Musculoskeletal Growth, Injury And Repair

Question 1

Define an axon?

Answer 1

Long processes of neurones which are coated in endometrium and grouped into fascicles

Question 2

Define fascicles?

Answer 2

Nerve bundles covered with perineurium

Question 3

What is a nerve covered with?

Answer 3

Epineurium

Question 4

A alpha fibre function?

Answer 4

Muscle stretch and tension sensory axons

Question 5

A beta fibre group function?

Answer 5

Touch, pressure, vibration and joint position sensory axons

Question 6

A gamma fibres function?

Answer 6

Gamma efferent motor axons

Question 7

A delta fibres function?

Answer 7

Sharp pain, very light touch and temperature sensation

Question 8

B fibres function?

Answer 8

Sympathetic preganglionic motor axons

Question 9

C fibres function

Answer 9

Dull, aching, burning pain and temperature sensation

Question 10

Classes of trauma that can cause nerve injury?

Answer 10

Direct (blow, laceration) or

Indirect (avulsion, traction)

Question 11

Define neurapraxia

Answer 11

Disorder of peripheral nuron system in which there is temporary loss of motor and sensory function due to blockage of nerve conduction

Question 12

Define Axonotmesis

Answer 12

Axons and myelin of peripheral nerve are damaged but endoneurium, epineurium and perineurium remain intact

Question 13

Define Neurotmesis?

Answer 13

Nerve and neuron sheath are damaged

Question 14

Common cause of neurapraxia

Answer 14

Stretched or bruised

Question 15

Common cause of axonotmesis

Answer 15

Stretched, crushed or direct blow

Question 16

Prognosis of axonotmesis?

Answer 16

Fair

Sensory recovery better than motor

Question 17

Can peripheral nerve regenerate?

Answer 17

Yes

Question 18

Common cause of neurotmesis?

Answer 18

Laceration or avulsion

Question 19

Grading system used to grade nerve trauma injury?

Answer 19

Sunderland grade 1-5

Question 20

The grades of Sunderland grading systems?

Answer 20

Grade1- neurapraxia
Grade 2- axonotmesis
Grade 3- neurotmesis
Grade 4- neurotmesis + (loss of perineurium)
Grade 5- neurotmesis ++ (loss of perineurium + epineurium)

Question 21

Define closed nerve injuries

Answer 21

Associated with nerve injuries in continuity eg neuropraxis, axonotmesis

Question 22

How do you treat closed nerve injury?

Answer 22

Surgery after 3 months 1

Question 23

Define open nerve injuries

Answer 23

Frequently related to nerve division eg neurotmetic injuries
Often caused by knives/ glass

Question 24

How are open nerve injuries treated?

Answer 24

Early surgery

Question 25

What happens 2-3 weeks after an open nerve injury in the distal portion of the nerve?

Answer 25

Wallerian degeneration

Question 26

Clinical features of a peripheral nerve injury?

Answer 26

Dysaethesiae, paresis or paralysis, dry skin, diminished or absent reflexes

Question 27

How fast is regeneration of peripheral nerves?

Answer 27

Rate of 1mm/day | Maybe 3-5mm/day in children

Question 28

What is the 1st modality to return in the healing process of peripheral nerves?

Answer 28

Pain

Question 29

What is the prognosis of regenerating peripheral nerves dependent on?

Answer 29

Whether nerve is “pure” or “mixed” and | How distal the lesion is (proximal is worse_

Question 30

How can you monitor the recovery of regenerating peripheral nerves?

Answer 30

Tinel’s test, | Electrophysiological nerve conduction studies

Question 31

What are the indications for nerve grafting?

Answer 31

Nerve loss, late repair

Question 32

What is the surgical timing in a traumatic peripheral nerve injury?

Answer 32

Immediate surgery within 3 days for clean and sharp injuries, Early surgery within 3 weeks for blunt/ contusion injuries Delayed surgery 3 months after injury, for closed injuries