Shoulder conditions Flashcards
Most common shoulder dislocation
Anterior (90%) (humerus head anterior to glenoid fossa)
Signs of shoulder dislocation (visible)
Deformed
Swelling
Bruising
Why do shoulder dislocations occur?
Glenoid fossa shallow
Weakest on inferior aspect (dislocates anterioinferiorly then displaces anterior)
Types of anterior dislocation
Subglenoid (30%)
Subcoracoid (60%)
Actions anterior dislocation
EXTERNAL ROTATION
ABDUCTION
(anterior rotator cuffs lax so rotator cuffs (infraspinatus, supraspinatus and teres minor pull externally)
How does anterior dislocation occur?
Arm in position of abduction and external rotation (throwing ball, hand behind head)
Force pushes on it posteriorly
OR
Direct posterior blow to shoulder
What can occur when humeral head is forced out of socket?
Bankart lesion/Labral tear
(glenoid labrum torn off and some bone can be torn off with it)
Hills-Sach lesion
What is hills sach lesion?
Humerus dislocates anteriorly
Posterior humeral head is pressed against anterior lip of glenoid fossa
Indentation in posterolateral humerus head
What do Hills-Sach lesions have a risk of?
Increase risk of secondary arthritis in joint
Posterior shoulder dislocations causes
VERY uncommon Epileptic fits Lightening strike Electrocution Blow to anterior shoulder Arm flexed, pushed posteriorly (fall on elbow)
Presentation posterior dislocation
Internally rotated and adducted
Squaring of shoulder
Coracoid process prominent
(posterior rotator cuffs lax so subscapularis pulls internally)
Sign of posterior dislocation on X ray
Lightbulb humeral head
Glenohumoral distance increased
(Rotated internally so head faces X ray - appears more rounded)
Inferior dislocation cause
RARE
When arm is fully extended above head forceful traction (HYPERABDUCTION)
Complications inferior dislocation
Damage to nerves
Rotator cuff tears
Injury to blood vessels
Complications of all shoulder dislocations
RECURRENT dislocation (damage to stabilising factors)
(can lead to OA)
Damage to neurovascular system shoulder dislocation
Axillary artery Axillary nerve (wraps around surgical neck of humerus, supplies deltoid and regimental badge area of skin)
Less common: damage to brachial cords/musculocutaneous nerve
Test for axillary damage
See if sensation is lost in regimental badge area
What other damage to structures can occur after shoulder dislocation?
Fractures (clavicle, acromion, head/greater tubercle of humerus)
Rotator cuff tears
Clavicle fractures: where do they most often occur?
middle third of clavicle (midclavicular)
Treatment clavicle fractures
Sling BUT surgery if:
Complete displacement
Severe displacement (tenting skin, risk of puncture)
Open fracture
Neurovascular compromise
Floating shoulder (fracture with glenoid neck fracture)
What happens to sections of clavicle when fractured?
Medial end: Sternocleidomastoid elevates
Lateral end: Weight of upper limb exceeds trapezius strength so drops
Arm pulled medially by pectoralis major
Complications of clavicular fracture
non-union/malunion of fracture
Pneumothorax
Suprascapular and supraclavicular nerve damage
Supraclavicular damage means
Paraesthesia over anterior upper chest (c3/C4)
Rotator cuff tears most common
Tendons torn more frequently than muscles
Supraspinatous most at risk
Where does supraspinatus usually tear?
At site of insertion on greater tubercle on humerus (passes under corocacromial arch)
What are most rotator cuff tears a result of?
Chronic (poor biomechanics/muscular imbalance) Extended use (lifting/overhead activity - swimming) AGE RELATED degeneration
What happens with age to rotator cuffs?
Blood supply decreases with age
Impairs body’s ability to repair minor injuries
Theory behind rotator cuff tears
Degenerative-microtrauma model
Age related tendon degeneration + microtrauma = partial tendon tears with become full tears
Body’s response after tear
Inflammatory cells
= Oxidative stress
= tenocyte (tendon cell) apoptosis
= further degeneration
Common presentation rotator cuff tear
Asymptomatic usually BUT
Anterolateral shoulder pain radiating down arm
(especially when leaning on arm rest, reaching forward/flexing)
Action weakness rotator cuff injury
Abduction weakness
Management and investigation rotator cuff tears
SOFT TISSUE
MRI
Ultrasound
Conservative or surgical
What is impingement syndrome?
When supraspinatous tendon rubs/catches on corocoacromial arch leading to irritation
Cause of impingement syndrome
Anything that narrows space between humerus and corocoacromial arch eg:
Thickening of corocoacromial ligament
Inflammation of supraspinatus tendon
Subacromial osteophytes
Bursitis
When does pain present in impingement syndrome?
When shoulder is abducted or flexed, space is narrowed further so can cause pain and reduced motion
Most common impingement syndrome
Impingement of supraspinatus tendon
Painful arc between 60-120 degrees of abduction
What is calcific supraspinatus tendonopathy?
Macroscopic deposits of hydroxyapatite (calcium phosphate) crystals on supraspinatus tendon
Signs/symptoms calcific supraspinatus tendonopathy
Chronic pain (aggrevated by abduction/flexion) Physical appearance of deposit Stiffness Snapping sensation Reduced range of movement
Why does calcific tendonopathy occur?
Regional hypoxia = tenocytes –> chondrocytes and lay down cartilage
Endochondral ossification produces calcified tendon
OR
Ectopic bone formation from metaplasia of mesenchymal stem cells
When is most pain caused by calcific tendonpathy?
Reabsoption by phagocytes
Look like toothpaste at this stage (cloudy and less defined on X ray)
Treatment calcific tendonpathy?
Conservative (rest, analgesia)
Surgical if persistent symptoms
Viewing calcific tendonpathy
X ray
What is adhesive capsulitis?
Frozen shoulder
Capsule of glenohumoral joint becomes inflamed and stiff
Worse in cold, at night and movement
Risk factors adhesive capsulitis
Autoimmune initiated by trauma? Female Epilepsy with seizures Diabetes mellitus (glucose binds to capsular collagen) Connective tissue disease Inactivity large periods of time
Treatment frozen shoulder
Physio
Analgesia
Anti-inflammatories
Manipulation under analgesia to break up scar tissue/adhesions
What can happen after frozen shoulder?
Can occur in opposite arm
Autoimmune hypothesis
Osteoarthiritis in shoulder usually affects
More common in acromioclavicular joint than glenohumoral
treatment OA shoulder (conservative)
NSAID’s
Analgesia
Viscosupplementation (hyaluronic acid injections to joint)
Nutritional supplements (glucosamine/chrondroitin sulfate)
Surgical treatment OA shoulder
Arthroscopy (keyhole) remove loose pieces of damaged cartilage
Hemiarthroplasty (humeral head replaced)
Or Total shoulder replacement (reverse)
