PBL 4

Question 1

what is vascular examination reveal and what does this mean

Answer 1

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

Question 2

What did neurological examination show to be intact

Answer 2

• 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

Question 3

what did the angiography show

Answer 3

Acute angiography was performed and showed complete vascular compromise at the inferior margin of the popliteal artery.

Question 4

what are the two types of fracture

Answer 4

Open (compound) = skin is broken and bone pierces the skin

Closed = bone fragments have not pierced the skin

Question 5

what does the type of fracture depend on

Answer 5

magnitude and direction of force

Question 6

what is a spiral or oblique fracture caused by

Answer 6

• caused by violence transmitted through limb from a distance specifically a twisting movement

Question 7

What is a crush or compression fracture

Answer 7

• This is a fracture in cancellous bone result of compression

Question 8

what vertebra are the most affected in a compression fracture

Answer 8

thoracic
lumbar
- these carry more weight

Question 9

what do burst fractures occur in

Answer 9

• Occur in short bones such as vertebra from strong direct pressure such as impaction of a disc

Question 10

what causes an avulsion fracture

Answer 10

• Caused by traction

Question 11

what is a fracture dislocation/subluxation

Answer 11

this is when the fracture involves a joint and this results in malalignment of joint surfaces
- therefore you have to get the joint realigned

Question 12

What is an impacted fracture

Answer 12

• this is when bone fragments are impacted and forced, pushed into each other

Question 13

What is a comminuted fracture

Answer 13

• 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

Question 14

What is a stress fracture

Answer 14

• abnormal stress on a normal bone (fatigue fracture)

- normal stress on abnormal bone (insufficiency fracture)

Question 15

Describe what happens in a torus fracture

Answer 15

• 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

Question 16

What is a greenstick fracture

Answer 16

• Bones soft and bend without fracturing completely

- the woven bone will allow the bones to bend fracturing them completely

Question 17

what type of fracture did the person have

Answer 17

• 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

Question 18

name the steps of fracture healing

Answer 18

Fracture haematoma (6-8 hours)

fibrocartilaginous callus (lasts about 3 weeks)

bony callus (after 3 weeks and lasts abut 3-4 months)

bone remodelling

Question 19

describe the steps of fracture healing

Answer 19

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

Question 20

How long does the lower limb and upper limb take to heal

Answer 20

upper limb

• Adult = 6-8 weeks
• child = 3-4 weeks

lower limb

• adult = 12-16 weeks
• child = 6-8 weeks

Question 21

what type of reduction do you use for an open fracture

Answer 21

As there is an open fracture then open reduction and stabilisation of the fracture was perfromed

Question 22

what are the factors that affect bone healing

Answer 22

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

Question 23

what muscles can be used for muscle replacement

Answer 23

• voluntary
• superficial
• not needed as other muscles do the same job
• e.g. gracilis and rectus femoris

Question 24

describe venous autograft

Answer 24

• 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

Question 25

What dermatome is located on the medial side of the dorsum of the foot? ( 1 mark)

Answer 25

L5

Question 26

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)

Answer 26

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

Question 27

When planning a free muscle/skin transfer state three major considerations as to what tissue can be used. (3 marks)

Answer 27

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

Question 28

Name the 3 stages of bone healing after the fracture hematoma has formed. (3 marks)

Answer 28

Soft callus
Hard callus
Bone remodelling

Question 29

What is the usual mechanism (force) that causes a comminuted fracture?

Answer 29

High energy force something like a road traffic accident that causes the bone to shattering to multiple pieces.

Question 30

Why was Sana given the broad spectrum antibiotics immediately even before the fracture was reduced?

Answer 30

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.

Question 31

• Explain why the saphenous vein can be used for this graft procedure?

Answer 31

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.

Question 32

Explain why a comminuted fracture may heal slower and have more complications than a simple transverse fracture does?

Answer 32

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.