Metabolic Bone Disease- Yoho Flashcards Preview

Clin Pod Med Exam III > Metabolic Bone Disease- Yoho > Flashcards

Flashcards in Metabolic Bone Disease- Yoho Deck (33)
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1
Q

_____ produce osteoid matrix an amorphous ground substance and collagen matrix

A

osteoblasts

2
Q

Bone is made of …

A

ions having crystallized (hydroxyapatite) on the osteoid matrix forming the bone unit

Composition:
Water (8%)
Organic substance (21%)
Inorganic substance (71%)

3
Q

cortical bone is black in ____ and white in _____

A

MRI

CT scan

4
Q

Osteoblasts make osteoid from ______

A

albumin

process is aided by vitamin A and C, estrogen and growth hormone

5
Q

osteogenesis is stimulated by … (2)

A

Stimulated by a low oxygen tension and acidic environmentAided by a local alkaline environmentwhy you measure alkaline phosphatase**

6
Q

Mineralization or calcification is triggered by

A

the high affinity of osteoid matrix for hydroxyapatite

7
Q

dissolution of bone

A

Osteolysis

Osteoclasts and PTH hormone stimulate an acid phosphatase to proteolytic action on the osteoid crystals

8
Q

Osteoclasts are stimulated by

A

Osteoclasts are stimulated by high oxygen tension

Aided by an acidic environment and a decrease in calcium and phosphate ions

9
Q

a descriptive term for a loss of bone density observed radiographically

A

Osteopenia

**50% bone loss is clinically significant
30% bone loss is radiographically detectable

10
Q

quantification of bone loss tools

A

DEXA or ultrasound as T-scores and Z-scores

11
Q

T-Score related to young adult

A

normal— Bone density is within 1 SD (+1 or −1) of the young adult mean.
low bone mass — Bone density is between 1 and 2.5 SD below the young adult mean (−1 to −2.5 SD).
osteoporosis —Bone density is 2.5 SD or more below the young adult mean (−2.5 SD or lower).

severe oseoporosis — Bone density is more than 2.5 SD below the young adult mean, and there have been one or more osteoporotic fractures.

12
Q

Z- Score

A

age and gender matched

13
Q

define generalized osteoporosis

A

Definition: decrease in bone density (mass per unit volume) of mineralized boneclinical and lab correlation required for classification

14
Q

radiographic findings for osteoporosis

A

Diminished bone density
Cortical thinning with endosteal resorption
Preferential resorption of transverse trabeculae
Anterior wedging of the vertebral bodies (dowager’s hump)

15
Q

how does scurvy cause generalized osteoporosis?

A
Vitamin C deficiency
Osteoblasts fail to produce osteoid
Lack of mineralization
Alcoholism/starvation
Slow wound healing, peau de orange
Hemorrhagic cutaneous lesions
16
Q

radiographic findings for scurvy

A

White line of scurvy Bone spicules at metaphyseal margins (Pelkin’s sign) (small arrows of washed out bone)
Corner sign (washed out bone in corner)
Trumifield zone
Epiphyseal displacement
Ringed epiphysis (preferential washing out of epiphysis)
Cortical deossification with ground glass appearance, its going to be generalized throughout the body

17
Q

osteomyelitis and tumors cause what type of osteoporosis

A

localized osteolytic osteoporosis

18
Q

CRPS chronic regional pain syndrome osteoporosis

A

sudeck’s atrophy - localized osteoporosis

19
Q

early –> final lcoalized osteoporosis radiographic findingings

A

Early: spotty loss of density with irregular rarefaction, loss of sharp outline of the articular cortex

Later: periarticular deossification

Final: uniform loss of density with a thin well-defined cortex

**In tumors and infection the process if referred to as lysis (lytic lesions)

20
Q

CRPS complex regional pain syndrome stages

A

Stage I: Acute

Stage II: Dystrophic

Stage III: Atrophic

21
Q

describe sudeck’s atrophy

A

Patchy osteoporosis
Accentuated joints
Subchondral bone resorption
Ground-glass appearance

22
Q

Defect in calcification with increased accumulation of uncalcified osteoid

A

Osteomalacia/Rickets

Vitamin D deficiency
Renal tubular insufficiency
Non-resorptive process
**Skeletal deformity*

23
Q

radiographic findings osteomalacia

A
Generalized decrease in bone density
Loss of trabecular detail
Cortex may be thin and lack definition
Skeletal deformities
Looser’s lines (milkman's false fx)
24
Q

radiographic findings Rickets

A
  • Widening of epiphyseal plate with a frayed appearance
  • Irregular zone of provisional calcification
  • Metaphyseal cupping
  • Milkman’s fracture
25
Q

radiographic features of endocrinopathies

A
  • Subperiosteal resorption
  • Generalized loss of bone density
  • Terminal tuft resorption
  • Brown tumors
  • **Soft tissue calcifications
26
Q

name the marrow packing disorders

A

Thalassemia
Multiple Myeloma
Leukemias

Radiographic findings:

  • Hyperplastic marrow response
  • Expansile areas of lytic destruction
  • Periosteal new bone formation
  • Pathologic fracture
27
Q

a descriptive term for an increase in bone density observed radiographically

A

Osteosclerosis

Mechanisms responsible:

  • Failure of primary spongiosa to be absorbed in the metaphysis during enchondral bone formation
  • Errors of internal modeling of compacta and spongiosa
  • Stimulation of normal endogenous osteoblasts to form excessive new bone
28
Q

describe paget’s disease

A

Incidence: 5th decade

Sites: skull, spine, pelvis and major long bones

Skeletal pain and deformity (increase in size)

tests: Alk Phosphatase, N-telopeptides and deoxypyridinoline

29
Q

radiographic findings for paget’s disease

A

Lytic phase:

  • Destructive changes
  • Flamed shaped-lesions***
  • Osteoporosis circumscripta

Sclerotic phase:
- Bizarre new bone formation

Combined phase:
-Malignant transformation (osteogenic sarcoma)

30
Q

Failure to absorb primary spongiosa

A

Osteopetrosis

31
Q

radiographic findings osteopetrosis

A
    • Uniform increase in bone density
    • Loss of distinction between cortical and medullary bone
    • Erlenmeyer flask appearance of tubular bones
    • Bone within bone appearance
    • Fractures are common
32
Q

radiographic findings osteopoikilosis

A
    • Multiple round/ovoid bone densities
    • Few mm to several cm
    • Non-progressive
    • Metaphyseal and epiphyseal involvement in long bones

Hereditary bone disorder
Unknown etiology
Incidental finding

33
Q

Heterotrophic soft tissue ossification

A

Myositis Ossificans

will have hx of trauma

Radiographic Findings:

    • Ill-defined calcifications
  • -Organization into bone
    • Follows axis of muscle
    • Adjacent periosteum may show changes
    • Differentiate from sarcoma