1- Upper limb MSQs Only Flashcards
(1-601) 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?
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.
(2 - 601)
Which of the following nerves supplies the skin on the palmar aspect of the thumb?
Median
The median nerve supplies cutaneous sensation to this region.
( 7 of 601)
A 63 year old lady is undergoing an axillary sentinel lymph node biopsy as part of her breast cancer treatment. Which of the structures listed below is most likely to be encountered?
Intercostobrachial nerve
A particularly careless surgeon could encounter all of these. However, during a routine level 1 axillary exploration which is where the majority of sentinel nodes will be located, the nerves most commonly encountered are the Intercostobrachial nerves.
(10 of 601)
A 35 year old farm labourer injures the posterior aspect of his hand with a mechanical scythe. He severs some of his extensor tendons in this injury. How many tunnels lie in the extensor retinaculum that transmit the tendons of the extensor muscles?
Six
There are six tunnels, each lined by its own synovial sheath.
(Question 12 of 601)
Which of the muscles listed below is not innervated by the median nerve?
Adductor pollicis
Adductor pollicis is innervated by the ulnar nerve.
Medial two lumbricals innervated by the ulnar nerve
( 14 of 601 )
A 23 year old man is involved in a fight outside a nightclub and sustains a laceration to his right arm. On examination, he has lost extension of the fingers in his right hand. Which of the nerves listed below is most likely to have been divided?
Radial
The radial nerve supplies the extensor muscle group
( 17 of 601 )
An injured axillary artery is ligated between the thyrocervical trunk of the subclavian and subscapular artery. Subsequent collateral circulation is likely to result in reversal of blood flow in which of the vessels listed below?
Transverse cervical artery
It is asking about the branches of the axillary artery and knowledge of the fact that there is an extensive collateral network around the shoulder joint
(23 of 601)
A 43 year old typist presents with pain at the dorsal aspect of the upper part of her forearm. She also complains of weakness when extending her fingers. On examination triceps and supinator are both functioning normally. There is weakness of most of the extensor muscles. However, there is no sensory deficit. Which of the following nerves has been affected?
Posterior interosseous
(29 of 601)
A 23 year old man falls and slips at a nightclub. A shard of glass penetrates the skin at the level of the medial epicondyle, which of the following sequelae is least likely to occur?
Claw like appearance of the hand
(31 of 601)
A 43 year old man is stabbed outside a nightclub. He suffers a transection of his median nerve just as it leaves the brachial plexus. Which of the following features is least likely to ensue?
Complete loss of wrist flexion
(33 of 601)
Which of the structures listed below articulates with the head of the radius superiorly?
Capitulum
The head of the radius articulates with the capitulum of the humerus.
39 of 601
At the level of the wrist joint, which of the statements below best describes the relationship of the ulnar artery to the ulnar nerve?
It lies on its radial side
40 of 601
Which of the following anatomical structures lies within the spiral groove of the humerus?
Radial nerve
The radial nerve lies in this groove and may be compromised by fractures involving the shaft.
41 of 601
A 24 year old man falls and sustains a fracture through his scaphoid bone. From which of the following areas does the scaphold derive the majority of its blood supply?
From the distal end
The blood supply to the scaphoid enters from a small non articular surface near its distal end. Transverse fractures through the scaphoid therefore carry a risk of non union
43 of 601
A patient sustains damage to the median nerve during a carpal tunnel release. Which of the following muscles will be affected?
Abductor pollicis brevis
Of the muscles listed, only the abductor pollicis brevis is innervated by the median. In questions like this one, ensure you don’t become confused between adductor and abductor.
52 of 601
Which of the nerves listed below is directly responsible for the innervation of the lateral aspect of flexor digitorum profundus?
Anterior interosseous nerve
The anterior interosseous nerve is a branch of the median nerve and is responsible for innervation of the lateral aspect of the flexor digitorum profundus.
55 of 601
Which of the structures listed below are most closely related to the axillary nerve within the quadrangular space?
Posterior circumflex humeral vessels
The posterior circumflex humeral vessels which are branches of the axillary artery are related to the axillary nerve within the quadrangular space
62 of 601
Which muscle initiates abduction of the shoulder?
Supraspinatus
The intermediate portion of the deltoid muscle is the chief abductor of the humerus. it can only do this after the movement has been initiated by supraspinatus. Damage to the te supraspinatus is a common form of rotator cuff disease.
69 of 601
The first root of the brachial plexus commonly arises at which of the following levels?
C5
It begins at C5 and has 5 roots. It ends with a total of 15 nerves of these 5 are the main nerves to the upper limb (axillary, radial, ulnar, musculocutaneous and median)
72 of 601
When the brachial plexus is injured in the axilla as a result of a crutch palsy, which of the nerves listed is most commonly affected?
Radial nerve
The radial nerve is most commonly injured and results in a wrist drop. The ulnar nerve arises from the medial cord and is rarely affected as a result of this injury mechanism.
81 of 601
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?
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 prios to the axillary vein. However, a PICC line is unlikely to enter this structure because of its angle of entry into the basilic vein
83 of 601
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
This is a common injury in children. In this case the angulation and displacement have resulted in median nerve injury
84 of 601
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
The interossei are supplied by the ulnar nerve
98 of 601
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?
Axillary
104 of 601
A 21 year old man is stabbed in the antecubital fossa. A decision is made to surgically explore the wound. At operation the surgeon dissects down onto the brachial artery. A nerve is identified medially, which nerve is it likely to be?
Median
Question 109 of 601
Which of the following muscles does not attach to the radius?
Brachialis
The brachialis muscle inserts into the ulna. The other muscles are all inserted onto the radius.
110 of 601
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?
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 gerve lies closest to it in the lateral position. In the cubital fossa it lies medial to it
111 of 601
What is the course of the median nerve relative to the brachial artery in the upper arm?
Lateral to anterior to medial
Relations of median nerve to the brachial artery Lateral >Anterior > 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.
124 of 601
The following statements relating to the musculocutaneous nerve are true except?
If damaged, then extension of the elbow joint will be impaired
It supplies biceps, brachialis and coracobrachialis. if damaged then elbow flexion will be impaired
136 of 601
Which of the muscles listed below is attached to the anterior aspect of the fibrous capsule that encases the elbow joint?
Brachialis
The brachialis inserts some of its fibres into the fibrous joint of the elbow capsule and when contracts, it helps to flex the joint
137 of 601 A 32
year old rugby player is hit hard on the shoulder during a rough tackle. Clinically, his arm is hanging loose on the side. It is pronated and medially rotated. What structure is most likely to have been compromised?
Brachial trunks C5-6
The patient has an Erb’s palsy involving brachial trunks C5-6
139 of 601
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
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. Injured, the trapezius muscle and SCM will be paralysed.
140 of 601 A 35
year tennis player attends 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
The 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
154 of 601
A 22 year old falls over and lands on a shard of glass. It penetrates the palmar aspect of his hand, immediately lateral to the pisiform bone. Which of the following structures is most likely to be injured?
Ulnar artery
The ulnar nerve and artery are at most immediate risk in this injury
159 of 601
A motorcyclist is involved in a road traffic accident. He suffers a complex humeral shaft fracture which is plated. Post operatively he complains of an inability to extend his fingers. Which of the following structures is most likely to have been injured?
Radial nerve
The racial nerve is responsible for innervation of the extensor compartment of the forarm
161 of 601
A 48 year old lady is undergoing an axillary node clearance for breast cancer. Which of the structures listed below are most likely to be encountered during the axillary dissection?
Thoracodorsal trunk
Beware of damaging the thoracodorsal trunk if a latissimus dorsi flap reconstruction is planned. The thoracodorsal trunk runs through the nodes in the axilla. If injured it may compromise the function and blood supply to latissimus dorsi, which is significant if it is to be used as a flap for a reconstructive procedure
162 of 601
A 53 year old lady is recovering following a difficult mastectomy and axillary nodal clearance for carcinoma of the breast. She complains of shoulder pain and on examination has obvious winging of the scapula. Loss of innervation to which of the following is the most likely underlying cause?
Serratus anterior
Winging of the scapula is most commonly the result of long thoracic nerve injury or dysfunction latrogenic damage during the course of the difficult axillary dissection is the most likely cause in this scenario. Damage to the rhomboids may produce winging of the scapula but would be rare in the scenario given.
163 of 601
How many phalanges are there in the hand?
14
Each digit has 3 phalanges, the thumb has two the total is therefore 14
183 of 601
A 23 year old climber falls and fractures his humerus. The surgeons decide upon a posterior approach to the middle third of the bone. Which of the following nerves is at greatest risk in this approach?
Radial
The radial nerve wraps around the humerus and may be injured during a posterior approach. An IM nail may be preferred as it avoids the complex dissection needed for direct bone exposure.
187 of 601
What is the largest branch of the brachial artery?
Profunda brachii artery
The profunda brachii artery is the largest branch and then continues in the radial groove of the humerus.
194 of 601
Which of the following nerves is responsible for innervation of the triceps muscle?
Radial
To remember nerve roots and their reflexes
1-2 Ankle (S1-S2)
3-4 Knee (L3-L4)
5-6 Biceps (C5-C6)
7-8 Triceps (C7-C8)
The radial nerve innervates all three heads of triceps, with a separate branch to each head.
203 of 601
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
The accessory nerve may be injured in operations in the posterior triangle. Injury will affect trapezius.
205 of 601
The cords of the brachial plexus are most closely related to which of the following vessels?
Axillary artery
The trunks are related to the subclavian artery superiorly. The cords of the plexus surround the axillary artery, they are named according to their positions relative to this structure
213 of 601
A 23 year old rugby player sustains a Smiths Fracture. On examination, opposition of the thumb is markedly weakened. Which of the following nerves is least likely to be working normally?
Median
This high velocity injury can often produce significant angulation and displacement. Both of these may impair the function of the median nerve with loss of function of the muscles of the thenar eminence.
223 of 601
A 73 year old lady suffers a fracture at the surgical neck of the humerus. The decision is made to operate. There are difficulties in reducing the fracture and a vessel lying posterior to the surgical neck is injured. Which of the following is this vessel most likely to be?
Posterior circumflex humeral artery
The circumflex humeral arteries lie at the surgical neck and is this scenario the posterior circumflex is likely to be injured. The thoracoacromial and transverse scapular arteries lie more superomedially. The posterior circumflex humeral artery is a branch of the axillary artery
212 of 601
Which structure separates the cephalic vein and the brachial artery in the antecubital fossa?
Biceps muscle
218 of 601
Which of the following muscles inserts onto the lesser tuberostiy of the the humerus?
Supscapularis
With the exception of subscapularis which inserts into the lesser tuberosity, the muscles of the rotator cuff insert into the greater tuberosity
233 of 601
Which of the following upper limb muscles is not innervated by the radial nerve?
Abductor digiti minimi
Mnemonic for radial nerve muscles: BEST Brachioradialis
Extensors
Supinator
Triceps
Abductor digiti minimi is innervated by the ulnar nerve
237 of 601
Which nerve supplies the skin at the medial aspect of the palm?
Ulnar
238 of 601
Which muscle is responsible for causing flexion of the distal interphalangeal joint of the ring finger?
Flexor digitorum profundus
Flexor digitorum superficialis and flexor digitorum profundus are responsible for causing flexion. The superficialis tendons insert on the bases of the middle phalanges; the profundus tendons insert on the bases of the distal phalanges. Both tendons fiex the wrist, MCP and PIP joints; however, only the profundus tendons flex the DIP joints
240 of 601
A 32 year old lady complains of carpal tunnel syndrome. The carpal tunnel is explored surgically. Which of the following structures will lie in closest proximity to the hamate bone within the carpal tunnel?
The tendons of flexor digitorum profundus
The carpal tunnel contains nine flexor tendons: Flexor digitorum profundus Flexor digitorum superficialis Flexor pollicis longus. The tendon of flexor digitorum profundus lies deepest in the tunnel and will thus lie nearest to the hamate bone
242 of 601
Which nerve supplies the interossei of the fourth finger?
Deep Ulnar
Mnemonic PAD and DAB Palmer interossei ADduct Dorsal interossei ABduct
251 of 601
A 45 year man presents with hand weakness. He is given a piece of paper to hold between his thumb and index finger. When the paper is pulled, the patient has difficulty maintaining a grip. Grip pressure is maintained by flexing the thumb at the interphalangeal joint. What is the most likely nerve lesion?
Deep branch of ulnar nerve
This is a description of Froment’s sign, which tests for ulnar nerve palsy. It mainly tests for the function of adductor pollicis. This is supplied by the deep branch of the ulnar nerve. Remember the anterior interosseous branch (of the median nerve), which innervates the flexor pollicis longus (hence causing flexion of the thumb IP joint), branches off more proximally to the wrist.