28. Common shoulder conditions

Question 1

How will a dislocated shoulder appear?

Answer 1

Visibly deformed and there may be visible swelling and/or bruising around the shoulder. Movement of the shoulder will be severely restricted

Question 2

What is the most common type of shoulder dislocation?

Answer 2

90-95% of dislocations are anterior (i.e. the head of the humerus sits anterior to the glenoid fossa)

2-4% posterior
0.5% inferior

Question 3

Which aspect of the shoulder joint is the weakest?

Answer 3

the joint is strengthened on its superior, anterior and posterior aspects, it is weak at its inferior aspect

Question 4

What are the 2 types of anterior dislocations?

Answer 4

The head of the humerus usually dislocates anteroinferiorly, but then often displaces in an anterior direction (subcoracoid location = 60% of cases) due to the pull of the muscles and disruption of the anterior capsule and ligaments.
Alternatively, the head of the humerus may come to lie antero-inferior to the glenoid (subglenoid location = 30% of cases). Both are types of anterior dislocation.

Question 5

How is the arm positioned in an anterior dislocation?

Answer 5

Arm is held in a position of external rotation and slight abduction

Question 6

What are common mechanisms of anterior dislocation.

Answer 6

The first episode of anterior dislocation usually occurs when an individual has their arm positioned in abduction and external rotation (“hand behind head”), and an unexpected small further injury forces the arm a little further posteriorly, pushing the shoulder into an extreme position, such that the humeral head dislocates antero-inferiorly from the glenoid. An alternative mechanism is a direct blow to the posterior shoulder.

Question 7

What are 5 complications of anterior dislocation?

Answer 7

• Bankart lesion
• Hill-Sachs lesion
• Axillary nerve damage
• humeral circumflex artery damage
• recurrent dislocation

Question 8

What is a Bankart lesion?

Answer 8

Force of the humeral head popping out of the socket often causes part of the glenoid labrum to be torn off.
Sometimes a small piece of bone can be torn off with the labrum

Question 9

What is a Hill-Sachs lesion?

Answer 9

compression fracture of posterior humeral head

Tone of the infraspinatus and teres minor muscles means that the posterior aspect of the humeral head becomes jammed against the anterior lip of the glenoid fossa. This can cause a dent (indentation fracture) in the posterolateral humeral head

Question 10

When do posterior dislocations tend to occur?

Answer 10

Occur when there are violent muscle contractions due to an epileptic seizure, electrocution or a lightning strike; when there is a blow to the anterior shoulder; or when the arm is flexed across the body and pushed posteriorly

Question 11

How is the arm positioned in a posterior dislocation?

Answer 11

Arm internally rotated and adducted

They demonstrate flattening / squaring of the shoulder with a prominent coracoid process. The arm cannot be externally rotated into the anatomical position.

Question 12

How can posterior shoulder dislocations be sptted on x-rays?

Answer 12

• A posterior dislocation of the shoulder can easily be missed on an X-ray as it looks ‘in joint’.
• However, because the arm is internally-rotated, the projection of the humeral head onto the X-ray film changes to a more rounded shape – the ‘light bulb’ sign. • The glenohumeral distance is also increased.
• The scapular or ‘Y’ view is also very useful for detecting dislocations of the shoulder radiologically.
• The head of the humerus should be directly in line with the glenoid fossa i.e. at the bifurcation of the Y.

Question 13

WHat injuries are commonly associated with posterior dislocations?

Answer 13

fractures, rotator cuff tears, and Hill-Sachs lesions

Question 14

What type of injury causes an inferior dislocation?

Answer 14

After inferior dislocation, the head of the humerus sits inferior to the glenoid. The mechanism is forceful traction on the arm when it is fully extended over the head, as may occur when grasping an object above the head to break a fall i.e. a hyperabduction injury.

Question 15

What structures are commonly injured in inferior dislocations?

Answer 15

damage to nerves (60%), rotator cuff tears (80%), and injury to blood vessels (3%).

Question 16

What is the most common complication of shoulder dislocation and why?

Answer 16

recurrent dislocation due to damage to the stabilising tissues surrounding the shoulder (glenoid labrum, capsule, ligaments etc.)

Question 17

What are the chances of recurrent dislocation?

Answer 17

60% but depends on age and activity level - As we age, our tissues lose elasticity, so the risk of recurrent dislocation is approximately 90% in 20-year-olds, falling to only 10% in 40-year-olds

Question 18

What is the effect of each dislocation on the risk of osteoarthritis?

Answer 18

Each dislocation results in further damage to the humeral head and glenoid, therefore it is unsurprising that the risk of osteoarthritis increases with the number of dislocations.

Question 19

How might axillary artery damage be detected in shoulder dislocations?

Answer 19

Patient may have a haematoma, absent pulses and/or a cool limb

Question 20

How common are axillary nerve injuries in dislocations?

Answer 20

10-40% of shoulder dislocations

Question 21

How would you test for axillary nerve damage?

Answer 21

test abduction

test sensation of the regimental badge area

Question 22

How are the symptoms of axillary nerve damage resolved?

Answer 22

Shoulder reduced (put back into place)

Question 23

In a shoulder dislocation, would you test axillary nerve damage by getting them to abduct arm?

Answer 23

NO - too painful - test sensation and then motor after shoulder has been put back in place

Question 24

Who are shoulder dislocation associated fractures more common in and in which bones?

Answer 24

More common when there is a traumatic mechanism of injury, first-time dislocation, or the person is aged over forty.
Commonly affected bones include the humeral head, greater tubercle, clavicle and acromion

Question 25

Which muscles are mainly affected in shoulder dislocation?

Answer 25

Rotator cuff muscle tears can also occur in association with shoulder dislocation, most commonly in older people. they are also a common complication of inferior dislocation in all age group. The integrity of the rotator cuff should always therefore be assessed as part of the follow-up of patients after reduction of a dislocated shoulder.

Question 26

What are the functions of the clavicle?

Answer 26

• transmits force from the upper limb to the axial skeleton

- protection to the brachial plexus, subclavian vessels and the apex of the lung

Question 27

Which part of the clavicle is most commonly fractured?

Answer 27

middle third - Most result from falls onto the affected

shoulder or onto the outstretched hand

Question 28

How are most clavicle fractures treated?

Answer 28

Treated conservatively (i.e. without surgery), using a sling

Question 29

What are the indications for surgical fixation of a clavicle fracture?

Answer 29

• Complete displacement (so the bone ends are not in apposition and cannot unite)
• Severe displacement causing tenting of the skin, with the risk of puncture
• Open fractures (fracture associated with a break in the integrity of skin)
• Neurovascular compromise
• Fractures with interposed muscle
• Floating shoulder: clavicle fracture with ipsilateral fracture of glenoid neck

Question 30

What will happen to the position of the arm and clavicular fragments in a displaced mid-clavicular fracture?

Answer 30

• The sternocleiodomastoid muscle elevates the medial segment
• Because the trapezius muscle is unable to hold the lateral segment up, and also because of the weight of the upper limb, the shoulder drops
• The arm is pulled medially by pectoralis major (adduction).

Question 31

What are some general complications associated with clavicle fracture healing?

Answer 31

nonunion (failure to unite) and malunion (uniting in a suboptimal position)

Question 32

What are complications of clavicle fracture?

Answer 32

• pneumothorax
• suprascapular nerve may be damaged by the elevation of the medial part of the fracture
• supraclavicular nerves (C3,4) may also be damaged resulting in paraesthesia over the upper chest anteriorly

Question 33

Which rotator cuff muscle is most commonly torn?

Answer 33

Supraspinatus

• where it passes beneath the coracoacromial arch, tearing at the site of its insertion into the greater tubercle of the humerus
• The tendons of the rotator cuff are torn much more frequently than the muscles and, of these, the supraspinatus tendon is the most frequently affected

Question 34

What is the most common cause of rotator cuff tears and how does this lead to tears?

Answer 34

Age-related degeneration

- blood supply to the rotator cuff tendons decreases, impairing the body’s ability to repair minor injuries

Question 35

What does degenerative-microtrauma model hypothesise?

Answer 35

Age-related tendon degeneration, compounded by chronic microtrauma, results in partial tendon tears that then develop into full rotator cuff tears. Inflammatory cells are recruited and oxidative stress leads to tenocyte (tendon cell) apoptosis, leading to further degeneration, thus a ‘vicious circle’ is created

Question 36

Are rotator cuff tears usually acute or chronic?

Answer 36

Although acute tears of the rotator cuff can occur (e.g. following shoulder dislocation), most rotator cuff tears are chronic, resulting from extended use in combination with other factors such as poor biomechanics or muscular imbalance.

Question 37

Which shoulder are rotator cuff tears more common in?

Answer 37

Dominant shoulder

Question 38

What type of activities are associated with rotator cuff tears?

Answer 38

Recurrent lifting and repetitive overhead activity are also risk factors (e.g. carpenters, painters), as are sports that involve repeated overhead motion (e.g. swimming, volleyball, tennis, weightlifting)

Question 39

What is the most common clinical presentation of rotator cuff tears?

Answer 39

Anterolateral shoulder pain, often radiating down the arm

- (most are asymptomatic)

Question 40

What actions cause pain in a rotator cuff tear?

Answer 40

• shoulder activity above the horizontal position, but itmay also be present at rest.
• when they lean on their elbow and push downwards, as this pushes the head of the humerus superiorly and decreases the space between the humeral head and the coracoacromial arch.
• They also experience pain in the shoulder when reaching forward (flexing the shoulder)

Question 41

What movement is restricted in rotator cuff tear?

Answer 41

weakness of shoulder abduction

Question 42

How are rotator cuff tears diagnosed?

Answer 42

As well as the history and examination, MRI and ultrasound both have a role in the diagnosis

Question 43

What is the treatment for rotator cuff tears?

Answer 43

The management may be conservative (rest, analgesia etc.) or operative

Question 44

What is impingement syndrome?

Answer 44

Supraspinatus tendon impinges (rubs or catches) on the coraco-acromial arch, leading to irritation and inflammation

Question 45

What can cause impingement syndrome?

Answer 45

Anything that narrows the space between the head of the humerus and the coracoacromial arch further e.g.

• thickening of the coracoacromial ligament,
• inflammation of the supraspinatus tendon,
• subacromial osteophytes (in osteoarthritis)
• (grinding & popping)

Question 46

What are the symptoms of impingement syndrome?

Answer 46

pain, weakness and reduced range of motion

Question 47

What causes the symptoms of impingement syndrome?

Answer 47

When the shoulder is abducted or flexed, the space becomes narrowed further

Question 48

What is the most common form of impingement?

Answer 48

Impingement of supraspinatus tendon under the acromion during abduction of the shoulder.

Question 49

What does Impingement of supraspinatus tendon lead to?

Answer 49

‘painful arc’ between 60 and 120 degrees of abduction

Patients often report pain on reaching upwards to brush their hair or to lift a food can from an overhead shelf

Question 50

Describe the onset of the pain in impingement sydrome

Answer 50

The onset of the pain may be acute if it is due to an injury, or may be insidious (gradually increasing) if it is due to a gradual process such as osteophyte formation. The pain is described as dull rather than sharp, and lingers for long periods of a time, making it hard to fall asleep at night. Other symptoms can include a grinding or popping sensation during movement of the shoulder

Question 51

How are impingement syndromes treated?

Answer 51

Treatment is directed at the underlying cause.

Question 52

What characterises Calcific supraspinatus tendinopathy?

Answer 52

• Presence of macroscopic deposits of hydroxyapatite in the tendon of supraspinatus
• It can occur in any tendon of the rotator cuff but is by far most commonly seen in supraspinatus.

Question 53

What are the mechanical symptoms of Calcific supraspinatus tendinopathy and what are they due to?

Answer 53

Physical presence of a large deposit, leading to stiffness, a snapping sensation, catching, or reduced range of movement of the shoulder

Question 54

What are 2 theories of calcific tendinopathy?

Answer 54

Regional hypoxia leads to tenocytes being transformed into chondrocytes and laying down cartilage in the tendon. Calcium deposits are then formed through a process resembling endochondral ossification.

Another theory involves ectopic bone formation from metaplasia of mesenchymal stem cells normally present in tendons into osteogenic cells.

Question 55

What are the symptoms of Calcific supraspinatus tendinopathy?

Answer 55

It can present with acute or chronic pain, often aggravated by abducting or flexing the arm above the level of the shoulder, or by lying on the shoulder

Question 56

What are the 2 stages of calcific tendinopathy?

Answer 56

• resting stage (crystalline calcific deposits)

- reabsorption stage (by phagocytes)

Question 57

When is the most pain felt in calcific tendinopathy?

Answer 57

Re absorption stage

Question 58

What is the treatment for calcific tendinopathy?

Answer 58

Treatment is initially conservative with rest and analgesia. Surgical treatment is sometimes required for persistent symptoms

Question 59

In the reabsorption stage, how do the calcific deposits appear on x-rays?

Answer 59

During the reabsorption stage they look macroscopically like ‘toothpaste’ and often appear ‘cloudy’ (i.e. less well-defined) on Xray

Question 60

What is Adhesive capsulitis (“Frozen shoulder”)?

Answer 60

a painful and disabling disorder in which the Capsule of the glenohumeral joint becomes inflamed and stiff, greatly restricting movement and causing chronic pa

Question 61

What exacerbates pain in Adhesive capsulitis?

Answer 61

The pain is usually constant, Worse at night and exacerbated by movement and cold weather

Question 62

What are the risk factors for adhesive capsulitis?

Answer 62

 Female gender
 Epilepsy with tonic seizures (i.e. sudden muscle contractions)
 Diabetes mellitus (the theory is that glucose molecules bond to the capsular collagen)
 Trauma to the shoulder
 Connective tissue disease
 Thyroid disease (hypo and hyperthyroidism)
 Cardiovascular disease
 Chronic lung disease
 Breast cancer
 Polymyalgia rheumatica (an inflammatory condition causing muscle pain and weakness)
 Parkinson’s disease
 Long periods of inactivity (from injury, stroke or illness) can precipitate frozen shoulder, and it can also occur alongside other shoulder problems e.g. calcific tendinopathy or rotator cuff tear

Question 63

What is the treatment for adhesive capculitis?

Answer 63

• physiotherapy, analgesia and anti-inflammatory
  medication
• Patients sometimes undergo manipulation under anaesthesia, which breaks up the adhesions and scar tissue in the joint to help restore range of motion.
• Intense post-operative physiotherapy then helps to maintain the movement that has been gained

Question 64

What is the prognosis for adhesive capsulitis?

Answer 64

Frozen shoulder typically resolves with time and most patients ultimately regain 90% of their shoulder motion. However, once frozen shoulder has resolved, the opposite shoulder becomes affected in 6% to 17% of patients within 5 years, lending further weight to the autoimmune hypothesis

Question 65

What are the effects of frozen shoulder on the patient?

Answer 65

Patients with frozen shoulder often experience severe pain and sleep deprivation for prolonged periods, resulting in severe interference with their work and activities of daily living. Some develop depression as a result.

Question 66

Which joint is more commonly affected in osteoarthritis of the shoulder?

Answer 66

acromioclavicular joint

Question 67

What is the treatment for OA of the shoulder?

Answer 67

Activity modification (avoiding activities that
precipitate symptoms), analgesia, and anti inflammatories (NSAIDs).

Some patients report a benefit from taking nutritional supplements e.g. glucosamine and chondroitin sulfate

Question 68

What can be done to reduce swelling of the joint?

Answer 68

Steroid injections
- Hyaluronic acid injections into the joint (viscosupplementation) may increase lubrication, although the evidence for this is limited.

Question 69

What surgical treatment can be done done?

Answer 69

• Arthroscopy (keyhole surgery): remove loose pieces of damaged cartilage from the glenohumeral joint
• hemiarthroplasty (replacement of the humeral head)
• or total shoulder replacement (replacement of the humeral head and the glenoid)