MSK: nerve, ligament, tendon injuries Flashcards Preview

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Flashcards in MSK: nerve, ligament, tendon injuries Deck (159)
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1
Q

What is a dermatome?

A

A sensory area of skin supplied by a single spinal nerve

2
Q

What is a way to memorise S1-4 dermatomes?

A

Stand on S1
Sleep on S2
Sit on S3
Shit on S4

3
Q

What is Hilton’s Law?

A

The nerves crossing a joint supply the muscles acting on it and the joint itself

4
Q

What is the hip joint supplied by?

A

Obturator nerve
Femoral nerve
Lateral femoral cutaneous nerve

5
Q

What is a myotome?

A

A group of muscles supplied by one segment of spinal cord

6
Q

What is the brachial plexus?

A

Large network of nerves supplying the upper limb, extending from cervical spine to axilla

7
Q

What are examples of what can happen if there are brachial plexus lesions?

A
Downward traction (fall on side of neck)
C5,6 damage
Arm 'porter's tip'
Upward traction
T1 damage (intrinsic muscles)
Hand 'clawed' (Klumpke's paralysis)
8
Q

What is another name for arm ‘porter’s tip’?

A

Erb-Duchenne paralysis

Erb’s palsy

9
Q

What is the anatomy of Erb’s palsy?

A

Shoulder adduction
Elbow extension
Forearm pronation
Wrist flexion

10
Q

What can cause an upward traction brachial plexus lesion?

A

Breech delivery

11
Q

What nerve roots at injured in Klumpke’s paralysis?

A

C8, T1

12
Q

When is the axillary nerve at risk?

A

Surgery - neck of humerus

Complication - fracture of humeral neck, shoulder dislocation, Saturday night palsy

13
Q

What is Saturday night palsy?

A

Radial nerve compression in the arm resulting from direct pressure against a firm object

14
Q

What movement is lost if there is motor deficit of the axillary nerve?

A

Loss of shoulder abduction (deltoid)

15
Q

What area is affected if there is sensory deficit of the axillary nerve?

A

Badge area

16
Q

What are the roots of the radial nerve?

A

C5-T1

17
Q

What artery is the radial nerve closely associated with?

A

Profunda brachii artery

18
Q

What does the radial nerve pass between when it enters the forearm?

A

Brachioradialis & brachialis

19
Q

Where is the radial nerve at risk?

A

Spiral groove of humerus & lateral intermuscular septum

20
Q

What can cause complications of the radial nerve?

A

Fracture of humeral shaft
Saturday night palsy
Exposure of proximal radius

21
Q

What is the sign if there is a motor deficit of the radial nerve?

A

Wrist drop (extensors)

22
Q

Which group of muscles of the forearm does the radial nerve supply?

A

Extensors

23
Q

If there is a sensory deficit of the radial nerve where does it affect?

A

1st web space dorsally

24
Q

What are the nerve roots of the median nerve?

A

C7,8, T1

25
Q

What is the median nerve closely related to in the arm?

A

Brachial artery

26
Q

What does the median nerve pass between when it enters the forearm?

A

Two heads of pronator teres

27
Q

Which area is at risk if the median nerve is damaged?

A

Volar aspect wrist (& cubital fossa)

28
Q

What can cause complications of the median nerve?

A

Carpal tunnel syndrome
Wrist lacerations
Supracondylar fractures

29
Q

What is the sign if there is a motor deficit of the median nerve?

A

Thenar wasting

Pointing finger

30
Q

If there is a sensory deficit of the median nerve where does it affect?

A

Volar aspect thumb

31
Q

What are the roots of the ulnar nerve?

A

C7,8, T1

32
Q

What is the ulnar nerve closely related to in the arm?

A

Superior ulnar collateral artery

33
Q

What does the ulnar nerve pass between when it enters the forearm?

A

Two heads of flexor carpi ulnaris

34
Q

Which area is at risk if the ulnar nerve is damaged?

A

Behind medial epicondyle of humerus

35
Q

What can cause complications of the ulnar nerve?

A

Fracture humeral condyles

Wrist lacerations

36
Q

What is the sign if there is a motor deficit of the ulnar nerve?

A

Claw hand

Hypothenar and 1st dorsal interosseous wasting

37
Q

If there is a sensory deficit of the ulnar nerve where does it affect?

A

Little finger

38
Q

Where does the lumbar plexus lie?

A

On surface of quadrates lumborum and within body of psoas muscle

39
Q

What are the roots of the femoral nerve?

A

L2-4

40
Q

What is the largest branch of the lumbar plexus?

A

Femoral nerve

41
Q

What is the route of the femoral nerve?

A

Passes through psoas muscle

Exits pelvis under inguinal ligament

42
Q

Where is the femoral nerve in the femoral triangle?

A

Lateral to femoral artery and vein

VAN - vein next to v of legs

43
Q

What does the femoral nerve supply?

A

Quadriceps muscles (anterior)

44
Q

What does the femoral nerve terminate as?

A

Saphenous nerve (sensory)

45
Q

What are the roots of the lateral femoral cutaneous nerve?

A

L2,3

46
Q

Where does the lateral femoral cutaneous nerve lie?

A

On surface of iliacus muscle

47
Q

What does lateral femoral cutaneous nerve supply?

A

Sensory to lateral aspect thigh

48
Q

What does compression of lateral femoral cutaneous nerve cause?

A

Meralgia paraesthetica

49
Q

What are the roots of the sciatic nerve?

A

L4-S3

50
Q

What is the main branch of the sacral plexus?

A

Sciatic

51
Q

Where does the sciatic nerve exit the pelvis?

A

Sciatic foramen below piriformis

52
Q

Where does the sciatic nerve run?

A

Deep to gluteus maximus

53
Q

What does the sciatic nerve supply?

A

Hamstring muscles (posterior), part of adductor magnus, lower leg and foot muscles via terminal branches

54
Q

What are the terminal branches of the sciatic nerve?

A

Tibial

Common fibular

55
Q

When is the sciatic nerve at risk?

A

Posterior dislocation of hip
Intra-muscular injections
Surgery

56
Q

What are the roots of the common fibular nerve?

A

L4-S2

57
Q

Where does the common fibular nerve pass?

A

Around lateral aspect of neck of fibula

58
Q

What is the most commonly injured nerve in lower limb?

A

Common fibular nerve

59
Q

How does a damaged common fibular nerve present?

A

Foot drop

Slapping gait

60
Q

Which nerve has a communicating branch to the sural nerve?

A

Common fibular

61
Q

Which nerve does the common fibular have a communicating branch to?

A

Sural nerve

62
Q

What does the common fibular nerve divide into?

A

Superficial fibular

Deep fibular

63
Q

What type of motor neurone injuries do peripheral nerve injuries cause?

A

Lower motor neurone injuries

64
Q

What type of cell provides myelin sheath in peripheral nerves?

A

Schwann cells

65
Q

What coats axons?

A

Endoneurium

66
Q

What coats fascicles?

A

Perineurium

67
Q

What coats a nerve?

A

Epineurium

68
Q

What are the largest an fastest neuron fiber type?

A

Aalpha

69
Q

What are different types of nerve compression injuries?

A

Entrapment
Carpal tunnel syndrome - median nerve
Sciatica
Morton’s neuroma

70
Q

What are the two types of trauma injuries?

A

Direct - blow, laceration

Indirect - avulsion, traction

71
Q

What is neuropraxia?

A

Reversible conduction block, local ischaemia and demyelination as a result of trauma

72
Q

What is axonotmesis?

A

Axons and myelin sheath damaged by trauma, endoneurium remains intact

73
Q

Can peripheral nerves regenerate?

A

Yes

74
Q

What usually causes axonotmesis?

A

Stretch injury

75
Q

What happens to motor and sensory functions in axonotmesis?

A

Completely lost over time leading to Wallerian degeneration

76
Q

What is Wallerian degeneration?

A

Part of axon distal to injury degenerates

77
Q

In axonotmesis is sensory or motor recovery better?

A

Sensory

78
Q

What is neurotmesis?

A

Complete nerve division

79
Q

How is neurotmesis usually caused?

A

Trauma: laceration or avulsion

80
Q

What is the management of neurotmesis?

A

No recovery unless repaired (by direct suturing or grafting)

81
Q

What is the general prognosis for neurotmesis?

A

Poor

82
Q

How is peripheral nerve injury graded?

A

Sunderland’s classification grade 1-5

83
Q

What are the two types of nerve injury description?

A

Open

Closed

84
Q

What is a closed nerve injury?

A

Nerve injuries in continuity e.g. neuropraxis or axonotmesis

85
Q

What is the management of a closed nerve injury?

A

Spontaneous recovery possible

Surgery after 3mo - clinical/electromyography

86
Q

How do closed nerve injuries typically occur?

A

Stretching of nerve

87
Q

What are open nerve injuries?

A

Frequently related to nerve division

88
Q

How are open nerve injuries managed?

A

Early surgery

89
Q

What happens to distal portion of nerve in open nerve injury?

A

Wallerian degeneration

90
Q

What are the 3 main clinical features of nerve injury?

A

Sensory
Motor
Reflexes

91
Q

What happens to sensory function in nerve injury?

A

Dysaethesiae (disordered sensation)

  • numbness (anaesthetic)
  • pins and needles (paraesthetic)
92
Q

What happens to motor function in nerve injury?

A

Paresis (weakness)
Paralysis +/- wasting
Dry skin

93
Q

What happens to reflexes in nerve injury?

A

Diminished or absent

94
Q

What is the regeneration rate of nerves?

A

1mm/day

95
Q

What is the first modality to return after nerve injury?

A

Pain

96
Q

What does the prognosis of nerve healing depend on?

A

Whether nerve is pure or mixed

How distal lesion is

97
Q

What is worse for prognosis in nerve injury: distal or proximal nerve injury?

A

Proximal

98
Q

What sign can monitor recovery in nerve injury?

A

Tinel’s sign

99
Q

How can you test Tinel’s sign?

A

Tap over site of nerve and paraesthesia will be felt as far distally as regeneration has progressed

100
Q

How can injury be assessed and recovery monitored in nerve injury?

A

Nerve conduction studies

101
Q

What are the two options for surgical nerve repair?

A

Direct repair

Nerve grafting

102
Q

What is the rule of three for surgical timing in a traumatic peripheral nerve injury?

A

Immediate surgery within 3 days - clean and sharp injuries
Early surgery within 3 weeks - blunt/contusion injuries
Delayed surgery within 3mo - closed injuries

103
Q

How can you tell the difference between peripheral or central nerve injury?

A

UMN vs LMN lesions

104
Q

In UMN lesion what is strength like?

A

Decreased

105
Q

In LMN lesion what is strength like?

A

Decreased

106
Q

In UMN lesion what is tone like?

A

Increased

107
Q

In LMN lesion what is tone like?

A

Decreased

108
Q

In UMN lesion what are deep tendon reflexes like?

A

Increased

109
Q

In LMN lesion what are deep tendon reflexes like?

A

Decreased

110
Q

In UMN lesion is clonus present or absent?

A

Present

111
Q

In LMN lesion is clonus present or absent?

A

Absent

112
Q

In UMN lesion is Babinski’s sign present or absent?

A

Present

113
Q

In LMN lesion is Babinski’s sign present or absent?

A

Absent

114
Q

In UMN lesion is atrophy present or absent?

A

Absent

115
Q

In LMN lesion is atrophy present or absent?

A

Present

116
Q

What are the collagen bundles in tendons covered by?

A

Endotenon

117
Q

What are the fascicles in tendons covered by?

A

Paratenon

118
Q

What is the tendon covered by?

A

Epitenon

119
Q

What are tendons connected to the tendon sheath by?

A

Vincula

120
Q

What is the purpose of tendons?

A

Provide movement

121
Q

What happens if tendons immobile?

A

Reduces water content and glycosaminoglycan concentration and strength

122
Q

What types of injury can happen to a tendon?

A
Degeneration
Inflammation
Enthesiopathy
Traction apophysitis
Avulsion +/- bone fragment
Tear
Laceration/incision
Crush/ischaemia/attrition
Nodules
123
Q

What is an example of degeneration of a tendon?

A

Achilles tendon - intrasubstance mucoid degeneration

124
Q

What are the signs/symptoms of a degenerated tendon?

A

Swollen
Painful
Tender
Asymptomatic

125
Q

What is an example of inflammation of a tendon?

A

De Quervain’s tenovaginitis

126
Q

What tendons are affected in De Quervain’s?

A

Extensor pollicis brevis

Abductor pollicis longus

127
Q

What are signs/symptoms of De Quervain’s?

A
Swollen
Tender
Hot 
Red
Positive Finklestein's test
128
Q

What is enthesiopathy?

A

Inflammation at insertion to bone

129
Q

What is traction apophysitis?

A

Excessive pull by a large tendon causes damage to the unfused apophysis to which it is attached

130
Q

What is an example of traction apophysitis?

A

Osgood Schlatter’s disease

131
Q

What is Osgood Schlatter’s disease?

A

Inflammation of the patellar ligament at the tibial tuberosity (apophysitis)

132
Q

Who does Osgood Schlatter’s disease tend to occur in?

A

Adolescent active males

133
Q

What triggers Osgood Schlatter’s disease?

A

Recurrent load

134
Q

What is an avulsion fracture?

A

An avulsion fracture occurs when a small chunk of bone attached to a tendon or ligament gets pulled away from the main part of the bone

135
Q

What is Mallet finger?

A

An injury to the thin tendon that straightens the end joint of a finger or thumb

136
Q

Where is the injury in Mallet finger?

A

Insertion of extensor tendon into dorsal of base of distal phalanx of finger

137
Q

What occurs as a result of Mallet finger?

A

Forced flexion of extended finger

138
Q

What is the treatment for avulsion?

A

Conservative: retraction tendon, stack splint
Operative: reattachment tendon, fixation bone fragment

139
Q

What is an intrasubstance rupture?

A

A partial tear of a tendon or cartilage. It is a tear that occurs in the middle layers of a tendon and not on the outside layers

140
Q

What is an example of an intrasubstance rupture?

A

Achilles tendon tear

141
Q

What are examples of the mechanism of a tendon rupture?

A

Pushing off with weight bearing forefoot whilst extending knee joint
Unexpected dorsiflexion of ankle
Violent dorsiflexion of plantar flexed foot

142
Q

What is the test for an Achilles tendon rupture?

A

Positive Simmond’s ‘squeeze’ test

Palpable tender gap

143
Q

What does Simmond’s test test for?

A

Ruptured Achilles tendon

144
Q

What happens in a Simmond’s test?

A

If the test is positive, there is no movement of the foot (normally plantarflexion) on squeezing the corresponding calf, signifying likely rupture of the Achilles tendon

145
Q

Where is a musculotendinous junction tear likely?

A

Medial head of gastrocnemius at musculotendinous junction with Achilles tendon

146
Q

What is the treatment for a tendon rupture?

A

Conservative: mobilise, splint/cast

Operative

147
Q

When would you operate to treat a ruptured tendon?

A

High risk re-rupture
High activity
Ends cannot be opposed

148
Q

What finger flexor tendons are at high risk of rupture?

A

FDS

FDP

149
Q

What is the management for laceration of tendons (finger flexors)?

A

Repair surgically and early

150
Q

What is a ligament?

A

Dense bands of collagenous tissue which span joints

151
Q

What do ligaments do?

A

Joint stability through range motion

152
Q

What type of collagen fibres make up ligaments?

A

Type 1

153
Q

What is the composition of ligaments compared to tendons?

A

Ligaments:

  • lower % collagen
  • higher % proteoglycans and water
  • less organised collagen fibres
  • rounder fibroblasts
154
Q

What are ligaments made up of?

A

Collagen fibres (type I)
Fibroblasts
Sensory fibres
Vessels

155
Q

How do ligament ruptures occur?

A

Forces exceed strength of ligament

156
Q

What are the stages of ligaments heal?ing

A

Haemorrhage/inflammation
Proliferative phase
Remodelling

157
Q

What is the treatment for ligament rupture?

A

Conservative

Operative: augmentation, repair, replacement

158
Q

When would you choose conservative repair for a ligament?

A

Partial rupture
No instability
Poor candidate surgery

159
Q

When would you choose surgical repair for a ligament?

A

Instability
Expectation
Compulsory