Term
| Describe the sequence of events of indirect bone union: |
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Definition
Intermittent bone contact:
1)Hemorrhage in the area
2)Clot formation
3)Inflammation and edema
4)Proliferation of pluripotential mesenchymal cells
5)Cartilage and bone formation
6)Remodeling of callus back to normal bone
(resoprtion of fracture ends).
Granulation tissue --> fibrous tissue --> cartilage --> Mineralized cartilage --> lamellar bone --> cortical bone
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Term
| What are the three types of callus formation based on location? |
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Definition
1) Medularry bridging callus
2) Periosteal bridging callus
3) Intercortical bridging callus |
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Term
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Definition
The point at which the bone is able to assume normal weight-bearing forces without dependence on the fixation device.
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Term
| What type of loading is responsible for delayed union? |
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Definition
| Excessive dynamic loading; transformation of callus from cartilage to bone is delayed because of the poor blood supply within the areas of excessive motion. |
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Term
| The amount of callus is in inverse relation to what? |
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Definition
| The degree of stability at the fracture site. |
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Term
| Describe direct bone union: |
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Definition
* Healing in areas of contact and high compression forces as well as in very small stable gaps <0.1mm
* This type of union bypasses other steps and goes directly to cortical remodeling. |
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Term
| Describe the union of cortices in direct bone union: |
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Definition
Achieved by internal remodeling of the haversian system w/o resorption of the fracture surfaces.
* Stabilization is characterized by no visible intercortical callus and smal amounts of medullary bridging callus. |
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Term
| What are the four principles of fracture treatment? |
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Definition
1. Anatomical reduction
2. Stable fixation
3. Preservation of the blood supply
4. Early active pain free mobilization |
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