MSK: nerve, ligament, tendon injuries Flashcards
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
What is the median nerve closely related to in the arm?
Brachial artery
26
What does the median nerve pass between when it enters the forearm?
Two heads of pronator teres
27
Which area is at risk if the median nerve is damaged?
Volar aspect wrist (& cubital fossa)
28
What can cause complications of the median nerve?
Carpal tunnel syndrome
Wrist lacerations
Supracondylar fractures
29
What is the sign if there is a motor deficit of the median nerve?
Thenar wasting
| Pointing finger
30
If there is a sensory deficit of the median nerve where does it affect?
Volar aspect thumb
31
What are the roots of the ulnar nerve?
C7,8, T1
32
What is the ulnar nerve closely related to in the arm?
Superior ulnar collateral artery
33
What does the ulnar nerve pass between when it enters the forearm?
Two heads of flexor carpi ulnaris
34
Which area is at risk if the ulnar nerve is damaged?
Behind medial epicondyle of humerus
35
What can cause complications of the ulnar nerve?
Fracture humeral condyles
| Wrist lacerations
36
What is the sign if there is a motor deficit of the ulnar nerve?
Claw hand
| Hypothenar and 1st dorsal interosseous wasting
37
If there is a sensory deficit of the ulnar nerve where does it affect?
Little finger
38
Where does the lumbar plexus lie?
On surface of quadrates lumborum and within body of psoas muscle
39
What are the roots of the femoral nerve?
L2-4
40
What is the largest branch of the lumbar plexus?
Femoral nerve
41
What is the route of the femoral nerve?
Passes through psoas muscle
| Exits pelvis under inguinal ligament
42
Where is the femoral nerve in the femoral triangle?
Lateral to femoral artery and vein
| VAN - vein next to v of legs
43
What does the femoral nerve supply?
Quadriceps muscles (anterior)
44
What does the femoral nerve terminate as?
Saphenous nerve (sensory)
45
What are the roots of the lateral femoral cutaneous nerve?
L2,3
46
Where does the lateral femoral cutaneous nerve lie?
On surface of iliacus muscle
47
What does lateral femoral cutaneous nerve supply?
Sensory to lateral aspect thigh
48
What does compression of lateral femoral cutaneous nerve cause?
Meralgia paraesthetica
49
What are the roots of the sciatic nerve?
L4-S3
50
What is the main branch of the sacral plexus?
Sciatic
51
Where does the sciatic nerve exit the pelvis?
Sciatic foramen below piriformis
52
Where does the sciatic nerve run?
Deep to gluteus maximus
53
What does the sciatic nerve supply?
Hamstring muscles (posterior), part of adductor magnus, lower leg and foot muscles via terminal branches
54
What are the terminal branches of the sciatic nerve?
Tibial
| Common fibular
55
When is the sciatic nerve at risk?
Posterior dislocation of hip
Intra-muscular injections
Surgery
56
What are the roots of the common fibular nerve?
L4-S2
57
Where does the common fibular nerve pass?
Around lateral aspect of neck of fibula
58
What is the most commonly injured nerve in lower limb?
Common fibular nerve
59
How does a damaged common fibular nerve present?
Foot drop
| Slapping gait
60
Which nerve has a communicating branch to the sural nerve?
Common fibular
61
Which nerve does the common fibular have a communicating branch to?
Sural nerve
62
What does the common fibular nerve divide into?
Superficial fibular
| Deep fibular
63
What type of motor neurone injuries do peripheral nerve injuries cause?
Lower motor neurone injuries
64
What type of cell provides myelin sheath in peripheral nerves?
Schwann cells
65
What coats axons?
Endoneurium
66
What coats fascicles?
Perineurium
67
What coats a nerve?
Epineurium
68
What are the largest an fastest neuron fiber type?
Aalpha
69
What are different types of nerve compression injuries?
Entrapment
Carpal tunnel syndrome - median nerve
Sciatica
Morton’s neuroma
70
What are the two types of trauma injuries?
Direct - blow, laceration
| Indirect - avulsion, traction
71
What is neuropraxia?
Reversible conduction block, local ischaemia and demyelination as a result of trauma
72
What is axonotmesis?
Axons and myelin sheath damaged by trauma, endoneurium remains intact
73
Can peripheral nerves regenerate?
Yes
74
What usually causes axonotmesis?
Stretch injury
75
What happens to motor and sensory functions in axonotmesis?
Completely lost over time leading to Wallerian degeneration
76
What is Wallerian degeneration?
Part of axon distal to injury degenerates
77
In axonotmesis is sensory or motor recovery better?
Sensory
78
What is neurotmesis?
Complete nerve division
79
How is neurotmesis usually caused?
Trauma: laceration or avulsion
80
What is the management of neurotmesis?
No recovery unless repaired (by direct suturing or grafting)
81
What is the general prognosis for neurotmesis?
Poor
82
How is peripheral nerve injury graded?
Sunderland's classification grade 1-5
83
What are the two types of nerve injury description?
Open
| Closed
84
What is a closed nerve injury?
Nerve injuries in continuity e.g. neuropraxis or axonotmesis
85
What is the management of a closed nerve injury?
Spontaneous recovery possible
| Surgery after 3mo - clinical/electromyography
86
How do closed nerve injuries typically occur?
Stretching of nerve
87
What are open nerve injuries?
Frequently related to nerve division
88
How are open nerve injuries managed?
Early surgery
89
What happens to distal portion of nerve in open nerve injury?
Wallerian degeneration
90
What are the 3 main clinical features of nerve injury?
Sensory
Motor
Reflexes
91
What happens to sensory function in nerve injury?
Dysaethesiae (disordered sensation)
- numbness (anaesthetic)
- pins and needles (paraesthetic)
92
What happens to motor function in nerve injury?
Paresis (weakness)
Paralysis +/- wasting
Dry skin
93
What happens to reflexes in nerve injury?
Diminished or absent
94
What is the regeneration rate of nerves?
1mm/day
95
What is the first modality to return after nerve injury?
Pain
96
What does the prognosis of nerve healing depend on?
Whether nerve is pure or mixed
| How distal lesion is
97
What is worse for prognosis in nerve injury: distal or proximal nerve injury?
Proximal
98
What sign can monitor recovery in nerve injury?
Tinel's sign
99
How can you test Tinel's sign?
Tap over site of nerve and paraesthesia will be felt as far distally as regeneration has progressed
100
How can injury be assessed and recovery monitored in nerve injury?
Nerve conduction studies
101
What are the two options for surgical nerve repair?
Direct repair
| Nerve grafting
102
What is the rule of three for surgical timing in a traumatic peripheral nerve injury?
Immediate surgery within 3 days - clean and sharp injuries
Early surgery within 3 weeks - blunt/contusion injuries
Delayed surgery within 3mo - closed injuries
103
How can you tell the difference between peripheral or central nerve injury?
UMN vs LMN lesions
104
In UMN lesion what is strength like?
Decreased
105
In LMN lesion what is strength like?
Decreased
106
In UMN lesion what is tone like?
Increased
107
In LMN lesion what is tone like?
Decreased
108
In UMN lesion what are deep tendon reflexes like?
Increased
109
In LMN lesion what are deep tendon reflexes like?
Decreased
110
In UMN lesion is clonus present or absent?
Present
111
In LMN lesion is clonus present or absent?
Absent
112
In UMN lesion is Babinski's sign present or absent?
Present
113
In LMN lesion is Babinski's sign present or absent?
Absent
114
In UMN lesion is atrophy present or absent?
Absent
115
In LMN lesion is atrophy present or absent?
Present
116
What are the collagen bundles in tendons covered by?
Endotenon
117
What are the fascicles in tendons covered by?
Paratenon
118
What is the tendon covered by?
Epitenon
119
What are tendons connected to the tendon sheath by?
Vincula
120
What is the purpose of tendons?
Provide movement
121
What happens if tendons immobile?
Reduces water content and glycosaminoglycan concentration and strength
122
What types of injury can happen to a tendon?
```
Degeneration
Inflammation
Enthesiopathy
Traction apophysitis
Avulsion +/- bone fragment
Tear
Laceration/incision
Crush/ischaemia/attrition
Nodules
```
123
What is an example of degeneration of a tendon?
Achilles tendon - intrasubstance mucoid degeneration
124
What are the signs/symptoms of a degenerated tendon?
Swollen
Painful
Tender
Asymptomatic
125
What is an example of inflammation of a tendon?
De Quervain's tenovaginitis
126
What tendons are affected in De Quervain's?
Extensor pollicis brevis
| Abductor pollicis longus
127
What are signs/symptoms of De Quervain's?
```
Swollen
Tender
Hot
Red
Positive Finklestein's test
```
128
What is enthesiopathy?
Inflammation at insertion to bone
129
What is traction apophysitis?
Excessive pull by a large tendon causes damage to the unfused apophysis to which it is attached
130
What is an example of traction apophysitis?
Osgood Schlatter's disease
131
What is Osgood Schlatter's disease?
Inflammation of the patellar ligament at the tibial tuberosity (apophysitis)
132
Who does Osgood Schlatter's disease tend to occur in?
Adolescent active males
133
What triggers Osgood Schlatter's disease?
Recurrent load
134
What is an avulsion fracture?
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
What is Mallet finger?
An injury to the thin tendon that straightens the end joint of a finger or thumb
136
Where is the injury in Mallet finger?
Insertion of extensor tendon into dorsal of base of distal phalanx of finger
137
What occurs as a result of Mallet finger?
Forced flexion of extended finger
138
What is the treatment for avulsion?
Conservative: retraction tendon, stack splint
Operative: reattachment tendon, fixation bone fragment
139
What is an intrasubstance rupture?
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
What is an example of an intrasubstance rupture?
Achilles tendon tear
141
What are examples of the mechanism of a tendon rupture?
Pushing off with weight bearing forefoot whilst extending knee joint
Unexpected dorsiflexion of ankle
Violent dorsiflexion of plantar flexed foot
142
What is the test for an Achilles tendon rupture?
Positive Simmond's 'squeeze' test
| Palpable tender gap
143
What does Simmond's test test for?
Ruptured Achilles tendon
144
What happens in a Simmond's test?
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
Where is a musculotendinous junction tear likely?
Medial head of gastrocnemius at musculotendinous junction with Achilles tendon
146
What is the treatment for a tendon rupture?
Conservative: mobilise, splint/cast
| Operative
147
When would you operate to treat a ruptured tendon?
High risk re-rupture
High activity
Ends cannot be opposed
148
What finger flexor tendons are at high risk of rupture?
FDS
| FDP
149
What is the management for laceration of tendons (finger flexors)?
Repair surgically and early
150
What is a ligament?
Dense bands of collagenous tissue which span joints
151
What do ligaments do?
Joint stability through range motion
152
What type of collagen fibres make up ligaments?
Type 1
153
What is the composition of ligaments compared to tendons?
Ligaments:
- lower % collagen
- higher % proteoglycans and water
- less organised collagen fibres
- rounder fibroblasts
154
What are ligaments made up of?
Collagen fibres (type I)
Fibroblasts
Sensory fibres
Vessels
155
How do ligament ruptures occur?
Forces exceed strength of ligament
156
What are the stages of ligaments heal?ing
Haemorrhage/inflammation
Proliferative phase
Remodelling
157
What is the treatment for ligament rupture?
Conservative
| Operative: augmentation, repair, replacement
158
When would you choose conservative repair for a ligament?
Partial rupture
No instability
Poor candidate surgery
159
When would you choose surgical repair for a ligament?
Instability
Expectation
Compulsory
