MSK pathoma Flashcards
Achondroplasia
whats it due to?
whats the mutation?
Short stature (midgets)
failure of longitudinal bone growth (endochondrial ossification)
-FGFR3: inhibits chondrocyte proliferation
Osteogenesis imperfecta
whats the defect?
other symptoms?
Brittle bone disease
AD defect in Type 1 collagen synth.
-blue sclera/hearing loss
why do you get blue sclera?
exposure of the chorodial veins
Osteopetrosis
where is the mutation?
what other problems can this lead to?
defect in bone reabsorption
fuck up of the osteoclasts
- mutation in the Carbonic anhydrase 2 (can no longer make acidic environment to reasbsorb bone
- pancytopenia due to thickening of bone replacing medulla
Osteomalacia/rickets
whats it due to?
defect in osteoid mineralization
due to a deficency of Vit. D
ricketts
who gets it? why? presentation?
children, due to deficiency in Vit. D
bowed legs, richitic rosary, pigeon chest, soft skull
Osteoporosis
Trabecular (spongy) bone loss
porous bone w/ incr. risk of fracture
how do bisphosphonates work?
they inhibit osteoclast activity
Pagets dz of bone
what does the bone look like?
how do you treat it?
what are some complications?
improper balance of osteoclast and osteoblast function
results in thick bone that fractures easily
calcitonin/bisphosphonates
- Incr. blood flow due to AV shunts. leads to High output cardiac failure
-osteosarcoma
Osteochondroma
most common benign bone tumor
grows off the metapiphysis growth plate (laterally)
has a cartiligenous cap
OsteoSarcoma
whats the age distribution?
predisposing factors?
xray finding?
malignant prolliferation of osteoblast (inside the long bones)
- bimodal: teenagers and elderly get it
- Familial retinoblastoma, Pagets Dz of bone, radiation
- Codman’s triangle (elevation of periosteum)
Giant Cell Bone tumor
where does it arise? whats it look like on xray
Epiphysis!
-Soap bubble on xray
Ewings sarcoma
where are they derived from
whats it look like on xray?
whats the translocation?
malignant tumor of diaphysis of long bones under 15.
- neuroectoderm.
- onion skinning of the periosteum
- small blue cells
t(11;22)
Chondroma
where does it arise
proliferation of Cartiledge
usually in the medulla of small bones (hands/feet)
Chondrosarcoma
malignant prolif of cartilage
arises in medulla of pelvis or central skeleton
Metastatic Bone tumors
what do they look like
Punched out osteolytic lesions
whats Articular cartilage made out of
Type 2 collagen (Cartwolage)
Rheumatoid Arthritis
whats the daily pattern of pain?
which joints are hit?
HLA-DR4
Autoimmune dz: inflammation of the synovium that leads to formation of a pannus
Destruction of the cartilage and anklosying (fusion) of the joint
morning stiffness that improves throughout the day
PIP (sparing dip)
whats rheumatoid factor?
IgM antibody AGAINST the Fc portion of IgG
(Anti-IgG antibody)
Characteristics of Seronegative Spondyloarhtopathies
No Rheumatoid factor
Axial skeleton involvement
HLA-B27
Ankylosing Spondylitis
Involvment ont eh spine and sacroiliac joints
(joint Fusion) Bamboo spine
uveitis, and aortic regurg
Reactive Arthritis
Cant see, cant pee, cant climb a tree
Conjunctivitis, Urethritis, Arthritis
Psoriatic Arthritis
DIP of hands and feet usually involved.
dactylitis aka sausage fingers
“pencil in cup” deformity
Gout
increased uric acid in blood (from purine metabolism)
deposition of monosodium urate crystals
needle shaped/ negative (-)biregringent under light
Crystals deposited in Big toe (podagra)
Psuedogout
Deposition of Calcium pyrophosphate
Rhomboid crystals
postive (+) biferingent under light
Dermatomyositis
clinical features
whats the lab findings?
what type of inflamaiton?
Inflam disorder of the skin and muscle
-bilateral Proximal muscle weakness
(cant comb hair/ climb stairs)
- rash of upper eyelids and malar rash (not lupus)
- red papules on elbows and kuckles (Grotton)
- Incr. Creatine Kinase (damaged muscle), +ANA,
+anti-Jo-1
-Perimysial Inflamation
Polymyositis
what kind of inflam?
Infalammatory Disorder of the muscle (skin is not involved)
-endomysial inflamn(CD 8 t cells)
X-linked Muscular dystrophy
whats the deletion
whats clinical presentation
whats the common cause of death?
Degenerative disorder characterized by muscle wasting
-replacement of skeletal muscle with fat (psuedohypertophy of calf muscle)
Deletion of Dystrophin
Gower sign
-Dilated cardiomyopathy
whats the role of dystrophin
it helps anchor muscle fibers. it connects the cytoskeleton (actin) to the transmembrane proteins. which are connected to the Extracellular matrix (ECM)
Becker muscular dystrophy
Mutation of Dystrophin
milder form of Duchennes
Myasthenia gravis
clinical signs?
whats a huge thing its associated with?
Autoantibodies to Post synaptic Ach receptors
Gets worse with muscle use
Ach E inhibitors work well
- Ptosis, diplopia, weakness
- thymic hyperplasia/ thymoma
Lambert Eaton
daily pattern
Antibodies against Presynaptic Calcium channels
(prevents/decreases Ach Release into synapse)
muscles improve w/ use
What are they symptoms of CREST
Calcinosis, Raynauds, Esophogeal dysmotility, Slceryldactyl, talengectias
esophageal dysmo is caused by Fibrous replacement of the esophagus which can lead to gerd
