06: MSK Flashcards
1
Q
List two common pediatric bone fractures.
A
- Greenstick (bending stress; incomplete extension through bone width)
- Torus (axial force; simple buckle fracture of cortex)
2
Q
Knee: Unhappy triad involves damage to which structures?
A
- MCL
- ACL
- Medial meniscus
3
Q
Nerve supply to “SITS” muscles
A
- Supraspinatus (suprascapular n)
- Infraspinatus (suprascapular n)
- Teres minor (axillary n)
- Subscapularis (upper and lower subscap nn)
4
Q
Which muscles play pivotal roles in arm abduction below 90 degrees?
A
Supraspinatus (0-15o) then deltoid (15-100o)
5
Q
Which muscles play pivotal roles in arm abduction above 90 degrees?
A
- Deltoid (15-100o)
- Traps
- Serratus anterior
6
Q
Most commonly fractured carpal bone
A
Scaphoid (typically due to fall of outstretched hand)
7
Q
Acute carpal tunnel syndrome may be a result of (X) carpal bone dislocation
A
X = lunate
8
Q
Which carpal bone is palpable in anatomical snuff box?
A
Scaphoid
9
Q
Humerus surgical neck fracture: (X) muscle will become flattened and (Y) movements will be compromised.
A
X = deltoid Y = abduction over 15o
(Axillary n injury)
10
Q
Humerus surgical neck fracture: sensation is lost in which areas?
A
Over deltoid and lateral aspect of upper arm (axillary n injury)
11
Q
Pitcher presents with shoulder pain and loss of sensation over lateral forearm. What movements would you expect to be compromised?
A
Forearm flexion and supination (musculocutaneous n injury)
12
Q
Humerus fractures: surgical neck injures (X) n, midshaft injures (Y) nerve, supracondylar injures (Z) n.
A
X = Axillary Y = Radial Z = Median (if anteromedial displacement of proximal humerus)
(“ARM” from proximal to distal fractures); if humerus displaced anterolateral in supracodylar fracture, RADIAL N injured
13
Q
67 yo M presents with finger drop on R hand. He denies history of trauma, is a retired police officer, and spends his days doing work around the house/yard. Sensation intact, and both elbow and wrist flexion/extension intact. Likely diagnosis/mechanism of injury?
A
Injury to posterior interosseous nerve (deep branch of radial) in supinator canal
(potentially due to repetitive pronation/supination such as excessive screwdriver use)
14
Q
Use of crutches may compress (X) nerve.
A
X = radial
15
Q
Which nerve travels with brachial artery between (X) upper arm muscles?
A
X = biceps and brachialis
Median n
16
Q
Median nerve enters forearm and travels between which muscles?
A
- Two heads of pronator teres
2. Then between FDS and FDP
17
Q
(X) nerve passes in Guyon’s canal, between which bones?
A
X = ulnar
Hook of hamate and pisiform
18
Q
A superficial palm laceration will likely compromise which sensation/muscle movements?
A
Recurrent branch of median nerve damage most likely;
Sensation intact
“OAF” (from 1/2 LOAF) will be compromised (loss of thenar muscle group - opposition, abduction, flexion of thumb; ape hand)
19
Q
“Waiter’s tip”, aka (X) palsy, is due to which injury?
A
X = Erb's Upper trunk (C5-6) of brachial plexus
20
Q
“Total claw hand”, aka (X) palsy, is due to which injury?
A
X = Klumpke Lower trunk (C8-T1) of brachial plexus
21
Q
Lumbricals have which actions and which joints?
A
Flex at MCP
Extend at PIP, DIP
22
Q
Clawing of hand (median or ulnar claws) is more prominent with (proximal/distal) nerve lesions.
A
Distal (clawing of fingers evident at rest)
23
Q
Housemaid’s knee: (X) is affected
A
X = pre-patellar bursa (bursitis due to repetitive kneeling)
24
Q
Carpal tunnel: excision of (X) improves symptoms.
A
X = transverse carpal ligament (aka flexor retinaculum)
25
Aside from median nerve, which structures travel in carpal tunnel?
Tendons of FDP, FDS, and FPL
26
Thoracic outlet syndrome most commonly occurs in (X) triangle.
X = Scalene
Formed by anterior and middle scalenes and the first rib
27
A patient with a cervical rib experiences exertional arm pain due to:
Compression of Subclavian artery
28
Scaphoid fractures are at risk for which key complication?
Avascular necrosis (blood supply from radial a branch easily interrupted by fracture)
29
Most of the space in greater sciatic foramen is occupied by:
Piriformis (hence potential compression of sciatic nerve in this foramen = piriformis syndrome)
30
Abdominal surgery (like appendectomy) can cause injury to (X) nerve, which would manifest with which Sx?
X = iliohypogastric (T12-L1)
Burning/tingling pain radiating to inguinal/suprapubic region
31
Absent cremaster reflex is due to (X) nerve compromise. What other Sx would you expect?
X = genitofemoral (L1-2)
Decreased sensation to scrotum/labia majora and medial thigh
32
Sciatic nerve roots:
L4-S3
33
Tibial nerve primarily responsible for which muscle actions?
"TIP" = Tibial Inverts and Plantarflexes (if injured, can't stand on TIP-toes)
34
Peroneal nerve primarily responsible for which muscle actions?
"PED" = Peroneal Everts and Dorsiflexes (if injured, foot dropPED)
35
Baker cyst would most likely compromise which nerve?
Tibial
36
Patient presents with hip drop on L side (when standing on R leg). Where's the injury?
R superior gluteal n
37
Pt presents with hip drop upon walking and tends to lean torso toward L side as she walks. Where's the injury?
L superior gluteal n (leans toward injured side to compensate for contralateral/R hip drop)
38
(X) nerve (enters/exits) pelvis via (Y) just to re-(enter/exit) via (Z).
```
X = pudendal (S2-4)
Exits
Y = greater sciatic foramen
Re-enter
Z = lesser sciatic foramen (near ischial spine)
```
39
Pudendal nerve muscle innervation:
External urethral and anal sphincters; pelvic floor muscles
40
Most common elbow injury in kids (usually ages 1-4)
Radial head subluxation ("Nursemaid's elbow") - tear of annular ligament from periosteal attachment at radial neck
41
2 yo brought in by mom due to refusal to move his L arm. You notice it's held close to his side, extended, and pronated. Kid doesn't seem distressed until you try to move his arm. Diagnosis/mechanism and treatment?
Nursemaid's elbow (radial head subluxation) likely due to sharp pull on arm when elbow was pronated and extended;
Can be resolved by supinating and flexing arm
42
Herniation of L3/L4 disc affects which spinal nerve(s)?
L4 and below (nerves inferior to site of herniation)
43
Difficulty in toe walking and loss of (X) reflex is due to injury at which disc level?
X = achilles
L5-S1 (weak plantar flexion)
44
Difficulty in heel walking is due to injury at which disc level?
L4-5 (weak dorsiflexion)
45
Loss of patellar reflex due to injury at which disc level?
L3-4 (weak knee extension)
46
(X) artery travels with (Y) nerve around surgical neck of humerus
```
X = posterior circumflex
Y = axillary
```
47
(X) artery travels with (Y) nerve around midshaft of humerus
```
X = deep brachial
Y = radial
```
48
(X) artery travels with (Y) nerve in popliteal fossa
```
X = popliteal
Y = tibial
```
49
Which 3 ions determine electrical potential difference (voltage) across membrane?
Na, K, Cl
50
Hip drop can occur with intramuscular injection in which location?
Superomedial quadrant of buttock
51
Pt with back pain that's worse with walking and relieved with bending forward and walking uphill. Diagnosis?
Spinal stenosis - usually due to degenerative arthritis of spine
52
Spinal stenosis can eventually lead to which changes/complications?
1. Intervertebral disc degeneration and herniation
2. Ligamentum flavum hypertrophy
3. Osteophyte formation at facet joints
53
Osteonecrosis of the femoral head most likely due to (X) artery compromise in femoral neck fracture.
X = medial circumflex (off deep femoral a)
54
Smooth muscle contraction: key initiator is (X), which activates (Y).
```
X = Ca (which binds calmodulin)
Y = Myosin light chain kinase
```
55
Smooth muscle relaxation: key initiator is (X), which comes from (Y) cells.
```
X = NO
Y = Endothelial (Ca stimulates NO synthase and NO then diffuses into smooth muscle)
```
56
Smooth muscle relaxation: NO stimulates (X) which then (stimulates/inhibits) (Y).
X = GTP to cGMP formation
Stimulates
Y = Myosin light chain phosphatase
57
Which aspect of bone formation is defective in achondroplasia?
Endochondrial ossification (axial, appendicular skeletons formed by cartilaginous model first, then replaced with woven/lamellar bone)
58
Calvarium, facial bones, and (X) are formed by (Y) ossification. What does this process entail?
```
X = clavicle
Y = membranous
```
Woven bone formed directly (no cartilage model), then remodeled to lamellar bone
59
Osteoblasts differentiate from (X) and osteoclasts from (Y)
```
X = mesenchymal stem cells (in periosteum)
Y = monocyte/macrophage precursors
```
60
Osteoclast activity measured mainly via:
Urine deoxypyridinoline
61
Achondroplasia: most commonly a(n) (X) mutation resulting in (activation/inhibition) of (Y)
X = point
Constitutive activation
Y = fibroblast growth factor (FGF) receptor (inhibits chondrocyte proliferation)
62
Osteoporosis med Rx:
1. Bisphosphonates (Risedronate)
2. SERMs
3. Denosumab (Ab against RANKL)
4. (Rarely) calcitonin
63
(X) drugs increase risk of fractures in osteoporosis patients by decreasing Ca absorption.
X = PPIs
64
Osteopetrosis: defect in (X)
X = osteoclasts (incapable of producing acidic environment for bone resorption)
65
Osteopetrosis: describe the characteristics of the bone
Thick, dense; diffuse/symmetrical sclerosis that makes bone prone to fracture
66
Osteopetrosis: treatment/cure is..
Bone marrow transplant (since osteoclasts are derived from monocytes)
67
Osteomalacia/rickets: (over/under)-activity of (X) cells and defective (Y).
Overactivity
X = osteoblasts (high ALP)
Y = mineralization of osteoid matrix
68
Bone and liver ALP can be distinguished by which test?
Boiling test (bone ALP will denature)
69
"Bead-like" chostochondral junction in kid is referred to as (X) rosary and is sign of:
X = rachitic
Rickets
70
Paget's disease: (over/under)-activity of (X) cells.
Overactivity
| X = osteoclasts and ostoblasts (poor quality bone formation)
71
T/F: Both Paget's disease and osteoporosis present with normal serum Ca, PTH, PO4, and ALP levels.
False - Paget's will have high ALP
72
How might Paget's disease affect the heart?
High blood flow from increased A-V shunts can cause high-output heart failure
73
Paget's: increased risk for (X) cancer
X = osteogenic sarcoma
74
Paget's disease Rx:
Bisphosphonates
75
53 yo M with Hx DM II and alcoholism presents with progressive R groin/hip pain that's exacerbated by walking. X-ray suggests osteonecrosis. What would you expect to see on microscopy?
Dead bony trabeculae (empty lacunae) and fat necrosis
76
Osteopetrosis: (high/low) Ca, (high/low) PO4, (high/low) PTH, (high/low) ALP.
All normal
| Note: Ca low in severe malignant disease
77
Osteoblastic aka (lytic/sclerotic) bone lesions seen in which cancers?
Sclerotic (more indolent); prostate, SCLC, Hodgkin
78
Osteolytic bone lesions seen in which cancers?
More aggressive lytic lesions (MM, NSCLC, NHL, RCC, Melanoma)
79
Most common benign bone tumor is (X), commonly in (young/old) (M/F) population
X = osteochondroma
| Young (under 25) males
80
30 year old F with bone growth on distal femur that has soap bubble appearance on x-ray.
Giant cell tumor (osteoclastoma)
81
Which bone tumor will have cells that express RANKL?
Giant cell tumor
82
Pt with Hx Paget's disease has unilateral knee pain and sunburst pattern on x-ray
Osteosarcoma
83
Anaplastic small blue cell malignant tumor
Ewing sarcoma, t(11;22)
84
Which hand joints are affected in osteoarthritis? Star the ones also affected in Rheumatoid arthritis.
1. DIP (Heberden nodes)
2. PIP* (Bouchard nodes)
3. 1st CMC
85
Which hand joints are commonly affected in rheumatoid arthritis and not in osteoarthritis?
MCP, wrist
86
Rheumatoid arthritis: risk factors
1. Female
2. HLA-DR4
3. Smoking
4. Silica exposure
87
Rheumatoid nodules histology
Fibrinoid necrosis with palisading histiocytes
88
Patient with Hx of Rheumatoid arthritis presents with dyspnea and cough. Which lung complications of RA would you be considering?
1. RA nodules (plus pneumoconiosis; Caplan syndrome)
2. Interstitial lung disease (pulm fibrosis)
3. Pleuritis
89
Pannus versus osteophyte formation. Which is seen in RA?
Pannus (proliferative granulation tissue that erodes cartilage/bone);
Osteophytes (bone spurs) seen in osteoarthritis
90
List two key facts in pt Hx that help distinguish gout from septic arthritis
1. Timeline (hours versus days/weeks)
2. Age
3. EtOH use (can precipitate gout)
91
Synovial fluid analysis: WBCs seen in (gout/septic arthritis).
Both (but much greater, over 100,000, in septic arthritis)
92
Rx for tumor lysis syndrome.
Hydration, urine alkalinization
Allopurinol for prophylaxis
93
Patient with Sjogern syndrome is at risk for which cancer?
MALT lymphoma (presents as parotid enlargement)
94
Pencil-in-cup deformity of DIP on X-ray
Psoriatic arthritis
95
Symmetric joint fusion, uveitis, and aortic regurgitation in 30 yo male
Ankylosing spondylitis
96
Presence of which Ab in SLE plays a role in prognosis?
Anti-dsDNA (poor prognosis; renal disease present)
97
List the three common causes of death in SLE
1. CV disease (accelerated atherosclerosis, early MI)
2. Infections
3. Renal disease
98
40 yo female with cough, elevated serum ACE levels, and elevated CD4/CD8 ratio in bronchoalveolar lavage.
Sarcoidosis
99
Pt with history of sarcoid presents with hepatomegaly. What do you expect to see on liver biopsy?
Scattered granulomas
100
Sarcoidosis Rx:
Steroids (if symptomatic)
101
T/F: Polymyalgia rheumatica symptoms include pain/stiffness in shoulders/hips, fever, weight loss, and proximal muscle weakness.
False - no muscle weakness
102
Progressive muscle weakness and endomysial inflammation with CD8 T cells.
Polymyositis
103
Malar rash and perimysial inflammation/atrophy with CD4 T cells.
Dermatomyositis
104
(X) gland type secretes via membrane-bound vesicles. Give example
X = apocrine ("pig snouting")
Mammary glands
105
Patient presents with severe acne. Their disease involves (X) gland secretion via (exocytosis/vesicles/lysis).
X = sebaceous (holocrine)
Cell lysis
106
Which epithelial cell junction includes cytokeratin in structure?
Desmosome (macula adherens)
107
Which epithelial cell junction includes Ca-dependent proteins and actin filaments?
```
Adherens junction (zonula adherens);
Cadherin proteins
```
108
Hypergranulosis is seen in which disease?
Lichen planus
| increased thickness of stratum granulosum
109
Albinism: what's the defect?
Low tyrosinase activity OR defective tyrosine transport (so low melanin production)
110
Hyperpigmentation associated with pregnancy or OCP use
Melasma ("mask of pregnancy")
111
Eczema, aka (X), cannot be diagnosed without which symptom/feature?
X = atopic dermatitis
Pruritis
112
How can you distinguish an intradermal nevus from compound/junctional nevi?
Intradermal is colorless (older; loses tyrosinase activity)
113
Painful, itchy, hyperpigmented papules on jaw/neck after shaving
Pseudofolliculitis barbae
114
Histology: decreased thickness of stratum granulosum, hyperkeratosis, and PMN clusters in superficial dermis.
Psoriasis
PMN clusters called "Munro microabscesses" and hyperkeratosis is characterized by rete ridges that extend to same level
115
Facial flushing in response to heat/alcohol and bulbous nose
Rosacea
116
Where along respiratory tract would you expect to find verrucae?
Verrucae = warts (HPV 6, 11)
True vocal cords (only place with SSE)
117
Chronic post-mastectomy lymphedema associated with increased risk of which tumor?
Angiosarcoma
118
Skin finding commonly mistaken for Kaposi's sarcoma in (X) patient population. Which characteristic distinguishes the two?
X = AIDs
Bacillary angiomatosis (cuased by B. henselae)
PMN infiltrate in bacillary angiomatosis versus lymphocytic in Kaposi
119
Cystic hygroma seen in (X) location and associated with (Y) patient population
```
X = neck
Y = Turner's
```
120
Tumor found under nailbed differential diagnosis:
1. Subungal melanoma
| 2. Glomus tumor
121
A glomus tumor arises from which cell type?
Modified smooth muscle cells (of glomus body, involved in thermoregulation)
122
T/F: Both Kaposi and Bacillary angiomatosis are pruritic and painful.
False - neither tumors have these characteristics
123
Erysipelas is caused by (X) and usually involves which layers/structures in skin?
X = S. pyogenes infection
Dermis and superficial lymphatics
124
Abscess formation: which organism most likely the cause?
Almost always S. aureus
Note: abscess caused by lysosomal enzyme release from PMNs and macros
125
Crepitus in (X) skin finding is the result of which substances?
X = necrotizing fasciitis
CO2 and methane production
126
Staph scalded skin syndrome versus toxic epidermal necrolysis: what part of epithelium is being targeted?
SSS: keratinocytes attachment to stratum granulosum
TEN: dermal-epidermal junction
127
IgA deposits at tips of dermal papillae
Dermatitis herpetiformis
128
Painful red inflammatory lesions of subcutaneous fat (panniculitis)
Erythema nodosum (usually on anterior shins)
129
List some infections associated with erythema nodosum
1. Coccidioidomycosis
2. Histoplasmosis
3. TB
4. Leprosy
5. Strep
130
Pt with Hx hep C presents with itchy red-purple papules on anterior wrist. What's the next step in examination/management?
Likely Lichen Planus (Pruritic, Purple, Polygonal, Planar Papules/plaques), so check mouth mucosa for Wickham striae (reticular white lines)
131
UV(A/B) dominant in sunburn. UV(A/B) dominant in photoaging.
B (sunBurn)
| A (photoAging)
132
T/F: Basal and squamous cell carcinoma are locally invasive but rarely metastasize.
True (unlike melanoma, with significant risk of metastasis)
133
Skin cancer with "palisading" nucleus
BCC
134
Skin cancer that's S-100 positive
Melanoma
135
Skin cancer associated with chronically draining sinuses and arsenic exposure
SCC
136
Melanoma: (activating/inhibiting) mutation in (X). Which drug treatment may be helpful with this mutation?
Activating
X = BRAF kinase (V600E)
Vemurafenib (VE-mutation-Raf-enib), a BRAF kinase inhibitor
137
(X) drugs both inhibit phospholipase A2 and stimulate (Y). What's the function of (Y)?
```
X = corticosteroids
Y = IKB2
```
Inhibitor protein of NF-KB, which originally activates COX2
138
Osteoporosis Rx that's a recombinant PTH analog (subQ)
Teriparatide
139
Teriparatide should be avoided in which patient populations? What are its side effects/risks?
Paget's or prior cancer/radiation patients (high risk of osteosarcoma)
