Session 8 Common Shoulder Conditions Flashcards
Most common shoulder dislocation
Anterior
Why does head of humerus displace in an anterior direction
Due to pull of muscles and disruption of anterior capsule and ligaments
Locations of displacement of humerus
60% are sub coracoid
30% are subglenoid
Arm held in what position during dislocated shoulder anteriorly
External rotation and slight abduction
Mechanisms of anterior shoulder dislocation
Hand behind head (abduction and external rotation). Forces arm further posterior
Direct blow to posterior shoulder
Force of humeral head popping out of socket often causes
Part of glenoid labrum to be torn off - Bankart lesion or labral tear
Sometimes a small piece of bone is torn off with labrum
Why does posterior aspect of humeral head sometimes become jammed against anterior lip of glenoid fossa in shoulder dislocation anteriorly
Tone of infraspinatus and teres minor muscles
Hills-Sachs lesion (indentation fracture)
Increased risk of secondary osteoarthritis
Posterior dislocations of shoulder mechanism
Violent muscle contractions due to seizure, electrocution or lightening strike
Arm flexed across body and pushed posteriorly
Blow to anterior shoulder
Posterior shoulder dislocation presentation
Internally rotated and adducted
Flattening of shoulder with prominent coracoid process
Cannot be externally rotated into anatomical position
X ray sign of posterior dislocation of shoulder
Lightbulb sign
Injuries commonly associated with posterior shoulder dislocation
Fractures, rotator cuff tears, Hills-Sachs lesions
Inferior dislocation mechanism
Forceful traction on arm when its fully extended over head
Injuries associated with inferior dislocation
Damage to nerves, rotator cuff tears, injury to blood vessel
Most common complication of shoulder dislocation
Recurrent dislocation due to damage to stabilising tissues leading to increased risk of osteoarthritis
Other complications of shoulder dislocation
Damage to axillary artery- haematoma, absent pulses or cool limb, more common in old as blood vessels less elastic
Axillary nerve injuries- usually recover fully
Cords of brachial plexus or musculocutaneous nerve damaged- rare
Fractures - usually traumatic, first-time dislocation, or age 40+
Rotator cuff muscle tears - older
80% of clavicle fractures occur in
Middle third
Common cause of clavicle fracture and treatment
Fall onto shoulder or outstretched hand
Sling or surgery
Surgery needed in clavicle fracture if
- Complete displacement, severe - - - -displacement causing tenting of skin with risk of puncture
- Open fractures
- Neurovascular compromise
- Interposed muscle
- Floating shoulder (clavicle fracture with ipsilateral fracture of glenoid neck)
What happens to position of arm and clavicular fragments in a displaced mid-clavicular fracture
Sternocleidomastoid muscle elevates medial segment
Trapezius unable to hold lateral segment up against weight of upper limb so shoulder drops
Arm is pulled medially by pectoralis major (adduction)
General complications associated with fracture healing
Non-union or malunion
Local complications of clavicle fracture
Pneumothorax injury
Injury to neurovascular structures- subscapular nerve damaged by medial elebation
or supraclavicular nerves (C3 and 4) results in Parasthesia of upper chest anterioly
Rotator cuff tear is
A tear of one or more tendons of the 4 rotator cuff muscles of shoulder
Most commonly Supraspinatus
Rotator cuff tears reason
Acute
Chronic
Age related degeneration - degenerative micro-trauma model
Principles of degenerative microtrauma model
Blood supply decreases Age-related degeneration Chronic microtrauma Partial tendon tears Full tears Inflammatory cells cause oxidative stress Tenocyte apoptosis Further degeneration
What shoulder injury is often asymptomatic
Rotator cuff tear
Most common rotator cuff tear presentation
Anterolateral shoulder pain, often radiating down the arm
Pain when leaning on elbow and pushing down
Pain when reaching forward/flexing shoulder
Pain-restricted movement above the horizontal position
Weakness of shoulder abduction
Scans for rotator cuff tear
MRI and ultrasound
What is impingement syndrome
Supraspinatus tendon impinges on coraco-Acromial arch leading to irritation and inflammation
3 causes of impingement syndrome
Thickening of coracoacromial ligament
Inflammation of Supraspinatus tendon
Subacromial osteophytes
Impingement syndrome symptoms
Shoulder abducted or flexed narrows space
Pain, weakness and reduced ROM
Worsened by shoulder overhead movement or at night
Dull lingering pain
Grinding or popping during movement
Most common form of impingement syndrome
Impingement of Supraspinatus tendon under acromion during abduction
Painful arc between 60 and 120 degrees
What is calcific Supraspinatus tendinopathy
Presence of deposits of hydroxyapatite in tendon of Supraspinatus
Can occur in any tendon of rotator cuff
Presentation of calcific Supraspinatus tendinopathy
Acute or chronic pain
Aggravated by abducting or flexing the arm above the level of the shoulder or by lying on the shoulder
Mechanical symptoms- stiffness, snapping sensation, catching, or reduced range of movement of the shoulder
Theories of calcific tendinopathy
Regional hypoxia leads to tenocytes being transformed into chondrocytes and laying down cartilage
Ectopic bone formation from metaplasia of mesenchymal stem cells normally present in tendons into osteogenic cells
Calcific deposits visibility
Visible on X ray
Crystalline in resting phase
Eventually re absorbed by phagocytes- this stage causes most pain. Look like toothpaste and appear cloudy on x ray
Calcific Supraspinatus tendinopathy
Treatment is initially conservative with rest and analgesia. Surgical treatment is sometimes required for persistent symptoms
What is adhesive capsulitis
Frozen shoulder
Capsule of glenohumoral joint becomes inflamed and stiff, greatly restricting movement and causing chronic pain
Frozen shoulder presentation
Constant pain
Worse at night
Exacerbated by movement and cold weather
Cause of frozen shoulder
Possible autoimmune component, triggered by localised trauma
Risk factors for frozen shoulder
Female Epilepsy with tonic seizures Diabetes Mellitis Trauma to shoulder CVD Parkinson’s
Frozen shoulder treatment
Physiotherapy, analgesia and anti-inflammatory medication
Manipulation under anaesthesia to break up adhesions and scar tissue to restore ROM
Typically resolves with time- 90% regain motion
More likely opposite shoulder will become affected
Features of osteoarthritis in shoulder
Usually 50+
Commonly affects acromioclavicular joint rather than glenohumoral
Treatment ladder for shoulder OA
Activity mods
Analgesia
NSAIDs
Glucosamine and chondroitin sulphate nutritional supplements
Steroid injections
Hyaluronic acid injections for lubrication
Arthroscopy (remove loose pieces of damaged cartilage)
Hemiarthroplasty (replace humeral head) or total shoulder replacement (and glenoid)
