MSK Flashcards
Embryology of MSK system
Mostly from mesoderm
Mesoderm separates-
paraxial -> somites -> scleromyotypes and dermomyotypes
Scleromyotpoes -? vertebral column
dermomyotome -> dermal and muscle
derm and lateral lum bud forms
What cells differentiate into one and cartilage
Mesenchymal cells
Histology of muscles
Striated muscle
Cross sections alternate from light and ark banking (Actin and myofibril)
Z discs - in-between z discs are sarcomere
SLE - pathophysiology
Autoimmune dysfunction involving -
B cells
dendritic cells
Autoantibodies
T cells
proinflammatory cytokines
Diagnosis criteria of SLE - 4 out of 11
malar rash
discoid rash
photosenitivity
oral ulcers
arthritic
serositis
proteinurina
seizures or psychosis
haematological disorder
anti-dna anti Sm or APA
Positive ANA
Management of SLE
Non-pharmacological - UV light avoidance, bone health, monitoring of renal, vaccinations of pneumoccous and influenza
NSAIS
Hydrochloroquine
Methotrexate
Rituximab
Which HLA is Behchets disease ass. with
HLA-B5
What is bEHCET’S DISEASE
Autoimmune
Uveitis
Oral and genital ulcers
Erythema nodosum
Juvenile idiopathic arthritis
Chronic arthritis affecting one or more joints which persist for longer than 6 weeks
What is common type of JIA
Oligoarticular (<4 joints involved)
JIA Pathophysiology
Imbalance of regulatory T cells, TH17 and TH1 of adaptive immunity
Cytokines and matriculates metalloproteinases lead to joint damage
JIA investigations
Clinical diagnosis
ESF, ferritin
ana
RF
HLA-B27
Systemic JIA
thrombocytosis
lymphocytosis
Management of JIA
NSAIDS
Steroid injections
methotrexate
Adalimumbar
Tocilizumab
Tofacitinib
How often do you need eyes screened in JIA
Screened for anterior uveitis as soon as possible after diagnosis
Bi-monthly screens for six months then by screening every 3 to 4 months up to age 12
Is chronic anterior uveitis in oligoartiuclar JIA bilateral or unilateral
bilateral in 70% of cases
How many joints does polyarticular JIA involved?
5 joints or more
Signs and symptoms of polyarticular JIA
Symmetrical
Small joints of hands and feet as well as large
minimal systemic symptoms
RF +ve
RF -ve
Ehthesitis-related arthritis
Teenage boys
Asymeetrical arthritis of lower-limbs
Acute anterior uveitis
HLA B27
Systemic-onset juvenile idiopathic arthritis
Stills disease
Prominent systemic features at onset in addition to one or more joints
High fever that spikes daily with a salmon coloured rash
Risk factors of DDH
Breech
Family Hx
Fixed foot deformities
Multiple pregnancies
Female
Spina bifida
Pahtophysiology of DDH
DDH occurs during fatal development when the femoral head is not fully in contact with acetabulum
Girls more likely due to circulating maternal hormone relaxin - increases laxity of ligaments
What is ortolans test
Hips and knees flexed,
Abduct hips - ?dislocate anterioly
Barlow test
Hips adducted and flexed at 90 degrees,
Gentle pressure placed on knees through femur to see if femoral head will dislocate posteriorly
What is the galaezzi sign
Hips and knees flexed at 90 degrees
3- 6motnhs
Unilateral femoral shortening suggested by different knee heights
Ewing’s sarcoma where?
Most common in shaft of femur, tibia or humerus
In diaphysis
NOT METAPHYSIS
Which enzymes separate strands of DNA or RND
helicases
Polyarteritis nodosa
Vasuclitis that affects renal arteries -> chronic renal failure
Cna occur 2nd to hep B
Singns and symptoms of polyarteritis nodes
HTN
thrombosis
infarction
aneurysms
necrotising arteritis
What does a renal biopsy show in polyarteritis nods
necrotising proliferative glomerulonephritis with crescentic formation
ANCA +Ve in 50% cases
Erb’s palsy level of maximal plexus injury
C5 - C6
What antibiodies causes congenital heart block
anti-Ro antiLo
Difference between SLE and drug-induced lupus
DIL - anti-single strand DNA, anti-histones >95% in cases
DIL - sudden onset of symptoms post medication use
Medications - antifungal AED
Where are buckle fractures most commonly seen?
Distal metaphysic
