eMRCS Upper Limb and Breast

Question 1

Which of the following forms the floor of the anatomical snuffbox?

Radial artery
Cephalic vein
Extensor pollicis brevis
Scaphoid bone
Cutaneous branch of radial nerve

Answer 1

Scaphoid bone

The scaphoid bone forms the floor of the anatomical snuffbox. The cutaneous branch of the radial nerve is much more superficially and proximally located.

Question 2

A 35 year old man falls and sustains a fracture to the medial third of his clavicle. Which vessel is at greatest risk of injury?

Subclavian artery
Subclavian vein
External carotid artery
Internal carotid artery
Vertebral artery

Answer 2

Subclavian vein

The subclavian vein lies behind subclavius and the medial part of the clavicle. It rests on the first rib, below and in front of the third part of the subclavian artery, and then on scalenus anterior which separates it from the second part of the artery (posteriorly).

Question 3

A 32 year old attends neurology clinic complaining of tingling in his hand. He has radial deviation of his wrist and there is mild clawing of his fingers, with the 4th and 5th digits being relatively spared. What is the most likely lesion?

Ulnar nerve damage at wrist
Ulnar nerve damage at elbow
Radial nerve damage at elbow
Median nerve damage at wrist
Median nerve damage at elbow

Answer 3

Ulnar nerve damage at elbow

The ulnar paradox - the higher the lesion, the less the clawing of the fingers seen clinically.

At the elbow the ulnar nerve lesion affects the flexor carpi ulnaris and flexor digitorum profundus.

Question 4

An 8 year old boy falls onto an outstretched hand and sustains a supracondylar fracture. In addition to a weak radial pulse the child is noted to have loss of pronation of the affected hand. Which nerve is compromised?

Median
Radial
Ulnar
Musculocutaneous
Axillary

Answer 4

Median nerve

This is a common injury in children. In this case the angulation and displacement have resulted in median nerve injury.

Question 5

Which of the following carpal bones is a sesamoid bone in the tendon of flexor carpi ulnaris?

Triquetrum
Lunate
Pisiform
Scaphoid
Capitate

Answer 5

Pisiform

This small bone has a single articular facet. It projects from the triquetral bone at the ulnar aspect of the wrist where most regard it as a sesamoid bone lying within the tendon of flexor carpi ulnaris.

Question 6

Which of the following nerves supplies the majority of the skin on the palmar aspect of the thumb?

Ulnar
Median
Radial
Musculocutaneous
None of the above

Answer 6

Median nerve

The median nerve supplies cutaneous sensation to this region.

Question 7

A patient presents to the clinic following a surgical procedure. She complains that she is unable to shrug her shoulder. What is the most likely underlying nerve injury?

Accessory nerve
Cervical plexus
Ansa cervicalis
Long thoracic nerve
Axillary nerve

Answer 7

Accessory nerve

The accessory nerve may be injured in operations in the posterior triangle. Injury will affect trapezius.

Question 8

A 38 year old man falls onto an outstretched hand. Following the accident he is examined in the emergency department. On palpating his anatomical snuffbox there is tenderness noted in the base. What is the most likely injury in this scenario?

Rupture of tendon of flexor pollicis
Scaphoid fracture
Distal radius fracture
Rupture of flexor carpi ulnaris tendon
None of the above

Answer 8

Scaphoid fracture

FOOSH is a common mechanism of injury for a scaphoid fracture. This should be suspected clinically if there is tenderness in the base of the anatomical snuffbox. A tendon rupture would not result in bony tenderness.

Question 9

A 78 year old man is lifting a heavy object when he feels a pain in his forearm and is unable to continue. He has a swelling over his upper forearm. An MRI scan shows a small cuff of tendon still attached to the radial tuberosity consistent with a recent tear. Which of the following muscles has been injured?

Pronator teres
Supinator
Anconeus
Brachioradialis
Biceps brachii

Answer 9

Biceps brachii

Biceps inserts into the radial tuberosity. Distal injuries of this muscle are rare but are reported and are clinically more important than more proximal ruptures.

Question 10

Through which of the structures listed below does the axillary nerve pass?

Quadrangular space
Triangular space
Subclavicular space
Subpectoral space
Intercostal space

Answer 10

Quadrangular space

Question 11

A 43 year old lady is due to undergo an axillary node clearance as part of treatment for carcinoma of the breast. Which of the following fascial layers will be divided during the surgical approach to the axilla?

Sibsons fascia
Pretracheal fascia
Waldeyers fascia
Clavipectoral fascia
None of the above

Answer 11

Clavipectoral fascia

The clavipectoral fascia is situated under the clavicular portion of pectoralis major. It protects both the axillary vessels and nodes.

During an axillary node clearance for breast cancer the clavipectoral fascia is incised and this allows access to the nodal stations. The nodal stations are; level 1 nodes inferior to pectoralis minor, level 2 lie behind it and level 3 above it.

During a Patey Mastectomy, surgeons divide pectoralis minor to gain access to level 3 nodes. The use of sentinel node biopsy (and stronger assistants!) have made this procedure far less common.

Question 12

A 73 year old lady with long standing atrial fibrillation develops a cold and pulseless white arm. A brachial embolus is suspected and a brachial embolectomy is performed. Which of the following structures is at greatest risk of injury during this procedure?

Radial nerve
Cephalic vein
Ulnar nerve
Median nerve
None of the above

Answer 12

Median nerve

The median nerve lies close to the brachial artery (medial to it) in the antecubital fossa. This is the usual site of surgical access to the brachial artery for an embolectomy procedure. The median nerve may be damaged during clumsy application of vascular clamps to the artery.

Question 13

A 73 year old man undergoes an excision biopsy of a lymph node that is closely applied to sternocleidomastoid. This muscle is mobilized and a nerve that is present is damaged. Which muscle below is most likely to be affected?

Trapezius
Rhomboid major
Deltoid
Supraspinatus
Rhomboid minor

Answer 13

Trapezius

The accessory nerve has a number of lymph nodes applied to it near the sternocleidomastoid muscle. It is particularly at risk if SCM is mobilized. If injured, the trapezius muscle and SCM will be paralysed.

Question 14

Which of the following structures separates the ulnar artery from the median nerve?

Brachioradialis
Pronator teres
Tendon of biceps brachii
Flexor carpi ulnaris
Brachialis

Answer 14

Pronator teres (deep head)

The ulnar artery lies deep to pronator teres and this separates it from the median nerve.

Question 15

Which of the following muscles lies medial to the long thoracic nerve?

Serratus anterior
Latissimus dorsi
Coracobrachialis
Pectoralis minor
None of the above

Answer 15

Serratus anterior

Question 16

A 10 year old boy is admitted to the emergency department following a fall. On examination, there is deformity and swelling of the forearm. The ability to flex the fingers of the affected limb is impaired. However, there is no sensory impairment. Imaging confirms a displaced forearm fracture. Which of the nerves listed below is likely to have been affected?

Ulnar nerve
Posterior interosseous nerve
Anterior interosseous nerve
Axillary nerve
Radial nerve

Answer 16

Anterior interosseous nerve

Forearm fractures may be complicated by neurovascular compromise. The anterior interosseous nerve may be affected. It has no sensory supply so the defect is motor alone.

Question 17

Which of the muscles listed below is attached to the anterior aspect of the fibrous capsule that encases the elbow joint?

Pronator teres
Biceps
Brachialis
Triceps
Extensor carpi radialis longus

Answer 17

Brachialis

The brachialis inserts some of its fibres into the fibrous joint of the elbow capsule and when it contracts, it helps to flex the joint.

Question 18

Which of the following muscles does not adduct the shoulder?

Teres major
Pectoralis major
Coracobrachialis
Latissimus dorsi
Supraspinatus

Answer 18

Supraspinatus

Supraspinatus is an abductor of the shoulder.

Question 19

What is the course of the median nerve relative to the brachial artery in the upper arm?

Medial to anterior to lateral
Lateral to posterior to medial
Medial to posterior to lateral
Medial to anterior to medial
Lateral to anterior to medial

Answer 19

Lateral to anterior to medial

The median nerve descends lateral to the brachial artery, it usually passes anterior to the artery to lie on its medial side.

It passes deep to the bicipital aponeurosis and the median cubital vein at the elbow.

It enters the forearm between the two heads of the pronator teres muscle

Question 20

Which nerve supplies the skin at the medial aspect of the palm?

Ulnar
Radial
Median
Musculocutaneous
Anterior interosseous

Answer 20

Ulnar

Originates from C8-T1.

Path: Posteromedial aspect of upper arm to flexor compartment of forearm, then along the ulnar. Passes beneath the flexor carpi ulnaris muscle, then superficially over the flexor retinaculum into the palm of the hand.

Question 21

A 40 year old lady trips and falls through a glass door and sustains a severe laceration to her left arm. Amongst her injuries it is noticed that she has lost the ability to adduct the fingers of her left hand. Injury to which of the following nerves is most likely to account for her examination findings?

Ulnar
Median
Radial
Musculocutaneous
Axillary

Answer 21

Ulnar nerve

The interossei are supplied by the ulnar nerve.

Question 22

A 23 year old man is injured during a game of rugby. He suffers a fracture of the distal third of his clavicle, it is a compound fracture and there is evidence of arterial haemorrhage. Which of the following vessels is most likely to be encountered first during subsequent surgical exploration?

Posterior circumflex humeral artery
Axillary artery
Thoracoacromial artery
Subscapular artery
Lateral thoracic artery

Answer 22

Thoracoacromial artery

The thoracoacromial artery arises from the second part of the axillary artery. It is a short, wide trunk, which pierces the clavipectoral fascia, and ends, deep to pectoralis major by dividing into four branches.

Question 23

The anterior interosseous nerve is a branch of which of the following?

Ulnar nerve
Superficial branch of radial nerve
Axillary nerve
Deep branch of radial nerve
Median nerve

Answer 23

Median nerve

Anterior interosseous nerve supplies the deep muscles on front of the forearm, except the ulnar half of FDP.

Accompanies anterior interosseous artery along anterior of interosseous membrane of forearm, in the interval between FPL and FDP

Supplies whole of FPL and radial half of FDP

Ends in the pronator quadratus and wrist joint

Question 24

A 56 year old man requires long term parenteral nutrition and the decision is made to insert a PICC line for long term venous access. This is inserted into the basilic vein at the region of the elbow. As the catheter is advanced, into which venous structure is the tip of the catheter most likely to pass from the basilic vein?

Subclavian vein
Axillary vein
Posterior circumflex humeral vein
Cephalic vein
Superior vena cava

Answer 24

Axillary vein

The basilic vein drains into the axillary vein and although PICC lines may end up in a variety of fascinating locations, the axillary vein is usually the commonest site following from the basilic.

The posterior circumflex humeral vein is encountered prior to the axillary vein. However, a PICC line is unlikely to enter this structure because of its angle of entry into the basilic vein.

Question 25

A 42 year old teacher is admitted with a fall. An x-ray confirms a fracture of the surgical neck of the humerus. Which nerve is at risk? ``` Median Radial Axillary Musculocutaneous Subscapular ```

Answer 25

Axillary nerve The axillary nerve winds around the bone at the neck of the humerus. It is also at risk during shoulder dislocation.

Question 26

Which of the following structures passes through the quadrangular space near the humeral head? ``` Axillary artery Radial nerve Axillary nerve Median nerve Transvere scapular artery ```

Answer 26

Axillary nerve ``` The quadrangular space is bordered by: Lateral - humerus Superior - subscapularis and teres minor Inferior - teres major Medial - long head of triceps ``` It lies lateral to the triangular space. It transmits the axillary nerve and posterior circumflex humeral artery.

Question 27

A 28 year old rugby player injures his right humerus and on examination is noted to have a minor sensory deficit overlying the point of deltoid insertion into the humerus. Which of the nerves listed below is most likely to have been affected? ``` Radial Axillary Musculocutaneous Median Subscapular ```

Answer 27

Axillary nerve This patch of skin is supplied by the axillary nerve

Question 28

Which nerve supplies the interossei of the fourth finger? ``` Radial Medial Superficial ulnar Deep ulnar Posterior interosseous ```

Answer 28

Deep ulnar Deep ulnar nerve supplies: hypothenar muscles, all interossei, 3rd and 4th lumbricals, adductor pollicis, medial head of flexor pollicis brevis Superficial ulnar supplies sensation to anterior palmar surfaces of medial 1.5 fingers

Question 29

A 23 year old man is involved in a fight, during the dispute he sustains a laceration to the posterior aspect of his right arm, approximately 2cm proximal to the olecranon process. On assessment in the emergency department he is unable to extend his elbow joint. Which of the following tendons is most likely to have been cut? ``` Triceps Pronator teres Biceps Brachioradialis Brachialis ```

Answer 29

Triceps The triceps muscle extends the elbow joint. The other muscles listed all produce flexion of the elbow joint.

Question 30

A 35 year tennis player attends clinic reporting tingling down his arm. He says that his 'funny bone' was hit very hard by a tennis ball. There is weakness of abduction and adduction of his extended fingers. Which nerve has been affected? ``` Ulnar Anterior interosseous Posterior interosseous Median Musculocutaneous ```

Answer 30

Ulnar nerve Arises from the medial cord of the brachial plexus (C8, T1 and contribution from C7). The nerve descends between the axillary artery and vein, posterior to the cutaneous nerve of the forearm and then lies anterior to triceps on the medial side of the brachial artery. In the distal half of the arm it passes through the medial intermuscular septum, and continues between this structure and the medial head of triceps to enter the forearm between the medial epicondyle of the humerus and the olecranon. It may be injured at this site in this scenario.

Question 31

A 23 year old man falls and injures his hand. There are concerns that he may have a scaphoid fracture as there is tenderness in his anatomical snuffbox on clinical examination. Which of the following forms the medial border of this structure? ``` Basilic vein Radial artery Extensor pollicis brevis Abductor pollicis longus Extensor pollicis longus ```

Answer 31

Extensor pollicis longus Boundaries of the anatomical snuffbox are extensor pollicis longus medially and laterally by the tendons of abductor pollicis longus and extensor pollicis brevis.

Question 32

A 25 year old man is stabbed in the upper arm. The brachial artery is lacerated at the level of the proximal humerus, and is being repaired. A nerve lying immediately lateral to the brachial artery is also lacerated. Which of the following is the nerve most likely to be? ``` Ulnar nerve Median nerve Radial nerve Intercostobrachial nerve Axillary nerve ```

Answer 32

Median nerve The brachial artery begins at the lower border of teres major and terminates in the cubital fossa by branching into the radial and ulnar arteries. In the upper arm the median nerve lies closest to it in the lateral position. In the cubital fossa it lies medial to it. The profunda brachii artery is related to the radial nerve.

Question 33

Which muscle initiates abduction of the shoulder? ``` Infraspinatus Latissimus dorsi Supraspinatus Deltoid Teres major ```

Answer 33

Supraspinatus The intermediate portion of the deltoid muscle is the chief abductor of the humerus. However, it can only do this after the movement has been initiated by supraspinatus. Damage to the tendon of supraspinatus is a common form of rotator cuff disease.

Question 34

What is the first branch of the axillary artery? ``` Subscapular artery Lateral thoracic artery Thoracoacromial artery Superior thoracic artery Anterior circumflex humeral artery ```

Answer 34

Superior thoracic artery ``` 1st part (proximal to pec minor): superior thoracic 2nd part (posterior to pec minor): thoracoacromial, lateral thoracic 3rd part (distal): subscapular, anterior and posterior circumflex humeral ```

Question 35

Which of the following nerves is responsible for innervation of the triceps muscle? ``` Radial Ulnar Axillary Median None of the above ```

Answer 35

Radial nerve The radial nerve innervates all three heads of triceps, with a separate branch to each head.

Question 36

The following are true of the ulnar nerve except: Innervates the palmar interossei Derived from medial cord of brachial plexus Supplies muscles of thenar eminence Supplies medial half of flexor digitorum profundus Passes superficial to flexor retinaculum

Answer 36

Supplies muscles of thenar eminence The muscles of the thenar eminence are supplied by the median nerve and atrophy of these is a feature of carpal tunnel syndrome.

Question 37

Which of the structures listed below articulates with the head of the radius superiorly? ``` Capitulum Trochlea Lateral epicondyle Ulna Medial epicondyle ```

Answer 37

Capitulum The head of the radius articulates with the capitulum of the humerus.

Question 38

The cephalic vein pierces the clavipectoral fascia to terminate in which of the veins listed below? ``` External jugular Internal jugular Axillary Azygos Brachial ```

Answer 38

Axillary vein Path of cephalic vein: dorsal venous arch drains laterally into cephalic vein Crosses anatomical snuffbox and travels laterally up arm At antecubital fossa, connected to basilic vein by median cubital vein Pierces deep fascia of deltopectoral groove to join axillary vein

Question 39

Which of the structures listed below are most closely related to the axillary nerve within the quadrangular space? ``` Posterior circumflex humeral arteries Anterior circumflex humeral arteries Axillary artery Radial artery Acromiothoracic artery ```

Answer 39

Posterior circumflex humeral arteries The posterior circumflex humeral vessels which are branches of the axillary artery are related to the axillary nerve within the quadrangular space.

Question 40

Which of the following fingers is not a point of attachment for the palmar interossei? ``` Middle finger Little finger Ring finger Index finger None of the above ```

Answer 40

Middle finger The middle finger has no attachment of the palmar interosseous. Note that there are 4 palmar interossei. The first is a small slip of muscle which arises from the ulnar side of the base of the first metacarpal and passes between the head of the first dorsal interosseous and the oblique head of adductor pollicis to insert into the ulnar base of the of the proximal phalanx of the thumb. The second arises from the ulnar side of the body of the second metacarpal and is inserted into` the ulnar side of the extensor hood of the index. The third and fourth palmar interossei arise from the radial sides of the bodies of the 4th and 5th metacarpals respectively and insert into the radial sides of the extensor hoods of the ring and little fingers.

Question 41

A 33 year old man sustains an injury to his forearm and wrist. When examined in clinic he is unable to adduct his thumb. What is the most likely underlying nerve lesion? ``` Radial nerve Superficial branch of ulnar nerve Median nerve Posterior interosseous nerve Deep branch of ulnar nerve ```

Answer 41

Deep branch of ulnar nerve Damage to the deep branch of the ulnar nerve may result in an inability to adduct the thumb. This is tested clinically by trying to withdraw a piece of paper from a patients hand grasped between thumb and index finger.`

Question 42

Which of the following structures is not closely related to the brachial artery? ``` Ulnar nerve Median nerve Cephalic vein Biceps Median cubital vein ```

Answer 42

Cephalic vein The cephalic vein lies superficially and on the contralateral side of the arm to the brachial artery. The relation of the ulnar nerves and others are demonstrated in the image below:

Question 43

A 24 year female is admitted to A&E with tingling of her hand after a fall. She is found to have a fracture of the medial epicondyle. What is the most likely nerve lesion? ``` Ulnar Radial Median Axillary Cutaneous ```

Answer 43

Ulnar nerve The radial nerve is located near the lateral epicondyle.

Question 44

Which of the following muscles does not attach to the radius? ``` Pronator quadratus Biceps Brachioradialis Supinator Brachialis ```

Answer 44

Brachialis The brachialis muscle inserts into the ulna. The other muscles are all inserted onto the radius.

Question 45

Which of the following is a branch of the third part of the axillary artery? ``` Superior thoracic Lateral thoracic Dorsal scapular Thoracoacromial Posterior circumflex humeral ```

Answer 45

Posterior circumflex humeral The other branches include: Subscapular, anterior circumflex humeral The dorsal scapular artery arises from the third part of the subclavian artery in most cases.

Question 46

The dorsal scapular artery arises from the third part of the subclavian artery in most cases ``` Radial Recurrent branch of median Anterior interosseous Ulnar Median ```

Answer 46

Median nerve

Question 47

A 23 year old man has a cannula inserted into his cephalic vein. Through which structure does the cephalic vein pass? ``` Interosseous membrane Triceps Pectoralis major Clavipectoral fascia Tendon of biceps ```

Answer 47

Clavipectoral fascia The cephalic vein penetrates the clavipectoral fascia (but not the pectoralis major) prior to terminating in the axillary vein. The cephalic vein is a favored vessel for AV fistula formation and should be preserved in patients with ESRF.

Question 48

Which of these muscles is not a component of the rotator cuff? ``` Subscapularis Teres minor Supraspinatus Infraspinatus Deltoid ```

Answer 48

Deltoid Deltoid may abduct the shoulder and is not a rotator cuff muscle.

Question 49

With respect to the basilic vein, which statement is false? Its deep anatomical location makes it unsuitable for use as an AV access site in fistula surgery It originates from dorsal venous network on the hand Travels up medial aspect of forearm Halfway between shoulder and the elbow it lies deep to muscle Joined by brachial vein to form axillary vein

Answer 49

Its deep anatomical location makes it unsuitable for use as an AV access site in fistula surgery It is used in AV fistula surgery during a procedure known as a basilic vein transposition.