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The Skeleton

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					The Skeleton




     Bone Fractures
Bones and Fractures

   Bones are the most rigid tissue of the body.
    They have the ability to flex and absorb
    pressure/tension.
   However, if bones undergo too much
    pressure they will break.
   When a bone breaks it is called a Fracture.
   http://www.youtube.com/watch?v=88I5IDrxF
    mw
Fractures

   There are two
    types of fractures:
    –   Simple (closed)
    –   Compound
        (open)
Fractures

   Of these two types of
    fractures there are 5
    subtypes of fractures:
    –   Spiral
    –   Comminuted
    –   Transverse
    –   Greenstick
    –   Oblique
Spiral Fracture

   Features an “S” shaped separation
   This is a common fracture of football and
    skiing or sports where the foot is firmly
    planted when the body is suddenly rotated in
    the opposing direction.
Comminuted Fracture

   Consist of 3 or more fragments at the
    fracture site
   Caused by a hard blow or a fall in an
    awkward position
   Difficult healing because of the displacement
    of bone fragments
Transverse Fracture

   Occur in a straight line, more or less at right
    angles
 A direct blow usually causes this injury
http://video.google.com/videoplay?docid=5248568873686668842&hl=en
Greenstick Fracture

   Incomplete breaks
   Imagine taking a new growth stick from a tree
    where it is still green. Try bending it until it
    breaks. Because the stick is so flexible it is
    difficult to break it completely.
Oblique Fracture

   Similar to spiral
   Occurs when one end of the bone receives
    sudden twisting while the other end is fixed
    or stabilized
Fracture Repair

    Even though bone is tough but can also
     break it has the ability to repair/rebuild
     itself.
    There are 4 steps to Fracture Repair:
    1.   Hematoma Formation
    2.   Fibrocartilaginous Callus Formation
    3.   Bony Callus Formation
    4.   Remodeling
Hematoma Formation

   When the bone is broken, blood vessels are
    torn & bleed
   As a result of bleeding, a hematoma forms at
    the fracture site
Fibrocartilaginous Callus Formation

   -Capillaries grow into the hematoma &
    phagocytic cells invade the area & begin to
    clean up the debris
   Fibroblasts & osteoblasts migrate to fracture
    site & begin reconstructing the bone,
    resulting in formation of the fibrocartilaginous
    callus
   Callus splints the bone
Bony Callus Formation

   Osteoblasts & osteoclasts migrate to
    fibrocartilaginous callus & convert it into a
    bony (hard) callus of spongy (woven) bone
   Bony callus formation begins 3-4 weeks after
    injury & continues until a firm union is formed
    2-3 months later
Remodeling

   Compact bone is laid down on the spongy
    bone as a final reconstruction to the injured
    area
   http://www.metacafe.com/watch/76772/bloop
    ers/

				
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posted:4/25/2012
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