Musculoskeletal - Fractures Flashcards
1
Q
Definition
A
- discontinuity of the bone
- occurs when more stress is put on a bone than it is able to absorb
2
Q
Categories
A
- fracture due to sudden injury
- fatigue / stress fractures (repeated wear on a bone)
- pathologic fractures (due to disease - ie - osteoporosis)
- direct
- indirect (trauma transmitted along the bone)
3
Q
Classifications
A
- proximal - closer to the midline
- midshaft - middle of the bone
- distal - further away from the midline
- open (compound)
- closed (simple)
- compression
- greenstick
- transverse - straight across the bone
- oblique - diagonally across the bone
- spiral - caused by a twisting force
- comminuted - bone broken into smaller fragments
- segmental - bone broken into one fragment
- butterfly - fragment that hasn’t broken through the whole bone
- impacted - one broken end is forced into another broken end (ie - hip fractures)
4
Q
4 stages of bone healing
A
- Haematoma formation
- Fibrocartilaginous callus development
- Ossification
- Remodelling
5
Q
Haematoma formation
A
- 1-2 days post #
- develops from torn blood vessels in periosteum and surrounding tissues
- 2-5 days post, haemorrhage forms large blood clot
- neovascularization occurs peripheral to the clot
- by day 7, most of the clot is organised by blood vessels & early fibrosis
- haematoma formation initiates bone healing
- clotting factors initiate fibrin meshwork, act as framework for the growth of fibroblasts and capillary buds
- migrating inflammatory cells and platelets release growth factors which stimulate osteoclast and osteoblast proliferation
6
Q
Fibrocartliaginous callus development
A
- fibroblasts & osteoblasts migrate into # site and begin reconstruction of bone
- fibroblasts produce collagen to connect bone ends and secrete and collagen matrix
- osteoblasts begin depositing bone into the matrix
- fibrocartlidge collar forms to connect bone segments
- bone formation begins after week 1
- in an uncomplicated #, tissue repair reaches maximum girth at the end of week 2-3. stabilizes the # but it is not yet strong enough for weight bearing
7
Q
Ossification
A
- deposition of mineral salts into the callus
- begins during week 3-4 of healing
- mature bone gradually replaces fibrocartilaginous callus
- excess callus is resorbed by osteoclasts
- # site feels firm & immovable and appears united on xray
- usually safe to remove the cast
8
Q
Remodelling
A
- resorbtion of the excess bony callus that develops in the marrow space & encircles the outside of the # site
- as the callus matures and transmits weight-bearing forces, the portions that are not stressed as resorbed
- medullary cavity is restored
9
Q
Healing time
A
- site of #
- condition of # fragments
- haematoma formation
- local & host factors
- children: 4-6 weeks
- adolescents: 6-8 weeks
- adults: 10-18 weeks
10
Q
Factors affecting bone healing
A
- nature of injury - displacement, oedema, arterial occlusion
- degree of fibrocartliage bridge formation
- amount of bone loss (if too much to bridge gap)
- type of bone injured (cancellous heals faster)
- degree of immobilisation achieved (keep # alligned)
- local infection
- local malignancy
- bone necrosis (prevents blood flow into # site)
11
Q
Impaired bone healing
A
- specific to person, type of injury and local factors
- age
- current medications
- debilitating diseases (ie - RA)
- local stress around # site
- circulatory problems & coagulation disorders
- poor nutrition
12
Q
Complications
A
- malunion - healing with deformity, angulation or rotation
- delayed union - failure of the # to unite within the normal period
- non-union - failure to produce union & cessation of the bone repair process
13
Q
Complications: Due to:
A
- loss of skeletal continuity
- injury from bone fragments
- pressure from swelling & haemorrhage
- involvement of nerve fibres
- development of fat emboli
