week 3:healing in bone Flashcards

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1
Q

what is a fracture, and the classifications?

A
  • discontinuation of a bone
  • no difference from a “break”

classifications:
- open (through skin)
- closed (within skin)
- incomplete (not complete break)
- displaced
- comminuted (bone fragments)

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2
Q

how do physios help with fractures?

A
  • muscle ROM
  • atrophy
  • soft tissue
  • ligaments
  • propioception
  • joint ROM
  • general conditioning
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3
Q

what are some similarities between general healing and fracture healing?

A

we would expect tissue healing to take place becuase of tissues being affected as well as bone. eg.
- inflammation
- proliferative
- remodelling

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4
Q

what are the differences between bone and tissue healing

A
  • bone can regenerate and fully replace injured bone
  • tissue cannot
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5
Q

bone anatomy

define periosteum

A

it covers the external surface of cortical bone

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6
Q

define endosteum

A

on the inner surface facing into the medullary cavity, somtimes will have cancellous bone eg. femur

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7
Q

what are mesenchymal cells/osteoprogenitor cells

A
  • dit on the endosteal and periosteal surfaces
  • decompose bone and remodel bone
  • they are a reserve supply of cells that action after a break

eg. chrondoblasts, osteoblasts, fibroblasts

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8
Q

purpose of osteoblasts

A

lay down bown

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9
Q

purpose of osteoclasts

A

resorb bone

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10
Q

purpose of fibroblasts

A

lay down collagen

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11
Q

purpose of chrondoblasts

A

lay down cartiliage

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12
Q

what are the stages of fracture healing?

A
  1. haematoma and inflammation (inflammation)
  2. soft callous formation (granulation tissue)
  3. hard callous formation
  4. consolidation and remodelling (remodelling)
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13
Q

describe the inflammatory stage

A
  • bones bleed
  • form a spindle shaped haemotoma - periosteum
  • blood clots (due to the meshwork of fibrin) seals fracture site
  • provides framework for inflammatory cells

at the fracture site: adjacent bone tissue dies
- bone/debris is digested and removed (increase of calcium required)
- **which releases cytokines **
- which cause proliferation of osteoprogenitor cells
- attract in growing blood cells
- can reuse excess clacium for formation of new bone

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14
Q

describe the soft callus stage

A
  • osteoprogenitor cells go into haemotoma and differentiate into chrondoblasts, osteoblasts, fibroblasts, stimulated by growth factors
  • invasion of cappilaries from endosteom & periosteum to continue inflammation
  • ongoing desturctution of the haemotoma and debris
  • laying down of collagen (fibroblasts), possible caritiliage (chrondoblasts) and early organic bone (osteoblasts)

results in a spindle shaped blob of cartilagenous, vascular and hypercellular tissue fo protection fo fracture

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15
Q

describe the 1st stage of hard callous process

A
  • osteoblasts start to secrete calcium and phosphate
  • forms ealry bone
  • it is irregular, temporary and weak
  • grows from the fratures edges across facture gaps
  • forms a colar and bridge of bone
  • protects fracture site
  • chrondoblasts and fibroblasts are resorbed
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16
Q

2nd stage of the hard callous process

A
  • 1-3months
  • second wave of osteoblasts and osteoclasts(resorb bone)
  • remove and relay bone
  • begins to resemble normal bony architecture
  • can weight bear
17
Q

describe the consolidation and remodelling process

A

3-12 months
- vital to have forces/mobility occuring
- removal of weak areas
- lamellar bone and haversian systems (normal bone architecture)
- laying down of correctly aligned bone (osteoblasts)

18
Q

what is lamellar bone

A

it is the bone of an adult skeleton
- can be trabecular (spongey)
- cortical (compact)

19
Q

what is the haversian system?

A
  • The Haversian canals surround blood vessels and nerve fibers throughout the bone and communicate with osteocytes
  • therfere bone is very vascular
20
Q

issues in fracture healing

A
  • immobility: wither as a feature of the fracture or imposed fixation (splints)
  • if the fracture is not stable, pseudeoarthrosis can occur. when two bones do not join properly and a joint is formed essentially
  • deformity with bony alignment
  • large fractures mean alrge bony gaps, therofre bones can heal short, therfore fixation is required to keep right length of bone