Bone tissue pathology Flashcards
1
Q
Achondroplasia –> problem
A
failure of longitudinal bone growth (endochondral ossification) –> short limbs
2
Q
Achondroplasia –> appearance
A
short extremities with normal sizes head and chest
large head RELATIVE to limbs
3
Q
Achondroplasia –> membranous ossification
A
not affected (normal head and chest)
4
Q
Achondroplasia –> pathophysiology
A
constitutive activation of FGFR3 –> inhibits chondrocyte proliferation –> impaired cartilage proliferation in growth plate –> impaired endochondral ossification
5
Q
mutation in achondroplasia
A
FGFR3 (activation)
6
Q
Achondroplasia –> sporadic vs inherited mutation
A
> 85% sporadic
7
Q
Achondroplasia –> inherited type - mode of inheritance
A
AD (if homozygosity –> lethal)
8
Q
homozygotic achondroplasia
A
lethal
9
Q
Achondroplasia is the MCC of
A
dwarfism
10
Q
Dwarfism is
A
a condition of short stature
11
Q
MCC of Dwarfism
A
achondroplasia
12
Q
achondroplasia - mental function
A
normal
13
Q
achondroplasia - life span
A
normal
14
Q
achondroplasia - fertility
A
normal
15
Q
achondroplasia - sporadic mutation frequency is increased with
A
paternal age
16
Q
osteopetrosis is also called
A
marble bone disease
17
Q
osteopetrosis (marble bone disease) - pathophysiology
A
Carbonic anhydrase –> impair ability of osteoclast to generate acidic environment (necessary for bone resorption) –> thickened, dense bones
18
Q
thickened, dense bones of osteopetrosis prone to
A
fractures
19
Q
osteopetrosis - clinical manifestations (why)
A
- pancytopenia (bone fills marrow space)
- extramedullary hematopoiesis (bone fills marrow)
- cranial nerve inmpingement and palsies (narrowed foramina)
- hydrocephalus (narrowing of the foramen magnum)
- bone fractures
- Renal tubular acidosis (carb anhydr II mut)
20
Q
foramen magnum?
A
the hole in the base of the skull through which the spinal cord passes.
21
Q
osteopetrosis - nerve inpingemeted and palsies can cause
A
vision and hearing impairment
22
Q
osteopetrosis - renal involvement
A
renal tubular acidosis (carb anhydr II mut) –> decreased tubular reabsorption of HCO3- –> metabolic acidosis
23
Q
osteopetrosis - X-RAY appearance
A
bone - in - bone appearance
24
Q
osteopetrosis - cranial nerve inmpingement and palsies due to
A
narrowed foramina
25
osteopetrosis - hydrocephalus due to
narrowing of the foramen magnum
26
treatment of osteopetrosis (why)
Bone marrow transplant is potentially curative as osteoclasts are derived from monocytes
27
types of osseous tissue
1. cortical bone
| 2. trabecular bone
28
trabecular bone is also called
spongy bone
29
Primary osteoporosis?
trabecular (spongy) bone loses mass an interconnections despite normal bone mineralization and lab values
30
primary osteoporosis - Ca2+ leves
normal
31
primary osteoporosis - Pi leves
normal
32
primary osteoporosis - diagnosis by
1. bone mineral density test (DEXA)
| 2. fragility fracture of hip or vertebra
33
DEXA - osteoporosis if
T-score less than -2.5
34
2ry osteoporosis can be caused by
A. DRUGS (1. long term exogenous steroid use 2. anticonvulsants 3. anticoagulants 4. thyroid replacement therapy 5. alcohol)
B. OTHER medical conditions (1. hyperparathyroidism 2. hyperthyroidism 3. MM 4. malabsorption syndromes)
35
primary osteoporosis can lead to
1. vertebral compression fractures
2. fractures of femoral neck
3. distal radius fracture
36
distal radius fracture is also called
Colles fracture
37
vertebral compression fractures - presentation
1. acute back pain
2. loss of height
3. kyphosis
38
Colles fracture is
distal radius fracture
39
primary osteoporosis types
```
type 1 (post-menopausal)
type 2 (senile)
```
40
type 1 (post-menopausal) osteoporosis - mechanism
decreased estrogen levels --> increased bone resorption
41
osteoporosis - alkanine phosphate levels
normal
42
type 2 (senile) affects
men and women >70 years old
43
primary osteoporosis - prophylaxis
- regular weight bearing exercise
| - Ca2+ and vitamin D intake throughout adulthood
44
primary osteoporosis - treatment
- biphosponates
- PTH analogs
- SERMs
- calcitonin
- denosumab
45
primary osteoporosis - treatment - mechanism of biphosponates
induce apoptosis of osteoclasts
46
denosumab - mechanism of action
monoclonal antibody against RANKL
47
Vitamin D deficiency can cause
adults --> osteomalacia (defective mineralization of osteoid)
children --> rickets (defective mineralization of cartilaginous growth plates)
48
Vitamin D deficiency --> condition of bones (mechanism)
Vitamin D deficiency --> defective mineralization/calcification of osteoid --> soft bones that bow out
49
Vitamin D deficiency - serum P level(mechanims)
decreased vitamin D --> decreased serum Ca2+ --> increased PTH secretion --> DECREASED SERUM Pi
50
Vitamin D deficiency - Ca2+
low
51
Vitamin D deficiency - ALP level (why)
increased ALP (because of osteoblast hyperactivity - osteoblasts require alkaline environment)
52
Osteonecrosis is AKA
avascular necrosis
53
osteonecrosis (avascular necrosis) - pathology
infraction of bone and marrow
54
osteonecrosis (avascular necrosis) - clinical presentation
painful
55
osteonecrosis (avascular necrosis) - MC site
femoral head
56
osteonecrosis (avascular necrosis) - MC site and why
femoral head
| due to insufficiency of medial circumflex femoral artery
57
causes of osteonecrosis (avascular necrosis)
```
mnemonic ASSEPTIC + slipped capital femoral epiphysis
Alcoholism
Sickle cell anemia
Storage (Gaucher disease)
Exogenous/Endogenous steroids
Pancreatitis
Trauma
Idiopathic (Legg-Calve-Perthes disease)
Caisson ("the bends")
slipped capital femoral epiphysis
```
58
Caisson disease is also called (why)
"bends" for joint or skeletal pain
59
idiopathic osteonecrosis (avascular necrosis) is AKA
Legg-Calve-Perthes disease
60
Legg-Calve-Perthes disease?
idiopathic osteonecrosis (avascular necrosis)
61
X-ray of femoral head osteonecrosis (avascular necrosis)
irregular lucencies in femoral heads with adjacent sclerosis
62
MRI of femoral head osteonecrosis (avascular necrosis)
dark serpiginous necrotic bone
63
Paget disease of bone is also called
osteitis deformans
64
Paget disease of bone (osteitis deformans) - frequency
common
65
Paget disease of bone (osteitis deformans) - localized or general
localized
66
Paget disease of bone (osteitis deformans) - pathophysiology
LOCALIZED disorder of bone remodeling caused by increased in both osteoblastic and osteoclastic activity
67
Paget disease of bone (osteitis deformans) - Ca2+ levels
normal
68
Paget disease of bone (osteitis deformans) - Pi levels
normal
69
Paget disease of bone (osteitis deformans) - PTH levels
normal
70
Paget disease of bone (osteitis deformans) - ALP levels
increased
71
Paget disease of bone (osteitis deformans) - increased risk of
osteogenic sarcoma
72
vitamin D deficiency in seen with
1. decreased sun exposure 2. liver failure 3. malabsorption 4. poor diet 5. renal failure
73
Paget disease of bone (osteitis deformans) - etiology
unknown
| probably viral
74
Paget disease of bone (osteitis deformans) - increased risk for
osteogenic sarcoma
75
Paget disease of bone (osteitis deformans) - clinical presentation
1. increased hat size
2. hearing loss
3. hight output cardiac failure
4. long bone chalk-stick fractures
76
Paget disease of bone (osteitis deformans) - mechanism of hearing loss
auditory foramen narrowing
77
Paget disease of bone (osteitis deformans) - mechanism cardiac failure
increased formation of arteriovenous shunts
78
Paget disease of bone (osteitis deformans) - architecture
Mosaic pattern of woven and lamellar bone pp> osteocytes with lacunae in chaoitic juxtapositions
79
Paget disease of bone (osteitis deformans) - stages (and process)
1. Lytic - osteoclasts
2. Mixed - osteoclasts and osteoblasts
3. Sclerotic - osteoblasts
4. Quiescent - minimal osteoclast/osteoblast activity
80
osteoporosis - serum Ca2+
normal
81
osteoporosis - Pi
normal
82
osteoporosis - ALP
normal
83
osteoporosis - PTH
normal
84
Osteopetrosis - PTH
normal
85
osteopetrosis - ALP
normal
86
osteopetrosis - Pi
normal
87
osteopetrosis - serum Ca2+
normal/decreased
88
osteopetrosis - serum Ca2+ - when is decreased
in severe malignant disease
89
Paget disease of bone (osteitis deformans) - serum Ca2+
normal
90
Paget disease of bone (osteitis deformans) - Pi
normal
91
Paget disease of bone (osteitis deformans) - ALP
increased
92
Paget disease of bone (osteitis deformans) - PTH
normal
93
osteomalacia/rickets - serum Ca2+
low
94
osteomalacia/rickets - Pi
low
95
osteomalacia/rickets - ALP
increased
96
osteomalacia/rickets - PTH
increased
97
causes of hypervitaminosis D
1. oversupplementation
| 2. granoulomatous disease
98
hypervitaminosis D - serum Ca2+
increased
99
hypervitaminosis D - Pi
increased
100
hypervitaminosis D - ALP
normal
101
hypervitaminosis D - PTH
low
102
primary hyperparathyroidism causes
osteitis fibrosa cystica
103
primary hyperparathyroidism is caused by
1. idiopathic
2. parathyroid hyperplasia
3. parathyroid adenoma
4. parathyroid carcinoma
104
osteitis fibrosa cystica is also called (why)
brown tumor
| because its is filled with brown
105
osteitis fibrosa cystica causes (appearance)
subperiosteal thinning
106
primary hyperparathyroidism - serum Ca2+
increased
107
primary hyperparathyroidism - Pi
decreased
108
primary hyperparathyroidism - ALP
increased
109
primary hyperparathyroidism - PTH
increased
110
secondary hyperparathyroidism - serum Ca2+
decreased
111
secondary hyperparathyroidism - Pi
increased
112
secondary hyperparathyroidism - ALP
increased
113
secondary hyperparathyroidism - PTH
increased
114
secondary hyperparathyroidism - is often due to
chronic rena disease
115
denosumab?
monoclonal antibody against RANKL
116
osteomalacia - x rays
osteopenia and Looser zones (pseudofractures)
117
rickets - x-rays
epiphyseal widening and metaphyseal cupping/fraying
118
children with rickets - presentation
bow legs. bead-like costochondral junctions (rachitic rosary), craniotabes (soft skull)
119
storage disease that causes osteonecrosis
Gausher disease
120
artery of the femoral head
- branch of obturator artery
| medial and lateral femoral arteries
