MSK week 3 Flashcards
What is osteogenesis imperfecta?
Brittle bone disease- defect of maturation and organisation of type 1 collagen.
How is osteogenesis imperfecta inherited?
Majority autosomal dominant.
Presentation of osteogenesis imperfecta
Multiple fractures in childhood Short stature Multiple deformities Blue sclera Hearing loss
On examination of osteogenesis imperfecta what would you expect to find
Mild cases- will have normal X-rays with a history of low energy fractures
Fractures tend to heal with abundant but poor quality callus.
How would you treat osteogenesis imperfecta?
Splintage, traction or surgical stabilisation.
Severe cases will need osteotomy.
What is skeletal dysplagia?
Medical term for short stature.
Genetic error resulting in abnormal development of bone or connective tissue.
Can be proportionate or disproportionate (limbs and spine are in proportion or not)
Commonest type of skeletal dysplagia
Achondroplasia
Describe the appearance of acondroplasia
Limbs will be disproportionate to the spine.
Prominent forehead
Widened nose
Lax joints
How is achondroplasia inherited?
Autosomal dominent
80% of cases are sporadic.
Treatment of skeletal dysplagia
Genetic testing of families should be considered
Orthopedic treatment comprises of deformity correction and limb lengthening.
What is generalised familial joint laxity?
“double jointed”
5% of normal people have hypermobility of joints’
What joint laxity a risk factor for?
More prone to soft tissue injuries and recurrent dislocations
How can Marfans syndrome affect the joints and limbs
Disproportionately long limbs and ligamentous laxity. Specifically scoliosis (abnormal twisting of the spine)
Treatment of Marfans syndrome
Patients can have surgery to repair scoliosis
However soft tissue stabilisation of dislocating joints generally has poor outcomes.
How is Marfans inherited? And what is it?
It is inherited autosomal dominantly. There is a mutation in the fibrillan gene resulting in tall stature and disproportionate limbs (with ligamentous laxity).
What is Ehler danlos syndrome
Abnormal collagen and elastin formation.
Clinical features of Ehler danlos syndrome
Profound joint hyper mobility
Vascular fragility with ease of bruising
Joint instability
Scoliosis (twisting of the spine)
Treatment of Ehler Danlos syndrome
Bony surgery may be required for dislocating joints (however bleeding can be a problem and wound healing can be poor)
Why do neuromuscular disorders occur?
Occur due to deficient or abnormal motor neurone signalling.
Could be a defect in the brain, spinal cord, peripheral nerve or muscle.
What is cerebral palsy?
Occurs due to insult to the immature brain before, during or after birth.
What causes cerebral palsy?
Genetic problems, brain malformation, intrauterine infection, prematurity, intracranial haemorrhage, hypoxia during birth, meningitis.
How does cerebral palsy present?
Expression of disease depends on the part of the brain that is involved- signs can be limited to one limb or can have total body involvement often along with learning difficulties.
When does cerebral palsy present?
Onset before 2-3 years.
What is spina bifida?
Failure of the two halves of the vertebral arch to fuse in the first 6 weeks of gestation.
How does spina bifida present?
Varies in severity from spina bifida occulta (no associated problems) to spina bifida cystic (contents of the vertebral canal herniate through the meninges.
What is polio?
Viral infection affecting the motor anterior horn cells in the spinal cord or brainstem resulting in a lower motor neurone defecit.
How does polio get into the person?
Enters via the GI tract which causes a flu like illness and paralysis will affect `a group of muscles within 2-3 days.
What can polio cause?
Can cause temporary paralysis or long term muscle weakness. Also can cause joint deformities and growth defects.
What is an obstetric brachial plexus palsy?
Injury to the brachial plexus during delivery.
What situations can bring about a brachial plexus palsy?
Most commonly arises in large babies, twin deliveries, and shoulder dystocia (compression of the shoulder on the pubic symphysis).
What is the most common type of brachial plexus palsy and from which nerve roots does it arise?
Erbs palsy
Nerve roots C5 and C6 become injured.
What does Erbs palsy result in?
Results in loss of innervation of the deltoid, supraspinatous, infraspinatous, biceps and brachiallis muscle.
This all leads to internal rotation of the humerus.
How is Erbs palsy treated?
Physiotherapy is required to prevent contractures early on.
How is prognosis of Erbs palsy predicted?
Return of the biceps function by 6months.
What other sort of palsy can you get with obstetric brachial plexus palsy?
Klampke’s palsy
What is Klampke’s palsy and what nerve roots are damaged?
C8 and T1 are damaged by forceful adduction. It results in paralysis of the intrinsic hand muscles and the finger and wrist flexors. (can also cause Horners syndrome due to the disruption of sympathetic ganglion in T1)
How does Klampke’s palsy present? How many recover from it?
Flexed fingers.
Less than 50% recover.
Describe the flow of alignment in normal limb development.
When you are first bone you are slightly varus. At 14 months you become neutral. At 3 years you become 10-15 degrees valgus and then by 7-9 you become physiologically 6 degrees valgus.
What is varus and valgus?
Varus- bow leggedness
Valgus- knock kneed.
What causes genu varum?
May be due to a growth disorder of the medial proximal tibial physis
Rarer causes include rickets, osteochondroma, traumatic physeal injury and skeletal dysplagia.
What causes genu valgum?
Rickets, endochondromatosis, trauma and neurofibromatosis.
Treatment of genu varum?
May require surgical correction by osteotomy.
Treatment of genu valgum
Excessive abnormalities can be corrected by osteotomy or growth plate manipulative surgery.
What is in-toeing?
Feet point towards the midline when walking or standing.