MRCS July 1/52

Question 1

insertion of lats dorsi?

Answer 1

bicipital groove of humerus

Question 2

nerve supply of lats dorsi

Answer 2

thoracodorsal nerve

Question 3

where do the axons of the ventral nerve roots lie?

Answer 3

grey matter horn of spinal cord

Question 4

where do the axons of the dorsal nerve roots lie?

Answer 4

in dorsal root ganglion

Question 5

describe the path of a spinal nerve

Answer 5

filaments of nerves arise from each side of the spinal cord on dorsal (sensory preganglionic) and ventral (motor postganglionic) side

filaments joint to form ventral/dorsal nerve roots

dorsal nerve root forms dorsal root ganglion at intervertebral foramen and then fuses with ventral nerve root

motor and sensory nerve fibres cross and then divide to form dorsal primary ramus and ventral primary ramus

Question 6

is the dorsal nerve root pre or post ganglionic?

Answer 6

pre ganglionic

Question 7

what is the course of sympathetic fibres from the spinal cord?

Answer 7

sympathetic fibres emerge from ventral root and join spinal nerve, they are carried in the ventral primary ramus, there the white ramus communicans arises to join the sympathetic ganglion where they synapse directly with post ganglionic fibres or ascend/descend along sympathetic chain

Question 8

primary examination findings for compression of the following nerve roots

L2, L3, L4, L5, S1

Answer 8

L2 & L3 - hip flexion
L3 & L4 - hip adduction 
L4 - knee extension
L5 - hip abduction
S1 - ankle plantarflexion

Question 9

a herniated disc compressing on which nerve root would give primarily weakness in knee extension?

Answer 9

L4

Question 10

what nerve roots tests in

hip flexion, hip extension, knee flexion, knee extension, foot dorsiflexion, foot plantarflexion?

Answer 10

Hip flexion: L2-3
Hip extension: L4-5
Knee flexion: L5-S1
Knee extension L3-4
Foot dorsiflexion L4-5
Foot plantar flexion S1-s2

Question 11

prostate cancer mets cause sclerotic or lytic lesions?

Answer 11

sclerotic

Question 12

6 types of spondylolisthesis

Answer 12

1) congenital
2) isthmic
3) degenerative
4) traumatic
5) pathological
6) iatrogenic

Question 13

what is the grading system used for spondylolisthesis? describe it

Answer 13

meyerding grading system (1-5)

0-25%, 26-50%, 51-75%, 76-100%, >100%

Question 14

describe how and why spondylolisthesis occurs

Answer 14

defect in pars interarticularis or facet causing forward slippage of superior vertebral body, commonly L5-s1 due to slope of L5-S1

Question 15

difference between monopolar and bipolar diathermy?

Answer 15

monopolar - has 2 modes, cutting and coagulating. cutting is high wattage, low frequency, continuous output. coagulative is pulsed output, high frequency. both require electropad

bipolar - between foreceps, for coagulation, low power low frequency

Question 16

cytokines released during inflammatory phase of bone healing

Answer 16

IL2, IL6, PDGF, BMP, TGF-B, ILGF, Fibroblast growth factor

Question 17

what type of collagen is laid down first in secondary bone healing?

Answer 17

type 2

Question 18

what type of bone is formed initially in secondary bone healing

Answer 18

woven bone

Question 19

what is mangled extremity scoring system and what score is significant

Answer 19

> 7 indication for amputation

1) nature of injury
2) ischaemia
3) shock/BP
4) age of pt

Question 20

examples of delayed local complications of fractures

Answer 20

infection
non-union/mal-union
joint stiffness 
secondary osteoarthritis
avascular necrosis
myositis ossificans
CRPS

Question 21

what symptoms to suggest fat emoblism syndrome

Answer 21

tachypnea/desat
neurological changes/AMS
petechial rash
pyrexia

Question 22

management for fat embolism syndrome

Answer 22

supportive

Question 23

what kind of bacteria is clos. perf?

Answer 23

gram positive anaerobic rod, spore forming

Question 24

clostridium perfringens produces exo or endo toxin?

Answer 24

exotoxin

Question 25

treatment for gas gangrene?

Answer 25

amputation- source control high dose antibiotics (penicillin) hyperbaric oxygen therapy

Question 26

antibiotics therapy for nec fasc

Answer 26

meropenam + vancomycin + clindamycin

Question 27

4 high risk sites of fractures for AVN

Answer 27

intracapsular femoral head scaphoid waist fracture causing proximal pole AVN humeral head talus

Question 28

features of complex regional pain syndrome

Answer 28

``` after trauma/fracture to area pain out of proportion swelling, stiffness redness or bluish tint hyperhidrosis, temperature changes ```

Question 29

describe the classification used for proximal humerus fractures

Answer 29

Neers classification, include no of part fracture group 1 = <1cm displacement and 45deg angulation group 2 = anatomical neck >1cm displacement group 3 = surgical neck w/ ^ displacement/angulation group 4 = greater tuberosity fracture group 5 = lesser tuberosity group 6 = fracture dislocations

Question 30

what lvl of displacement and angulation is acceptable for nonsurgical management of humeral shaft fracture?

Answer 30

up to 20deg AP displacement with <30deg varus/valgus angulation

Question 31

grading of renal trauma based on american association for the surgery of trauma staging system

Answer 31

grade 1 = contusion, haematoma, subscapular injury not involving renal capsule grade 2 = involvement of cortex but not medulla grade 3 = involvement of cortex and medulla but not of collecting system grade 4 = major laceration involving collecting system grade 5 = completely smashed or renal avascularisation

Question 32

borders of femoral canal superomedial anterolateral posterior

Answer 32

superiomedial: sartorius anteriolateral: vastus medius posterior: adductor longus/magnus