Shoulder

Question 0

Palpable osseous structures of the arm

Answer 0

Greater and lesser tubercle of humerus

Lateral and medial epicondyle of humerus

Question 1

Superficial veins of right arm

Answer 1

Median cubital vein
Cephalic vein- Drains lateral forearm and arm into axillary vein
Basilic vein- Drains medial forearm and distal arm into axillary vein

Question 2

Humerus

Answer 2

• Long bone
• Proximal head articulates with glenoid cavity of scapula
• Distal medial and lateral epicondyles articulate at elbow with ulna and radius
• Surgical neck common fracture site > endangers axillary nerve.

Question 3

Fractures of humerus

Answer 3

Proximal 
• Humeral head
• Lesser tuberosity 
• Greater tuberosity 
• Surgical neck 
Midshaft 
Usually from direct trauma 
Distal 
Uncommon in adults

Question 4

Muscles of the arm

Answer 4

Intermuscular septum divides arm into anterior (flexor) & posterior (extensor) compartments.

Question 5

Anterior compartment

Answer 5

Biceps brachii, brachialis and coracobrachialis muscle.
• Muscles are primarily flexors of forearm at elbow
• Secondarily flexors of arm at shoulder (biceps brachii & coracobrachialis)
• Innervated by musculocutaneus nerve
• Blood supply by brachial artery

Question 6

Posterior compartment

Answer 6

Triceps brachii and anconeus muscle
• Primarily extensors of the forearm at elbow.
• Blood supply from deep artery of arm (profunda brachii).
• Innervated by radial nerve.

Question 7

Blood supply of the upper limb

Answer 7

Aorta ->Brachiocephalic trunk -> Subclavian artery -> Axillary artery -> Brachial artery -> Radial artery / Ulnar artery
Brachial artery supplies anterior arm muscles
Deep brachial artery (profunda brachii) supplies posterior arm
muscles

Question 8

Venous drainage

Answer 8

Brachial veins -> Basilic vein -> Axillary vein + Cephalic vein -> Subclavian vein

Question 9

Neurovascular bundle

Answer 9

Axillary vein
Axillary artery and brachial artery
Median nerve and ulnar nerve
Well protected as wrapped in fascia

Question 10

Innervation of arm muscles

Answer 10

Musculocutaneous nerve (lateral cord of brachial plexus)
-Biceps brachii
-Brachialis
-Coracobrachialis
Radial nerve (posterior cord of brachial plexus)
-Triceps brachii
-Anconeus

Question 11

Clavicle

Answer 11

• Cylindrical bone.
• Slight “s” curve
• Formed by intra-membranous ossification (1st long bone to ossify).
• Most commonly fractured bone.
• Acts as a strut to keep limb away from trunk

Question 12

Scapula

Answer 12

• Flat triangular bone.
• Shallow glenoid cavity.
• Attachment location for 17 muscles.
• Uncommon to fracture.

Question 13

Joints of the pectoral girdle & shoulder

Answer 13

• Acromioclavicular joint
• Glenohumeral joint
• Sternoclavicular joint

Question 14

Acromioclavicular joint

Answer 14

• Synovial plane joint.
• Allows gliding movement as arm is raised and scapula rotates.
• Includes:
• Acromioclavicular joint capsule & ligament
• Coracoclavicular (conoid and trapezoid ligaments)

Question 15

Glenohumeral joint

Answer 15

• Multi-axial synovial ball-and-socket joint.
• Shallow articulation.
• Most common dislocated joint (95% anterior: subcoracoid, subglenoid, subclavicular)
• Stabilised by rotator cuff muscles.
• Permits flexion, extension, abduction, adduction, protraction,
retraction, circumduction.

Question 16

Sternoclavicular joint

Answer 16

Saddle-type synovial joint with articular disc
Surrounded by a capsule that allows elevation, depression, protraction, retraction, circumduction
Anterior & posterior sternoclavicular ligaments between clavicle and manubrium
Interclavicular ligament connects the two sternoclavicular joints.
Costoclavicular ligament anchors clavicle to first rib.

Question 17

Ligaments of the sternoclavicular joint

Answer 17

Costoclavicular, interclavicular, anterior sternoclavicular ligament

Question 18

Bursae

Answer 18

Cushion the joint from overlying muscles, tendons and bones

Subacromial, subdeltoid, subscapular bursae

Question 19

15 Shoulder Muscles

Answer 19

• Superficial back muscles, deltoid and teres major muscles, rotator cuff muscles & superficial pectoral muscles.
• Deltoid
• Rotator cuff: SITS
• Supraspinatus
• Infraspinatus
• Teres minor
• Subscapularis
• Teres major
• Pectoralis minor & major
• Serratus anterior
• Subclavius
• Trapezius
• Latissimus dorsi
• Levator scapulae
• Rhomboid minor & major

Question 20

Rotator Cuff Injuries

Answer 20

• Wear & tear.
• Degeneration of subacromial bursa => degeneration of underlying supraspinatus muscle.
• Tearing of supraspinatus tendon.
• Difficulty in initiating abduction