Musculoskeletal - Skin - Connective Tissue_1 Flashcards
What are the epidermis layers from surface to base?
Stratum Corneum (keratin • Stratum Lucidum • Stratum Granulosum • Stratum Spinosum • Stratum Basale
what are the spines in the stratum spinosum?
desmosomes
which epidermal layer is the stem cell site?
Stratum Basale
what are the 3 epidermal appendages?
Sebaceous gland • Eccrine gland • Apocrine gland
mechanism of sebaceous gland secretion?
holocrine secretion of sebum
sebaceous gland associated with what?
hair follicle
eccrine gland secretes what?
sweat
eccrine glands are found where?
throughout the body • Eccrine glands are every where
apocrine glands secrete what?
milky viscous fluid
apocrine glands are found where?
axillae, genitalia, areolae
when are apocrine glands functional?
do not become functional until puberty
why are apocrine glands malodorous?
because of bacterial action
functions of tight junctions?
zona occludens: • prevents paracellular movement of solutes
tight junctions are composed of what?
claudins and occludins
where are adherens junctions?
zonula adherins: below tight junctions
adherens junctions form what?
belt connecting actin cytoskeletons of adjacent cells with Cadherins
what are Cadherins?
Ca++ dependent adhesion proteins
loss of E-cadherin does what?
promotes metastasis
what is the function of desmosomes?
structural support via keratin interactions
atoantibodies to desmosomes cause what?
pemphigus vulgaris
components of desmosomes?
keratin • desmoplakin
what happens in gap junctions?
channel proteins called connexons permit electrical and chemical communication between cells
function of a hemidesmosome?
connects keratin in basal cells to underlying basement membrane
autoantibodies to hemidesmosomes cause what?
bullous pemphigoid
what are integrins?
membrane proteins that maintain integrity of basement membrane by binding to laminin in BM
how does unhappy triad happen?
common injury in contact sportsL lateral force applied to a planted leg
unhappy triad includes which injuries?
tear of ACL, MCL and meniscus (classically medial, but lateral more common)
treatment for unhappy triad?
often requires surgical reconstruction
A and P in ACL and PCL refer to what?
sites of tibial attachment
positive anterior drawer test means what?
ACL tear
abnormal passive abduction at the knee means what?
MCL tear
what is the important landmark for pudendal nerve block?
ischial spine
what is the important landmark in finding the appendix?
2/3 of the way from the umbilicus to the anterior superior iliac spine (McBurney’s point)
what is the important landmark in lumbar puncture?
iliac crest
what are the shoulder muscles that form the rotator cuff?
Supraspinatus • Infraspinatus • teres minor • Subscapularis • SItS (small t is for teres minor)
what is the most common rotator cuff injury?
Supraspinatus
action of supraspinatus?
abducts arm initially (before deltoid)
which rotator cuff muscle is a common pitching injury?
Infraspinatus
action of infraspinatus?
laterally rotates arm
action of teres minor?
adducts and laterally rotates arm
action of subscapularis?
medially rotates and adducts arm
rotator cuff muscles are innervated by what?
C5-C6
what are the bones of the wrist?
Scaphoid • Lunate • Triquetrum • Pisiform • Trapezium • Trapezoid • Capitate • Hamate • Some Lovers Try Positions That They Can’t Handle
what is the most commonly fractured carpal bone?
scaphoid
scaphoid is prone to which complication?
avascular necrosis owing to retrograde blood supply
dislocation of which wrist bone may cause acute carpal tunnel syndrome?
lunate
what is carpal tunnel syndrome?
entrapment of median nerve in carpal tunnel
what is the pathogenesis of carpal tunnel syndrome?
nerve compression → paresthesia, pain, and numbness in distribution of median nerve
cause of lesion in upper trunk of brachial plexus?
trauma
cause of lesion in C7 root of brachial plexus?
compressed by cervical disk lesion
cause of lesion in axillary nerve?
fracture of surgical neck of humerus • dislocation of humerus • intramuscular injections
cause of lesion to lower trunk of brachial plexus?
compressed by cervical rib or by pancoast tumor of lung
lesion of lower trunk of brachial plexus leads to what?
Klumpke’s palsy
cause of lesion to radial nerve in spiral groove?
lesioned by midshaft fracture of the humerus
cause of radial nerve compression in the axilla?
incorrect use of a crutch
cause of lesion in proximal median nerve?
compressed by supracondylar fracture of humerus • pronator teres syndrome
cause of lesion to deep branch of radial nerve?
stretched by subluxation of radius
cause of proximal ulnar nerve lesion?
lesioned by repeat minor trauma • fracture of medial epicondyle of humerus
caused of lesion to anterior interosseous nerve?
compressed in deep forearm
cause of lesion in distal median nerve?
compressed in carpal tunnel syndrome and by dislocated lunate
cause of distal ulnar nerve lesion?
lesioned by trauma to heel of the hand • fracture of hook of hamate
cause of lesion to recurrent branch of median nerve?
lesioned by superficial laceration
nerve root of top of shoulder dermatome?
C4
nerve root of lateral humerus dermatome?
C5
nerve root of medial arm → lateral forearm→ thumb and index finger dermatome?
C6
nerve root of middle finger and middle palm dermatome?
C7
Nerve root of ring/little finger and medial palm dermatome?
C8
Nerve root of medial forearm and distal medial arm dermatome?
T1
nerve root of medial proximal arm and inferior shoulder dermatome?
T2
cutaneous sensory nerve distribution on hand of the ulnar nerve?
little + 1/2 ring finger on palmar and dorsal surface of hand
cutaneous sensory nerve distribution on hand of median nerve?
thumb → half of ring finger on palmar surface • inner half of thumb, distal half of index to 1/2 ring finger on doral surface
cutaneous sensory nerve distribution on hand of radial nerve?
proximal edge of palmar thenar eminence on palmar and whole dorsum of thenar eminence
lesion to long thoracic nerve causes what?
winged scapula
lesion to upper trunk of the brachial plexus causes what?
Waiter’s tip (Erbs palsy)
lesion to lower trunk of brachial plexus causes what?
Claw hand (Klumpke palsy)
lesion to posterior cord of the brachial plexus causes what?
wrist drop
damage to the axillary branch of the brachial plexus causes what?
deltoid paralysis
damage to radial branch of the brachial plexus causes what?
Saturday night palsy (wrist drop)
damage to musculocutaneous branch of brachial plexus causes what?
Difficulty flexing elbow, variable sensory loss
damage to the median branch of the brachial plexus causes what?
decreased thumb function (pope’s blessing)
damage to the ulnar branch of the brachial plexus causes what?
intrinsic muscles of the hand, claw hand
roots that contribute to the long thoracic nerve?
C5, 6, 7
roots that contribute to upper trunk of the brachial plexus?
C5-6
roots that give rise to middle trunk of brachial plexus?
C7
roots that give rise to lower trunk of brachial plexus?
C8-T1
how many divisions in the brachial plexus?
6
trunks that contribute to the lateral cord of the brachial plexus?
upper • middle
trunks that give rise to posterior cord of the brachial plexus?
upper • middle • lower
trunks that give rise to medial cord of the brachial plexus?
lower
nerve roots that give rise to lateral cord of brachial plexus?
C5, 6, 7
nerve roots that give rise to posterior cord of brachial plexus?
C5, 6, 7, 8, T1,
nerve roots that give rise to medial cord of brachial plexus?
C8, T1
trunks that give rise to axillary branch of brachial plexus?
upper • middle • lower
trunks that give rise to radial branch of brachial plexus?
upper • middle • lower
trunks that give rise to musculocutaneous branch of brachial plexus?
upper • middle
trunks that give rise to median branch of brachial plexus?
upper • middle • lower
trunks that give rise to ulnar branch of brachial plexus?
lower
cords of brachial plexus that innervate flexors of forearm?
lateral • medial
cords of brachial plexus that innervates extensors of forearm?
posterior
nerve roots that contribute to axillary nerve?
C5-C6
nerve roots that contribute to radial nerve?
C5-T1
nerve roots that contribute to musculocutaneous nerve?
C5-C7
nerve roots that contribute to median nerve?
C5-T1
nerve roots that contribute to ulnar nerve?
C8-T1
brachial plexus is protected from clavicle fracture by what?
subclavius muscle
typically injury of axillary nerve?
fractured surgical neck of humerus • dislocation of humeral head
motor deficit in axillary nerve injury?
Deltoid- arm abduction at shoulder
sensory deficit in axillary nerve injury?
over deltoid muscle
sign associated with axillary nerve injury?
atrophied deltoid
what is the typical injury of the radial nerve?
fracture at midshaft of humerus • extended compression of axilla by back of chair or crutches
motor deficit seen in radial nerve injury?
BEST extensors • Brachioradialis • Extensors of wrist and fingers • Supinator • Triceps
sensory deficit seen in radial nerve injury?
posterior arm and dorsal hand and thumb
sign seen in radial nerve injury?
wrist drop
typical injury to the median nerve?
fracture of supracondylar humerus
motor deficit in proximal lesion to median nerve?
opposition of thumb • lateral finger flexion • wrist flexion
sensory deficit in proximal lesion to median nerve?
dorsal and palmar aspects of lateral 3 1/2 fingers • thenar eminence
sign seen in median nerve lesion?
ape hand • popes blessing
typical injury to ulnar nerve?
fracture of medial epicondyle of humerus • funny bone
motor deficit in proximal ulnar nerve injury?
medial finger flexion • wrist flexion
sensory deficit in proximal ulnar nerve lesion?
medial 1 1/2 fingers • hypothenar eminence
sign seen in proximal ulnar nerve lesion?
radial deviation of wrist upon wrist flexion
typical injury to musculocutaneous nerve?
upper trunk compression
motor deficit in musculocutaneous nerve injury?
biceps • brachialis • coracobrachialis • flexion of forearm at elbow
sensory deficit in musculocutaneous nerve injury?
lateral forearm
what causes erb-duchenne palsy ‘waiters tip’?
traction or tear of the upper trunk of the brachial plexus (C5-C6)
erb duchenne palsy ‘waiters tip’ seen in who?
infants following trauma during delivery
findings in erb-duchenne palsy ‘waiters tip’?
limb hangs by side (paralysis of abductors) • medially rotated (paralysis of lateral rotators) • forearm is pronated ( loss of biceps)
what are the causes of Klumpke palsy and thoracic outlet syndrome?
an embryologic or childbirth defect affecting inferior trunk of brachial plexus (C8-T1) • cervical rib can compress subclavian artery and inferior trunk, resulting in thoracic outlet syndrome
findings in klumpke palsy/thoracic outlet syndrome?
atrophy of thenar and hypothenar eminences • atrophy of interosseous muscles • sensory deficits on the medial side of the forearm and hand • disappearance of the radial pulse upon moving the head toward the ipsilateral side
clawing of the hand is conceptualized how?
as loss of the lumbricals, which flex the MCP joints and extend both the DIP and PIP joints
ulnar claw can be caused by what?
long-standing injury to ulnar nerve at hook of hamate (falling onto outstretched hand)
pathogenesis of ulnar claw?
distal ulnar nerve lesion → loss of medial lumbrical function→ inability to extend 4th and 5th digits when trying to open hand
median claw can be caused by what?
carpal tunnel syndrome or dislocated lunate
pathogenesis of median claw?
distal (after branches containing C5-C7 branches off to feed forearm flexors) median nerve lesion→ loss of lateral lumbrical function→ 2nd and 3rd digit are clawed upon attempted finger extension
what causes pope’s blessing?
proximal median nerve lesion causes loss of lateral finger extension and thumb opposition
finding in pope’s blessing?
when asked to make a fist, 2nd and 3rd digits remain extended and thumb remains unopposed, which looks like the hand of benediction
pathogenesis of ape hand?
proximal median nerve lesion → loss of opponens pollicus muscle function → unopposable thumb
pathogenesis of klumpke’s total claw?
lesion of lower trunk (C8-T1) of brachial plexus → loss of function of all lumbricals; • forearm finger flexors (fed by part of median nerve with C5-C7) and finger extensors (fed by radial nerve) are unopposed→ clawing of all digits
muscle innervated by LTN?
serratus anterior
action of serratus anterior?
anchors scapula to thoracic cage • used for abduction above horizontal position
LTN can be injured how?
mastectomy
what happens when LTN is injured in mastectomy?
winged scapula and ipsilateral lymphedema
what innervates the muscles of the thenar eminence?
median
what innervates the muscles of the hypothenar eminence?
ulnar
what are the muscles in the thenar eminence?
Opponens pollicus • Abductor pollicus brevis • Flexor pollicus brevis
what are the muscles in the hypothenar eminence?
opponens digiti minimi • abductor digiti minimi • flexor digiti minimi
function of the dorsal interosseous muscles?
abduct the fingers
action of the palmar interosseous muscles?
adduct the fingers
action of the lumbrical muscles?
flex at the MCP joint • extend PIP and DIP joints
roots of obturator nerve?
L2-L4
roots of femoral nerve?
L2-L4
roots of common peroneal nerve?
L4-S2
roots of tibial nerve?
L4-S3
roots of superior gluteal nerve?
L4-S1
roots of inferior gluteal nerve?
L5-S2
cause of injury to obturator nerve?
anterior hip dislocation
motor defect in obturator nerve injury?
thigh adduction
sensory deficit in obturator nerve injury?
medial thigh
cause of injury to femoral nerve?
pelvic fracture
motor deficit in femoral nerve injury?
thigh flexion and leg extension
sensory deficit in femoral nerve injury?
anterior thigh and medial leg
cause of injury to common peroneal nerve?
trauma or • compression of lateral aspect of leg or • fibula neck fracture
motor deficit in common peroneal nerve injury?
foot eversion and dorsiflexion; • toe extension; • foot drop, foot slap, steppage gait
sensory deficit in common peroneal nerve injury?
anterolateral leg and dorsal aspect of foot
what is the cause of injury to tibial nerve?
knee trauma
what is the motor deficit in tibial nerve injury?
foot inversion and plantarflexion; • toe flexion
what is the sensory deficit in tibial nerve injury?
sole of foot
cause of injury to superior gluteal nerve?
posterior hip dislocation or polio
motor deficit in superior gluteal nerve lesion?
thigh abduction (positive trendelenberg sign)
cause of injury to inferior gluteal nerve?
posterior hip dislocation
motor deficit in inferior gluteal nerve injury?
cant jump, climb stairs, or rise from seated position • can’t push inferiorly
mnemonic for common peroneal nerve?
PED= Peroneal Everts and Dorsiflexes; if injured, foot dropPED
mnemonic for Tibial Nerve?
TIP= Tibial Inverts and Plantarflexes; if injured, can’t stand on TIPtoes
root of sciatic nerve?
L4-S3
course of sciatic nerve?
posterior thigh,splits into common peroneal and tibial nerve
6 steps in muscle excitation/ contraction?
- AP depolarization opens presynaptic VG-Ca channels→ NT release • 2. postsynaptic ligand binding → muscle cell depolarization in motor end plate • 3. depolarization travels along muscle cell + down T tubule • 4. depolarization of VS-DHPR, mechanically coupled to ryanodine receptor on SR→ conformational change → Ca release from SR • 5. released Ca binds to troponin C → conformational change that moves tropomyosin out of myosin binding groove on actin filaments • 6. myosin releases bound ADP and is displaced on the actin filament (powerstroke). contraction → shortening of H and I bands and between Z lines (HIZ shrinkage), but the A band remains the same length
which band of sarcomere is always same length in contraction?
A band
which bands shrink during muscle contraction?
HIZ
what are the types of muscle fibers?
Type 1 muscle • Type 2 muscle
action of type 1 muscle?
slow twitch
;how do the morphologic features of type 1 muscle correspond to its action?
red fibers resulting from ↑ mitochondria and myoglobin concentration (↑OxPhos)→sustained contraction
action of Type 2 muscle?
fast twitch
morphology of type 2 muscle?
white fibers resulting from ↓ mitochondria (↑ anaerobic glycolysis)
weight training results in hypertrophy of which type of muscle?
type 2
4 biochemical changes that drive mechanical skeletal and cardiac muscle contraction?
- Ca binds troponin C→ conformational change→displacement of tropomyosin and actin/myosin cycling • 2. Pi is released, changing myosin head conformation, causing power stroke • 3. ATP binds myosin head→ release from actin filament • 4. ATP hydrolysis cocks myosin head
4 states in mechanical skeletal muscle contraction?
- cocked state • 2. cross bridged state • 3. power-stroke state • 4. released state
what does lack of ATP do to muscle contraction?
causes rigor mortis
what are the 2 types of bone formation?
endochondrial ossification • membranous ossification
where does endochondrial ossification take place?
bones of axial and appendicular skeleton • base of the skull
what happens in endochondrial ossification?
cartilaginous model of bone is first made by chondrocytes • osteoclasts and osteoblasts later replace with woven bone and then remodel to lamellar bone
in adults, woven bone occurs when?
after fractures • Paget’s disease
where does membranous ossification take place?
bones of calvarium and facial bones
what happens in membranous ossification?
woven bone formed directly without cartilage • later remodelled to lamellar bone
action of osteoblasts?
build bone by secreting collagen and catalyzing mineralization
origin of osteoblasts?
differentiate from mesenchymal stem cells in periosteum
what are osteoclasts?
multinucleated cells that dissolve bone by secreting acid and collagenases
osteoclasts differentiate from what?
monocytes/macrophages
effects of PTH on bone at low, intermittent levels?
exerts anabolic effects (building bone) on osteoblasts and osteoclasts (indirect)
effects of chronic high PTH on bone?
catabolic effects (osteitis fibrosa cystica)
effect of estrogen on bones?
inhibits apoptosis in bone forming osteoblasts and induces apoptosis in bone resorbing osteoclasts
what happens to bone in estrogen deficiency (surgical or postmenopausal)?
excess remodeling cycles and bone resorption lead to osteoporosis
pathogenesis of achondroplasia?
failure of longitudinal bone growth (endochondral ossification)→ short limbs • membranous ossification is not affected → large head relative to limbs
molecular cause of achondroplasia?
constitutive activation of FGFR3 actually inhibits chondrocyte proliferation
inheritance of achondroplasia?
> 85% of mutations occur sporadically and are associated with ↑ paternal age • also demonstrates AD inheritance
achondroplasia is a common cause of what?
dwarfism
prognosis of achondroplasia?
normal life span and fertility
what happens in osteroporosis?
trabecular (spongy) bone loses mass and interconnections despite normal bone mineralization and lab values (Ca and PO4)
osteoporosis can lead to what?
vertebral crush fractures- acute back pain, loss of height, kyphosis
what is type I osteoporosis?
post menopausal- ↑ bone resorption due to ↓ estrogen
injuries common to type I osteoporosis?
femoral neck fracture • distal radius (colles fracture)
what is type II osteoporosis?
senile osteoporosis- men and women >70yo
prophylaxis for type II osteoporosis?
regular weight bearing exercise and adequate calcium and VitD intake throughout adulthood
treatment for osteoporosis?
estrogen (SERMs) +/- calcitonin • bisphosphonates or pulsatile PTH for severe cases
what meds are CI in osteoporosis?
glucocorticoids
osteopetrosis AKA?
marble bone disease
pathogenesis of osteopetrosis?
failure of normal bone resorption due to defective osteoclasts → thickened, dense bones that are prone to fracture
hematologic complications of osteopetrosis?
bone fills marrow space → pancytopenia, extramedullary hematopoiesis
molecular cause of osteopetrosis?
mutations (carbonic anhydrase II) ↓ ability of osteoclast to generate acidic environment necessary for bone resorption
Xray findings in osteopetrosis?
bone in bone appearance
osteopetrosis can result in what?
cranial nerve impingement and palsies as a result of narrowed foramina
tx for osteopetrosis?
BM transplant is potentially curative since osteoclasts are derived from monocytes
what causes osteomalacia/rickets?
vitamin D deficiency
pathogenesis of osteomalacia/rickets?
defective mineralization/calcification of osteoid→ soft bones that bow out
hormonal changes in osteomalacia/rickets?
↓ VitD→ ↓ serum Ca → ↑ PTH secretion → ↓ serum PO4
result of hyperactive osteoblasts in osteomalacia/rickets?
↑ ALP (osteoblasts require alkaline environment)
Paget’s disease of bone AKA?
osteitis deformans
what is Paget’s disease of bone?
common, localized disorder of bone remodeling caused by ↑ in both osteoblastic and osteoclastic activity
lab values in pagets disease of bone?
serum Ca, PO4, PTH= NL • ↑ ALP
findings in pagets disease of bone?
mosaic woven bone pattern • long bone chalk stick fractures • hat size ↑ • hearing loss due to auditory foramen narrowing
CV complication of pagets disease of bone?
↑ blood flow from ↑ arteriovenous shunts may cause high output cardiac failure
pagets disease of bone carries ↑ risk of what?
osteogenic sarcoma
lab values in osteoporosis?
↓ bone mass with normal Ca, PO4, ALP, PTH
lab values in osteopetrosis?
thickened dense bones with • ↓ Ca • ↑ ALP • normal PO4 and PTH
lab values in osteomalacia/rickets?
soft bones with • ↓ Ca and PO4 • ↑ ALP and PTH
lab values in osteitis fibrosa cystica?
brown tumors of hyperparathyroidism • ↓ PO4 • ↑ Ca, ALP, PTH
lab findings in paget’s disease of bone?
abnormal bone architecture with • ↑ ALP • normal Ca, PO4, PTH
what happens in polyostotic fibrous dysplasia?
bone is replaced by fibroblasts, collagen, and irregular bony trabeculae
what is McCune-Albright syndrome?
form of polyostotic fibrous dysplasia characterized by multiple unilateral bone lesions associated with endocrine abnormalities (precocious puberty) and cafe au lait spots
what are the benign primary bone tumors?
- giant cell tumor (osteoclastoma) • 2. osteochondroma (exostosis)
epidemiology/location of Giant cell tumor/osteoclastoma?
20-40yo • epiphyseal end of long bones
presentation of giant cell tumor/osteoclastoma?
locally aggressive benign tumor often around the distal femur, proximal tibial region
Xray appearance of giant cell tumor/osteoclastoma?
double bubble or soap bubble appearance
histopathology in giant cell tumor/osteoclastoma?
spindle shaped cells with multinucleated giant cells
what is the most common benign primary bone tumor?
osteochondroma (exostosis)
epidemiology of osteochondroma?
males <25yo
characteristics of osteochondroma?
- mature bone with cartilaginous cap • 2. commonly originates from long metaphysis • 3. malignant transformation to chondrosarcoma is rare
what are the malignant primary bone tumors?
osteosarcoma • ewings sarcoma • chondrosarcoma
what is the 2nd most common primary malignant bone tumor?
osteosarcoma (1st is multiple myeloma)
epidemiology of osteosarcoma?
M>F • 10-20yo 1°
what are the predisposing factors for osteosarcoma?
pagets disease of bone • bone infarcts • radiation • familial retinoblastoma
location of osteosarcoma?
metaphysis of long bones, often around distal femur, proximal tibial region
xray findings in osteosarcoma?
codman’s triangle (from elevation of periosteum) or sunburst patten
prognosis of osteosarcoma?
aggressive
tx for osteosarcoma?
surgical en bloc resection (with limb salvage) and chemotherapy
epidemiology of ewings sarcoma?
boys <15yo
ewings sarcoma commonly appears where?
in diaphysis of long bones, pelvis, scapula, ribs
severity of ewings sarcoma?
extremely aggressive with early metastases, but responsive to chemotherapy
histopathology of ewings sarcoma?
anaplastic small blue cell malignant tumor • onion skin appearance in bone • ‘going out for ewings and onion rings’
genetic cause of ewings sarcoma?
t(11;22) • 11+22=33 patrick ewings jersey number
epidemiology of chondrosarcoma?
men 30-60yo
location of chondrosarcoma?
usually located in pelvis, spine, scapula, humerus, tibia, or femur
what type of cancer is chondrosarcoma?
malignant cartilaginous tumor
where does chondrosarcoma come from?
may be of primary origin or from osteochondroma
histopathology of chondrosarcoma?
expansile glistening mass within the medullary cavity
epihphyseal bone tumor?
giant cell tumor (soap bubble)
metaphyseal bone tumor?
benign= osteochondroma -exostosis • malignant= osteosarcoma- codmans triangle
diaphyseal bone tumor?
malignant: • ewings sarcoma • chondrosarcoms
etiology of osteoarthritis?
mechanical- joint wear and tear destroys articular cartilage
etiology of RA?
autoimmune- inflammatory destruction of synovial joints • type III HSR
joint findings in osteoarthritis?
subchondral cysts • sclerosis • osteophytes (bone spurs) • eburnation (polished, ivory like appearance of bone) • Heberden’s nodes (DIP) • Bouchard’s nodes (PIP) • no MCP involvement
joint findings in RA?
pannus formation in joints (MCP, PIP) • subcutaneous rheumatoid nodules • ulnar deviation of fingers • subluxation • Baker’s cysts • no DIP involvement
pathology in subcutaneous rheumatoid nodules in RA?
fibrinoid necrosis
location of Baker’s cysts in RA?
popliteal fossa
predisposing factors for OA?
age • obesity • joint deformity
predisposing factors for RA?
F>M • 80% RF (+) • anti-cyclic citrullinated peptide antibody is more specific • strong association with HLA-DR4
classic presentation of OA?
pain in weight bearing joints after use (EOD) improving with rest • knee cartilage loss medially (bowlegged) • noninflammatory • no systemic symptoms
classic presentation of RA?
morning stiffness > 30min improving with use • symmetric joint involvement • systemic symptoms
systemic symptoms of RA?
fever • fatigue • pleuritis • pericarditis
Tx for OA?
NSAIDs • intra-articular glucocorticoids
Tx for RA?
NSAIDs • glucocorticoids • disease modifying agents (MTX, sulfasalazine, TNF-α inhibitors)
what happens in Sjogrens syndrome?
lymphocytic infiltration of exocrine glands, especially lacrimal and salivary
classic triad of sjogrens syndrome?
xerophthalmia (dry eyes, conjunctivitis) • xerostomia (dry mouth, dysphagia) • arthritis
sjogrens causes what complications?
parotid enlargement • ↑ risk of B cell lymphoma • dental caries
markers present in sjogrens syndrome?
autoantibodies to ribonucleoprotein antigens: SS-A (Ro), SS-B (La)
sjogrens predominantly affects who?
females 40-60yo
sjogrens associarted with what?
RA
what are the findings in gout?
precipitation of monosodium urate crystals into joints due to hyperuricemia
hyperuricemia that causes gout can be caused by what?
lesch-nyhan syndrome • PRPP excess • ↓ excretion of uric acid (thiazides) • ↑ cell turnover • von gierkes disease
percentage of gout due to underexcretion?
90%
percentage of gout due to overproduction?
10%
features of crystals in gout?
needle shaped and negatively birefringent = yellow crystals under parallel light
gout is more common in who?
men
symptoms of gout?
asymmetric joint distribution • joint is swollen, red and painful • painful MTP joint of the big toe (podagra) • tophus formation
common location of tophus formation in gout?
external ear • olecranon bursa • Achilles tendon
acute attack of gout tends to occur when?
after large meal or alcohol consumption
why does alcohol precipitate a gout attack?
alcohol metabolites compete for same excretion sites in kidney as uric acid, causing ↓ uric acid secretion and subsequent build up in blood
treatment for acute gout?
NSAIDs (indomethacin) • glucocorticoids
treatment for chronic gout?
xanthine oxidase inhibitors (allopurinol, febuxostat)
pseudogout is caused by what?
deposition of calcium pyrophosphate crystals within the joint space
pseudogout forms crystals with which features?
basophilic, rhomboid crystals that are weakly positively birefringent
typical location of pseudogout?
usually affects large joints (classically the knee)
pseudogout affects who?
> 50yo, M=F
treatment for pseudogout?
NSAIDs for sudden severe attacks • steroids • colchicine
difference between gout and pseudogout crystals under parallel light?
gout= yellow • pseudogout=blue
what are the common causes of infectious arthritis?
S aureus • Streptococcus • Neisseria gonorrhea
what is gonococcal arthritis?
STD that presents with migratory arthritis with asymmetric pattern
presentation of gonococcal arthritis?
affected joint is swollen, red and painful • STD= Synovitis (knee), Tenosynovitis (hand), Dermatitis (pustules)
cause of osteonecrosis (avascular necrosis)?
infarction of bone and marrow
symptoms of osteonecrosis?
pain associated with activity
osteonecrosis is caused by what?
trauma • high dose corticosteroids • alcoholism • SCD
most common site of osteonecrosis?
femoral head
what are the seronegative spondyloarthropathies?
PAIR • Psoriatic arthritis • Ankylosing spondylitis • Inflammatory bowel disease • Reactive arthritis
what are seronegative spondyloarthropathies?
arthritis without rheumatoid factor ( no anti-IgG antibody)
seronegative spondyloarthropathies have strong association with what?
HLA-B27 (gene that codes for HLA MHC class II)
sernegative spondyloarthropathies occur more often in who?
males
what is psoriatic arthritis?
joint pain and stiffness associated with psoriasis
how does psoriatic arthritis present?
asymmetric and patchy involvement • dactylitis (sausage fingers) • pencil in cup deformity on xray
frequency of psoriatic arthritis?
seen in fewer than 1/3 of patients with psoriasis
pathogenesis of ankylosing spondylitis?
chronic inflammatory disease of spine and sacroiliac joints→ ankylosis (stiff spine due to fusion of joints), uveitis, and aortic regurgitation
common presentation of ankylosing spondylitis?
bamboo spine (vertebral fusion)
why is IBS considered a seronegative spondyloarthropathy?
Crohns and UC are often accompanied by ankylosing spondylitis or peripheral arthritis
classic triad in reactive arthritis (reiters syndrome)?
conjunctivitis and anterior uveitis • urethritis • arthritis • can’t see can’t pee can’t climb a tree
when does reiters syndrome occur?
post GI or chlamydia infection
epidemiology of SLE?
90% are female 14-45yo
SLE most common and most severe in who?
black females
presentation of SLE can include what?
fever • fatigue • weight loss • Libmann-Sacks endocarditis • hilar adenopathy • Raynauds phenomenon
what is libmann sacks endocarditis?
verrucous, wart like, sterile vegetations on both sides of valve
what is the common cause of death in SLE?
nephritis
what type of nephritis causes death in SLE?
DPGN if nephritic • MGN if nephrotic
SLE pts test false positive for what?
syphilis RPR/VDRL due to antiphospholipid antibodies, which cross react with cardiolipin used in tests
Lab tests for SLE detect the presence of what?
ANA • Anti-dsDNA • anti-Sm • antihistone Ab
use of ANA test for SLE?
sensitive (primary screening) but not specific for SLE
use of anti-dsDNA test for SLE?
very specific, poor prognosis
use of anti-Sm test for SLE?
very specific, but not prognostic
use of antihistone test for SLE?
more sensitive for drug induced lupus
mnemonic for SLE?
I’M DAMN SHARP • Immunoglobulins (anti-dsDNA, anti-Sm, antiphospholipid) • Malar rash • Discoid rash • Antinuclear antibody • Mucositis • Neurologic disorders • Serositis • Hematologic disorders • Arthritis • Renal disorders • Photosensitivity
sarcoidosis is characterized by what?
immune-mediated, widespread noncaseating granulomas and elevated serum ACE levels
sarcoidosis is common in who?
black females
typical presentation of sarcoidosis?
often asymptomatic except for enlarged lymph node. incidental findings on CXR of bilateral hilar adenopathy or reticular opacities
sarcoidosis is associated with what?
restrictive lung disease (interstitial fibrosis) • erythema nodosum • bells palsy • epithelial granulomas containing microscopic Schaumann and asteroid bodies • uveitis • hypercalcemia
what causes hypercalcemia in sarcoidosis?
elevated 1α-hydroxylase-mediated vitD activation in epitheloid macrophages
what is the treatment for sarcoidosis?
steroids
what are the symptoms of polymyalgia rheumatica?
pain and stiffness in shoulders and hips, often with fever, malaise, and weight loss • does not cause muscular weakness
polymyalgia rheumatica is more common in who?
women >50yo
polymyalgia rheumatica is associated with what?
temporal (giant cell) arteritis
findings in polymyalgia rheumatica?
↑ ESR • normal CK
treatment for polymyalgia rheumatica?
rapid response to low dose corticosteroids
fibromyalgia is most commonly seen in who?
women 20-50yo
presentation of fibromyalgia?
chronic widespread musculoskeletal pain associated with stiffness, paresthesia, poor sleep, and fatigue
what is polymyositis?
progressive symmetrical proximal muscle weakness, characterized by endomysial inflammation with CD8+ T cells
polymyositis most often involves which location?
shoulders
