Full transcript
0:00a fracture is defined as a loss of
0:02integrity in a bone
0:04which is usually the result of
0:05mechanical trauma
0:07bone healing intends to restore the
0:10continuity of the bone
0:11once a fracture has occurred bone
0:14healing occurs in
0:15four stages in the first stage which is
0:18known as the hematoma phase
0:20or the blood clot stage this occurs from
0:230 to 48 hours post fracture
0:26in this phase ruptured blood vessels
0:29leak
0:30blood into the fracture site which fills
0:33the gap between the two fracture ends
0:36this clotted blood then provides a
0:39fibrous mesh
0:40framework between the gaps which allows
0:44white blood cells to come into the area
0:46such as neutrophils
0:48and macrophages which clean up
0:50phagocytose
0:52and get rid of necrotic tissue
0:54fibroblasts come in
0:55and lay down collagen and endothelial
0:58cells start to lay down new blood
1:00vessels
1:01in the second stage which is known as
1:03the soft callus stage
1:05which occurs from zero to two weeks
1:08platelets and white blood cells come in
1:12and release certain growth factors such
1:14as
1:15pdgf and fgf which causes the
1:19proliferation of bone cells
1:21and chondrocytes by the end of the first
1:23week the soft callus phase
1:25is well underway this is also sometimes
1:27known as the pro callous stage
1:30osteoblasts lay down woven tissue
1:34which is also known as ostoid or
1:38an organic tissue as well as
1:40chondrocytes
1:41lay down some cartilage
1:45moving into the bony color stage which
1:48occurs between
1:49the second and 12 weeks post fracture
1:52the soft callus which is all the ostoid
1:55tissue
1:56starts to become mineralized so calcium
2:00and minerals such as phosphate this is
2:02sometimes known as hydroxyapatite
2:05starts to mineralize and make the callus
2:08hardened moving into the remodeling
2:11phase
2:12as we start to weight bare so as we
2:14start to put
2:15force down into the bone
2:18this causes remodeling so
2:21starts to take away tissue that is not
2:24physically stressed
2:26so we start to lose some tissues
2:29whereas the areas that are stress will
2:31thicken
2:32and this ultimately will reduce the size
2:34of the bony callus
2:36and hopefully restore the bone to its
2:39original integrity