MSK conditions: Fractures, Anatomy

Question 1

What muscles does the radial N innervate

Answer 1

1. Triceps
2. all EXTENSOR forearm muscles (eg brachioradialis, supinator, extensor policis longus, brevis)
3. An industry (tiny muscle in olecranon fossa)

Question 2

What muscles does the median N innervate

Answer 2

1. Most FLEXOR forearm muscles
   (Except flexor carpi ulnaris)
2. med-LOAF hand muscles:
   - 2 lumbricals on radial side
   - opponens pollicis
   - abductor pollicis brevis
   - flexor pollicis brevis

Question 3

What muscles does the ulnar N innervate

Answer 3

1. Most hand muscles
   (Except med LOAF)
2. Flexor carpi ulnaris

Question 4

What N is affected in an anterior shoulder dislocation

What are the motor/ sensory effects of this

Answer 4

Shoulder dislocated = axillary N

MOTOR
Deltoid cannot abduct arm
Teres minor cannot externally rotate arm

SENSORY
Deficit over Sergeants patch

Question 5

What N is affected in a mid-shaft humerus fracture

What are the motor/ sensory effects of this

Answer 5

mid-shaft humerus fracture = radial nerve

MOTOR
Wrist drop
Can’t extend wrist/ fingers

SENSORY
Deficit over radial part of dorsum of hand

Question 6

Thigh innervation

• anterior
• medial
• posterior

Answer 6

Thigh

Anterior = femoral N
Medial = obturator N
Posterior = tibial N

Question 7

Leg innervation

Anterior
Lateral
Posterior

Answer 7

Leg

Anterior = deep branch of common fibular N
Posterior = tibial N
Lateral = superficial branch of common fibular N

Question 8

What N is affected with these symptoms:

Weak knee extension
Loss of patella reflex
Numb thigh

Answer 8

Femoral N

Question 9

What N is affected with these symptoms:

Weak ankle dorsiflexion
Numb calf/ foot

Answer 9

Peroneal N aka fibula N (branch of sciatic N)

Question 10

What N is affected with these symptoms:

Weak knee flexion
Pain/ numbness from glutes to ankle

Answer 10

Sciatic N

Question 11

What N is affected with these symptoms:

Cannot adduct hips
Numbness on medial thigh

Answer 11

Obturator N

Question 12

What N is affected in a hip dislocation

Answer 12

Sciatic N

Question 13

What N is affected in a knee dislocation (neck of fibula)

Answer 13

Peroneal/fibula N

Question 14

Management for the following:

NOF fracture
Intra-capsular + not displaced
Good pre-morbid status

Answer 14

Internal fixation

Question 15

Management for the following:

NOF fracture
Intra-capsular + not displaced
Poor pre-morbid status

Answer 15

Hemiarthroplasty

Question 16

Management for the following:

NOF fracture
Intra-capsular + displaced
Good pre-morbid status, Age <70

Answer 16

Internal fixation

Question 17

Management for the following:

NOF fracture
Intra-capsular + displaced
Good pre-morbid status, Age >70

Answer 17

Total hip replacement

Question 18

Management for the following:

NOF fracture
Intra-capsular + displaced
Poor pre-morbid status

Answer 18

Hemiarthroplasty

Question 19

Management for the following:

NOF fracture
Extra-capsular
Non-special type

Answer 19

Dynamic hip screw

Question 20

Management for the following:

NOF fracture
Extra-capsular
Reverse oblique/ transverse/ sub-trochanteric

Answer 20

Intramedullary nail

Question 21

Immediate fracture complications

Answer 21

• Bleeding, shock

* Neurovascular, visceral damage

Question 22

Early fracture complications

Answer 22

• Infection
• Fat embolism (ARDS)
• Rhabdomyolysis

Question 23

Late fracture complications

Answer 23

• Delayed/ mal-union
• Avascular necrosis
• Complex regional pain syndrome
• Myositis ossificans
• Joint stiffness
• Growth disturbance

Question 24

Describe Salter Harris fractures type 1-5

Answer 24

Salter Harris = fracture involving growth plate in children

1. Straight across = physis
2. Above = physis + metapiphysis
3. Lower = physis + epiphysis
4. Through everything
5. Rammed (crushed)

Question 25

Describe Gardens fractures type 1-4

Answer 25

Gardens = intra-capsular NOF fractures 1. Incomplete 2. Complete, NOT displaced 3. Complete, displaced slightly 4. Complete, completely not in line

Question 26

Which types of fractures are at greatest risk of compartment syndrome

Answer 26

- Humerus supracondylar fractures | - Tibial shaft fractures

Question 27

Signs/symptoms of compartment syndrome

Answer 27

* Pain on active and passive movement * Parasthesia * +/- Pallor * +/- Pulse: arterial pulse may be present as necrosis is due to microvascular compromise * +/- Paralysis

Question 28

How to differentiate compartment syndrome vs acute limb ischaemia

Answer 28

Compartment syndrome: limb is warm and red Acute limb ischaemia: limb is cold and pale

Question 29

How might compartment syndrome lead to an AKI

Answer 29

1. Compartment syndrome 2. Muscle death and Rhabdomyolysis 3. Myoglobin accumulates in renal tubules 4. AKI (thus give fluids as part of compartment syndrome treatment)

Question 30

Signs of rhabdomyolysis

Answer 30

1. Muscle pain/ weakness 2. Dark red/brown urine 3. Decreased urine output

Question 31

Which fractures are at greatest risk of avascular necrosis

Answer 31

1. NOF (intra-capsular) 2. Scaphoid 3. Talus (in foot)

Question 32

What causes a proximal humerus fracture? Signs of proximal humerus fracture

Answer 32

FOOSH injury Swollen elbow held semi-flexed

Question 33

What is a Galeazzi fracture? What causes this?

Answer 33

Fracture of Distal radius + Dislocation of Distal radio-ulnar joint Due to FOOSH injury

Question 34

What is a Monteggia fracture? What causes this?

Answer 34

Fracture of Ulnar shaft + Dislocation of Radial head Due to direct blow

Question 35

Signs of a fat embolus on - observations - skin - eyes

Answer 35

- observations: low sats - skin: non-blanching rash over torso - eyes: retinal haemorrhage, intra-arterial fat globules on fundoscopy

Question 36

Describe A to C of Weber's classification of fibula fractures

Answer 36

A: below level of syndemosis B: at level of syndemosis C: above level of syndemosis

Question 37

Management of Weber A Fibula fracture

Answer 37

Walking boot, below-knee cast | Can weight bear

Question 38

Management of Weber B Fibula fracture

Answer 38

Walking boot, below-knee cast Avoid weight bearing (ORIF if talar shift involved)

Question 39

Management of Weber C Fibula fracture

Answer 39

ORIF

Question 40

Management of Maisonneubre Fibula fracture

Answer 40

ORIF