Dr. Yoho

Question 1

Osteogenesis

Answer 1

• osteoblasts make osteoid from albumin –> aided by vit A and C, estrogen and growth hormone
• mineraliztion or calcification is triggered by the high affinity of osteoid matrix for hydroxyapatite
• STIMULATED BY LOW OXYGEN tension and ACIDIC environment
• Aided by local alkaline environment
  
  • created by alkaline phosphatase

Question 2

Osteolysis

Answer 2

• osteoclasts and PTH hormone stimulate an ACID PHOSPHATASE to proteolytic action on osteoid crystals
• osteoclasts are stimualted by HIGH OXYGEN tension
• Aided by an acidic enviornment and a DECREASE in Ca and Phosphate ions

Question 3

CLASSIFICATION OF OSTEOPENIA

Answer 3

• osteopenia –> descriptive term for a LOSS of bone density observed RADIOGRAPHICALLY
  
  • 50% = clinical significant
  • 30% = radiographicaly detectable
• QUANTIFIED BY DEXA or ULTRASOUND AS T-SCORE and Z-SCORE
  
  • normal = bone density is within 1 SD of the young adult mean
  • Low bone mass = 1-2.5 SD below young adult mean
  • osteoporosis = 2.5 SD or more below young adult mean
  • severe osteoporosis = 2.5 or more below young adult mean and one or more osteoporotic fractures

Question 4

Generalized osteoporosis

Answer 4

• Definition = decrease in bone density of mineralized bone
• Classification = CLINICAL AND LAB CORRELATION REQUIRED
  
  • congenital (osteogenesis imperfecta)
  • Acquired (aging)
  • Disuse
  • deficiencies (vitamins, proteins, calcium)
• Radiographic findings:
  
  • diminished bone density
  • cortical thinning with endosteal resorption
  • anterior wedging of the vertebral bodies

Question 5

Scruvy –> generalized osteoporosis

Answer 5

• vitamin C deficiency –> osteoblasts fail to produce osteoid
• lack of mineralization
• have slow wound healing with hemorrhagic cutaneous lesions
• alcoholism/starvation population

RADIOGRAPHIC FINDINGS:

• White line of scurvy
• bone spicules at metaphyseal margins (pelkin’s sign)
• corners sign
• Epiphyseal displacement (washed out) –> ringed epiphysis

Question 6

Localized osteoporosis

Answer 6

• disuse atrophy, inflammatory (RA, osteomyelitis)

RADIOGRAPHIC FINDINGS:

• 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

Question 7

Complex regional pain syndrome

Answer 7

• radiographic findings:
  
  • SUDECK’s ATROPHY
    
    • pathcy osteoporosis
    • accentuated joints
    • subchondral bone resorption
    • ground-glass appearance

Question 8

Osteomalacia

Answer 8

• defect in calcification with icnreased accumualtion of uncalcified osteoids (vitamin D deficiency
• Non-resoprtive process

Radiographic Findings:

• generalized decrease in bone density
• loss of trabecular detail
• cortex may be thin and lack definition
• skeletal deformities
• looser’s lines (look like fractures)

Question 9

Rickets radiographic findings

Answer 9

• widening of epiphyseal plate with frayed appearance
• irregular zone of provisional calcification
• metaphyseal cupping
• milkman’s fracture

Bending of the bone and washing out of matrix

• related to vit D deficiency

Question 10

Radiographic features of endocrinopathies

Answer 10

found in hyperparathyroidism, hyperthyroidism, hyperadrenalism, DM

• Subperiosteal resorption
• generalized loss of bone density
• terminal tuft resorption
• browns tumors (hyperthyroidism)

Question 11

Marrow packing disorders

Answer 11

• Hyperplastic marrow response
• EXPANSILE AREA OF LYTIC DESTRUCTION
• periosteal new bone formation
• pathologic fracture

Question 12

Osteoclerosis

Answer 12

• descriptive term for an INCREASE in bone density observed radiographically

Question 13

Paget’s disease

Answer 13

• EXTREMELY HIGH ALK PHOSPHATASE
• Radiographic findings
  
  • Lytic phase
    
    • destructive changes
    • flamed shaped-lesions
    • osteoporosis circumscripta
  • Sclerotic phase
    
    • bizarre new bone formation

Question 14

Osteopetrosis

Answer 14

• failure to absorb primary spongiosa
• Radiographic findings:
  
  • UNFIORM INCREASE IN BONE DENSITY
  • loss of DISTINCTION BETWEEN CORTICAL AND MEDULLARY BONE
  • bone within bone appearance
• So brittle that fractures occur frequently

Question 15

Osteopoikilosis

Answer 15

• MULTIPE areas of round/ovoid bone densities
• few mm to severl cm
• non-progressive
• metaphyseal and epiphyseal involvement in long bones

Question 16

Myositis Ossificans

Answer 16

• heterotrophic soft tissue ossification
• radiographic findings
  
  • ill-defined calcifications
  • organization into bone
  • follows axis of muscle
  • adjacent periosteum may show changes
  • diffrentiate from sarcoma