MSK Review Flashcards
1
Q
Epidermis layers from surface to base
A
Stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, statum basale
(californians like girls in string bikinis)
2
Q
Tight junctions
A
Zonula occludens. Prevents paracellular movement of solutes. Composed of claudins and occludins
3
Q
Adherens junctions
A
Zonula adherens, below the tight junction, forms a belt connecting actin cytoskeletons of adjecent cells with Cadherins (calcium dependent adhesion proteins). Loss of e-cadherin promotes mets
4
Q
Desmosomes
A
Macula adherens – spot rivets made of keratin and desmoplakin. Structural support.
5
Q
Disease with autoantibodies against desmosomes
A
Pemphigus vulgaris
6
Q
Disease with autoantibodies against hemidesmosomes
A
Bullous pemphigoid
7
Q
Mcmurray test
A
Pain on external rotation of the knee indicates a medial meniscus tear. Pain on internal rotation indicates a lateral meniscus tear
8
Q
Unhappy triad
A
ACL, MCL, medial meniscus typically.
But lateral meniscus injury is more likely
9
Q
What is the landmark of a pudendal nerve block
A
Ischial spine
10
Q
Where is mcburney’s point
A
Between ASIS and umbilicus. 2/3 to ASIS
11
Q
Landmark for lumbar puncture?
A
Iliac crest
12
Q
Rotator cuff muscles
And their innervations
A
Rotator cuff muscles all innervated by c5-c6 roots.
Supraspinatus infraspinatus teres minor subscapularis
Supra and infraspinatus innervated by the suprascapular nerve.
Teres minor innervated by the axillary nerve.
Subscapularis innervated by the subscapular nerve
13
Q
Prepatellar bursitis
A
Anterior knee problem from kneeling
14
Q
Baker Cyst
A
not a true cyst, but a communication with the knee bursa. Can cause DVT, seen with RA.
15
Q
Wrist bone that is prone to avascular necrosis. Why?
A
Scaphoid because of retrograde blood supply.
Most commonly fractured too.
16
Q
Lunate dislocation causes
A
Carpal tunnel syndrome
17
Q
Carpal tunnel syndrome
A
Entrapment of the median nerve in the carpal tunnel, which cases paresthesia, pain, and numbness in median nerve distribution
18
Q
Causes of carpal tunnel syndrome
A
Pregnancy, hypothyroidism, rheumatoid arthritis
19
Q
Guyon Canal Syndrome
A
Compression of the ulnar nerve at the wrist or hand, classically seen in cyclists from the pressure of their handlebars.
20
Q
Function of rotator cuff muscles
A
Supraspinatus - abducts arm initially
Intraspinatus - laterally rotates arm (pitching injury)
Teres Minor - adducts the arm and laterally rotates
Subscapularis- adducts and medially rotates
21
Q
Fall on outstretched hand
A
Damaged hook of hamate and ulnar nerve injury
22
Q
Erbs palsy
A
Traction or tear of upper trunk C5 - C6. Arm is at side pronated and straight
Caused by a neck injury in infants, and trauma in adults.
Muscle deficits include deltoid and supraspinatus - no abduction. Infraspinatus - no lateral rotation. Biceps - no flexion or supination
23
Q
Klumke palsy
A
Traction or tear of lower trunk (c8-T1). Claw hand.
In infants due to upward arm traction, in adults due to trauma (grabbing tree branch to brace fall)
Loss of intrinsic hand muscles. Lumbricals cannot flex MCP or extend PIP or DIP
24
Q
Thoracic outlet syndrome
A
From pancoast tumor or cervical rib injury. Compression of lower trunk and subclavian vessels. Causes pain, weakness of hand, edema. Claw hand
25
Winged scapula
From LTN, happens in mastectomy. Serratus anterior keeps scapula anchored. ALso cannot abduct arm above horizontal
26
Axillary nerve injury
C5-C6. Injured with a surgical neck of the humerus injury or an anterior dislocation. Flattened deltoid, loss of sensation over deltoid and lateral arm
27
Musculocutaneous nerve injury
C5-C7 from compression of upper trunk. Loss of forearm flexion and supination. Loss of sensation over lateral forearm
28
Radial nerve injury
c5-T1. From midshaft fracture of humerus (because runs in spiral groove) or compression of axilla (saturday night palsy).
Causes loss of sensation over dorsum of hand, posterior forearm and arm. Causes wrist drop (loss of extension), decreased grip strength.
29
Median nerve injury
Supracondylar humerus fracture (proximal lesion), carpal tunnel syndrome/wrist laceration (distal lesion).
Proximal lesion causes popes hand when trying to make fist.
Distal lesion causes resting okay sign.
30
Tinel sign
Tingling on percussion in carpal tunnel syndrome
31
Ulnar nerve injury
C8-T1
Proximal injury is medial epicondyle fracture.
Distal lesion is fractured hook of hamate (fall on outstretched hand)
Proximal injury causes inability to make fist without doing the okay sign.
Distal injury causes resting pope hand.
32
Injury of recurrent median nerve?
Causes apes hand -- loss of thenar muscle group.
NO LOSS OF SENSATION
33
Thenar Muscles
Innervated by the median nerve.
| Include opponens pollicis brevis, abductor pollicis brevis, flexor pollicis brevis.
34
Hypothenar muscles
Innervated by the ulnar nerve
include the opponens digiti minimi, abductor digiti minimi, flexor digiti minimi.
35
Interosseus muscles
Innervated by the ulnar nerve.
Dorsal abduct
Palmar adduct
36
Obturator nerve (roots, cause of injury, presentation)
L2-L4. Injury from pelvic surgery, presents with loss of sensation over medial thigh, no adduction.
37
Femoral nerve (roots, cause of injury, presentation)
L2-L4 Injury from pelvic fracture. Presents with decreased thigh flexion and leg extension
38
Common peroneal nerve (roots, cause of injury, presentation)
L4-S2 Injury from trauma or compression of lateral leg. Fibular neck fracture.
Causes decreased sensation over dorsum of foot, foot drop. No eversion or dorsiflexion
39
Tibial nerve (roots, cause of injury, presentation)
L4-S3. Injury from knee trauma, baker cyst, tarsal tunnel syndrome. Inability to curl toes, no sensation at sole of foot. At proximal lesions, foot is everted at rest, no inversion or plantar flexion
40
Superior gluteal (roots, cause of injury, presentation)
L4-S1 From posterior hip dislocation or polio. Causes trendelenberg gait. Opposite side drops due to loss of ipsilateral medial gluteal muscle.
41
Inferior gluteal (roots, cause of injury, presentation)
L5-S2 Trouble climbing stairs or rising from chair. Can't extend hip.
42
Long thoracic nerve neurovascular pair
Lateral thoracic artery
43
Axillary nerve neurovascular pair
Posterior Circumflex artery
44
Radial nerve neurovascular pair
Deep brachial artery
45
Median nerve neurovascular pair
Brachial artery
46
Tibeal nerve at popliteal fossa neurovascular pair
Popliteal artery
47
Tibeal nerve at medial malleolus
Posterior tibeal artery
48
Steps of muscle contraction
Action potential depolarization opens voltage gated ca channels inducing NT release. NT bind to motor end plate and depolarization occurs. This mechanically opens the ryanodine receptor on SR and causes efflux of calcium, which binds to troponin, slides tropomyosin out of the way. Myosin releases bound ADP and power stroke occurs. ATP binds and Myosin releases.
49
Contraction effect on sarcomere
Shortening of H and I bands and between Z lines.
A band is always the same length
50
Type 1 muscle
Slow twitch red fibers due to increased mitochondria and myoglobin. Sustained contraction
51
Type 2 muscle
Fast twitch, white fibers resulting from decreased mitochondria and myoglobin concentration. Increase in anaerobic glycolysis.
52
Steps of smooth muscle contraction
Action potential leads to calcium influx. Ca binds calcmidulin and phosphorylates MLCK. MLCK phosporylates myosin and cross linking occurs.
Nitric oxide increases cGMP and causes activation of MLKPhosphatase, which removes P from myosin and causes relaxation
53
Endochondral ossification
Bones of the axial and appendicular skeleton. Cartilagenous model of bone is made first by chondrocytes, then osteoclasts and osteoblasts replace woven bone with lamellar bone.
54
Where is woven bone in adults?
Always pathological, seen in fractures and pagets disease
55
Membranous ossicfication
Seen in bones of calvarium and face. Woven bone is formed directly without cartilage and is later remodeled to lamellar bone
56
Osteoblasts
Build bone by secreting collagen and catalyzing mineralization. Differentiate from mesenchymal stem cells in periosteum
57
Osteoclasts
Multinucleated cells that dissolve bone by secreting acid and collagenases. Differentiate from monocytes and macrophages
58
Parathyroid hormone at low intermittant levels
Can actually build bone
59
How does estrogen affect osteoblasts/osteoclasts
Induces apoptosis in osteoclasts
60
Achondroplasia
Activating mutation of FGFR3 causes failure of long bone growth. Membranous ossification not affected. Normal life span and fertility
61
Normal activity of FGFR3
Inhibits chondrocyte proliferation, so activation in FGFR3 means no chondrocyte proliferation.
62
Inheritance pattern of achondroplasia
Sporadic associated with advanced paternal age, but also can be autosomal dominant.
63
Osteoporosis labs
Normal Ca, PO4, PTH.
64
Pathogenesis of osteoporosis
Spongy bone loss and interconnection loss despite normal lab values. Diagnose with DEXA scan and with a T score of
65
Osteoporosis type I
Due to decreased estrogen levels. Can cause femoral neck fracture or colles fracture.
66
Type II osteoporosis
Senile osteoporosis affects males and females >70. Prevent with exercise, adequate calcium and vitamin D intake. Also treat with bisphosphonates.
67
Osteopetrosis
Failure of normal bone resorption due to defective osteoclasts. No carbonic anhydrase so no acidic enviroment to resorb bone. Bone fills the marrow space causing pancytopenia and extramedullary hematopoesis.
Can cause cranial nerve impingment and palsies.
68
How to treat osteopetrosis
Bone marrow transplant because osteoclasts are derived from monocytes
69
Systemic consequence of osteopetrosis
Renal tubular acidosis. No bicarb regenerated so metabolic acidosis ensues.
70
Osteomalacia/rickets
Lack of vitamin D. Defective mineralization and calcification of osteoid causes soft bones that bow out. Decreased Vit D means decreased serum calcium, increased PTH, and decreased PO4. Osteoblasts are overactive too which causes increased alkaline phosphatase.
71
Findings of rickets in children
rachitic rosary, soft bones with varus defect
72
Paget Disease of Bone
A localized disease of bone that is caused by increased osteoclastic activity, followed by a mixed osteoblastic/clastic, then osteoblastic phase. Ca, PTH, and phosphorus levels are normal but alk phos increased. Mosaic pattern with cement lines. Also av shunts cause high output cardiac failure. Also an increased risk of osteosarcoma.
Hat size may increase with hearing loss.
73
Osteonecrosis
Infarction of bone and marrow frequently in femoral head. Caused by trauma, high dose corticosteroids, alcoholism, sickle cell. Due TO DEFICIENCY IN MEDIAL CIRCUMFLEX FEMORAL ARTERY.
74
Caisson's DIsease
Nitrogen bubbles leading to osteonecrosis
75
Labs in osteomalacia
Decreased vit D, vit C, increased PTH, decreased phos
76
Labs in hypervitaminosis D
Increased D, increased C, decreased PTH, increased phos
77
Labs is osteocitis fibrosa cystica
Primary hyperparathyroidism -- increased pth, increased ca, increased alk phos, decrease po4
ESRD - Decreased serum calcium, increased PTH, increased PO4.
78
Giant cell tumor
Bubble sign in epiphysis. Benign. Locally agressive though. generally in knee. Has multinucleated giant cells, mostly in females
79
Osteoblastoma
Large osteoid osteoma, generally bigger than 2cm. Pain doesn't respond to aspirin
80
Osteoma
Benign tumor of facial bones seen in gardner's syndrome
81
Osteoid osteoma
Benign tumor of osteoblasts surrounded by sclerotic bone. Occurs in
82
Osteochondroma
Most common benign tumor. In males
83
Osteosarcoma
Second most common malignant bone tumor after multiple myeloma. Occurs in metaphysis region. Bimodal distribution in teens and older adults (especially due to pagets.) Pleomorphic cells making osteoid, lifts the periosteum and forms codman's angle with a sunburst appearance. Treat with en block resection and chemotherapy.
Predisposing factors: pagets, li-fraument (germline p53 mutation), retinoblastoma, radiation.
84
Ewing Sarcoma
Neuroectodermal cells that are malignant and appear in the diaphysis of long bones. Starts in medulla and lays down periosteum in an onion skin pattern. Can present with FEVER.
Anaplastic small blue cell malignant tumor. Looks like lymphoma or wilm's tumor. Treat with dactinomycin.
Associated with 11;22 translocation
85
Chondrosarcoma
Rare malignant bone tumor seen in medulla and diaphysis. Seen in men 30-60.
86
Chondroma
Benign mass in medulla of small bones of hands and feet
87
Metastatic tumors
More common than primary tumors. From breast, lung, thyroid, kidney, prostate (blastic).
88
Osteoarthritis
Mechanical joint wear and tear. Causes eburnation of joints with production of osteophytes and subchondral cysts. Heberdens and bouchards nodes (PIP and DIP).
Predisposing factors are age, obesity, joint deformity, traums.
Presents with pain in weight baring joints that gets worse as the day goes on. Knee cartilage loss begins medially
Treat with NSAIDS or intraarticular glucocorticoids
89
RA antibody markers
HLA DR4. Rheumatoid factor (not specific) is an IgM anti Fc IgG. ANTI CYCLIC CITRULLINATED PEPTIDE IS MOST SPECIFIC!!!!!
90
Rheumatoid arthritis
Autoimmune destruction of synovial joints mediated by cytokines and type III/IV HSR. Synovitis with pannus formation. Involvement of the wrist but sparing of the DIP.
Ulnar deviation of fingers due to myofibroblasts. Baker cyst formation. C1/C2 subluxation.
Morning stiffness lasting about 30 minutes and improving with use.
Often with systemic symptoms, fever, fatigue, pleuritis, pericarditis.
Can also cause anemia of chronic isease with amyloidosis
91
Sjogren Syndrome antibody markers
Anti Ro anti La. Also known as SSA and SSB.
These are ribonucleoproteins
92
Sjogren syndrome
Autoimmune destruction of exocrine glands, especially lacrimal and salivary. Lymphocytic sialadenitis. Dry eyes, dry mouth, dental caries. Bilateral parotid enlargement due to destruction of submandibular glands.
Can cause MALT lymphoma.
93
What can present with sjogren's like symptoms
Sarcoidosis, amyloidosis
94
Gout
Acute inflammatory monoarthritis with negatively birefringent needles depositing in joints. Can be precipitated by underexcretion of uric acid (can be exacerbated by thiazides), or overproduction of uric acid from tumor lysis syndrome, lesch nyhand syndrome, and von gierke's disease
Joint is red swollen and painful. There is tophus formation on ear, olechranon bursa or achilles. Acute attack tends to occur after a large meal or alcohol
95
Why does alcohol exacerbate gout?
Because alcohol metabolites compete for same excretion sites in kidney as uric acid.
96
How to treat gout
Acute: give nsaids, glucocorticoids, or colchicine
Chronic: allopurinol, febuxostat, probenecid
97
Pseudogout
Presents with pain and effusion in a joint, caused by deposition of calcium pyrophosphate crystals within the joint space. Rhomboid cristals that are positively birefringent. Usually affects large joints and can be seen with hemochromatosis, hyperparathyroidism, and hypoparathyroidism.
98
Infectious arthritis
Red hot joint that is painful. Affects knees hands and skin.
Usually caused by S. aureus, N. gonorrheae, and streptococcus
99
Psoriatic arthritis
Pencil in cup bone deformity. Joint pain and stiffness. Patchy involvement that is asymmetric. Dactylitis. Seen in fewer than 1/3 of patients with psoriasis.
100
Ankylosing spondylitis
Sacroileitis that causes bamboospine. Can also cause aortic regurgitation and upper lobe pulmonary fibrosis
101
Reactive arthritis
Seen with campylobacter, shigella, salmonella, yersinia, or chlamydia infections.
Conjunctivitis/uveitis
Urethritis
Arthritis
102
SLE
Rash, joint pain, fever. Usually in african american female.
Rash (malar/discoid)
Arthritis
Serositis (pericarditis, pleuritis)
Hemolytic anemia (pancytopenia due to type II attack)
Oral/nasopharyngeal ulcers
Renal disease (membranous, or diffuse proliferative)
Photosensitivity/Positive VDRL
Anti-phospholipid syndrome/ANA/ AntidsDNA
Immunosuppressants for treatment
Neurologic involvement (seizures/psychosis)
103
Serology in SLE
```
ANA
Anti-dsDNA
Anti-Smith (snRNP)
Anticardiolipin antibodies
Decreased C3, C4, and CH50
```
104
Drug induced lupus
Caused by hydralazine, procainamide, isoniazid
Generally no CNS/renal issues. Antihistone antibodies
105
Antiphospholipid syndrome
Seen in lupus due to antibodies against cardiolipid (false positive VDRL)
Anti beta 2 microglobulin
Anticoagulant (will increase PTT) but actually predispose to emboli
106
Sarcoidosis
Immune mediated widespread noncaseating granulomas.
Elevated serum ace, elevated vitamin D. Restrictive lung disease, erythema nodosum, schaumann and asteroid bodies, uvitis, hypercalcemia. Can appear to be sjogrens.
107
polymyalgia rheumatca
pain/stiffness in sholders/hips assoc w/ giant cell art. elevated esr an crp, but normal ck.
108
Fibromyalgia
Mostly seen in females 20-50. Chronic, widespread musculoskeletal pain associated with stiffness, paresthesias, poor sleep, and fatigue. Treat with regular exercise, TCA, SNRI, anticonvulsants
109
Duchenne's MD
X-linked deletion of dystrophin gene. Proximal muscle weakness leads to fibrofatty replacement of muscles. Increased CK. Death due to cardiac or respiratory failure.
110
Becker MD
Mutated dystrophin, milder disease
111
Polymyositis
Weakness of shoulder and pelvic muscles. Characterized by endomesial inflammation and CD8 mediated damage.
112
Dermatomyositis
Weakness of proximal muscles, but includes skin findings like malar rash, gottron's papules, shawl sign, heliotrope,
Increased risk of occult malignancy especially gastric cancer.
Perimysial imflammation and cd4 cell predominance.
113
Serology of Poly/dermatomyositis
Increased CK, ANA, anti-jo-1, anti- SRP
114
Scleroderma
Fibrosis and collagen deposition everywhere. Can cause renal crisis, pulmonary findings (most common cause of death), CV, and GI symtpoms. Diffuse scleroderma associated with anti-scl 70 (which is a DNA TOPOISOMERASE I antibody)
115
CREST
You know this, associated with centromere.
