Traum - Fractures Flashcards
Pathophysiology (part 1):
of a bone break
bleed blood vessels in bone, periosteum
bleeding, inflamm around bone due soft tissue damage
haematoma/clot forms in medullary canal under periosteum
between ends bone fragments
necrosis end broken bones - torn vessels unable deliver nutrients
inflammatory response develops
Pathophysiology continued (part 2):
What does the haematoma serve as the basis for at fracture sites?
fibrin network - granulation tissue grows
new capillaries extend into tissue
phagocytotic cells, fibroblasts migrate to it
chondroblasts form cartilage
two bones become splinted by procallus/fibrocartilaginous callus (collar)
What does chondroblast do?
(form cartilage)
What do phagocytic cells do?
(removing debris)
What do fibroblasts do?
(laying down new collagen fibres)
How strong are broken bones splinted by procallus (or fibrocartilaginous callus) collar?
not strong enough to bear weight, but constitutes preliminary bridge to repair in the bone
Pathophysiology continued (part 3):
osteoblasts from periosteum and endosteum begin generate new bone - fill gap
gradually fibrocartilaginous callus replaced by bone through extensive osteogenic activity
- forms a bony callus
damaged bone repaired by new bone formation, not scar tissue
subsequent months remodelled by osteoblastic and osteoclastic activity - response mechanical stresses
excessive bone in callus removed
more compact laid down
eventually the bone assumes nowmal appearance
To summarise…
What are the five stages of bone healing?
- Haematoma
- Granulation Tissue
- Procallus(fibrocartilage)
- Bony Calluse
- Remodelling
What is the 1st stage of bone healing?
- Haematoma
What is the 2nd stage of bone healing?
- Granulation Tissue
What is the 3rd stage of bone healing?
- Procallus(fibrocartilage)
What is the 4th stage of bone healing?
- Bony Calluse
What is the 5th stage of bone healing?
- Remodelling
Approximately how long does it take for fractures to heal in Children?
1 month
Approximately how long does it take for fractures to heal in Adults?
2 or more months
Approximately how long does it take for fractures to heal in an Elderly Person?
Many months
Factors affecting the healing of a bone:
- amount of local damage to bone and soft tissue e.g prolonged inflammation, extensive damage periosteum, blood vessels
- more closely approximated ends of bones are, smaller gap - faster filled
- secondary problems e.g. infection at the site
- numerous systemic factors
-immobilisation
Why is it necessary to for bones to be realigned (reduced) in the proper position before healing can occur?
promote healing
prevent deformity
most important to maintain immobilisation to prevent disturbance or damage to developing fragile bridge of tissue
Examples of systemic factors that reduce healing:
Older persons
Circulatory Problems
Anemias
Diabetes mellitus
Nurtitional deficits
Those taking drugs e.g. glucocorticoids
Complications that may affect healing in patients who sustain severe injuries.
8. Fractures IN or NEAR the joint:
Fractures in or near the joint may have long-term residual effects e.g. osteoarthritis, stunted growth in epiphyseal plate
Complications that may affect healing in patients who sustain severe injuries.
7. Non-union and Malunion:
Failure to heal (nonunion)
Healing with deformity(malunion)
may result if the bone is not stabilised with ends closely approximated and aligned
Complications that may affect healing in patients who sustain severe injuries.
3. Ischemia:
develops in a limb following cast tx as oedema increases during first 48 hrs after the trauma and the limb is compressed by the cast
if the peripheral area (e.g. toes, fingers) becomes pale or cold and numb or if the peripheral pulse has decreased or is absent it is likely that the cast has become too tight and is compromising circulation in the limb
the cast must be released to prevent secondary tissue damage
during the later stages of healing, it is also important that the cast does not become to lose and oedema decreased and muscle atrophies because of the newly formed procallus may break down if there is any bone movement
Complications that may affect healing in patients who sustain severe injuries.
4. Compartment Syndrome:
may develop shortly after fracture occurs when there is more extensive inflammation e.g. crush injuries
increased pa of fluid within the fascia, nonelastic covering of the severe pain and ischemia or necrosis of the muscle
pressure effects may be aggravated by a cast
Complications that may affect healing in patients who sustain severe injuries.
5.Fat Emboli:
risk when fatty marrow escapes from the bone marrow into a vein within the first week after injury
more common in pts with fracture of pelvis, long bones, e.g. femur esp when site has not been well immobilised during transportation immediately after injury
