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Semester 2 Musculoskeletal System > L9: The shoulder, osteology of the scapula, clavicle and proximal humerus > Flashcards

L9: The shoulder, osteology of the scapula, clavicle and proximal humerus Flashcards

1
Q

What types of bone is the scapula?

A

Irregular bone

Triangular flat bone

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2
Q

What does the scapular articulate with?

A

Glenoid cavity and humerus–> glenohumeral joint
Acromion and clavicle–> acromioclavicular joint
Anterior surface of scapular and rib cage–> Scapulothoracic joint (articulation) (not a true joint)

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3
Q

Describe the anatomy of the anterior surface of the scapula?

A

Anterior surface –> costal surface
Subscapular fossa–> Large concave depression
Coracoid process–> Superolateral surface , projects anterior laterally
Scapular notch–> medial to coracoid process

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4
Q

Describe the anatomy of the posterior surface of the scapula?

A

Spine–> prominent feature, runs transversely across the scapular
Acromion–> large projection, lateral, arches over the glenohumeral joint, articulates with the clavicle (acromioclavicular joint)
Infraspinous fossa–> depression below spine of scapula
Supraspinous fossa–> depression above the spine of scapula

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5
Q

Describe the anatomy of the lateral surface of the scapula?

A 
Glenoid fossa (cavity)--> shallow cavity, located superiorly on the lateral border (articulates with head of humerus)
Supraglenoid tubercle-->  roughening superior to glenoid fossa (origin of long head of Biceps brachii)
Infraglenoid tubercle--> roughening inferior to glenoid fossa (origin of long head of triceps brachii)
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6
Q

Does the scapular fracture?

A

It can but its rare–> high speed collision, indication of severe chest trauma
Doesn’t typically require fixation–> muscles hold fragments in place

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7
Q

Where is the clavicle located?

A

Between the manubrium of the sternum and the acromion of the scapula

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8
Q

What are the functions of the scapula?

A
  1. Attaches the upper limb to the trunk as part of the shoulder girdle
  2. Protects the underlying neurovascular structures supplying the upper limb
  3. Transmits forces from the upper limb to the axial skeleton
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9
Q

What type of bone is the clavicle classified as?

A

Long bone

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10
Q

Describe the anatomy of the clavicle?

A

S shaped, medial (sternal) end and lateral (acromial) end
Medial portion- convex anteriorly
Lateral portion- concave
Shaft–> between two ends
Sternal end–> facet for articulation
Inferior surface of sternal end–> rough oval depression (costoclavicular ligament)
Acromial end–> conoid tubercle and trapezoid line

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11
Q

What is the name of the joint between the clavicle and the scapula?

A

Acromioclavicular joint

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12
Q

What type of joint is the acromioclavicular joint? What are the atypical features of this joint?

A

A plane-type synovial joint
Joint capsule–> loose fibrous layer, lined by synovial membrane secrete synovial fluid
Posterior aspect of joint–> reinforced by trapzeius fibres
Atypical features
–> Articular surfaces lined with fibrocartilage
–> Joint cavity is partially divided by an articular disc (wedge of fibrocartilage suspended from the upper part of the capsule)

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13
Q

What ligaments help to strengthen the acromioclavicular joint?

A

Intrinsic–> Acromioclavicular ligament

Extrinsix–> coracoclavicular ligament formed from conoid ligament and trapezoid ligament

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14
Q

What are the attachment sites for the acromioclavicular ligament?

A

Horizontal
From acromion to the lateral clavicle
Superficial to joint capsule
Reinforces superior aspect

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15
Q

What are the attachment sites for the coracoclavicular ligament?

A

Conoid ligament–> Vertically - Coracoid process of scapula to the conoid tubercle of the clavicle
Trapezoid ligament–> Vertically - Coracoid process of scapula to the trapezoid line of the clavicle

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16
Q

What does the acromioclavicular joint allow?

A

Small degree of axial rotation
Anteroposterior movement
No muscles act directly –> passive movements

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17
Q

What is name of the joint between the clavicle and the manubrium of the sternum?

A

Sternoclavicular joint

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18
Q

What type of joint is the sternoclavicular joint?

A

Synovial joint –> saddle type
Between the manubrium of the sternum, sternal (medial) end of clavical (and the 1st costal cartilage)
Articular surfaces lined with fibrocartilage
Separated into two compartments by the fibrocartilagenous articular disc –> manubrium and clavicle can slide over each other

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19
Q

What type of movements are permitted by the sternoclavicular joint?

A

Large degree of mobiltiy–> but a very strong joint
Elevation of shoulder over 90 degrees
Depression of the shoulder
Protraction of the shoulder (anteriorly)
Retraction of the shoulder (posteriorly)
Rotation–> arm over head, flexion at glenohumeral joint, clavicle rotates passively because of scapular, force transmitted by the coracoclavicular ligaments

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20
Q

What does the humerus articulate with?

A

Head articulates with the glenoid fossa (cavity)–> glenohumeral joint
Distal end articulates with the head of radius and trochlear notch of ulna

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21
Q

Describe the anatomy of the proximal humerus?

A

Head–> faces medially, superiorly and posteriorly
Anatomical neck–> separates head from tubercles, attachment of articular capsule, region of epiphseal growth plate
Surgical neck–> beneath the tubercles
Greater and lesser tubercles
–> Greater–> posterolateral aspect, rounded projection
–> Lesser–> smaller more medially located
Intertubercular sulcus–> depression, separates the two tubercles, edges known as lips

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22
Q

Which of the necks of the humerus is more commonly fractured? What is a consequence of fracture to this neck?

A

The surgical neck
May cause damage to the axillary nerves and posterior circumflex humeral artery
Axillary nerve damage–> paralysis to deltoid and teres minor

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23
Q

Describe the anatomy of the shaft of the humerus?

A

Circular cross section proximally
Flattened cross section distally
Lateral side roughened–> deltoid tuberosity– muscle attach
Radial (spiral) groove–> shallow depression, runs diagonally on posterior surface –> radial nerve and profunda brachial artery lie in this groove

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24
Q

What muscles attach to the humerus along the shaft?

A

Anterior aspect–> coracobrachialis, deltoid, brachialis and brachioradialis
Posterior aspect–> Medial and lateral heads of the triceps

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25
Q

What type of joint is the glenohumeral joint?

A

Synovial joint
Ball and socket
Head of humerus covered in hyaline cartiliage
Glenoid fossa- shallow- line with cartilgae –> facilitates motion and flexibility, at expense of stability (easily dislocated)

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26
Q

What helps to stabilise the glenohumeral joint?

A

Glenoid labrum–> Rim of fibrocartilage–> deepens the socket reducing risk of dislocation
Joint capsule relatively loose–> reinforces superiorly by rotator cuff muscles (inferior- weakest- no reinforcement)
Glenohumeral ligaments–> superior, middle and inferior –> reduce risk of anterior dislocation
Coracohumeral ligament–> coracoid process to greater tubercle of humerus

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27
Q

What is the function of the transverse humeral ligament and the coraco-acromial ligament?

A

Prevent bowstringing of tendons when muscle is in use
Transverse humeral ligament–> between greater and lesser tuberosity–> passage on long head of biceps brachii tendon
Coracoacromial ligament–> between coracoid process and acromion–> roof of subacromial space–> passage of supraspinatus tendon –> prevents superior dislocation

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28
Q

How are the muscle of the shoulder region classified?

A

Extrinsic–> originate in torso, insert onto bone in the shoulder (scapula, clavicle or humerus)
Intrinsic–> originate from scapular and/or clavicle and insert onto the humerus

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29
Q

How are the extrinsic muscle of the shoulder further classified?

A

Superficial: Trapezius or latissimus dorse
Deep: Levator scapulae, rhomboid major and rhomboid minor

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30
Q

What is the origin, insertion, innervation and function of the Trapezius?

A

Broad, flat, triangular muscle
Most superficial

O: External occipital protuberance, nuchal ligament and spinous process of C7-T12

I: Clavicle, acromion and spine of scapula

Innervation: Spinal accessory nerve and propioception from C3 and C4 spinal nerves

F:

  • -> upper fibres–> elevate the scapular
  • -> middle fibres–> retract the scapular
  • -> lower fibres–> pull scapular inferiorly
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31
Q

What is the origin, insertion, innervation and function of the Lattisimus dorsi?

A

Wider area of lower back
Deep to trapezius

O: Spinous process of T6-12, iliac crest, thoracolumbar fascia, inferior 3 ribs

I: Tendon onto the intertubercular sulcus of humerus

Innervation: Thorcodorsal nerve

F: Extends, adduct and medially rotates the arm

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32
Q

What is the origin, insertion, innervation and function of the Levator scapulae?

A

Small strap like muscle
Deep to trapezium
Superficial to rhomboid muscles

O: transverse process of C1-C4 vertebrae

I: Medial border of scapula

Innervation: Dorsal scapular nerve

F: Elevate the scapula

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33
Q

What is the origin, insertion, innervation and function of the Rhomboid minor?

A

Smaller than rhomboid major
Sits superiorly

O: Spinous processes of C7 to T1 vertebrae

I: Medial border of scapula at level of spine of scapula

Innervation: Dorsal scapular nerve

F:

  • -> Retracts the scapula
  • -> rotates medial border so glenoid fossa faces inferiorly, helps return it to normal position after arm abduction >90
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34
Q

What is the origin, insertion, innervation and function of the Rhomboid major?

A

O: Spinous process of T2- 5

I: medial border of scapula, inferior to spine of scapular, superior to inferior angle of scapular

Innervation: dorsal scapular nerve

F: same as rhomboid minor

  • -> retracts the scapular
  • -> rotate the medial border so that the glenoid fossa faces inferiorly, helpss return to normal position after arm abduction >90
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35
Q

How many intrinsic muscles of the shoulder are there?

A

6 intrinsic muscles –> originate on bone in shoulder (scapula or clavicle), insert onto humerus
Deltoid, Teres major, rotator cuff muscles; supraspinatus, infraspinatus, subscapularis and teres minor)

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36
Q

What is the origin, insertion, innervation and function of the deltoid muscle?

A

Functionally divided into anterior, middle and posterior parts

O: anterior, lateral 1/3 of clavicle, acromion and spine of scapula

I: deltoid tuberosity

Innervation: Axillary nerve

F:

  • -> Anterior fibres–> flex and medially rotate the arm
  • -> Middle fibres–> abduct the arm 15-90 degrees
  • -> Posterior fibres–> extend and laterally rotate the arm at shoulder
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37
Q

What is the origin, insertion, innervation and function of the Teres major?

A

Inferior border of quadrangular space

O: Posterior surface of inferior angle of scapula

I: Medial lip of intertubercular groove of humerus (anteromedial surface)

Innervation: lower subscapular nerve

F: Adduct and extends arm
–> medially and internally rotates

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38
Q

What are the rotator cuff muscles?

A

Group of four muscles
Pull the humeral head into the glenoid fossa
Large amount of dynamic stability

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39
Q

What is the origin, insertion, innervation and function of the supraspinatus?

A

O: Supraspinous fossa

I: Greater tubercles of humerus

Innervation: Suprascapular nerve (branch of upper trunk if BP –> C5, C6)

F: Abducts the arm from 0-15 degrees, assists deltoid 15-90 degrees

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40
Q

What is the origin, insertion, innervation and function of the Infraspinatous?

A

O: Infraspinous fossa

I: Greater tubercle between insertion of supraspinatous and teres minor

Innervation: Suprascapular nerve

F: Laterally rotates the arm

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41
Q

What is the origin, insertion, innervation and function of the subscapularis?

A

O: subscapular fossa (costal surface)

I: Lesser tubercle of humerus

Innervation: Upper and lower subscapular nerves

F: Medially rotates the arm

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42
Q

What is the origin, insertion, innervation and function of the Teres minor?

A

O: Posterior surface adjacent to lateral border (superior to teres major)

I: Greater tubercle, inferior to infraspinatus

Innervation: Axillary nerve (C5, 6)

F: Laterally rotates arm

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43
Q

Where is the ‘arm’ located?

A

Distal to the shoulder

Proximal to the elbow

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44
Q

What are the muscles of the arm?

A

Anterior compartment: Biceps Brachii, Brachialis, and Coracobrachialis –> BBC muscles
Posterior compartement: Triceps Brachii

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45
Q

What innervates the anterior compartment of the arm?

A

Musculocutaneous nerve C5, 6 and 7

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46
Q

What is the origin, insertion, innervation and function of the biceps brachii?

A

No attachment to the humerus

O: Long head= supraglenoid tubercle passes through the should joint through the capsule
Short head= coracoid process

I: Unite to form a single muscle belly, inserts onto radial tuberosity via biceps tendon
–> deep fascia via bicipital aponeurosis

F: Strong supinator of forearm at radioulnar joint –_ flexes arm at elbow and shoulder joint

Innervation: Musculocutaneous nerve (C5, 6 and 7)

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47
Q

What happens when someone ruptures there Biceps brachii?

A

Normally long head near to the scapular origin
Reported as ‘snap’ in the shoulder region
Flexion at elbow produces lump in lower arm
Unopposed contracted muscle belly - Popeye sign
Not much muscle weakness–> supinator (supination) brachioradialis (flexion)
Weightlifters can rupture distal tendon of biceps brachii

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48
Q

What is the origin, insertion, innervation and function of the coracobrachialis?

A

Deep to short head of biceps brachii

O: Coracoid process of scapula

I: Medial side of humeral shaft

F: Flexes arm at shoulder and weak adductor of arm

Innervation: Musculocutaneous (C5, 6, and 7)

49
Q

What is the origin, insertion, innervation and function of the brachialis?

A

Deep to biceps brachii
Floor of cubital fossa

O: Anterior surface of distal half of shaft of humerus

I: Coronoid process of ulnar and ulnar tuberosity

F: Flexes forearm at elbow

Innervation: Musculocutaneous (C5, 6 and 7) and small input from radial

50
Q

What is the bicipital aponeurosis?

A

Thick fascial band
Originates at musculotendinous junction of biceps brachii
Roof of cubital fossa
Blends with deep fascia at ulnar border of forearm

51
Q

What is the origin, insertion, innervation and function of the triceps brachii?

A

3 heads, medial head deep to lateral and long head
Arterial supply via profunda brachii artery

O: Long head= Infraglenoid tubercle
Lateral head= Shaft of humerus, superior to spiral (radial) groove
Medial head= Shaft of humerus, inferior to spiral (radial) groove

I: Tendon onto olecranon of ulnar

F: Extension of forearm at elbow

I: Radial nerve (C5, 6, 7, 8 and T1)

52
Q

What does the biceps tendon reflex test test?

A

Spinal cord segment 6

Myotome predominantly responsible for flexion and supination

53
Q

What does the triceps tendon reflex test test?

A

Spinal cord segment 7

Myotome predominantly responsible for extension

54
Q

What are the quadrangular and triangular spaces and the triangular interval?

A

Passageways between the muscles of the shoulder region

Important for passage of arteries and vein and nerves into the arm

55
Q

What are the borders of the quadrangular space? Why is it important?

A

Superior: inferior margin of teres minor
Inferior: Superior margin of teres major
Medial: Long head of triceps brachii
Lateral: Surgical neck of humerus
Important for passage of axially nerve and posterior circumflex humeral artery enter the posterior compartment

56
Q

What are the borders of the triangular space? Why is it important?

A

Superior: Inferior margin of teres minor
Inferior: Superior margin of teres major
Lateral: Long head of triceps brachii
Important for passageway of circumflex scapular vessels

57
Q

What are the borders of the triangular interval? Why is it important?

A

Superior: Inferior margin of the teres major
Medially: Long head of the triceps brachii tendon
Laterally: Shaft of humerus, or lateral head of triceps brachii
Passageway for radial nerve and profunda brachii artery as they wind around in the spiral (radial) groove

58
Q

What are bursae?

A

Fluid filled sacs that provide a cushion between the tendon and a bone (or ligament) to allow smooth gliding action of tendon

59
Q

What are the bursae of the shoulder joint?

A

Subacromial bursae: Lies under the acromion
–> separates the supraspinatus tendon from the coracoacromial ligament, coracoid process and deep surface of deltoid muscle

Subscapular bursae: between tendon of subscapularis and neck of the scapula, protects the tendon as it passes inferior to the root of the coracoid process and over the neck of the scapula

60
Q

What is the subacromial space?

A 
Space between the coraco-acromion arch (coracoid process, coraco-acromial ligament and acromion) and the head of humerus 
Normally 1-1.5cm 
Packed into the space are:
- Subacromial bursae
- Supraspinatus tendon
- Joint capsule
- Long head of biceps brachii
61
Q

What are the main muscles involved in abduction of the shoulder?

A

0-15 degrees–> supraspinatus muscle
15-90 degrees–> Deltoid muscles
>90 degrees–> movement at scapulothoracic ‘joint’–> upper fibres of trapezius and serratus anterior

62
Q

What are the main muscles involved in adduction of the shoulder?

A

Pectoralis major
Latissimus dorsi
Teres major

63
Q

What are the main muscles involved with flexion of the shoulder?

A

Anterior fibres of deltoid
Clavicular head of pectoralis major
Coracobrachialis
Biceps brachii

64
Q

What are the main muscles involved in extension of the shoulder?

A

Posterior fibres of deltoid
Latissiumus dorsi
Teres major

65
Q

What are the main muscles involved in medial (internal) rotation?

A

Subscapularis
Teres major
Sternal head of pectoralis major
Latissimus dorsi

66
Q

What are the main muscles involved in lateral (external) rotation?

A

Infraspinatus

Teres minor

67
Q

What do the tendons of the rotator cuff muscles fuse to form?

A

Tendinous ‘cuff’ which fuses with the joint capsule and strengthens it

68
Q

Mobility and stability are inversely related, what stabilises the glenohumeral joint?

A

Static stabilisers

  • Congruency of the humeral head and glenoid cavity
  • Glenoid labrum –> circumferential stability
  • Joint capsule
  • Glenohumeral ligaments provide stability
  • Extra-capsular ligaments–> coracoacromial arch, coracohumeral ligament etc…
  • Negative intra-articular pressure

Dynamic stabilisers

  • Rotator cuff muscles
  • Biceps brachii
  • Tricpes brachi
  • Deltoid
  • Pectroalis major
  • Coracobrachialis
69
Q

What is the main artery to supply the shoulder? What is it derived from?

A

Axillary artery

Subclavian artery–> passes lateral border of first rib it becomes the axillary artery

70
Q

Describe the arterial supply to the shoulder?

A

Axillary artery–> posterior to pectoralis minor–> level of the surgical neck gives off anterior and posterior circumflex humeral arteries (supply the head of the humerus)
Anastomosis around anterior scapular –> subscapular artery (3rd part of axillary) with suprascapular artery and transverse cervical artery

71
Q

What is the arterial supply to the shoulder joint?

A

Anterior and posterior circumflex humeral arteries and the suprascapular artery

72
Q

At what point does the axillary artery become the brachial artery?

A

Inferior border of the teres major

73
Q

Describe the arterial supply to the arm?

A

Brachial artery at levels of inferior border of teres major
Immediately gives off profunda brachii (deep brachial artery) –> travels in spiral (radial) groove with radial nerve to posterior compartment of the arm –> terminates by anastomosing at the elbow joint
Brahcial artery descends down anterior arm–> passes thorugh cubital fossa under the brachialis muscle–> terminates by bifurcating into the radial and ulnar arteries

74
Q

What pulse can be palpated in the cubital fossa?

A

Brachial pulse

Median to the tendon of biceps brachii

75
Q

How are the cords of the brachial plexus and the axillary artery related?

A

Cords close relationship to axillary artery
Name according to anatomical relationship with second part of artery
Lateral to axillary artery
Posterior to axillary artery
Medial to axillary artery

76
Q

What is the nerve supply to the shoulder?

A

From the axillary nerve, suprascapular nerve and lateral pectoral nerve all from C5 and C6
C5 dermatome overlies the shoulder

77
Q

What are some common clinical conditions to the shoulder?

A 
Dislocation 
Clavicle fracture 
Rotator cuff tears
Impingement syndrome
Calcific supraspinatous tendinopathy
Adhesive capsulitis (Frozen shoulder)
Ostreoarthritis
78
Q

What sort of dislocations can occur at the shoulder? Which are the most common?

A 
Anterior (anterior inferior)--> 90-95%
- Bankart lesion 
- Bony Bankart
- Hill-Sachs lesion 
Posterior dislocation (2-4%)
Inferior dislocations (0.5%)
79
Q

Why are dislocations common?

A

Glenoid fossa is shallow
Supported in anterior, posterior and superior direction
Inferior aspect weakest
Supported by muscles (rotator cuff) and joint capsule (relatively lax)

80
Q

Why are anterior dislocations more common?

A

Inferior aspect weakest
Often dislocate inferiorly and move anteriorly due to pull of muscles and disruption of the anterior capsule and ligaments

81
Q

Where does the humeral head come to lie in anterior dislocations?

A

60% in subcoracoid location

30% subglenoid location

82
Q

What position does the arm hold in anterior dislocation? What other signs/symptoms would they present with?

A

Externally (laterally) rotated (infraspinatous and teres minor)
Abduction (supraspinatus)
Visible shoulder deformity, swelling/ bruising around the shoulder and severely restricted movement

83
Q

What causes anterior dislocation?

A

Usually occurs when arm in abducted and externally rotated position –> Arm forced posteriorly causes it to pop out anterior-inferiorly
Or direct blow to back of shoulder

84
Q

What are the different types of anterior dislocation? What is the key features to these dislocations?

A

Bankart lesion–> tear of glenoid labrum and stretch of glenohumeral ligaments
Bony Bankart–> Anterior part of glenoid fossa breaks off
Hill-Sachs lesion–> head pushed forward–> teres minor and infraspinatous pull it back–> posterior part of humeral head gets jammed against the anterior lip of the glenoid fossa–> indentation fracture in posteriolateral humeral head (up to 50% >40 and 80% recurrent dislocations suffer from this)

85
Q

What is posterior dislocation of the shoulder?

A

Humeral head goes posteriorly

Much less common (2-4% of cases)

86
Q

What are the causes of posterior dislocation?

A

Violent muscle contraction –> epilepsy, electrocution or lightening strike
Blow to anterior shoulder
Arm flexed across the body and pushed posteriorly (fallen on straight arm)

87
Q

How does a patient with posterior dislocation present?

A

Arm internally rotated and adducted
Flattening/ squaring of the shoulder with a prominent coracoid process
Arm cannot be externally rotated
(as well as other symptoms- disformed shoulder shape etc)

88
Q

What is significant about a posterior dislocation x-ray?

A

PD easily missed on x-ray
Humeral head more rounded shape- internal rotation –> light bulb sign
Glenohumeral distance is increased

89
Q

What is useful about the scapular/ ‘Y’ view?

A

Show anterior or posterior dislocation well

Head of humerus should be inline with glenoid fossa

90
Q

What happens in inferior dislocation?

A

Head of humerus inferior to glenoid cavity

91
Q

What is the mechanism for inferior dislocation?

A

Forceful traction on the arm when fully extended
Occurs when grasping object above the head
Hyperabdution–> inferior dislocation

92
Q

What other injuries are associated with inferior dislocation?

A

Damage to nerves (60%)
Rotator cuff tear (80%)
Injury to blood vessels (3%)

93
Q

What is the most common complication with shoulder dislocation?

A

Recurrent dislocation
1st dislocation–> damages stabilising tissue surrounding joint
Chance–> 20yrs old 90%, 40yrs old 10%
Due to loss of elasticity in tissues
Risk of osteoarthritis increases with each dislocation

94
Q

What other complications can occur due to dislocation?

A

Axillary artery damage 1-2%–> ↑in elderly due to loss of elasticity
Axillary nerve damage 10-40%–> wraps around neck of humerus–> supplies deltoid and regimental badge area
Less commonly could damage brachial plexus
Fracture–> 25% dislocations –> head or tubercle of humerus, acromion or clavicle
Rotator cuff muscle tears–> inferior dislocation

95
Q

What does the clavicle do?

A

Strut to brace the shoulder from the trunk
Transmits forces from the upper limb to skeleton
Protection for brachial plexus, subclavian vessel and apex of lung

96
Q

Where do most of the fractures of clavicle occur?

A

80% in middle third of clavicle (mid-clavicular fracture)

97
Q

How do fractures to the clavicle occur?

A

Falls onto the shoulder or outstretched arm

98
Q

How are clavicular fracture treated?

A

Conservatively–> using a sling (most of the time)
Surgery–> fixation–>
-complete dislocation
-severe displacement causing tenting of skin
-open fractures
-neurovascular compromise
-fractures with interposed muscle
-floating shoulder- clavicle fracture with ipsilateral fracture of glenoid neck

99
Q

What happens to the position of the arm and clavicle upon fracture?

A

Arm pulled medially by pectoralis major–> sternocostal head
Clavicle–> elevated medial segment–> sternocleidomastoid muscle
Arm and shoulder drop–> trapezius unable to hold the lateral segment up against the weight of the upper arm

100
Q

What complications could potentially occur due to clavicle fracture?

A

Clavicle–> non union, malunion
Local complication–> pneumothorax, injury to surrounding neurovascular structures
Suprascapular nerve damage
Supraclavicular nerve damage

101
Q

What do we mean by rotator cuff tear?

A

Tear to one or more of the tendons of the four rotator cuff muscles
Tendons tear more then the muscles
Supraspinatous tendon most frequently affected

102
Q

What can cause the rotator cuff to tear?

A

Acute tears–> following shoulder dislocation

Chronic tears–> extended use, poor biomechanics or muscular imbalance

103
Q

What is the most common cause of rotator cuff damage?

A

Age-related degeneration –> blood supply reduced –> impaired ability to repair
Degenerative microtrauma model–> age related degeneration with chronic microtrauma–> partial tendon tears –> full rotator cuff tears –> Inflammatory cells recruited–> oxidative stress–> tenocyte apoptosis –> further degeneration
Recurrent lifting and repetitive overhead activity

104
Q

What is the most common symptom of rotator cuff tears?

A

Anterolateral shoulder pain–> radiates down arm
At rest or during activity
Pain in shoulder when leaning on elbows–> pushes head superiorly decreasing space between head and coracoacromial arch
Pain when flexing shoulder
Pain in horizontal position and weakness of shoulder abduction

105
Q

How are rotator cuff tears diagnosed and managed?

A

Diagnosed–> history and examination, MRI and ultrasound

Managed–> Conservative (rest) or surgery

106
Q

What is impingement syndrome?

A

Supraspinatous tendon impinges on coraco-acromial arch–> irritation and inflammation
Space between humerus and coraco-acromial arch small–> 1-1.5cm
Impingement caused by anything that reduces it further
(thickening of lig, inflammation of tendon, subacromial osteophyte formation)

107
Q

When does the pain in impingement syndrome occur?

A

When shoulder is abducted or flexed
Space becomes narrower
Pain weakness and reduced range of motion
Pain described as dull, lingering pain

108
Q

What is ‘painful arc’?

A

60-120 degrees arm abduction

When pain is the worst

109
Q

What is calcific supraspinatus tendinopathy?

A

Microscopic deposits of hydroxyapatite in tendon of supraspinatus (most common)
Acute or chronic pain
Aggravated by abducting or flexing the arm above the level of the shoulder or lying on shoulder
Mechanical symptoms–> stiffness, snapping sensation, catching, reduced range of motion

110
Q

What causes calcific supraspinatous tendinopathy?

A

Multifactorial
Theory–> regional hypoxia–> tenocytes converted to chondrocytes–> lay down cartilage in tendon –> calcium deposits formed by process like endochondrial ossification
Another–> ectopic bone formation–> metaplasia of mesenchymal stem cells
Calcific deposits visible on x-ray –> crystalline in resting phase–> reabsorbed by phagocytes–> pain

111
Q

What is the treatment for calcific supraspinatous tendinopathy?

A

Rest and analgesia

Surgical treatment for persistent symptoms

112
Q

What is adhesive capsulitis?

A

Aka Frozen shoulder
Capsule of glenohumeral joint becomes inflamed and stiff
Restricts movement, causes chronic pain
Pain constant–> usually worse at night, exacerbated by movement and cold weather
Exact cause unknown
Potentially autoimmune component- possible triggered by local trauma

113
Q

What are the risk factors for adhesive capsulitis?

A 
Female
Epilespy with tonic seizure
Diabetes mellitus
Trauma to shoulder
Connective tissue disease
Thyroid disease
CVD
Breast cancer 
Chronic lung disease
Polymyalgia rheumatica --> inflammatory condition causes muscle pain and weakness
Parkinsons disease
Long period of inactivity 
*dont need to memorise them all
114
Q

What is the main problem with adhesive capsulitis?

A

Experience severe pain and sleep deprivation
Interrupts work and activities
Some develop depression

115
Q

What is the treatment for adhesive capsulitis?

A

Physiotherapy
Analgesia
Anti-inflammatory medication
Typically resolves with time–> 90% restored motion
Sometimes–> manipulation under anaesthesia–> breaks up adhesion and scar tissue–> restore movement

6%-17% patients experience problems in opposite shoulder

116
Q

What is osteoarthritis?

A

Articular cartilage lining joint breaks down
Bone on bone contact
More commonly affects acromioclavicular joint than glenohumeral joint

117
Q

What is the treatment of osteoarthritis?

A

Activity modification
NSAID (anti-inflammatories)
Analgesics
Nutritional supplements–> some people benefit
Steroid injections–> reduce swelling, alleviate shoulder stiffness and pain
Hyaluronic acid injections into joint increase lubrication–> evidence limited

118
Q

What is athroscopy? Why is it used in osteoarthritis?

A

Keyhole surgery
Remove loose pieces of cartilage from glenohumeral joint
Some patients will progress to hemiarthroplasty (replacement of humeral head)
Some total shoulder replacement–> replace head and glenoid cavity–> head then placed where cavity would normally be

Semester 2 Musculoskeletal System (12 decks)

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