Upper Limb

Question 1

What is the pectoral girdle?

Answer 1

Clavicle and scapula

Question 2

What is the clavicle?

Answer 2

Collarbone
Extending between sternum and acromium
Long bone

Question 3

Function of clavicle

Answer 3

Attaches upper limb to trunk
Protects underlying neurovascular structures supplying the upper limb
Transmits force from upper limb to axial skeleton

Question 4

Articulations of clavicle

What kind of joints do they form?

Answer 4

Sternoclavicular joint
Acromioclavicular joint

Both are fibrocartilaginous joints

Question 6

Bony landmarks of scapula

Answer 6

Sternal end - large facet for sternoclavicular joint
Shaft - acts as point of origin and attachment for muscles
Acromial end - small facet for acromioclavicular joint, attachment point for conoid tubercle and trapezoid line

Question 7

What is the scapula?

Articulations of the scapula

Answer 7

Shoulder blade

Glenohumeral joint (hyaline cartilage) 
Acromioclavicular joint - connects upper limb to trunk

Question 8

What are the different surfaces of the scapula? Bony landmarks of each surface

Answer 8

Costal(anterior), lateral, posterior

Costal - a concave depression called subscapular fossa on its surface, coracoid process on superolateral surface (hook like projection) lying underneath clavicle

Lateral - glenoid fossa which articulates with humerus to form glenohumeral joint, supraglenoid tubercle immediately superior to glenoid fossa, infraglenoid tubercle inferior to glenoid fossa

Posterior - spine which runs transversely across scapula, infraspinous fossa below spine, supraspinus fossa above spine, acromion which is a projection of spine that arches over glenohuneral joint articulating with clavicle

Question 9

Scapula fracture:
Common? 
Cause? 
What does it indicate? 
Intervention?

Answer 9

Relatively uncommon, cause by high speed road collisions, crushing injuries, sports injuries
Indication of severe chest trauma
Doesn’t need much intervention as tone of surrounding muscles holds pieces in place for healing

Question 10

What is the humerus?

Answer 10

Long bone of the upper arm

Question 11

Role of humerus

Answer 11

Attachment site for many muscles and ligaments

Question 12

Anatomical features of the proximal humerus

Answer 12

Head - connected to greater and lesser tubercles by anatomical neck

Greater tubercle - lateral, attachment site for supraspinatus, infraspinatus and teres minor

Lesser tubercle - medial, attachment site for subscapularis

Tubercles separated by intertubercular sulcus

Surgical neck runs from tubercles to shaft

Question 13

Anatomical features of shaft of humerus

Answer 13

Deltoid tuberosity - lateral, where deltoid muscle attaches

Radial groove - runs diagonally down posterior surface of humerus parallel to deltoid tuberosity, radial nerve and profunda brachii artery lie here
Attachment site for coracobrachialis, deltoid, brachialis, brachioradialis anteriorly and medial and lateral heads of triceps posteriorly

Question 14

Anatomical features of distal humerus

Answer 14

Medial and lateral Supraepicondylar ridges - formed by lateral and medial borders of humerus

Lateral and medial epicondyles - distal to supraepicondylar ridges, ulnar nerve passes into forearm along posterior side of medial epicondyle

Trochlea - medial, extends posteriorly
Capitulum - lateral, articulates with radius

3 depressions - anterior: coronoid, radial and posteriorly olecranon fossa

Question 15

Fractures of humerus

Answer 15

Surgical neck fracture - direct blow to area or falling on outstretched hand, risk of damage to axillary nerve and posterior circumflex artery

Mid-Shaft fracture - could damage radial nerve and profunda brachii artery (lie in radial groove). Radial nerve damage = wrist drop (unopposed flexion), sensory loss on posterior surface of hand and proximal ends of lateral 3 and half fingers posteriorly

Distal humeral fracture - supracondylar fracture and epicondyle fractures are common. Supracondylar fracture caused by falling on a flexed elbow, spans between two epicondyles
Direct damage could cause interference to brachial artery = ischaemia = uncontrolled flexion go hand
Medial epicondyle frActure could damage ulnar nerve = ulnar claw, loss of sensation over medial 1.5 fingers of hand on both dorsal and palmar surface

Question 16

Articulations of humerus

Answer 16

Glenohumeral joint

Elbow joint - trochlea and capitulum articulate with ulna and radius respectively

Question 17

Why is the glenohumeral joint susceptible to dislocation?

Answer 17

Humerus disproportionately larger than glenoid fossa = poor fit = unstable

Question 18

What is the elbow joint?

Answer 18

Joint connecting the proximal arm to the forearm
2 articulations:
Trochlear notch of ulna to trochlear of ulna
Head of radius to capitulum of humerus

Question 19

What is the ulna?

Answer 19

Medial bone of forearm

Question 20

Role of ulna and radius

Answer 20

Ulnar - stabilising bone

Radius - pivots to produce movement

Question 21

Different parts of ulna and it’s anatomical features

Answer 21

Proximal, shaft, distal

Proximal
Articulations: trochlear notch + trochlea = elbow joint, radial notch and head of radius = proximal radioulnar joint
Bony landmarks: olecranon - forms part of trochlear notch, coronoid process - ridge of bone projecting outward anteriorly, forms part of trochlear notch, trochlear notch = olecranon + coronoid process, radial notch laterally, ulna tuberosity = immediately distal of coronoid process

Shaft
Anterior surface - muscle attachment
Posterior - muscle attachment
Medial

Anterior border
Interosseous - attachment site for interosseous membrane; spans distance between 2 forearms
Posterior - palpable along entire length

Posterior
Much smaller in diameter than proximal end
Distal projection = ulnar styloid processes
Head articulates with ulnar notch of radius forming distal radioulnar joint

Question 22

Different types of ulna fractures and their causes

Answer 22

Shaft fracture - normal muscle tone pulls ulna posteriorly, Occurs as a result of ulna being hit by an object

Olecranon process fracture - less common, caused by patient falling on flexed elbow

Ulna and radius attached by interosseous membrane and so force of trauma to one bone can be transmitted to the other by this membrane. Both bone fractures are common:
Monteggia’s - caused by force from behind ulna, proximal shaft fractured, head of radius dislocates anteriorly at elbow
Galeazzi’s - fracture to distal radius with ulna head dislocating at the distal radio-ulnar joint

Question 23

What is the radius?

Answer 23

The lateral bone of the forearm

Question 24

Anatomical features of proximal radius

Answer 24

Head - disk shaped, thicker medially, articulates with capitulum of humerus forming elbow joint, articulates with radial notch forming proximal radioulnar joint
Neck - narrow area between head and tuberosity
Radial tuberosity - attachment site of biceps brachii

Question 25

Anatomical features of shaft of radius

Answer 25

Expands in diameter as it moves distally

Roughening at Middle of lateral surface for attachment of probator teres muscle

Question 26

Anatomical features for distal radius

Answer 26

Lateral side projects forming radial styloid process Ulnar notch medially articulating with ulna head forming distal radioulnar joint 2 facets on distal surface for articulation with scaphoid and lunate carpal bones making up wrist joint

Question 27

Fractures of radius

Answer 27

Colles’ - most common, cause = FOOSH causing fracture to distal radius, structures distal to fracture displaced posteriorly (wrist and hand) forming dinner fork deformity Fractures of radial head - cause FOOSH, radial head forced in capitulum of humerus causing it to fracture Smiths - cause falling onto back of hand, distal fragment placed anteriorly Monteggia’s fracture Galleazzi’s fracture

Question 28

What is the wrist joint?

Answer 28

Aka radiocarpal joint Synovial joint, marking transition of forearm to hand

Question 29

Articulating surfaces of radiocarpal joint

Answer 29

Distally - proximal row of carpal bones (not pisiform) Proximally - distal end of radius and fibrocartilaginous ligament called articular disk (not ulnar)

Question 30

Injuries to wrist joint

Answer 30

Scaphoid fracture - if FOOSH, scaphoid takes most of force. Can disrupt blood supply to proximal portion - emergency as failure to revascularise the scaphoid = avascular necrosis + future arthritis Main clinical sign = tenderness in anatomical snuffbox Anterior dislocation of lunate - caused by falling on a dorsiflexed wrist, lunate forced anteriorly and compressed carpal tunnel causing carpal tunnel syndrome Colles fracture - most common

Question 31

Function of bones of hand

Answer 31

Provide support and flexibility to the soft tissues

Question 32

What are bones of hands categorised into?

Answer 32

Carpals - most proximal, 8 irregularly shaped bones Metacarpals - 5, each related to a digit Phalanges - most distal, bones of finger

Question 33

Names of carpals

Answer 33

``` Proximal Row: (lateral to medial) Scaphoid Lunate Triquetrum Pisiform - sesamoid bone formed within tendon of flexor Carpi ulnaris ``` ``` Distal Row: (lateral to medial) Trapezium Trapezoid Capitate Hamate - projection on palmar surface called hook of hamate ```

Question 34

Names of metacarpals

Answer 34

``` Metacarpal I - thumb Metacarpal II - index finger Metacarpal III - middle finger iV - ring finger V - little finger ```

Question 35

Structure of metacarpals

Answer 35

Base, shaft, head

Question 36

Structure of phalanges

Answer 36

Thumb - proximal and distal phalanx | Rest of digits have proximal, middle and distal phalanges

Question 37

Joints in hand

Answer 37

Metacarpophalangeal joints Interphalangeal Carpometacarpal

Question 38

Fracture of metacarpals

Answer 38

Boxers - fracture of 5th metacarpal neck, caused by clenched fist striking hard object, distal part of fracture displaced posteriorly = shorter affected finger Bennett’s - fracture of 1st metacarpal base, extending into carpometacarpal joint, caused by hyperabduction of thumb