Paediatric Orthopaedics Presentation 2 nd July 2014.
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Transcript of Paediatric Orthopaedics Presentation 2 nd July 2014.
Paediatric Orthopaedics Presentation2nd July 2014
IntroductionMotor neuron disorders are neurologic disorders
that selectively affect motor neuronsGenerally progressive causing increasing disabilityOf orthopaedic interest due to contractures,
subluxations and spine deformities that may occur as a consequence
Can be:AcquiredHereditaryUpper motorLower motor
Lower motor neuronThis originates from
the brainstem cranial nerve nuclei or
Anterior horn cells of the spinal cord
They directly innervate skeletal muscles
Clinical presentationMuscle paresis/paralysis
Hypotonia/atonia
Fibrillation/Fasciculation
Hyporeflexia/areflexia
Muscle atrophy
ClassificationAcquired:
PoliomyelitisTraumaIatrogenic
Hereditary:Spinal Muscular AtrophyHMSNs
Poliomyelitis Acute infectious disease caused by a neurotrophic
virus; type I,II and II poliovirus
Spread via faecal – oral route
Virus causes necrosis of anterior horn cells
Results in loss of innervation of motor units
Virtually eradicated by extensive vaccination campaigns
PathologyMost commonly affect lumbar and cervical
enlargement
Involvement from minimal injury with recovery to complete irreversible injury
Percentage of damaged motor units varies corresponding with resulting muscle weakness
Clinical course
Acute: 5 – 10 days. Pre paralytic and paralytic phases. Complete when fever absent for 48 hrs. Asymmetric paralysis
Convalescent: 16 – 18 months. Varying degree of recovery. Sensitive and insensitive phase
Chronic: after recovery of muscle power has occurred
Prognosis
Recovery most marked in the first 3 – 6 months, potential for recovery upto 18 months
Total paralysis beyond 2 months, chance of recovery poor
Muscle spasm, antagonist muscle contracture, deformity and inadequate care influence recovery
Treatment: acute phaseSupportive by paediatric team
Patient positioning in correct anatomic alignment
Frequent turning
Passive range of motion exercises
Moist heat application for muscle pain
Convalescent phaseAttainment of maximal recovery in individual
muscles
Restoration and maintenance of normal joint ROM
Prevention and correction of deformities
Serial muscle testing: monthly 1st four months, bimonthly next 8 months then quarterly upto 2 years
Attaining maximal recovery
Replacement of action of weaker muscle by stronger synergistic muscles avoided by physical therapy centred on strengthening this muscle
Avoiding fatigue of weak muscle which may retard it’s recovery
Restoration of normal joint ROM
Vigorous passive stretching exercises
Night splints to keep joint in anatomical position
Prevention and correction of deformitiesActive exercises preventing fatigue to
address muscle imbalance
Passive stretch and nigh splints to prevent contractures
Pain relief to reduce muscle pain and sensitivity
Readjustment to cater for growth
Chronic phase: physical therapy
Active hypertrophy exercises. To increase strength of synergistic muscles to obtain function
Passive stretch exercises: to prevent deformity. Augmented by night splints to maintain joint in anatomical position
Functional training: teaching to use all available muscles to perform tasks
Chronic phase: orthosesSupport:
Enable walking and functional capabilitiesPrevent deformity and malpositionProtect weak muscle form overstretching
Substitution:Augment weak muscleReplace paralysed muscles
Correction:Stretch muscle that have contracted
Lower limb orthosisPlantar flexion assist
- dosriflexion stop ankle orthosis– weak/paralysed plantar flexors and vice versa
Surgical management
Performed for correction of paralytic deformities
Examples: Tendon transfersFasciotomyCapsulotomyOsteotomyArthrodesis
Tendon transfer
Moving insertion of muscle to new site with aim of replacing paralysed muscle or to restore dynamic muscle balance
Principles (Green – 1957)Muscle to be transferred must have adequate
motor strength to carry out new function
Range of motion of muscle transferred must equal that of muscle being replaced
Gain from transferred muscle > loss from donor site
Joints on which transferred muscle is to act must have functional ROM
Smooth gliding channel must be created – use native tendon sheath, sub muscular, wide opening in septa
Preserve neurovascular supply of muscle
Ensure straight line of contraction without angles or pulleys
Reattachment with sufficient tension to allow maximal range of contraction
Post operative rehabilitationSupport joint in overcorrected position until
full function achieved
Preoperative training to localise contraction of muscle to be transferred
Training of patient to use previously localised muscle to perform new movement
Incorporation of transfer into new functional pattern
ExamplesIlipsoas or external oblique transfer to GT in hip
abductor paralysis
Erector spinae or iliotibial band transfer to GT for G max paralysis
Anterior transfer of peroneus longus in dorsiflexor paralysis
Semitendinosus and biceps femoris transfer to patella in quadriceps paralysis
FasciotomyIliotibial band
contracture contributes to multiple lower limb deformities
Flexion, abduction, external rotation contracture of the hip
Flexion and valgus deformity of the knee joint with external torsion of tibia upto posterolateral subluxation
Pelvic obliquity
Lumbar scoliosis
Subluxation of contralateral hip
Exaggerated lumbar lordosis – bilateral flexion contractures
FasciotomyInitial conservative management
Ober’s fasciotomy – proximal lateral incision with release of fascia over the sartorius, rectus femoris, tensor fasciae lata, and gluteus medius and minimusSection of lateral intermuscular septum and iliotibial
band upto greater trochanter
Yount procedure – excision of segment of iliotibial band and lateral intermuscular septum in distal thigh
May be combined with fractional hamstring lengthening to correct the tibial version
Post operative care
Bilateral long leg cast
Suspension traction
Passive extension, adduction and internal rotation exercises
For 3 weeks
Paralytic hip dislocationMuscle imbalance – weak abductors, normal
flexors and adductorsProgressive coxa valgus deformity upto neck
shaft angle of 180 degreesExcessive anteversionCapsular laxitySubluxation then dislocationAcetabular dysplasia late
Surgical managementTendon transfers to address muscle imbalance
Indicated at 4 – 5 years of age with coxa valga < 150o
Coxa valga > 1500, then a varization osteotomy performed with tendon transfer later
Varization osteotomy – intertrochanteric oblique osteotomy to correct coxa valga and excessive anteversion
Osteotomy and arthrodesisSupracondylar osteotomy for fixed flexion
deformity of knee
Dome osteotomies of proximal tibia for genu recarvatum
Knee arthrodesis for flail knee
Hip athrodesis
ShoulderDeltoid paralysis managed with transfer of
trapezius to proximal humerus
Supraspinatus – levator scapulae transfer
Infraspinatus – latissmus dorsi
Subscapularis – upper 2 digitations of serratus anterior
Trapezius transfer for deltoid paralysis
Serratus anterior transfer for subscapularis paralysis
Levator scapulae transfer for supraspinatus paralysis
Shoulder arthrodesis
Indicated in paralytic subluxation/dislocation and extensive paralysis of the scapulohumeral muscles
Optimum position – 50o abduction, 20o flexion, 25o internal rotation
Scapulo-thoracic motion compensates to position hand in space for function
Elbow flexor paralysis
Morbidity high due to inability to lift hand to face, trunk
Steindler flexorplasty
Pectoralis major transfer
Anterior transfer of triceps brachii
Steindler’s flexorplasty
Brooks and Seddon
Clark
Anterior transfer of triceps brachii
Supination contracture of forearmParalysed forearm flexors with normal biceps
Progressive supination contracture due to interosseous membrane contraction and radial bowing
Radial corrective osteotomy performed to correct
Transfer of insertion of biceps to radial aspect of radius (pronator)
Spinal muscular atrophyHereditary disease characterised by
degeneration of anterior horn cells of the spinal cord
Progressive hypotonia
Lower limb > upper limbs
Proximal > distal muscles
1:15,000 – 20,000 live births
PathogenesisAutosomal recessive in chromosome 5q
Neuronal Apoptosis Inhibitory protein (NAIP) abnormal in 67% of patients
Survival Motor Neuron (SMA) abnormal in 98% of patients
Leads to unregulated apoptosis of α motor neurons
1st trimester molecular genetic technology diagnosis possible
*Type I – acute infantile/Werdnig-Hoffmann SMAOnset between 0 – 6 months
Floppy and inactive, frog leg posture, unable to lift head, fingers and toes active
Tongue fasciculation characteristic
Progressive course, usually death by 2 years due to respiratory failure
*Byers and Banker classification
Type II – chronic infantileOnset 6 – 12 months
Achieve head control, 75% sitting. Wheelchair ambulators
Tongue fasciculation and upper limb tremors
Patella areflexia, biceps and triceps reflex may be present
Survival upto 5th decade
Type II - Kugelberg-WelanderOnset 2 – 15 years
Proximal muscle weakness – difficulty climbing stairs, trendelenburg gait, lumbar hyperlordosis
Ambulant upto adolescence, wheelchair bound as adults
Normal lifespan
Orthopaedic complications
Contractures
Hip subluxation/dislocation
Scoliosis
ContracturesHip and knee flexion contractures in non
ambulant patients
Gentle passive stretch exercises to prevent and treat
Surgical releases of dubious value in non ambulant child and frequently recur
Orthoses to prevent equinus and cavovarus foot deformities
Hip subluxation/dislocationProximal muscle weakness – coxa valga –
subluxation – dislocation
Bilateral dislocation – lumbar hyperlordosis
Unilateral dislocation – pelvic obliquity – pressure sores – aggravate scoliosis
Passive stretch exercises to prevent, derotation osteotomies to reduce the hip
Poor results of surgical procedures reported
ScoliosisUniversal in non ambulatory patients, prevalent in
type III
Predominance of thoracolumbar curves
Typically more flexible but progress rapidly
Orthoses assist sitting posture but do not retard progression
Surgical management – posterior fusion and segmental instrumentation
Herditary Motor and Sensory NeuropathiesGroup of hereditary neuropathies
Characteristics:Predominant motor involvementAutosomal dominantSlowly progressiveSymmetric
Charcot –Marie – Tooth (CMT) disease most common
Has six other types
CMTMost common heritable neuropathy. 1:2500 – 5000
Multiple subtypes
Defects in genes that regulate myelin sheath formation
Lead to demyelination and axonal degeneration
Onset variable but most common in 2nd decade
Clinical featuresSymmetric distal muscle atrophy
Areflexia proceeding proximally
Palpable enlargement of peripheral nerves
More involvement of peroneal muscles as opposed to tibial muscles
Leads to toe, midfoot and ankle deformities
Sensory loss variable
Orthopaedic manifestationsPes cavovarus:Increased
longitudinal arch due to intrinsic muscle atrophy and fibrosis
Imbalance between tibialis posterior and anterior puts hind foot in varus
Meary’s angle between longitudinal axis of talus and 1st metatarsal
On standing lateral radiograph
Normal 0 – 5o
Average 18o in CMT
ManagementSoft tissue releases – capsulotomies and
plantar fascia release
Muscle transfers – posterior tibial to dorsum
Proximal metatarsal osteotomies to correct forefoot plantar flexion
Triple arthrodesis when deformity fixed
Orthopaedic manifestations
Hip subluxation/dislocation
Scoliosis
Managed as for the previous muscle paralysis