Congenital MSK Disorders Flashcards
What is osteogenesis imperfecta and what causes it?
Brittle bone disease
–> collagen defect
What are the clinical features of osteogenesis imperfecta?
Multiple frailty fractures in childhood Short stature + multiple deformities Blue sclerae Hearing loss (may be mistaken for NAI fractures)
What is skeletal dysplasia?
Short stature (dwarfism no longer use)
What is the most common type of skeletal dysplasia and what are its features?
Achondroplasia
- disproportionately short limbs with prominent forehead + widened nose
- joints lax
- mental development normal
Joint hyper mobility is caused by disorders of what?
Collagen
Give some examples of conditions causing joint laxity
Generalised (familial) joint laxity
Marfan’s syndrome
Ehlers-Danlos syndrome
Down syndrome
What are the features of generalised joint laxity?
‘Double jointed’
- prone to soft tissue injuries and recurrent dislocations
Which gene is implicated in Marfan’s syndrome?
Fibrillin gene
What are the clinical features of Marfan’s syndrome?
Tall + long limbs Ligamentous laxity High arched palate Scoliosis Flattened chest (pectus excavatum) Lens dislocation + retinal detachment Aortic aneurysm, aortic dissection, aortic + mitral regurgitation Spontaneous pneumothorax Sudden cardiac death
What are the clinical features of Ehlers-Danlos syndrome?
Profound joint hyper mobility + instability
Vascular frailty –> easy bruising
Scoliosis
What are the MSK manifestations of Down syndrome?
Short stature
Joint laxity –> recurrent dislocations
Atlanto-axial instability
What is the inheritance pattern of muscular dystrophies?
Usually X-linked recessive –> only boys
What are the cardinal features of muscular dystrophies?
Progressive muscle weakness and wasting
What is the usual presentation of Duchenne muscular dystrophy?
Muscle weakness noticed when boy starts to walk
–> difficulty standing (Gower’s sign) + going up stairs
What is the progression of Duchenne muscular dystrophy?
Can’t walk by age 10
Death in early 20s due to progressive cardiorespiratory failure
How is Duchenne muscular dystrophy diagnosed?
High serum creatinine phosphokinase
Abnormal muscle biopsy
What are some treatments used to prolong mobility in muscular dystrophy?
Physio
Splintage
Deformity correction
What are the features of Becker’s muscular dystrophy?
Similar to Duchenne but milder
- able to walk into teens and may survive until 30-40
What causes cerebral palsy?
Insult to immature brain before, during or after birth e.g.
- genetics
- brain malformation
- infection in early pregnancy
- prematurity
- intra-cranial haemorrhage
- hypoxia during birth
- meningitis
- idiopathic
What are the different types of cerebral palsy?
Spastic (most common - 80%) –> weakness + spasticity
Ataxic –> balance + co-ordination
Athetoid –> uncontrolled writhing, sudden changes in tone + difficulties controlling speech
What is it called if only one limb is affected in cerebral palsy?
Monoplegic
What is it called if ipsilateral arm and leg are involved in cerebral palsy?
Hemiplegic (most common)
What is it called if both legs are involved in cerebral palsy?
Diplegic
What is it called if all four limbs are affected in cerebral palsy?
Quadriplegic
- usually learning difficulties
What are some of the management options for cerebral palsy?
Physiotherapy and splintage
Baclofen + botox for spasticity
Surgical management of specific problems e.g. joint contractures, scoliosis + hip dislocation
What causes spina bifida?
Failed fusion of two halves of posterior vertebral arch in early gestation
What are the two types of spina bifida?
Spina bifida occulta (mild)
Spina bifida cystica (severe)
What are the features of spina bifida occulta?
May be no problems
Tethering of spinal cord/roots –> high arched foot (pes cavus) + clawing of toes
Tell-tail dimple/tuft of hair
What are the features of spina bifida cystica?
Herniation of meninges +/- spinal cord through defect
–> neuro deficit below lesion
May have associated hydrocephalus
What is the immediate management of spina bifida cystica?
Defect closure within 48 hours to prevent drying or infection
Shunt if hydrocephalus
What is poliomyelitis?
Viral infection affecting motor tracts –> LMN lesion
What are the features of polio?
Virus enters GI tract –> flu like illness + variable degree of paralysis (usually group of muscles in one limb)
Sensation preserved
Residual paralysis can occur –> deformity, growth defects + shortening of limb
Which babies are most likely to get a brachial plexus injury during delivery?
Large babies (macrosomia in DM) Twin deliveries Shoulder dystocia
What is the most common type of brachial plexus injury?
Erb’s palsy
Which nerves are injured in Erb’s palsy?
C5 + C6
What are the features of Erb’s palsy?
Internal rotation of humerus
–> classic waiter’s tip posture
What is the management of Erb’s palsy?
Physiotherapy early to prevent contractures
biceps function usually returns within 6 months
Which nerves are affected in Klumpke’s palsy and how are they injured?
C8 + T1
- forceful adduction during delivery
What are the clinical features of Klumpke’s palsy and what is the management?
Paralysis of intrinsic hand muscles +/- finger + wrist flexors
Possible Horner’s syndrome
Fingers typically flexed
Worse prognosis than Erb’s palsy, no specific treatment
