Station 2: Upper limb - applied osteology

Question 1

What is the function of the clavicle?

Answer 1

Connects axial skeleton to upper limb

Question 2

What would happen to the position of the upper limb if the clavicle was fractured?

Answer 2

Unilateral drooping of the affected shoulder

Movement at shoulder decreases due to pain

Question 3

What happens to the proximal and distal bone fragments in a fractured clavicle?

Answer 3

Proximal part pulled upwards towards SCM

Distal part drops due to gravity and pulled medially by pectoralis major

Question 4

What important structures can be damaged with fractures of the clavicle?

Answer 4

Subclavian/axillary artery
Internal jugular vein
Brachial plexus
Apex of lung - pneumothorax/haemothorax

Question 5

Why are anterior dislocations more common for glenohumeral dislocations?

Answer 5

Scapula spine and tendons of rotator cuff muscles prevent posterior dislocations

Question 6

What are the functions of the rotator cuff muscles?

Answer 6

Supraspinatus:

• helps deltoid abduct arm
• helps hold humeral head in glenoid cavity

Infraspinatus/teres minor:

• externally/laterally rotates arm
• helps hold humeral head in glenoid cavity

Subscapularis:

• medially/internally rotates arm
• helps hold humeral head in glenoid cavity

Question 7

What structures are vulnerable to injury in shoulder dislocations?

Answer 7

Axillary nerve

Axillary artery

Question 8

Which locations does the humerus commonly fracture and which associated structures may be injured?

Answer 8

Surgical neck: axillary nerve
Spiral groove (mid shaft): radial nerve
Distal humerus (supracondylar fracture): often child - fallen on outstretched hand -> damage to brachial artery, median nerve, compartment syndrome

Question 9

Which associated structures may be injured in a dislocated elbow?

Answer 9

Ulnar nerve**
Median nerve
Brachial artery

Question 10

What is a Colle’s fracture?

Answer 10

Fracture to distal radius +/- ulnar
Leads to a:
- posterior displacement of wrist/hand
- dorsal tilt, radial shortening, loss of ulnar inclination, radial angulation