Shoulder (Session 7) Flashcards
How does a dislocated shoulder present?
Visibly deformed shoulder, swelling/bruising, movement= severely restricted
In which position are the majority of shoulder dislocations?
Anterior (90-95%)
Why are the majority of shoulders dislocated anteriorly?
- Humerus sits anterior to glenoid fossa and glenoid foss=shallow
- Joint=weak on anterior aspect
- Pull of muscles anteriorly
What are the 2 types of anterior dislocation? shoulder
1, Subcoracoid location (60% cases)
2, Subglenoid location (30% cases)
How is the arm held in an anterior dislocation? shoulder
External rotation
Slight abduction
How might an anterior dislocation (of the shoulder) occur?
1, Arm positioned in abduction and external rotation–> arm forced slightly posteriorly.
2, Direct blow to posterior shoulder
What is a Bankart Lesion?
(aka labral tear) part of glenoid labrum torn off- due to force of humeral head popping out of socket
What is a Hill-sachs lesion?
Dent in posterolateral humeral head.
What causes a Hill-sachs lesion?
Posterior aspect of humeral head jammed against anterior lip-glenoid fossa due to infraspinatus and teres minor muscles
How prevalent are Hill-sachs lesions?
80% with recurrent dislocation with have lesion
What may cause a posterior dislocation? shoulder
1,Violent muscle contraction due to: a, Epileptic seizure b, Electrocution- lighting 2,Blow to anterior shoulder 3, Arm= flexed across body and pushed posteriorly.
How do patients present with a posterior dislocation (usually)? shoulder
1, Internally rotated and adducted.
2, Flattening/Squaring of shoulder
3, Prominent coracoid process
What other (secondary) injuries are commonly associated with posterior dislocation? shoulder
Fractures, rotator cuff tears, Hill-sachs lesions
What is the prevalence of posterior shoulder dislocations?
2-4%?
What is the prevalence of inferior dislocations? shoulder
0.5%
What causes an inferior dislocation? shoulder
Forceful traction on arm when fully extended over head. (e.g. fall holding only branch)(hyperabduction injury)
What injuries are associated with inferior dislocation? shoulder
Nerve damage 60%, Rotator cuff tears 80%, blood vessel injury 3%
What is the most common complication of a shoulder dislocation?
Recurrent dislocation (due to damage to stabilising tissues surrounding shoulder)
What is the chance of dislocation your shoulder again? (roughly)
60% (but decreases with with age)
Apart from recurrent dislocation, what else increases in risk following each dislocation?
Developing osteoarthritis
How common is damage to the axillary artery in shoulder dislocations?
1-2%
Why is damage to the axillary artery more common in older age groups?
Blood vessels less elastic
How will a patient present if they have damaged their axillary artery?
Haematoma, absent pulses/ cool limb
How common are axillary nerve injuries in shoulder dislocations?
10-40% dislocations
What is the outcome for the patient is their axillary nerve gets damaged?
Full recovery (most) when shoulder put back
Apart from the axillary nerve- what other nerves can be damaged from a shoulder dislocation?
Chords of brachial plexus
Musculocutaneous nerve
How common are fractures in shoulder dislocations?
25% dislocations
What factors would make a fracture more common in a shoulder dislocation?
1- Traumatic mechanism of injury
2- First-time dislocation
3-Aged over 40
Which bones are most commonly affected by fractures in a shoulder dislocation?
Humeral head
Greater tubercle
Clavicle
Acromion
In which circumstances are rotator cuff muscle tears common?
Inferior dislocations
Older people
(should always be checked after reduction of dislocated shoulder)
Where to fractures usually occur within the clavicle?
Middle third (80%)
What causes most clavicle fractures?
Falls onto shoulder/outstretched hand
How are clavicle fractures treated?
Conservatively (using sling)
In what instances would surgical fixation be necessary after a clavicle fracture?
1, Complete displacement (bone ends can’t unite)
2, Severe displacement w./ tenting of skin (risk of puncture and open fracture)
3, Neurovascular compromise
4, Fractures with interposed muscle
5, Floating Shoulder- clavicle fracture w./ ipsilateral fracture of glenoid neck
What happens to the position of the arm and clavicular fragments in a displaced mid–clavicular fracture?
1- Strenocleiodomastoid muscle elevates medial segment (2 segments)
2- Shoulder drops- trapezius muscle unable to hold lateral segment up + weight of upper limb
What are the complications associated with fracture healing?
- Non-union
- Malunion (uniting in wrong place)
- Pneumothorax (collapsed lung)
- Injury to neurovascular structures
Which nerves may be damaged by the elevation of the medial part of a displaced mid-clavicular fracture?
- Suprascapular
- Supraclavicular nerves (C3,4)
What would damage to supraclavicular nerves result in?
Parasthesia over upper chest anteriorly
What is the role of the rotator cuff?
1- Stabilising glenohumeral joint
2- Abducting, externally and internally rotating humerus
Which of the rotator cuff tendons is most frequently affected?
Supraspinatus tendon (passes beneath coracoacrominal arch) (tears at site of insertion(greater tubercle of humerus)
What are the two types of tears of the rotator cuff that can occur?
Acute-eg. shoulder dislocation
Chronic
What causes a chronic rotator cuff tear in the shoulder?
1- Age related degeneration- blood supply= decreases- impairs ability to repair injuries
2-Extended use + other factors (e.g. poor biomechanics/muscular imbalance)
What is the ‘Degenerative-microtrauma model’?
Age related degeneration- compounded by chronic micro trauma- results in partial tendon tears- then rotator cuff tears-Inflammatory cells recycled-oxidative stress- apoptosis- further degeneration- cycle
How do rotator cuff tears commonly present clinically?
-Anterolateral shoulder pain, often radiating down arm
(at rest/ with certain activity)
- Pain restricted movement above horizontal position
-Weakness of shoulder abduction
When might a patient who has rotator cuff tears experience pain?
When leaning on their elbows + pushing down
When reaching forward
Apart from taking a history and examination, what else is used to diagnose rotator cuff tears?
MRI/ Ultrasound
How might rotator cuffs be managed?
Conservatively (rest&analgesia)
What is ‘Impingement Syndrome’?
When supraspinatus tendon impinges (rubs and catches) on coraco-acrominal arch= leads to irritation and inflammation
What may cause the space (1-1.5cm) between the coracoacromial arch and the head of the humerus to shrink?
- Thickening of coracoacrominal ligament
- Inflammationof supraspinatus tendon
- Subacrominal osteoarthritis
When do the symptoms of impingement syndrome: pain, weakness and range of motion present?
When shoulder= abducted/flexed- further narrowing of space
Worsened- overhead movement / lying on shoulder
In what circumstance would the pain from impingement symdrome be acute?
If= injury
Apart from pain, weakness and range of motion, what other symptoms might impingement syndrome present with?
Grinding/popping sensation during movement
What’s the painful arc?
(Impingement of supraspinatus tendon under acromion during shoulder abduction. )
Between 60-120 degrees- pain experienced
Outside range- less/no pain
(patients report pain reaching upwards e.g. brushing hair)
How is impingement syndrome treated?
Treat underlying cause
What is ‘Calcific supraspinatus tendionopathy’?
Presence- macroscopic deposits- hydroxyapatite (crystals) in supraspinatus tendon. (can occur in any tendon of rotator cuff)
How does Calcific supraspinatus tendionopathy present?
=Acute/chronic pain- aggravated by abducting/flexing arm above level of shoulder
=Pain when lying on shoulder
MECHANICAL SYMPTOMS (due to presence of large deposit):
- Stiffness
- Snapping sensation
- Catching
-Reduced range of movement
What causes calcific supraspinatus tendionapathy ?
=Multifactorial- possible causes:
- Regional hypoxia- tenocytes- transformed to chondrocytes- laying cartilage in tendon then calcium deposits (like bon formation)
- Etopic bone formation- metaplasia of mesenchymal stem cells- osteogenic cells
How does calcific supraspinatus tendionopathy present on an x-ray?
Calcific deposits visible
=crystaline in resting stage
= toothpaste appearance when reabsorbed by macrophages
How is calcific supraspinatous tendionpathy treated?
1- conservative- rest and analgesia
2- surgical- is persistent symptoms
What is a ‘frozen shoulder’?
(aka adhesive capsulitis) capsule of glenohumeral joint= inflamed + stiff–> restricting movement and causing chronic pain (constant, worse at night, exacerbated by movement and cold weather)
What are the risk factors for a frozen shoulder?
1- autoimmune condition- triggered by localised trauma to shoulder
2- being female
3- epilepsy with tonic seizures
4- Diabetes - glucose binds to capsular collagen
5- CVS disease
6- Long periods of inactivity
7- having the shoulder problems
What secondary symptoms might a patient with a frozen shoulder present with?
Sleep deprivation (due to sever pain) Depression (due to disability)
How is a ‘frozen shoulder’ treated?
1, Physiotherapy, analgesia, anti-inflammatory medication
2, Manipulation under anaesthesia- breaks adhesions and scar tissue- restore range of motion. Then intense post operative physiotherapy.
What are the outcomes for patients with frozen shoulders?
Typically resolves with time- patients regain 90% motion
BUT 6-17% of other shoulder will be affected within 5 years
What age group does osteoarthritis usually affect?
Over 50 years
Which joint does of the shoulder does the osteoarthritis usually affect?
Acromioclavicular joint rather than glenohumeral shoulder joint.
How is osteoarthritis treated?
- Activity modification, analgesia, anti-inflammatories. Hyaluronic acid injections into joint (increase lubrication)
- Steroid injections- reduce swelling- alleviate stiffness and pain.
- Arthroscopy (keyhole surgery)- removes loose pieces- damaged cartilage from joint.
- Complete replacement- humeral head
- Complete shoulder replacement (humeral head and glenoid)
What’s the likely mechanism of injury of rupture to the biceps tendon? (Near its scapula origin)
Patients over 50yrs
Minimal trauma
Patient reports ‘snap’ whilst lifting
How does a patient with a ruptured biceps tendon near to its scapula origin present?
Flexion at elbow- firm lump produced- lower part of arm
‘Popeye sign’
How is a ruptured biceps tendon near to its scapula origin managed?
Conservative
