Term
| What happedn in Inflammatory phase of bone healing? |
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Definition
Hematoma form at the fracture site:1-3
Organization of Hematoma (3-10)
Formation of fibrous/cartilageneous callus |
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Term
| What happen in the repair stage? |
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Definition
1st bone callus:
callus becomes denser & bone matrix bridge fx site (40-80days)
Absorption of 1st bone callus:
transfer of material to 2rd bone callus-80-120 days |
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Term
| What happen in remodeling of new bone? |
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Definition
| Responding to stress after 120 days |
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Term
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Definition
| bone formation-called osteoid to calcify to form mature bone |
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Term
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Definition
| reside in haversian system, participate in both bone formation and bone destruction |
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Term
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Definition
| bone resorption and remodeling, reside in Howship's lacunae |
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Term
| What is primary bone healing? |
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Definition
| Direct/inramembranoeous with rigid fixation with compression, and minimal to no callus formation |
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Term
| What is secondary bone healing? |
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Definition
| Indirect/endochondral with some motion at fracture site and callus formation |
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Term
| What are two basic requirements for primary bone healing? |
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Definition
Intact vascular supply to the bone
Stable rigid fixation of fracture fragment |
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Term
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Definition
if the distance b/w the ends of bone is small a unique variation of bone healing can occur. A medulary derived arteriole can be seen oriented perpendicular b/w the gap
Bone is deposited b/w the two opposing surfaces.
No FIbrocartilages is formed prior to bone deposition
Mature lamelar bone is deposited |
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Term
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Definition
If the fracture is compressed then the gap can be eliminated
Capillary budding from harversian canal directly across fracture interface. These advancing columns formed of specifically functioning cells are called: "CUTTING CONES" |
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Term
| In contact healing, in Cutting Cones: |
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Definition
| the tip of this complex is made up of osteoclasts. They cut their way throughj osteoid and cross fx; and osteoblasts then produce a concentric pattern of new lamellar bone |
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Term
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Definition
Any motion at the fracture site during this delicate process would disrupt the migration of the cutting cone and the haversian structure
Motion would initiate hemorrhage, produce fibrocartilage, and the formation of callus= Secondary bone Healing |
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Term
| In secondary bone healing |
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Definition
fracture body naturally attempts to prevent motion by pain, edema, muscle splinting
Decrease motion at the fracture site allow for healing
Body also aids in immobilization by a cellular process called "Callus Formation" |
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Term
| What is in secondary bone healing? |
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Definition
Impaction
Induction
Inflammation
Soft callus
Hard callus
Remodeling |
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Term
| What is impaction in 2rd bone healing? |
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Definition
Fracture
small blood vessels are severed
Hypoxia induces osteoblast function
Osteocytes necrose
Release of lysosomal enzymes to remove necrotic tissue |
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Term
| What is Induction of 2nd bone healing? |
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Definition
| surviving local cells: mitogen make precussor cells proliferate |
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Term
| What is inflammation of 2nd bone healing? |
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Definition
Hematoma formation from osseous and periosteal vessels damaged at the time of injury
Hematoma fills the fracture gap and is invaded by a multitude of cells with varying form and function |
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Term
| What is soft callus/procallus in 2rd bone healing? |
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Definition
Precussor cells differentiate to form new vessels, fibroblasts and intracellular materials and supporting cells
Fibroblast: invade within several days and begin to deposit collagen fibrils and fibrocartilage. These substances stiffen the clot, making it more effective for limiting motion between fracture ends |
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Term
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Definition
| Low oxygen tension: necrosis at the interface of fracture fragments and responsible for the production of fibrocartilage as the basic ground substance in the initial phases of callus formaiton or soft callus formation |
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Term
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Definition
| resorption of necrotic bone occurs as the harversian system which begins the process of remodeling with the removal of nonviable osseous tissue |
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Term
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Definition
Oxygen tension of the procallus increases and the product of these osteoprogenitor cells becomes osteoid
Osteoid is composed of calcium hydroxyapetite, therefore, this phase of bone healing is visible on x-ray
Osteoid is more rigid, increaseing the strength of the callus at this point in healing |
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Term
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Definition
the amount of callus formed at the fracture site is directly proportional to the amount of motion at the fracture site
Therefore, ther is no motion at the fracture site...then there is no callus formation |
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Term
| Remodeing 2nd bone healing? |
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Definition
remodeling: mature callus creates clinical union of the bone fragments. However, callus is temporary
Woven bone of the fixation callus is remodeled as the harversian network invades and resorbs this temporary callus and replaces it with mature lamellar bone |
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Term
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Definition
Distraction Osteogenesis: bone lengthening via traction to correct congenital hereditary, traumatic and septic sources of foot and extremity deformity
Procedures can be done using external fixators |
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Term
| What is distraciton osteogenesis? |
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Definition
Distraciton is initiated
Gap is created and hematoma forms
Vascular channel appear
At either end of the gap fibrocartilage is seen
Corticalization forms around 4-6 months after sx
Can continue to model for up to year |
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Term
| Complication of bone healing? |
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Definition
2rd bone healing
Malunion
Delayed Union
Non-union
Pseudoarthrosis |
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Term
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Definition
| formation of fibrous tissue |
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Term
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Definition
| misalignment of fx fragments 2rd poor reduction |
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Term
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Definition
Inability of fx to heal in an acceptable time:
diagnosis with radiographs
treat with internal or external fixation. Bone drilling, grafts and internal or external bone stimulator |
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Term
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Definition
end stage of delayed union
greater than 8 months to dx
Untreated results in pseudoarthrosis |
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