MSK Flashcards
duchenne muscular dystrophy is inherited in what pattern ? mutation and define
X-linked recessive
due to mutation in the dystrophin gene, leading to muscle cell necrosis. progressive weakness from the lower to upper body
at what age does duchenne’s muscular dystrophy usually present at? how may it present
2-3 Years
difficulty walking and jumping
also causes learning difficulties
what clinical findings may be seen in someone with duchennes muscular dystrophy?
Gowers sign
calf pseudo hypertrophy
at 12 years old children with duchenne muscular dystrophy are typically?
chair bound
scoliosis
poor pulmonary function
mean life expectancy with duchenne muscular dystrophy? cause of death usually
22 -cardiorespiratory compromise
cardiac complication of duchenne muscular dystrophy?
dilated cardiomyopathy
diagnosis of duchenne muscular dystrophy?
- very high plasma creatine kinase
- definitive diagnosis by genetic analysis (muscle biopsy is generally not needed)
management of duchenne muscular dystrophy?
- MDT approach
- physiotherapy + splints + steroids (slow down skeletal damage and progression of weakness)
- surgery for complications such as scoliosis
- CPAP for advanced disease (respiratory support)
inheritance of spinal muscular atrophy? gene involved
autosomal recessive
SMN1 gene (5q13)
classification of spinal muscular atrophy?
type 1: most severe, with an onset within the first 6 months, never able to sit, dies before 2
type 2: onset of 6-18 months, able to sit and walk with support and dies after 2 years
type 3: mildest, unveiled onset, deteriorating in the 30s
how many an infant present with spinal muscular atrophy? chronic
hypnotic
breathing difficulties
unable to suck or swallow
define juvenile idiopathic arthritis ?
defined as arthritis occuring for more than 6 weeks in those younger than 16 years
how is juvenile idiopathic arthritis classified?
oligoarthritis
poly arthritis
systemic
oligoathritis juvenile idiopathic arthritis is defined as involvement of < … number of joints
5 and is often asymmetric
most common joint involved in oligoarthritis idiopathic juvenile arthritis ?
ankle, knee, wrist
presentation of poly arthritis idiopathic juvenile arthritis ?
5 or more joints involved and usually symmetric
small and large joints (can involve TMJ and cervical spine
what extra-articular manifestation is commonly associated with Oligoarticular juvenile idiopathic arthritis ?
chronic anterior uveitis
polyarthritis juvenile idiopathic arthritis can be ….factor positive or negative
rheumatoid
Oligoarthritis and poly arthritis juvenile idiopathic arthritis is common diagnosed before the age of ….? and is more common in (sex)
6
females
typical age of onset of systemic juvenile idiopathic arthritis ? more common in females or males
1-10
male = female
what are systemic features associated with systemic juvenile idiopathic arthritis ?
high grade fever
salmon pink rash macular rash
anemia and raised CRP and ESR
lymphadenopathy and hepatosplenomegaly
presentation of systemic juvenile idiopathic arthritis is similar to ? 3
SLE
Kawasakis
rheumatic fever
what are 2 other types of junvenile idiopathic arthritis ? (no oligo, poly, systemic)
psoriatic athritis
enthesitis-related arthritis
elements of management of juvenile idiopathic arthritis ?
- MDT approach
- analgesia
- NSAIDs
- joint steroid injections
- methotrexate for poly arthritis — methotrexate-resistant disease consider biologic agents such as infliximab
- systemic steroids: for severe disease
define rickets disease?
a disease caused by the failure of mineralization of the growing bone (when the same happens in the mature bone, it is called osteomalacia), due to deficiency of vitamin D
causes of vitamin D deficiency?
poor sun exposure
low dietary intake of vitamin D, calcium, or phosphate
malabsorption (CF, celiac, liver disease)
defects in processing of vitamin D: chronic liver, renal, falcon syndrome (proximal tubule dysfunction)
drugs: Phenobarbital
clinical features of rickets ?
craniotabes (softening of the skull)
costochondral rachitic rosary
wide wrists and ankles
Harrison sulcus
bowed legs
infants may present with seizures from hypocalcemia
diagnosis of rickets ?
- dietary assessment
- blood tests revealing: decreased calcium, phosphate, and , 25-hydroxyvitamin D. Increased PTH and ALP
- x-ray of wrists showing cupping (widening)
management of rickets ?
- identify cause, treat and supplement
- nutritional rickets: optimize diet and supplement with cholecalciferol
- hypophosphatemic rickets: X-linked dominant hereditary disorder which is resistant to vitamin D, supplemented with phosphate and Calcitriol
….. Is the most common cause of acute limp in 2-12 years old
transient synovitis
features of transient synovitis?
- decreased range of motion
- no pain at rest
- all tests are negative
what must be exclude before diagnosing transient synovitis ?
septic arthritis
what is the management of transient synovitis ?
rest and NSAIDs
presentation of septic arthritis?
- high fever
- acutely unwell
- erythematous tender joint
what is the most common organism that causes septic arthritis ?
staph aureus
diagnosis of septic arthritis ?
joint aspiration and blood for culture and sensitivity
management of septic arthritis ?
depends on the causative organism but generally IV flucloxacillin + gentamicin for 2-4 weeks
define perthes disease?
idiopathic avascular necrosis of femoral epiphysis, occurring in 5-10 year olds, more commonly in males
presentation of perthes disease?
insidious onset of hip pain associated with activity
x-ray findings of perthes disease?
bone x-ray shows increased density of the femoral head early in the disease, progressing to show irregular edges later
management of perthes disease?
conservative measures
surgical intervention if severe
define slipped capital femoral epiphysis ?
femoral head displaces postero-infeeriorly, most commonly in 10-15 year old obese males
presentation slipped capital femoral epiphysis ?
acute limp referred to knee with reduced ROM
management of slipped capital femoral epiphysis ?
surgical intervention to prevent avascular necrosis
genetics of achondroplasia?
50% of cases are autosomal dominant, and 50% are from sporadic mutations
features of achondroplasia?
short stature
short limbs
frontal bossing
lumbar lordosis
define osteogenesis imperfecta?
a group of disorders of collagen metabolism causing bone fragility, most common is type 1 which is autosomal dominant (type 2 is a severe and lethal form at birth)
features of osteogenesis imperfecta?
unexplained fractures, blue sclera, hearing loss in a few (deformity in the ossicles of the middle ear)
management of osteogenesis imperfecta
bisphosphonates
