PBL 4 Flashcards
what is vascular examination reveal and what does this mean
Vascular examination revealed absence of both dorsalis pedis and posterior tibial pulses
- blood supply cut of from both anterior tibial which leads to the dorsals pedis and posterior tibial
What did neurological examination show to be intact
- Neurological assessment of the left lower extremity revealed intact plantar sensation. - means that the tibia nerve is in tact
- Plantar flexion of the ankle and toes was noted to be intact. = tibial nerve intact
- Extensor function at the toes was absent along with no dorsal foot sensation. = no extension means that deep perineal nerve is not intact, no dorsal foot sensation means that there is a common perineal problem
what did the angiography show
Acute angiography was performed and showed complete vascular compromise at the inferior margin of the popliteal artery.
what are the two types of fracture
Open (compound) = skin is broken and bone pierces the skin
Closed = bone fragments have not pierced the skin
what does the type of fracture depend on
magnitude and direction of force
what is a spiral or oblique fracture caused by
- caused by violence transmitted through limb from a distance specifically a twisting movement
What is a crush or compression fracture
- This is a fracture in cancellous bone result of compression
what vertebra are the most affected in a compression fracture
thoracic
lumbar
- these carry more weight
what do burst fractures occur in
- Occur in short bones such as vertebra from strong direct pressure such as impaction of a disc
what causes an avulsion fracture
- Caused by traction
what is a fracture dislocation/subluxation
this is when the fracture involves a joint and this results in malalignment of joint surfaces
- therefore you have to get the joint realigned
What is an impacted fracture
- this is when bone fragments are impacted and forced, pushed into each other
What is a comminuted fracture
- this is a high impact trauma where two or more bone pieces
- for example he middle part of the bone might be completely detached and thus completed detached from the blood supply
What is a stress fracture
- abnormal stress on a normal bone (fatigue fracture)
- normal stress on abnormal bone (insufficiency fracture)
Describe what happens in a torus fracture
- common injuries to children
softer bones and compression applied to them - axial loading causing trabecular compression
- one side of the bone may buckle
- bulging of the cortex
these heal quickly
What is a greenstick fracture
- Bones soft and bend without fracturing completely
- the woven bone will allow the bones to bend fracturing them completely
what type of fracture did the person have
- An isolated injury to her left leg below the knee was noted with exposed muscle and bone = Open fracture
- Radiologic evaluation confirmed the comminuted fracture of the tibia and fibula. = broken into two or more pieces
name the steps of fracture healing
Fracture haematoma (6-8 hours)
fibrocartilaginous callus (lasts about 3 weeks)
bony callus (after 3 weeks and lasts abut 3-4 months)
bone remodelling
describe the steps of fracture healing
Fracture haematoma
- blood clot forms via the broken blood vessels
- 6-8 hours after the initial injury
- hypoxia is caused due to a lack of blood vessels as they are broken this lowers the pH and allows pro inflammatory neutrophils, lymphocytes and macrophages to move in and to take away necrotic bone cells, blood vessels and any dead cells to make the site nice and clean
- there is swelling and inflammation to dead bone cells at fracture site
Fibrocartilagenous callus
- lasts about 3 weeks
- new capillaries organise fracture haematoma into granulation tissue - procallus
- fibroblasts and osteogenic cells invade the procalllus
- make collagen fibres which connect ends together
- chondroblast begin to produce fibrocartilage
- Fibroblasts enter and differentiate as chondrocytes
- chondrocytes produce collagen that bridges fracture site cartilage and trabecular bone is laid down
Bony callus
= after 3 weeks and lasts about 3-4 months
- bony callus forms as the bone starts to be made
- osteoblasts make the woven bone which replaces the fibrocartilage
Bone remodelling
- Osteoclasts remodel woven bone into compact (lamellar) bone and trabecular bone
- often there is no trace of fracture line on Xray
How long does the lower limb and upper limb take to heal
upper limb
- Adult = 6-8 weeks
- child = 3-4 weeks
lower limb
- adult = 12-16 weeks
- child = 6-8 weeks
what type of reduction do you use for an open fracture
As there is an open fracture then open reduction and stabilisation of the fracture was perfromed
what are the factors that affect bone healing
Factors increasing the rate
- youth
- nutrition
- blood supply
- adequate hormones
- early immobilisation of fracture fragments
Factors decreasing the rate of bone healing
- age
- extensive soft tissue damage
- bone loss due to the severity of the fracture
- infection
- inadequate immobilisation
- avascular necrosis
what muscles can be used for muscle replacement
- voluntary
- superficial
- not needed as other muscles do the same job
- e.g. gracilis and rectus femoris
describe venous autograft
- Most successful and most used clinically
- Saphenous vein, cephalic and basilic veins for limbs
Types
- Reverse and in situ
- Patency of reversed 80-90% at 1 year, 55-86% at 5 years
What dermatome is located on the medial side of the dorsum of the foot? ( 1 mark)
L5
2 Explain why the saphenous graft is able to:
a. Substitute for an artery (2 marks)
b. Why the vein is reversed
(3 marks in total)
a. it has more smooth muscle in the walls than most veins which means it is more accommodating to stretch ( 1 mark). The smooth muscle is able to proliferate when under pressure to make graft more artery like.
b. The valves need to kept open so they do not impede the flow of blood
When planning a free muscle/skin transfer state three major considerations as to what tissue can be used. (3 marks)
Muscle and overlying skin means the muscle must be superficial
Muscle must be expendable (other muscles doing the same function)
Must be able to also remove nerve and blood supply to attach to existing nerves and vessels
Name the 3 stages of bone healing after the fracture hematoma has formed. (3 marks)
Soft callus
Hard callus
Bone remodelling
What is the usual mechanism (force) that causes a comminuted fracture?
High energy force something like a road traffic accident that causes the bone to shattering to multiple pieces.
Why was Sana given the broad spectrum antibiotics immediately even before the fracture was reduced?
She had an open fracture with the bone exposed. Therefore it is very likely that bacteria would have entered the wound and if not treated would not only delay wound healing but could cause osteomyletisis or even systemic infection.
• Explain why the saphenous vein can be used for this graft procedure?
It is close to the surface so easy to harvest. It is outside of the deep fascia and so has more smooth muscle in its walls than most veins which makes it suitable to form more smooth muscle when under arterial pressure. It also has numerous perforators and other superficial veisn are able to make sure that the venous blood returns to the deep veins.
Explain why a comminuted fracture may heal slower and have more complications than a simple transverse fracture does?
For bones to heal they need to re-establish the blood supply if there are numerous small pieces most of these may not have a blood supply and so cannot contribute to the bone healing process actively. They can still perform an osteoconductive role but they may not have living osteoprogenitor cells because of the lack of a blood supply.
