Updated: 6/15/2021

Bone Circulation

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https://upload.orthobullets.com/topic/9005/images/venous vascularization of long bone.jpg
  • Introduction
    • Bone receives 5-10% of cardiac output
    • Bones that receive tenuous blood supply
      • scaphoid
      • talus
      • femoral head
      • odontoid
    • Blood supply to long bone comes from three sources
      • nutrient artery system
      • metaphyseal-epiphyseal system
      • periosteal system
  • Nutrient Artery System
    • High pressure system that branches from major systemic arteries
    • Enter the cortex through the nutrient foramen and enter the medullary canal
      • then branch into ascending and descending branches
        • then branch into arterioles and supply the inner 2/3 of mature bone via the haversion system
  • Metaphyseal epiphyseal system
    • Arteries arise from periarticular vascular plexus
      • e.g. geniculate arteries
  • Periosteal System
    • Low pressure system that supplies the outer 1/3 of bone
      • connected by
        • Volkman's artery (perpendicular to long axis)
        • Haversion system (parallel to long axis)
  • Intracortical Vascularization
    • Intracortical vessels travel within canals
      • Primary Haversian canals
      • Secondary Volkmann canals
  • Direction of Arterial Flow
    • Normal intraosseous blood flow rate is 5-20ml/min/100g of bone
    • Mature bone
      • flow is centrifugal (inside to outside)
        • because of high pressure nutrient artery system and low pressure periosteal system
    • Immature bone
      • flow is centripetal (outside to inside)
        • because low pressure periosteal system predominates
    • Factors increasing blood flow
      • hypoxia
      • hypercapnia
      • sympathectomy
  • Direction of Venous Flow
    • Mature bone
      • flow is centripetal (outside to inside)
        • cortical capillaries drain to venous sinusoids, which drain to the emissary venous system
  • Growth Plate
    • Perichondrial artery is the major source of nutrition of the growth plate
  • Pathoanatomy
    • Fractures
      • patterns of blood flow following fracture
        • immediate phase
          • initial decrease in blood flow after fracture
          • flow is centripetal (outside to inside)
            • because high pressure nutrient artery system is disrupted
            • low pressure periosteal system predominates
      • hours to days
        • increase in blood flow (regional acceleratory phenomenon)
        • peaks at 2 weeks and returns to normal in 3-5 months
    • Intramedullary nails
      • unreamed intramedullary nails preserve endosteal blood supply
      • reaming devascularizes inner 50-80% of the cortex and delays revascularization of endosteal blood supply
      • loose fitting nails spare cortical perfusion and allow more rapid reperfusion
      • tight fitting nails compromise cortical perfusion and reperfusion is slow
Flashcards (2)
Cards
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Questions (2)

(OBQ12.157) Which of the following arteries provides the blood supply to the outer third of a long bone diaphysis?

QID: 4517
1

Nutrient artery

14%

(598/4327)

2

Periosteal arterioles

82%

(3563/4327)

3

Medullary artery

1%

(51/4327)

4

Emissary artery

1%

(27/4327)

5

Perichondral artery of LaCroix

2%

(65/4327)

L 2 B

Select Answer to see Preferred Response

(OBQ05.107) Disruption of which of the following interrupts the major source of nutrients to the growth plate?

QID: 993
1

Diaphyseal artery

2%

(29/1272)

2

Metaphyseal artery

32%

(401/1272)

3

Perichondrial artery

64%

(817/1272)

4

Synovial fluid

1%

(16/1272)

5

Synovial blood vessels

0%

(4/1272)

L 3 D

Select Answer to see Preferred Response

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EXPERT COMMENTS (3)
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