Bone Pathology - Sheet1

Question 1

non-neoplastic bone disease

Answer 1

fractures involving healthy bone, osteoporosis (esp post menopausal) AND associated fractures, osteomalacia, osteomyelitis, avascular bone necrosis/infarction.

Question 2

osteopenia differential

Answer 2

(decrease in bone mineralization) associated with osteoporosis (common), osteomalacia, malignancy, rare hereditary disorder.

Question 3

osteomalacia definition

Answer 3

Definition: decreased bone mineralization with excess osteoid (wide osteoid seams)

Radiologically appears osteopenic (like osteoporosis) May present with diffuse skeletal pain (without fracture)

Question 4

metastatic tumors to skeleton

Answer 4

neoplasm that is secondary metastatic site (from non-bone primary sites)

Question 5

What is a pathological fracture?

Answer 5

fracture thorugh diseased bone

usually refers to fracture through tumorous or tumor-like bone

Question 6

periosteum–Its response to trauma…

Answer 6

Periosteum functions to **repair bone **

full of nerves (so this hurts when you get kicked!)

Question 7

puberty does what to the cartilagenous epiphyseal plate?

Answer 7

promotes vacularization… which promotes cartilage calcification.

Question 8

What are the two critical regulatory molecules/enzymes for calcium homeostasis?

Answer 8

PTH and Vitamine D(OH)2

Question 9

What vitamin is required for normal mineralization of bone osteoid?

Answer 9

Vit D(OH)2

Question 10

Name some possible complications of healing bone

Answer 10

mal-alignment, non-union, mal-union, osteomyelitis, growth disturbance via breaking of epiphyseal plate), arthritis,

Question 11

osteoporosis

Answer 11

A type of osteopenia due to bone atrophy caused by an imbalance of the bone remodeling process.

No markers, no clinical manifestations.

Currently defined as bone mineral density ≥ 2.5 standard deviations.

Question 12

What are common observations for osteoporosis

Answer 12

kyphosis,

vit D(OH) –> Vit D(OH)2 rxn impaired = Diminished PTH

Question 13

Why should osteoporosis be a diagnosis of exclusion?

Answer 13

Remember the often more treatable / reversible causes of secondary osteoporosis such as osteopenia (differential?)

Decreased bone mineralization (osteopenia) does not automatically = osteoporosis

Question 14

What are the two most common causes of osteopenia?

Answer 14

decreased bone density; osteoporosis and osteomalacia

Question 15

Best prevention for osteoporosis?

Answer 15

maximize peak bone mass (teens/young adults)

Question 16

Primary Hyperparathyroidism

Answer 16

Hypercalcemia due to primary hyperplasia or Neoplastic enlargement of parathyroid glands.

High PTH promotes osteoclastic bone resorption/peritrabecular fibrosis = osteitis fibrosa.

Question 17

Classic Primary Hyperparathyroidism

Answer 17

asymptomatic and detected on biochemical screening studies primary type — *increased Ca and decreased P*

Question 18

Osteomalacia in children is called?

Answer 18

Rickets

Question 19

Osteomalacia: Biochemical profile/Labs

Answer 19

increased serum alkaline phosphatase (>90%)

Low serum Ca or P (50%)

Decreased urinary Ca excretion (33%)

increased PTH (40%)

Decreased 1, 25 dihydroxyvitamin D3 (50%)

Question 20

Parathyroid hormone

Answer 20

At low levels –> exerts anabolic effects (building bone) on osteoblasts and osteoclasts (indirect).

Chronic high PTH levels (primary hyperparathyroidism) –> causes an increase in blood [Ca++].

Question 21

What is the best prevention for osteoporosis?

Answer 21

maximize peak bone mass (teens/young adults) encourage weight-bearing exercise and Ca supplementation

Question 22

Bone pain, fever, local swelling and erythema, and no trauma. What should you think of?

Answer 22

Osteomyelitis

Staphylococcus aureus (95%)

Treatment is aggressive I.V. antibiotics.

Question 23

Most common cause of fungal osteomyelitis in non-immunosuppressed patients

Answer 23

Blastomycosis and coccidioidomycosis

Question 24

Avascular bone necrosis/infarction

Answer 24

infarction due to ischemia

Clinically: subchondral infarcts, medullary infarcts, multiple infarcts.

Common causes: femoral neck fractures or chronic corticosteroid Rx, SLE.

Treatment: often requires joint replacement

Question 25

Paget’s Disease of Bone

Answer 25

(Osteitis Deformans): deforming bone disease of middle-aged to elderly adults.

Epidemiology: Anglo-Saxon heritage highly associated

Pathophysiology: accelerated bone resporption followed by haphazard new bone formation.

Labs: increased alkaline phosphatase.

Three phases: i. Lytic—osteoclasts with bone resorption/ vascularity

ii. Mixed—osteoclasts with osteoblasts, vascularity
iii. Sclerotic—most characteristic radiologically (osteoblastic phase)

Question 26

Osteogenesis imperfecta

Answer 26

congenital disorder of type 1 collagen

Question 27

Tumor/tumor-like lesions involving bones

Answer 27

(bone pain, swelling, local redness, pathologic fracture)

Most common sources = most common visceral cancers: **lung, breast, prostate cancer **

Leukemia: always affects bone marrow

Question 28

Primary bone tumors/tumor-like lesions

Answer 28

most types arise in metaphyses of long bones

Malignant vs. Benign

Question 29

most common primary malignant tumor of children/young adults

Answer 29

Osteosarcoma

Question 30

Most common primary malignant tumor of middle-aged/older adults. May grow very large.

Answer 30

Chondrosarcoma

Question 31

Patients with sickle-cell anemia tend to get _________ osteomyelitis

Answer 31

salmonella