Goljan's MSK Flashcards
(176 cards)
1
Q
What causes osteogenesis imperfecta?
A
Defect in synthesis of type I collagen (AD)
2
Q
What is the mechanism of blue sclera in OI?
A
Reflection of the underlying choroidal veins through thin sclera
3
Q
What causes achondroplasia?
A
AD mutation in the FGFR3 gene
4
Q
How does achondroplasia present?
A
Normal head/axial skeleton, short arms/legs, impaired proliferation of cartilage at growth plate
5
Q
What is the pathogenesis of osteopetrosis?
A
Deficiency of osteoclasts (AR); “too much bone”
6
Q
What are the clinical findings in osteopetrosis?
A
Pathologic fractures, visual/hearing loss, anemia
7
Q
How does osteomyelitis spread?
A
Usually spreads hematogenously to bone
8
Q
What is the most common site of osteomyelitis?
A
Metaphysis
9
Q
What is the most common pathogen causing osteomyelitis?
A
S. aureus
10
Q
What is the most common pathogen causing osteomyelitis in sickle cell disease?
A
S. paratyphi
11
Q
What is Pott disease?
A
Tuberculous osteomyelitis involving the vertebral column
12
Q
What pathogen causes osteomyelitis following puncture of foot through rubber footwear?
A
P. aeruginosa
13
Q
What is sequestra?
A
Devitalized bone
14
Q
What is involucrum?
A
Reactive bone formation in periosteum
15
Q
What is a late complication of draining sinus tracts?
A
Danger of SCC at sinus drainage orifice
16
Q
What is the most common metabolic abnormality of bone?
A
Osteoporosis
17
Q
What defines osteoporosis?
A
Loss of both mineralized bone and organic bone matrix (osteoid)
18
Q
What is primary osteoporosis?
A
Idiopathic; most common in children and young adults
19
Q
Who is prone to type I osteoporosis?
A
Postmenopausal women
20
Q
What is type II osteoporosis?
A
Senile type; occurs in men and women
21
Q
What are some causes of secondary osteoporosis?
A
↑ cortisol, heparin, hypogonadism, malnutrition, space travel
22
Q
What is the role of estrogen in maintaining bone mass?
A
Estrogen normally inhibits production of osteoclasts and enhances the activity of osteoblasts
23
Q
How does decreased estrogen affect bone mass?
A
↓EGN: ↑IL-1, IL-6, TNF → ↑osteoclastogenesis
24
Q
What cytokines mediate osteoclastogenesis?
A
IL-1, IL-6, TNF
25
What are the effects of IL-1, IL-6, and TNF on bone?
↑ expression of RANK, RANKL genes, ↓ expression of osteoprotegerin (OPG)
26
What is the mechanism of bone loss in postmenopausal bone mass?
↓EGN: osteoclast activity > osteoblast activity
27
Which fractures occur most commonly in postmenopausal osteoporosis?
Vertebral compression fractures, Colles fracture
28
How is osteoporosis diagnosed?
Dual photon absorptiometry
29
How can osteoporosis be prevented?
Weight-bearing exercises, supplementation of calcium + vit D, smoking cessation
30
How is osteoporosis treated?
Bisphosphonates (first-line), Estrogen replacement in women
31
What is avascular necrosis?
Death of bone cells from blood supply interruption
32
What is the most common site of avascular necrosis?
Femoral head
33
What is the most common cause of avascular necrosis?
Long-term use of corticosteroids
34
What is the mechanism of avascular necrosis in the femoral head?
Subcapsular fracture disrupts blood supply (retinacular arteries from medial circumflex femoral artery)
35
Which wrist bone is most commonly fractured?
Scaphoid bone; susceptible to avascular necrosis
36
What is the most sensitive early test for avascular necrosis?
MRI
37
What is osteochondrosis?
Avascular necrosis of ossification centers in children
38
What is Legg-Calvè-Perthes disease?
Avascular necrosis of the femoral head ossification center; boys > girls
39
What is osteochondritis dissecans?
Variant of osteochondrosis limited to articular epiphysis
40
What causes osteochondritis dissecans?
Trauma is primary insult; ischemia is secondary injury
41
What is the most common site of osteochondritis dissecans?
Lateral surface of medial femoral condyle
42
What occurs in osteochondritis dissecans of the knee?
Piece of cartilage along with a thin layer of bone detaches
43
What is a late complication of osteochondritis dissecans?
Osteoarthritis
44
What is Osgood-Schlatter disease?
Painful swelling of tibial tuberosity at patellar tendon insertion; affects physically active boys
45
What is a typical finding associated with Osgood-Schlatter disease?
Permanent knobby-appearing knees
46
What population is typically affected by Paget disease?
Primarily occurs in men >50 years of age
47
What is the etiology of Paget disease?
Unknown; possible paramyxovirus infection of osteoclasts
48
What bones are targeted in Paget disease?
Pelvis, skull, femur
49
What is the pathogenesis of Paget disease?
Osteoclastic phase followed by an osteoblastic phase
50
What are are the clinical findings in Paget disease?
↑ALP in osteoblastic phase, weak thick vascular bone
51
How does Paget disease typically present?
pain, ↑hat size
52
What are some complications of Paget disease?
Fractures, osteogenic sarcoma, high output heart failure
53
What causes fibrous dysplasia?
Defect in osteoblastic differentiation/maturation
54
What occurs in fibrous dysplasia?
Medullary bone replaced by fibrous tissue with cyst formation
55
What is the most common site of fibrous dysplasia?
Ribs
56
What are the features of [McCune]-Albright syndrome?
Polyostotic bone involvement, cafe au lait spots, precocious puberty
57
What are the complications of fibrous dysplasia?
Pathologic fracture, osteogenic sarcoma, fibrosarcoma
58
What is the most common bone malignancy?
Metastasis (breast cancer is most common source)
59
What is the most common benign bone tumor?
Osteochondroma
60
What are the characteristics of monosodium urate crystals?
Monoclinic (needle-shaped), Negative birefringence (yellow when parallel to slow ray)
61
What are the characteristics of calcium pyrophosphate crystals?
Monoclinic-like (needle-like) or triclinic (rhomboid), Positive birefringence (blue when parallel to slow ray)
62
What does a mucin clot test for?
Joint viscosity; hyaluronic acid is the key lubricant in synovial fluid
63
What joint disorders are classified as group I?
Noninflammatory: osteoarthritis, neuropathic joint
64
What joint disorders are classified as group II?
Inflammatory: rheumatoid arthritis, gout
65
What joint disorders are classified as group III?
Septic: lyme disease, dissemminated gonococcemia
66
What joint disorders are classified as group IV?
Hemorrhagic: trauma, hemophilia
67
Morning stiffness is a characteristic finding in which diseases?
Rheumatoid arthritis, SLE, polymyalgia rheumatica
68
What are some examples of joint effusion?
Blood, exudate
69
What is implied by a hot joint?
Acute inflammation; septic arthritis
70
What is joint crepitus?
Crackling feeling when joint moves; characteristic of osteoarthritis
71
What are some general signs and symptoms of joint disease?
```
Arthralgia (joint pain), Arthritis (pain associated with joint swelling)
Morning stiffness
Abnormal joint mobility
Swelling of joint (effusion)
Redness and warmth of the joint
Joint crepitus with motion
```
72
What is osteoarthritis?
Degeneration of articular cartilage; most common disabling joint disease
73
What is alkaptonuria?
Homogentisic acid deposits in intervertebral disks causing osteoarthritis; characteristic black color
74
What sites are commonly affected in osteoarthritis?
Femoral head, Knee
Cervical/lumbar vertebrae
Hands
75
What are the components of normal articular cartilage?
Proteoglycans (provide elasticity), Type II collagen (provides tensile strength)
76
What is the pathogenesis of osteoarthritis?
Cytokines activate metalloproteinases → degrade proteoglycans/collagen
77
What are the joint findings in osteoarthritis?
Osteophytes at joint margins, Clefts, subchondral cysts
| No joint fusion
78
What is the most common clinical complaint in osteoarthritis?
Pain aggravated by movement
79
When does joint stiffness present in osteoarthritis?
After inactivity
80
How does osteoarthritis affect the hands?
Heberden nodes: DIP joint enlargement/pain, Bouchard nodes: PIP joint enlargement/pain
81
What are the vertebral findings in osteoarthritis?
Degenerative disk disease, compressive neuropathies , Typically in cervical/lumbar region
82
What occurs in neuropathic arthropathy (Charcot joint)?
Loss of proprioception and deep pain sensation, leading to recurrent trauma
83
What are some common causes of neuropathic arthropathy?
Diabetes mellitus, Syringomyelia
| Tabes dorsalis
84
What population is typically affected by rheumatoid arthritis?
Women > men, HLA-DR4
85
What is the role of T cells in the pathogenesis of rheumatoid arthritis?
Activated CD4+ T-cells release proinflammatory agents
86
What is the role of B cells in the pathogenesis of rheumatoid arthritis?
B cells produce rheumatoid factor (IgM antibody against Fc portion of IgG)
87
What is a pannus?
Granulation tissue formed within the synovial tissue by fibroblasts and inflammatory cells
88
What role does pannus play in the pathogenesis of rheumatoid arthritis?
Pannus (granulation tissue): releases cytokines that destroy articular cartilage
89
How does ankylosis occur in rheumatoid arthritis?
Repair of damaged cartilage causes fusion of the joint
90
How does rheumatoid arthritis affect the hands?
MCP and PIP joints, Bilateral ulnar deviation
Swan neck deformity
Boutonnière deformity
91
What is a swan neck deformity?
DIP flexed, PIP extended
92
What is a boutonnière deformity?
DIP extended, PIP flexed
93
What are the pulmonary complications of rheumatoid arthritis?
Interstitial fibrosis, effusions
94
What are the hematologic complications of rheumatoid arthritis?
```
Anemia of chronic disease, Autoimmune hemolytic anemia
Felty syndrome (autoimmune neutropenia, splenomegaly)
```
95
How does rheumatoid arthritis affect the cervical spine?
Subluxation of atlantoaxial joint, cord/vertebral artery compression
96
What common neurologic syndrome can affect the hand in rheumatoid arthritis?
Carpal tunnel syndrome; median nerve entrapment
97
Where do rheumatoid nodules typically occur?
Extensor surface of forearms; lungs
98
What are the cardiovascular complications of rheumatoid arthritis?
Pericarditis, Aortitis
| Vasculitis
99
What is a Baker cyst?
Outpouching of semimembranous bursa into posterior joint space
100
What are the characteristic lab findings in rheumatoid arthritis?
Positive serum rheumatoid factor (RF), Positive antinuclear antibody (ANA)
Polyclonal gammopathy
101
What is Sjögren's syndrome?
Destruction of minor salivary glands and lacrimal glands; female dominant
102
What are the characteristic findings of Sjögren's syndrome?
Rheumatoid arthritis, Dry eyes
| Dry mouth
103
What are the characteristic lab findings in Sjögren's syndrome?
Positive serum ANA, RF, anti-SS-A/anti-SS-B, Lip biopsy confirms diagnosis
104
What lab finding differentiates juvenile rheumatoid arthritis from the adult form?
RF usually negative
105
What is Still disease?
Form of juvenile rheumatoid arthritis that presents with fever, rash, polyarthritis
106
What is the main finding of polyarticular juvenile rheumatoid arthritis?
Disabling arthritis predominates
107
What is the main finding of pauciarticular juvenile rheumatoid arthritis?
Limited arthritis
108
What is gout?
Deposition of monosodium urate in tissue; due to prolonged hyperuricemia
109
In which gender does gout predominate?
Males
110
What is the most common mechanism of gout?
Underexcretion of uric acid
111
What clinical conditions are commonly associated with gout?
Urate nephropathy, Renal stones
Hypertension
Coronary artery disease
Lead poisoning
112
What causes an episode of acute gout?
Free uric acid crystals in joint are responsible for initiating the attack
113
How is acute gout diagnosed?
Must confirm with joint aspiration; hyperuricemia does not define gout
114
What is a tophus?
Monosodium urate deposits in soft tissue around the joint
115
What are the effects of tophi?
Erosive arthritis; bone distintegrates, leaving overhanging edges
116
What is the nonpharmalogical treatment of gout?
Eliminate high-purine diet, Moderate alcohol intake
117
What is the pharmacologic treatment of acute gout?
NSAIDS or colchicine
118
What drugs can be used to prevent gout?
1) Uricosuric agents for underexcretors, 2) Allopurinol for overproduces
119
What is calcium pyrophosphate dihydrate deposition disease?
Calcium pyrophosphate deposited in tissues
120
Incidence of CPPD increases in the presence of which diseases?
Hemochromatosis, Hemosiderosis
| Primary hyperparathyroidism
121
What is the most common variant of CPPD?
Osteoarthritis variant; most commonly affects knee; chondrocalcinosis present
122
What is chondrocalcinosis?
Linear deposits of calcium pyrophosphate in articular cartilage
123
What is the meaning of "seronegative" in seronegative spondyloarthropathies?
RF negative arthritis
124
What are the key characteristics of seronegative spondyloarthropathies?
Negative RF, Positive HLA-B27
Male
Sacroiliitis
125
What are the four main types of seronegative spondyloarthropathies?
Ankylosing spondylitis, Reactive arthritis
Psoriatic arthritis
Enteropathic arthritis
126
What is the typical progression of ankylosing spondylitis?
Begins with bilateral sacroiliitis; over time, vertebrae fuse (bamboo spine)
127
What extra-articular signs are associated with ankylosing spondylitis?
Aortitis, Uveitis with potential for blindness
128
What is Reiter syndrome?
C. trachomatis urethritis, arthritis, conjunctivitis, circinate balanitis
129
What is the diagnostic sign of Reiter syndrome?
Achilles tendon periostitis
130
What are the characteristic findings of psoriatic arthritis?
Sausage-shaped DIP joints, Pencil-in-cup deformity
131
What is the most common cause of nongonococcal septic arthritis?
S. aureus
132
What is the most common cause of septic arthritis in urban populations?
N. gonorrhoeae
133
What are the signs of disseminated gonococcemia?
Septic arthritis, Tenosynovitis, and Dermatitis (STD), Associated with C6-C9 deficiency
134
What causes Lyme disease?
B. burgdorferi (gram-negative spirochete) via Ixodes tick bite
135
What are the animal reservoirs for B. burgdorferi?
White-footed mouse (nymphs; most common cause), White-tailed deer (adult ticks)
136
What is the geographic distribution of B. burdorferi?
Northeast, Upper Midwest US
137
Where does Lyme disease tend to localize?
Skin, CNS, joints, heart, eyes
138
What is the mechanism of Lyme disease?
Organism causes inflammation; cross-reactivity leads to type II/III hypersensitivity
139
What is the pathognomonic sign of early localized infection with B. burgdorferi?
Erythema migrans
140
What are the treatment implications of erythema migrans?
When erythema migrans is observed (sign of early localized infection), empiric treatment can be given without laboratory confirmation
141
What characterizes the early disseminated phase of Lyme disease?
Migratory polyarticular to monoarticular arthritis (Knee is most common site), Neuroborreliosis (bilateral facial nerve palsy)
Meningeal irritation
142
What are the signs of chronic Lyme disease?
Disabling arthritis (knee)
143
What is Babesiosis?
Tick-transmitted hemolytic anemia; may accompany Lyme disease
144
What causes septic arthritis and tendinitis due to a cat/dog bite?
Pasteurella multocida
145
What are type I muscle fibers?
```
Slow twitch (red), Rich in mitochondria and oxidative enzymes
Poor in ATPase enzymes
```
146
What are type II muscle fibers?
```
Fast twitch (white), Poor in mitochondria and oxidative enzymes
Rich in ATPase enzymes
```
147
What is the pathogenesis of muscle weakness?
Abnormality of motor neuron, Abnormality of neuromuscular synapse
Muscle dysfunction
148
What occurs in neurogenic atrophy?
Motor neuron or axon degenerates
149
What causes Trichinosis?
Trichinella spiralis (nematode); from eating encysted larvae in pig muscle
150
What findings are associated with Trichinosis?
Calcified larvae visible on x-ray
151
What is the presentation of Trichinosis?
Muscle pain, Periorbital edema
| Splinter hemorrhages
152
What invasive infections are caused by group A streptococcus?
Necrotizing fasciitis, myositis
153
What is the pathogenesis of invasive group A streptococcus?
Exotoxin A (superantigen), Exotoxin B (protease)
154
What is the morphology of C. tetani?
Gram-positive anaerobic rod
155
How is tetanus transmitted?
Spores enter via closed wounds, skin-popping IVDA, umbilical cord/circumcision site
156
What promotes germination of tetanus spores?
Enhanced with necrosis, poor blood supply
157
What is the mechanism of tetanospasmin?
Inhibits release of glycine/GABA by binding to ganglioside receptors on spinal afferent fibers
158
What are the presenting features of tetanus?
Lockjaw, Risus sardonicus
| Opisthotonus
159
What is the role of vaccination in tetanus?
No permanent immunity; require tetanus toxoid vaccine every 10 years
160
What are the morphologic features of C. perfringens?
Gram-positive anaerobic rod
161
What infections are caused by C. perfringens?
```
Myonecrosis (gas gangrene), Food poisoning
Sepsis
Peritonitis
PID
Septic endometritis
```
162
What causes Duchenne muscular dystrophy?
X-linked recessive absence of dystrophin
163
What is one of the characteristic physical findings in Duchenne muscular dystrophy?
Pseudohypertrophy of calf muscles
164
What is one of the characteristic clinical findings in Duchenne muscular dystrophy?
Waddling gait due to weakness of pelvic muscles
165
What lab findings are associated with Duchenne muscular dystrophy?
↑↑↑serum CK at birth; ↓as muscles degenerate
166
What causes myotonic dystrophy?
CTG trinucleotide repeat; autosomal dominant, most common adult muscular dystrophy
167
What is myotonia?
Inability to relax muscles
168
What are the clinical findings in myotonic dystrophy?
Sagging face, Frontal balding
Cataracts
Testicular atrophy
Cardiac involvement
169
What is myasthenia gravis?
Autonomic disorder of postsynaptic neuromuscular transmission
170
What is the mechanism of myasthenia gravis?
Antibodies block and/or destroy ACh receptors
171
What is the most common initial finding of myasthenia gravis?
Ptosis; diplopia common
172
What are some other clinical findings in myasthenia gravis?
Oropharyngela dysphagia for solids/liquids
173
What is the mechanism of Tensilon?
Inhibits acetylcholinesterase
174
What is a Dupuytren contracture?
Fibromatosis of palmar fascia
175
What is a Desmoid tumor?
Fibromatosis of anterior abdominal wall; associated with polyposis syndromes
176
What is the most common adult sarcoma?
Liposarcoma
