Updated: 6/4/2021

Types of Bone

0%
Topic
Review Topic
0
0
100%
0%
Evidence
2
0
0
Topic
Images
https://upload.orthobullets.com/topic/9001/images/lamellar bone.jpg
https://upload.orthobullets.com/topic/9001/images/cancellous.jpg
https://upload.orthobullets.com/topic/9001/images/woven bone.jpg
https://upload.orthobullets.com/topic/9001/images/lamellar bone histo.jpg
  • Introduction
    • Bone can be classified based on both anatomy and structure
      • anatomic
        • long bones
        • flat bones
      • structure
        • macroscopic level
          • cortical
          • cancellous
        • microscopic level
          • lamellar
          • woven bone
  • Anatomic classification
    • Long bones
      • e.g. femur, humerus, tibia, forearm bones
      • three anatomic regions in long bones
        • diaphysis
          • thick cortical bone surrounding a central canal of cancellous bone
          • outer region covered by periosteum
        • metaphysis
          • thin cortical bone surrounding loose trabecular bone
        • epiphysis
          • end of bone that forms the articular surface
          • contains the physis and the subchondral region under the articular cartilage
    • Flat bones
      • e.g. skull, pelvis, scapula
      • varied structure of either purely cortical bone or cortical bone with a thin central trabecular region
  • Macroscopic structural classification
    • Cortical
      • 80% of skeleton
      • metabolism
        • characterized by slow turnover rate and high Young's modulus
      • structure
        • made of packed osteons or Haversian systems
          • osteons
            • outer border defined by cement lines
          • vascular canals
            • contain arterioles, venules, capillaries, and nerves
            • if oriented along long axis of bone: Haversian canals
            • if oriented transversely to long axis of bone: Volkmann canals
          • interstitial lamellae
            • the region between osteons
    • Cancellous bone (spongy or trabecular bone)
      • metabolism
        • lower Young's modulus and more elastic
        • high turnover to remodel according to stress across the bone
      • structure
        • boney struts organized into a loose network
        • each strut is approximately 200 micrometers in diameter
        • 30-90% of bone is porous and contains bone marrow
        • increased porosity in osteoporosis
  • Microscopic structural classification
    • Woven bone
      • immature or pathologic bone that is woven and random and is not stress oriented
      • compared to lamellar bone, woven bone has:
        • more osteocytes per unit of volume
        • higher rate of turnover
      • weaker and more flexible than lamellar bone
    • Lamellar bone
      • secondary bone created by remodeling woven bone
      • organized and stress oriented
      • stronger and less flexible than woven bone
Flashcards (0)
Cards
1 of 0
Evidence (2)
VIDEOS & PODCASTS (1)
EXPERT COMMENTS (27)
Private Note