovery of
damaged, but not destroyed, anterior horn cells. Most clinical recovery occurs
during the first month after the acute illness and is almost complete within 6
months, although limited recovery may occur for about 2 years. A
muscle paralyzed at 6 months remains paralyzed.
CLINICAL COURSE
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Approximately 95% of patients infected with poliovirus
remain asymptomatic. Nonspecific findings such as fever and
sore throat occur in 4% to 8% of people infected. Between
0.5% and 2% of patients will progress to poliomyelitis. The
course of poliomyelitis can be divided into three stages:
acute, convalescent, and chronic.
• General guidelines for treatment are described here. Specific
indications and techniques for operative procedures are
discussed in specific sections
ACUTE STAGE
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The acute stage generally lasts 7 to 10 days, and up to 95% of all anterior horn cells may be
infected. Symptoms range from mild malaise to generalized encephalomyelitis with
widespread paralysis. With upper spinal cord involvement, diaphragmatic dysfunction and
respiratory compromise can be life threatening. A high index of suspicion of this is necessary,
especially in patients with shoulder involvement, given the close proximity of their respective
anterior horn cells. In younger children, systemic symptoms include restlessness, sore throat,
and a slight temperature elevation; these may resolve, but recurrent symptoms, including
hyperesthesia or paresthesia in the extremities, severe headache, sore throat, vomiting,
nuchal rigidity, back pain, and limitation of straight-leg raising, culminate in characteristically
asymmetrical paralysis. In older children and adults, symptoms include slight temperature
elevation, marked flushing of the skin, and apprehension; muscular pain is common. Muscles
are tender even to gentle palpation. Superficial reflexes usually are absent first, and deep
tendon reflexes disappear when the muscle group is paralyzed. Differential diagnoses
include Guillain- Barre syndrome and other forms of encephalomyelitis. In rare cases,
transverse myelitis can follow receipt of OPV.
Treatment of poliomyelitis in the acute stage generally consists of bed rest, analgesics, and
anatomical positioning of the limbs to prevent contractures. Gentle, passive range-of motion
exercises of all joints should be performed several times daily.
CONVALESCENT STAGE
• The convalescent stage begins 2 days after the temperature
• returns to normal and continues for 2 years. It has been
estimated
• that approximately half of the infected anterior horn
• cells survive the initial infection, and muscle power improves
• spontaneously during this stage, especially during the first 4
• months and more gradually thereafter.
• Treatment during this stage is similar to that during the acute
stage. Muscle strength should be assessed monthly for 6
months and then every 3 months. Physical therapy should
emphasize muscle activity in normal patterns and
development of maximal capability of individual muscles.
Muscles with more than 80% return of strength recover
spontaneously without specific therapy.
• According to Johnson, an individual muscle with less than 30%
of normal strength at 3 months should be considered
permanently paralyzed.
• Vigorous passive stretching exercises and wedging casts can
be used for mild or moderate contractures. Surgical release of
tight fascia and muscle aponeuroses and lengthening of
tendons may be necessary for contractures persisting longer
than 6 months. Orthoses should be used until no further
recovery is anticipated.
CHRONIC STAGE
• The chronic stage of poliomyelitis usually begins 24 months
after the acute illness. During this time, the orthopaedist
attempts to help the patient achieve maximal functional
activity by management of the long-term consequences of
muscle imbalance. Goals of treatment include correcting any
significant muscle imbalances and preventing or correcting
soft tissue or bony deformities. Static joint instability usually
can be controlled indefinitely by orthoses. Dynamic joint
instability eventually results in a fixed deformity that cannot
be controlled with orthoses. Young children are more prone to
develop bony deformity than are adults because of their
growth potential. Soft tissue surgery, such as tendon transfers,
• should be done in young children before the development of
any fixed bony changes; bony procedures for correcting a
deformity usually can be delayed until skeletal growth is near
completion.
Surgery
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For soft tissue contracture >>>>> Release
For shortening of muscle>>>>>> Lengthening
For bone deformities>>>> osteotomy
For paralysed muscle>>>> tendon transfer
For degenerative joint>>> tenodesis or
arthrosesis
• For scoliosis >>> Brace >>>>> operation
THANKS
TENDON TRANSFERS
• Tendon transfers are indicated when dynamic muscle
imbalance results in a deformity that interferes with
ambulation or function of the upper extremities. Surgery
should be delayed until the maximal return of expected
muscle strength in the involved muscle has been achieved.
The objectives of a tendon transfer are (1) to provide active
motor power to replace function of a paralyzed muscle or
muscles, (2) to eliminate the deforming effect of a muscle
when its antagonist is paralyzed, and (3) to improve stability
by improving muscle balance.
the following factors must be
carefully considered:
• 1. Strength. The muscle to be transferred must
be strong enough to accomplish what the
paralyzed muscle did or to supplement the
power of a partially paralyzed muscle.
• A muscle to be transferred should have a
rating of good or better because a transferred
muscle loses at least one grade in power after
transfer
• 2. Efficiency. The transferred tendon should be
attached as close to the insertion of the
paralyzed tendon as possible and should be
routed in as direct a line as possible between
the muscle’s origin and its new insertion
• 3. Excursion. The tendon to be transferred
should have a range of excursion similar to the
one it is reinforcing or replacing. It should be
retained in its own sheath or into the sheath
of another tendon or it should be passed
• through tissues, such as subcutaneous fat,
that would allow it to glide. Routing a tendon
through fascial or osseous tunnels can lead to
scarring and decreased excursion.
• 4. Neurovascular. The nerve and blood supply
to the transferred muscle must not be
impaired or traumatized in making the
transfer.
• 5. Articular. The joint on which the muscle is
to act must be in a satisfactory position; any
contractures must be released before the
tendon transfer. A transferred muscle cannot
be expected to correct a fixed deformity.
• 6. Tension. The transferred tendon must be
securely attached under tension slightly
greater than normal. If tension is insufficient,
excursion is used in removing slack in the
musculotendinous unit, rather than in
producing the desired function.
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Muscle transfers, whenever possible, should occur
between agonistic muscles that are phasic, or active at the
same time in the gait cycle. The anterior muscles of the leg
are predominantly swing-phase muscles, and the posterior
muscles, or flexors, are stance-phase muscles; in the thigh,
the quadriceps is characteristically a stance-phase muscle,
and the hamstrings are swing-phase muscles. In general,
phasic transfers retain their preoperative phasic activities and
regain their preoperative duration of contraction and
electrical intensity.
• The ideal muscle for tendon transfer would have the
• same phasic activity as the paralyzed muscle, would
be of about the same size in cross section and of
equal strength,and could be placed in proper
relationship to the axis of the joint to allow maximal
mechanical effectiveness
• Paralytic deformities from muscle paralysis can be
• dynamic or static, and often both types are present. The
extent to which the paralytic deformity is dynamic or static
should be determined because a static deformity can be
controlled with a brace in a growing child or with arthrodesis
in an adult. A dynamic deformity is more likely to be
appropriate for tendon transfer in children and adults. In a
growing child with dynamic deformity, recurrence is possible
with arthrodesis alone; in a child with static deformity,
however, recurrence after arthrodesis is rare. In a growing
child with dynamic deformity, an appropriate tendon transfer
with minimal external support redistributes muscle power,
preventing permanent deformity until the patient is old
enough for an arthrodesis.
ARTHRODESIS
• A relaxed or flail joint is stabilized by
restricting its range of motion.
• Arthrodesis is the most efficient method of
permanent stabilization of a joint. Tenodeses
that use flexor or extensor tendons to stabilize
joints of the fingers
• Because the lower extremities are designed
primarily to support the weight of the body, it is
important that their joints are stable and their
muscles have sufficient power.
• When the control of one or more joints of the foot
and ankle is lost because of paralysis, stabilization
may be required. In the upper extremity, reach,
grasp, pinch, and release require more mobility than
stability and more dexterity than power
• Arthrodesis of the shoulder is useful for
• some patients but has certain cosmetic and functional
disadvantages that must be weighed. Arthrodesis of the
elbow is rarely indicated in poliomyelitis. Arthrodesis of the
wrist, although useful for some patients, may increase the
disability of other patients. A patient who must use a
wheelchair or crutches and has a wrist that is fused in the
“optimal” position (for grasp and pinch) may be unable to rise
from a chair or to manipulate crutches because he or she
cannot shift the body weight to the palm of the hand with the
wrist extended.
FOOT AND ANKLE
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The most common deformities of the foot and ankle include
claw toes, cavovarus foot, dorsal bunion, talipes equinus,
talipes equinovarus, talipes cavovarus, talipes equinovalgus,
and talipes calcaneus. When the paralysis is of short duration,
these dynamic deformities are not fixed and may be evident
only on contraction of unopposed muscles or on weight
bearing; later, as a result of muscle imbalance, habitual
posturing, growth, and abnormal weight-bearing alignment, a
• permanent deformity can occur from contracture of the soft
• tissues and eventual osseous changes.
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Ambulation requires a stable plantigrade foot with even
weight distribution between the heel and forefoot and no
significant fixed deformity. In the foot, muscle transfer is
performed to prevent contracture formation, balance the
muscles responsible for dorsiflexion and plantar flexion and
for inversion and eversion, and reestablish as normal a gait
as possible. Arthrodesis to correct deformity or stabilize the
joints usually should be delayed until about age 10 to 12 years
to allow for adequate growth of the foot.
TENDON TRANSFERS
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Tendon transfers around the foot and ankle after 10 years of
age can be supplemented by arthrodesis to correct fixed
deformities, to establish enough lateral stability for weight
bearing, and to compensate in part for the loss of function in
the evertor and invertor muscles of the foot. When tendon
transfers and arthrodesis are combined in the same
operation, the arthrodesis should be performed first.
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Transfer of a tendon usually is preferable to excision, not
only to preserve function but also to prevent further atrophy
of the leg. When the paralysis is severe enough to require
arthrodesis, there usually is some weakness of the dorsiflexor
or plantar flexor muscles. In this case, the invertor or evertor
muscles can be transferred to the midline of the foot
anteriorly or posteriorly into the calcaneus and Achilles
tendon. In the rare instance when a muscle function is
discarded, 7 to 10 cm of its tendon should be excised to
prevent scarring of the tendon ends by fibrous tissue. In
addition to arthrodesis and tendon transfers, any deformities
of the leg, such as excessive tibial torsion, genu varum, or
genu valgum (bowlegs), should be corrected because
otherwise they might cause recurrence of the foot deformity.
PARALYSIS OF SPECIFIC MUSCLES
• Anterior Tibial Muscle. Severe weakness or paralysis of the
• anterior tibial muscle results in loss of dorsiflexion and
inversion power and produces a slowly progressive
deformity— equinus and cavus or varying degrees of
planovalgus—that is first evident in the swing phase of gait.
The extensors of the long toe, which usually assist
dorsiflexion, become overactive in an attempt to replace the
paralyzed anterior tibial muscle, causing hyperextension of
the proximal phalanges and depression of the metatarsal
heads. A cavovarus deformity occasionally results from
unopposed activity of the peroneus longus combined with an
active posterior tibial muscle.
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Passive stretching and serial casting can be tried before
surgery to correct the equinus contracture. Posterior ankle
capsulotomy and Achilles tendon lengthening occasionally
are required and are combined with anterior transfer of the
peroneus longus to the base of the second metatarsal. The
peroneus brevis is sutured to the stump of the peroneus
longus to prevent a dorsal bunion. As an alternative, the
extensor digitorum longus can be recessed to the dorsum of
the midfoot to supply active dorsiflexion. Claw toe deformity
is managed by transfer of the long toe extensors into the
metatarsal necks
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Plantar fasciotomy and release of intrinsic muscles may
be necessary before tendon surgery for a fixed cavovarus
deformity. In this situation, the peroneus longus is transferred
to the base of the second metatarsal and the extensor hallucis
longus is transferred to the neck of the first metatarsal. The
claw toe deformity frequently recurs because of reattachment
of the extensor hallucis longus; this can be prevented by
• suturing its distal stump to the extensor hallucis brevis.
• Anterior and Posterior Tibial Muscles. If the anterior tibial
• and the posterior tibial muscles are paralyzed, development of hindfoot
and forefoot equinovalgus is more rapid and the deformity becomes fixed
as the Achilles tendon and peroneal muscles shorten. This deformity may
be similar to congenital vertical talus on a standing lateral radiograph, but
the apparent vertical talus is not confirmed when a plantar flexion
• lateral view is obtained. Serial casting is used before surgery to stretch the
tight Achilles tendon and to avoid weakening the gastrocnemius-soleus. If
the peroneal muscles are normal, and both tibialis muscles are paralyzed,
one of the peroneal muscles must be transferred. Because of its greater
excursion, the peroneus longus is transferred to the base of the second
• metatarsal to replace the anterior tibial and one of the long toe flexors
replaces the posterior tibial. The peroneus brevis is sutured to the distal
stump of the peroneus longus tendon
• Posterior Tibial Muscle. Isolated paralysis of the posterior
• tibial muscle is rare but can result in hindfoot and forefoot eversion. The
flexor hallucis longus and the flexor digitorum longus have been used for
tendon transfers in this situation.
• Through a posteromedial incision, the intrinsic plantar muscles are
dissected sharply from their calcaneal origin, and one of the long toe
flexors is exposed and divided. If the flexor digitorum longus is used, it is
dissected from its tendon sheath posterior and proximal to the medial
malleolus, rerouted through the posterior tibial sheath, and attached to
• the navicular. In rare cases, as an alternative, the extensor hallucis longus
can be transferred posteriorly through the interosseous membrane and
then through the posterior tibial tunnel
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For children 3 to 6 years old, Axer recommended bringing
the conjoined extensor digitorum longus and peroneus
tertius tendons through a transverse tunnel in the talar neck
and suturing the tendon back onto itself. For fixed equinus
deformity, lengthening of the Achilles tendon may be required
before tendon transfer. For severe valgus, Axer recommended
transfer of the peroneus longus into the medial side of the
talar neck and transfer of the peroneus brevis into the lateral
side. Isolated transfer of the peroneus brevis should not be
done because it can cause a forefoot inversion deformity.
After surgery, cast immobilization is continued for 6 weeks,
followed by 6 months of orthosis wear.
FLEXION CONTRACTURE OF THE
KNEE
• Flexion contracture of the knee can be caused by a
contracture of the iliotibial band; contracture of this band can
cause not only flexion contracture but also genu valgum and
an external rotation deformity of the tibia on the femur.
Flexion contracture also can be caused by paralysis of the
quadriceps muscle when the hamstrings are normal or only
partially paralyzed. When the biceps femoris is stronger than
the medial hamstrings there may be genu valgum and an
external rotation deformity of the tibia on the femur; often
the tibia subluxates posteriorly on the femur.
• Contractures of 15 to 20 degrees or less in young children can be treated
with posterior hamstring lengthening and capsulotomy. More severe
contractures usually require a supracondylar extension osteotomy of the
femur .Flexion contractures of more than 70 degrees result in
• deformity of the articular surfaces of the knee. In a growing child with
poliomyelitis, a decrease in pressure and a tendency toward posterior
subluxation cause increased growth on the anterior surface of the
proximal tibia and distal femur. The quadriceps expansion adheres to the
femoral condyles, and the collateral ligaments are unable to glide easily.
Severe knee flexion contractures in growing children can be treated
• by division of the iliotibial band and hamstring tendons, combined with
posterior capsulotomy. Skeletal traction after surgery is maintained
through a pin in the distal tibia; a second pin in the proximal tibia pulls
anteriorly to avoid posterior subluxation of the tibia. Long-term use of a
long-leg brace may be required to allow the joint to remodel.
QUADRICEPS PARALYSIS
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Disability from paralysis of the quadriceps muscle is severe because the knee may be
extremely unstable, especially if there is even a mild fixed flexion contracture. When there is
slight recurvatum, the knee may be stable if the gastrocnemiussoleus is active.
Tendons usually are transferred around the knee joint to reinforce a weak or paralyzed
quadriceps muscle; transfers are unnecessary for paralysis of the hamstring muscles because,
in walking, gravity flexes the knee as the hip is flexed. Several muscles are available for
transfer to the quadriceps tendon and patella: the biceps femoris, semitendinosus, sartorius,
and tensor fasciae latae. When the power of certain other muscles is satisfactory, transfer of
the biceps femoris has been the most successful. Transfer of one or more of the hamstring
tendons is contraindicated unless one other flexor in the thigh and the gastrocnemius-soleus,
which also acts as a knee flexor, are functioning. If a satisfactory result is to be
expected after hamstring transfer, the power not only of the hamstrings, but also of the hip
flexors, the gluteus maximus, and the gastrocnemius-soleus must be fair or better; when the
power of the hip flexor muscles are less than fair, clearing the extremity from the floor may
be difficult after surgery. Transfer of the tensor fasciae latae and sartorius muscles, although
theoretically more satisfactory, is insufficient because these muscles are not strong enough
to replace the quadriceps.
GENU RECURVATUM
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Genu recurvatum from poliomyelitis is of two types: that
caused by structural articular and bone changes stemming
from lack of power in the quadriceps and that caused by
relaxation of the soft tissues around the posterior aspect of
the knee. In the first type, the quadriceps lacks the power to
lock the knee in extension; the hamstrings and
gastrocnemiussoleus usually are normal. The pressures of
weight bearing and gravity cause changes in the tibial
condyles and in the proximal third of the tibial shaft.
• The condyles become elongated posteriorly; their anterior margins are
depressed compared
• with their posterior margins; and the angle of their articular surfaces to
the long axis of the tibia, which isnormally 90 degrees, becomes more
acute. The proximal third of the tibial shaft usually bows posteriorly, and
partial subluxation of the tibia may gradually occur. In the second type, the
hamstrings and the gastrocnemius-soleus muscles are weak.
Hyperextension of the knee results from stretching
• of these muscles, often followed by stretching of the posterior capsular
ligament. The prognosis after correction of the first type of recurvatum is
excellent. The skeletal deformity is corrected first,
• and then one or more hamstrings can be transferred to the patella. Irwin
described an osteotomy of the proximal tibia to correct the first type of
genu recurvatum caused by structural bone changes. Storen modified the
Campbell osteotomy by immobilizing the fragments of the tibia with a
Charnley clamp.