{"id":599,"date":"2021-01-18T03:08:04","date_gmt":"2021-01-18T03:08:04","guid":{"rendered":"https:\/\/pressbooks.publishdot.com\/anatomyphysiology\/chapter\/10-5-fractures-bone-repair\/"},"modified":"2021-12-07T09:38:35","modified_gmt":"2021-12-07T09:38:35","slug":"10-5-fractures-bone-repair","status":"publish","type":"chapter","link":"https:\/\/pressbooks.publishdot.com\/anatomyphysiology\/chapter\/10-5-fractures-bone-repair\/","title":{"raw":"10.5 Fractures: Bone Repair","rendered":"10.5 Fractures: Bone Repair"},"content":{"raw":"
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Learning Objectives<\/strong><\/p>\n\n<\/header>\n

\n\nBy the end of this section, you will be able to:\n
    \n \t
  • Differentiate among the different types of fractures<\/li>\n \t
  • Describe the steps involved in bone repair<\/li>\n<\/ul>\n<\/div>\n<\/div>\nA\u00a0fracture<\/strong>\u00a0is a broken bone. It will heal whether or not a physician resets it in its anatomical position. If the bone is not reset correctly, the healing process will keep the bone in its deformed position.\n\nWhen a broken bone is manipulated and set into its natural position without surgery, the procedure is called a\u00a0closed reduction<\/strong>.\u00a0Open reduction<\/strong>\u00a0requires surgery to expose the fracture and reset the bone. While some fractures can be minor, others are quite severe and result in grave complications. For example, a fractured diaphysis of the femur has the potential to release fat globules into the bloodstream. These can become lodged in the capillary beds of the lungs, leading to respiratory distress and if not treated quickly, death.\n

    Types of Fractures<\/h2>\nFractures are classified by their complexity, location, and other features (Figure 10.5.1). Table 10.5.1 outlines common types of fractures. Some fractures may be described using more than one term because it may have the features of more than one type (e.g., an open transverse fracture).\n\n \n\n[caption id=\"attachment_598\" align=\"aligncenter\" width=\"551\"]\"Types Figure 10.5.1. Types of fractures.<\/strong> Compare healthy bone with different types of fractures: (a) closed fracture, (b) open fracture, (c) transverse fracture, (d) spiral fracture, (e) comminuted fracture, (f) impacted fracture, (g) greenstick fracture, and (h) oblique fracture.[\/caption]\n\nTable 10.5.1 <\/strong>Types of Fractures\n\n\n\n\n\n\n\n\n\n\n\n
    Type of fracture <\/strong><\/td>\nDescription <\/strong><\/td>\n<\/tr>\n
    Closed (or simple)<\/td>\nA fracture in which the skin remains intact<\/td>\n<\/tr>\n
    Comminated<\/td>\nSeveral breaks result in many small pieces between two large segments<\/td>\n<\/tr>\n
    Greenstick<\/td>\nA partial fracture in which only one side of the bone is broken<\/td>\n<\/tr>\n
    Impact<\/td>\nOne fragment is driven into the other, usually as a result of compression<\/td>\n<\/tr>\n
    Oblique<\/td>\nOccurs at an angle that is not 90 degrees<\/td>\n<\/tr>\n
    Open (or compound)<\/td>\nA fracture in which at least one end of the bone tears through the skin; carries high risk of infection<\/td>\n<\/tr>\n
    Spiral<\/td>\nBone segments are pulled apart as a result of a twisting motion<\/td>\n<\/tr>\n
    Transverse<\/td>\nOccurs straight across the long axis of the bone<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

    Bone Repair<\/h2>\nWhen a bone breaks, blood flows from any vessel torn by the fracture. These vessels could be in the periosteum, osteons, and\/or medullary cavity. The blood begins to clot, and about six to eight hours after the fracture, the clotting blood has formed a\u00a0fracture haematoma <\/strong>(Figure 10.5.2a). The disruption of blood flow to the bone results in the death of bone cells around the fracture.\n\n[caption id=\"attachment_598\" align=\"aligncenter\" width=\"940\"]\"Diagram Figure 10.5.2. Stages in Fracture Repair.<\/strong> The healing of a bone fracture follows a series of progressive steps: (a) A fracture haematoma forms. (b) Internal and external calli form. (c) Cartilage of the calli is replaced by trabecular bone. (d) Remodelling occurs.[\/caption]\n\nWithin about 48 hours after the fracture, chondrocytes from the endosteum have created an\u00a0internal callus<\/strong>\u00a0(plural = calli) by secreting a fibrocartilaginous matrix between the two ends of the broken bone, while the periosteal chondrocytes and osteoblasts create an\u00a0external callus<\/strong>\u00a0of hyaline cartilage and bone, respectively, around the outside of the break (Figure 10.5.2b). This stabilises the fracture.\n\nOver the next several weeks, osteoclasts resorb the dead bone; osteogenic cells become active, divide, and differentiate into osteoblasts. The cartilage in the calli is replaced by trabecular bone via endochondral ossification (Figure 10.5.2c).\n\nEventually, the internal and external calli unite, compact bone replaces spongy bone at the outer margins of the fracture, and healing is complete. A slight swelling may remain on the outer surface of the bone, but quite often, that region undergoes remodelling (Figure 10.5.2d), and no external evidence of the fracture remains.\n
    \n

    Section Review<\/strong><\/p>\n\n<\/header>\n

    \n\nFractured bones may be repaired by closed reduction or open reduction. Fractures are classified by their complexity, location, and other features. Common types of fractures are transverse, oblique, spiral, comminuted, impacted, greenstick, open (or compound), and closed (or simple). Healing of fractures begins with the formation of a haematoma, followed by internal and external calli. Osteoclasts resorb dead bone, while osteoblasts create new bone that replaces the cartilage in the calli. The calli eventually unite, remodelling occurs, and healing is complete.\n\n<\/div>\n<\/div>\n
    \n

    Review Questions<\/strong><\/p>\n\n<\/header>\n

    \n\n[h5p id=\"296\"]\n\n<\/div>\n<\/div>\n
    \n

    Critical Thinking Questions<\/strong><\/p>\n\n<\/header>\n

    \n\n[h5p id=\"297\"]\n\n[h5p id=\"298\"]\n\n<\/div>\n<\/div>\nClick the drop down below to review the terms learned from this chapter.\n\n[h5p id=\"299\"]","rendered":"
    \n
    \n

    Learning Objectives<\/strong><\/p>\n<\/header>\n

    \n

    By the end of this section, you will be able to:<\/p>\n

      \n
    • Differentiate among the different types of fractures<\/li>\n
    • Describe the steps involved in bone repair<\/li>\n<\/ul>\n<\/div>\n<\/div>\n

      A\u00a0fracture<\/strong>\u00a0is a broken bone. It will heal whether or not a physician resets it in its anatomical position. If the bone is not reset correctly, the healing process will keep the bone in its deformed position.<\/p>\n

      When a broken bone is manipulated and set into its natural position without surgery, the procedure is called a\u00a0closed reduction<\/strong>.\u00a0Open reduction<\/strong>\u00a0requires surgery to expose the fracture and reset the bone. While some fractures can be minor, others are quite severe and result in grave complications. For example, a fractured diaphysis of the femur has the potential to release fat globules into the bloodstream. These can become lodged in the capillary beds of the lungs, leading to respiratory distress and if not treated quickly, death.<\/p>\n

      Types of Fractures<\/h2>\n

      Fractures are classified by their complexity, location, and other features (Figure 10.5.1). Table 10.5.1 outlines common types of fractures. Some fractures may be described using more than one term because it may have the features of more than one type (e.g., an open transverse fracture).<\/p>\n

       <\/p>\n

      \"Types
      Figure 10.5.1. Types of fractures.<\/strong> Compare healthy bone with different types of fractures: (a) closed fracture, (b) open fracture, (c) transverse fracture, (d) spiral fracture, (e) comminuted fracture, (f) impacted fracture, (g) greenstick fracture, and (h) oblique fracture.<\/figcaption><\/figure>\n

      Table 10.5.1 <\/strong>Types of Fractures<\/p>\n\n\n\n\n\n\n\n\n\n\n\n
      Type of fracture <\/strong><\/td>\nDescription <\/strong><\/td>\n<\/tr>\n
      Closed (or simple)<\/td>\nA fracture in which the skin remains intact<\/td>\n<\/tr>\n
      Comminated<\/td>\nSeveral breaks result in many small pieces between two large segments<\/td>\n<\/tr>\n
      Greenstick<\/td>\nA partial fracture in which only one side of the bone is broken<\/td>\n<\/tr>\n
      Impact<\/td>\nOne fragment is driven into the other, usually as a result of compression<\/td>\n<\/tr>\n
      Oblique<\/td>\nOccurs at an angle that is not 90 degrees<\/td>\n<\/tr>\n
      Open (or compound)<\/td>\nA fracture in which at least one end of the bone tears through the skin; carries high risk of infection<\/td>\n<\/tr>\n
      Spiral<\/td>\nBone segments are pulled apart as a result of a twisting motion<\/td>\n<\/tr>\n
      Transverse<\/td>\nOccurs straight across the long axis of the bone<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

      Bone Repair<\/h2>\n

      When a bone breaks, blood flows from any vessel torn by the fracture. These vessels could be in the periosteum, osteons, and\/or medullary cavity. The blood begins to clot, and about six to eight hours after the fracture, the clotting blood has formed a\u00a0fracture haematoma <\/strong>(Figure 10.5.2a). The disruption of blood flow to the bone results in the death of bone cells around the fracture.<\/p>\n

      \"Diagram
      Figure 10.5.2. Stages in Fracture Repair.<\/strong> The healing of a bone fracture follows a series of progressive steps: (a) A fracture haematoma forms. (b) Internal and external calli form. (c) Cartilage of the calli is replaced by trabecular bone. (d) Remodelling occurs.<\/figcaption><\/figure>\n

      Within about 48 hours after the fracture, chondrocytes from the endosteum have created an\u00a0internal callus<\/strong>\u00a0(plural = calli) by secreting a fibrocartilaginous matrix between the two ends of the broken bone, while the periosteal chondrocytes and osteoblasts create an\u00a0external callus<\/strong>\u00a0of hyaline cartilage and bone, respectively, around the outside of the break (Figure 10.5.2b). This stabilises the fracture.<\/p>\n

      Over the next several weeks, osteoclasts resorb the dead bone; osteogenic cells become active, divide, and differentiate into osteoblasts. The cartilage in the calli is replaced by trabecular bone via endochondral ossification (Figure 10.5.2c).<\/p>\n

      Eventually, the internal and external calli unite, compact bone replaces spongy bone at the outer margins of the fracture, and healing is complete. A slight swelling may remain on the outer surface of the bone, but quite often, that region undergoes remodelling (Figure 10.5.2d), and no external evidence of the fracture remains.<\/p>\n

      \n
      \n

      Section Review<\/strong><\/p>\n<\/header>\n

      \n

      Fractured bones may be repaired by closed reduction or open reduction. Fractures are classified by their complexity, location, and other features. Common types of fractures are transverse, oblique, spiral, comminuted, impacted, greenstick, open (or compound), and closed (or simple). Healing of fractures begins with the formation of a haematoma, followed by internal and external calli. Osteoclasts resorb dead bone, while osteoblasts create new bone that replaces the cartilage in the calli. The calli eventually unite, remodelling occurs, and healing is complete.<\/p>\n<\/div>\n<\/div>\n

      \n
      \n

      Review Questions<\/strong><\/p>\n<\/header>\n

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      \n