R2 LOCO1

Question 1

Describe happens when muscle fibres become deinnervated [1]

Answer 1

All muscle fibres innervated by a damaged motor unit undergo atrophy

Damaged: arrow

Question 2

Describe what a target fibre is [1]
Why does a target fibre arise? [1]
Describe the apperance [1]

Answer 2

When a damaged muscle is re-innervated; nuclei of muscle moves centrally and causes the production of new actin and myosin fibres

Occurs due to satellite cells differentiating and proliferating

Question 3

Which are the slow & fast fibres in this stain? [2]

Answer 3

Slow fibres (Type 1): more mitochondria - darker stain

Fast fibres (Type 2): less mitochondria - light stain

Question 4

Describe the pathophysiology of sarcopenia

Answer 4

• 0.5 - 1% of muscle mass is lost each year after age of 50; 3-5% if inactive
• Muscle replaced with fat
• No difference in men and women
• Causes an increase likelihood of fractures
• Impaired balance

Question 5

Which muscle fibres degenerate more in sarcopenia? [1]

Answer 5

Generally, a significant decline of type II, but not type I muscle fibers are observed in sarcopenic patients

Question 6

How does an EMG present with patients who have myopathy?

Compared to healthy and neuropathy patients [2]

Answer 6

In myopathic motor units, the number of functional muscle fibers is reduced. Therefore motor unit action potentials (MUAPs) are smaller in amplitude and duration. Because of the asynchronous firing of affected muscle fibers, the morphology of MUAPs become polyphasic.

Question 7

How does a patient with dermatoymositis present? [4]

Answer 7

Rash around eyes
Peri-orbital oedema
V sign of neck due to increased photosynsetivity
Gottron’s sign

Question 8

How does a biospy from a patient with polymyositis / dermatomyositis present? [1]

Answer 8

• (some have subclinical muscle involvement)
• Muscle generally not involved; CD8 T cells cells infiltrate the periphery of the muscle fasicle
• Central nuclei
• Variation in fibre size

Question 9

Describe the effect of CD8 infiltration in dermatomyositis [1]

Answer 9

CD8 T cells bind to MHC 1 to create: CD8-MHC1 complex

(also note the central nuclei)

Question 10

Describe the change that occurs in subcutaneous calcifications [3]

Answer 10

Dermis-epidermal junction: vacuoles develop, mucin deposite and calcifications

Question 11

Describe treatment regime of dermatomyositis [4]

Answer 11

Prednisilone (type of corticosteroid):
* 1 mg / kg per day until creatine kinase normal

Azthioprine

Methotrexate

Rituximab

Question 12

Which muscular dystrophies are the most common? [2]

Describe their inheritance [1]

Answer 12

Duchenne & Becke Muscular Dystrophies;

X-linked - recessive

Question 13

Describe pathophysiology of Duchenne MD [2]

Which serum marker is raised in DMD? [1]

Answer 13

Healthy muscle: dystrophin is a ring around muscle fibre that connects the ECM to contractile apparatus so that endomesium moves with muscle

Duchenne: no muscle fibres with dystrophin; causes elevated creatine kinase

Question 14

Which muscle groups are most at risk in Duchenne MD? [2]

What does this mean clinically? [2]

Answer 14

Respiratory muscles & diaphragm; die from resp. failure

Dilated cardiomyopathy occurs; heart failure

Question 15

How does early DMD appear histologically? [3]

Answer 15

Fibre size variation
endomysial & perimysium fibrosis
Degenerating muscle fibres undergoing myophagocytosis

Question 16

How does late DMD appear histologically? [2]

Answer 16

Loss of muscle; atrophy of fibres and death - replaced with fibrotic material and fat

Question 17

Treatment for DMD? [2]

Answer 17

Prednisilone
Gene alterations

Question 18

How do statins affect 10% muscle? [2]

Answer 18

Rhabdomyolysis; get vacuoles in type 2 muscle fibres

Question 19

Name and describe how two therapeutic drugs cause myopathy [2]

Answer 19

Corticosteroids; cause dose dependent type 2 atrophy

Hydroxychloroquine: not dose dependent atrophy; lysosomes damaged

Hydroxychloroquine causing lysosome damage

Question 20

Which tissue is affected in fibromyalgia? [1]

Which muscles are painful? [1]

Which antibodies are present in 50% of patients? [1]

Answer 20

Connective tissue damaged; causes widespread pain in both sides and above & below waist axial skeleton pain

Antipolymer antibodies

Question 21

How do you diagnose fibromyalgia? [1]

Answer 21

Apply 2kg of pressure on 18 specific tender points in the body; 11/18 is a positive diagnosis

Question 22

Treatment options for fibromyalgia? [4]

Answer 22

Amitriptyline (TCA)
Fluxetine (SSRI)
Exercise
Complementary therapy

Question 23

Give three pieces of evidence that RA is autoimmune disease [3]

Answer 23

1- Patients produce auto-antibodies (in blood and joints).

2- Inflamed joints are filled with activated immune cells, cytokines

3- Joint conditions are strongly associated with MHC genes, required for T cell activation.

Question 24

What is the role of MHC class molecules? [3]

Answer 24

• MHC determines which peptides are presented to T-lymphocytes.
• MHC molecules determines T-lymphocyte tolerance in the thymus (i.e. what mature T cells enter the periphery / survive) and also determines if and how mature T lymphocytes respond to antigens upon encounter.

Therefore: any strongly recognised self-T cells are killed off

Question 25

Which vertebrae have costal facets Cervical Thoracic Lumbar Sacral

Answer 25

**Thoracic**

Question 26

Which vertebrae have a large vertebral body Cervical Thoracic Lumbar Sacral

Answer 26

Lumbar

Question 27

Which vertebrae have a downward-sloping spinous process Cervical Thoracic Lumbar Sacral

Answer 27

**Thoracic**

Question 28

Which vertebrae have a small vertebral foramen Cervical Thoracic Lumbar Sacral

Answer 28

Thoracic

Question 29

What is a Jefferson Fracture? [1]

Answer 29

**bone fracture of the vertebra C1**

Question 30

What is Hangman's fracture? [1]

Answer 30

fracture which involves the **pars interarticularis of C2 on both sides**, and is a result of hyperextension and distraction.

Question 31

Answer 31

Correct! A Jefferson fracture is a burst fracture of the atlas, usually the result of axial loading injurues like diving headfirst into shallow water. This one is an example of a four-part fracture

Question 32

Describe a wedge fracture [1]

Answer 32

Wedge fracture: This fracture usually occurs in the front of the vertebra, collapsing the bone in the front of the spine and leaving the back of the same bone unchanged, which results in the vertebra taking on a wedge shape.

Question 33

Answer 33

Pectoralis major and latissimus dorsi are both adductors of the shoulder, and they attach to the proximal humerus. Normally, the clavicle holds the arm laterally away from the body, but this fracture causes it to collapse. The humerus is pulled medially, dragging the lateral fragment of clavicle with it.

Question 34

Which nerves supply the: supraspinatous [1] infraspinatous [1] teres minor [1] subscapularis [2]

Answer 34

supraspinatous: **suprascapular nerve** infraspinatous: **suprascapular nerve** teres minor: **axillary nerve** subscapularis: **upper & lower subscapular nerves**

Question 35

Which rotator cuff is innervated by the axillary nerve: supraspinatous infraspinatous teres minor subscapularis

Answer 35

Which rotator cuff is innervated by the axillary nerve: supraspinatous infraspinatous **teres minor** subscapularis

Question 36

Which rotator cuff medially rotates the shoulder supraspinatous infraspinatous teres minor subscapularis

Answer 36

**subscapularis** infraspinatous teres minor are both lateral rotators

Question 37

On the MRI below, a tendon passing deep to the acromion appears thickened and abnormally bright. To which muscle does this tendon belong? [1]

Answer 37

Acceptable responses: **supraspinatus**

Question 38

Answer 38

Question 39

Which structure(s) is (are) most at risk in a supracondylar fracture? [2]

Answer 39

**median nerve & brachial artery**

Question 40

Which structure(s) is (are) most at risk in the injury below? Select all that apply.

Answer 40

Question 41

Answer 41

Question 42

Answer 42

Question 43

Answer 43

Question 44

Describe what a Colles fracture is [1]

Answer 44

**Colles fracture** * extra-articular (not involving the joint) **fracture of the distal radius** with **dorsal** **angulation** and **impaction**.

Question 45

Describe what a Smith fracture looks like [2]

Answer 45

extra-articular fracture of the **distal radius** with **volar (anterior) angulation and impaction.**

Question 46

What type of pelvic fracture causes bladder damage? [1]

Answer 46

Diastasis (seperation) of the pubic symphysis

Question 47

What type of fracture causes superior gluteal nerve damage? [1]

Answer 47

sacroiliac joint disruption

Question 48

How can you classify intracapsular neck of femur fractures? [3] How can you classify extracapsular neck of femur fractures? [2]

Answer 48

Intracapsular fractures include **subcapital, transcervical and basicervical.** Extracapsular fractures include **intertrochanteric and subtrochanteric.**

Question 49

Which type of fracture is shown subcapital transcervical basicervical subtrochanteric intertrochanteric

Answer 49

**intertrochanteric** fracture Common extracapsular fractures of the proximal femur at the level of the greater and lesser trochanter

Question 50

Which type of fracture is shown subcapital transcervical basicervical subtrochanteric intertrochanteric

Answer 50

**Basicervical fracture**. There is a fracture at the base of the neck of the right femur, just proximal to the trochanters (white arrows). There is varus deformity (white line) of the femoral shaft.

Question 51

Which type of fracture is shown subcapital transcervical basicervical subtrochanteric intertrochanteric

Answer 51

**Comminuted intertrochanteric fracture.** There is a fracture from the greater to the lesser trochanter (blue arrow). There are separate fragments of the greater trochanter (white arrow) and lesser trochanter (red arrow). There is varus deformity (white line) of the femoral shaft.

Question 52

Which type of fracture is shown subcapital transcervical basicervical subtrochanteric intertrochanteric

Answer 52

**Sub-capital hip fracture**. On the frontal view, there is a step-off in the cortex superiorly (red arrow) while there is abnormal overlapping of the femoral head and neck (white arrows) due to impaction. On the lateral view, the same step-off can be seen (red arrow) as well as the impaction (white arrow).

Question 53

Following neck of femur fracture, patients commonly present with shortening and external rotation of the affected lower limb. Which muscle is responsible for this clinical appearance? [1]

Answer 53

Acceptable responses: *psoas, psoas major, iliopsoas*

Question 54

Which strong ligament reinforces the hip joint anteriorly, and therefore makes anterior dislocations far less common than posterior dislocations? [1]

Answer 54

Acceptable responses: *iliofemoral ligament, iliofemoral*

Question 55

How does local acupuncture work? [4]

Answer 55

Stimulates **nerve fibres** in **skin and muscle** **Vasodilation** / Blood vessel proliferation **Nerve growth** Acupuncture promotes **local healing**

Question 56

State 4 clincial applications of local acupuncture [4]

Answer 56

Skin lesions Ulcers Scars Warts

Question 57

Describe mechanism of segmental effect of acupuncture

Answer 57

Action potentials travel up to spinal segment Depress the activity of the dorsal horn ↓ response to painful stimuli **Acupuncture reduces** pain in the segment where the **needles are inserted**

Question 58

Give an example of a clinical use of segmental effect of acupuncture [1]

Answer 58

knee OA.

Question 59

What is a myofascial trigger point? [1]

Answer 59

**hyperirritable spot,** usually within a taut band of skeletal muscle, which is painful on compression and can give rise to characteristic referred pain, motor dysfunction, and autonomic phenomena.

Question 60

Name 4 clincial applications of acupuncture? [4]

Answer 60

Primary myofascial pain Nociceptive musculoskeletal pain Functional disorders Allergies Skin conditions Depression / Anxiety / Other psychiatric disorders Fibromyalgia Neuropathic pain

Question 61

How can you implement sham acupuncture to try and elicit acupuncture research [2]

Answer 61

NON-PENETRATING SHAM CONTROLS PENETRATING SHAM CONTROLS Several attempts to provide a device (e.g. ‘’Stage dagger’’ needle) Difficult to conceal from pt. Can be used in limited situations. Prevents proper acupuncture (i.e. Depth of insertion) Can be: A.in the wrong site (but often not credible to patient), B. Right site but superficial and without stimulation (still have an effect –segmental and extrasegmental and central-), C. Both

Question 62

NICE suggests acupuncture for which pathologies [2]

Answer 62

Headache Chronic primary pain Fecal incontinence Overactive bladder