Ses 8 Shoulder Injuries Flashcards
Anterior dislocation of the shoulder
notion
Most are anterior - weakness in inferior aspect of glenoid fossa so goes from anteroinferior to anterior direction (subcoracoid space). Also due to pull of muscles and disruption of anterior capsule and ligaments.
Can be anteroinferior- sub-glenoid.
Held in external rotation and abduction.
Mechanism:
arm positioned in abduction and external rotation (“hand behind head”) and pushed back so shoulder dislocates - humeral head dislocated from glenoid.
Direct blow to posterior.
Complications:
Labral tear
Hill-Sachs lesion - humeral head becomes jammed against the anterior lip of the glenoid fossa due to infraspinatus and teres minor - dent on head.
Secondary OA
Posterior dislocations notion
Cause:
Epilepsy
Electrocution
Blow to anterior
Arm flexed and pushed posterior
Present:
internally rotated and adducted
prominent coracoid process
On X ray - light bulb’ sign. The glenohumeral distance is also increased.
The head of the humerus should be directly in line with the glenoid fossa i.e. at the bifurcation of the Y on scapula.
Complications:
fractures, rotator cuff tears, and Hill–Sachs lesions.
Inferior dislocations notion
Mechanism:
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.
Complications:
Rotator cuff tears
Dislocation consequences on joint integrity and function
Consequences:
1. recurrent dislocation due to damage to the stabilising tissues
2. OA
3. Damage to axillary artery - haematoma, absent pulses, cool limb.
4. injuries of the axillary nerve - supplies deltoid and regimental patch - symptoms resolve when shoulder is reduced. Maybe damage cords of brachial plexus or MS nerve.
5. Fractures esp head, clavicle
6. Rotator cuff muscle tears - always assess as part of the follow-up.
Clavicle fractures notion
provides protection to the brachial plexus, subclavian vessels and apex of the lung.
Usually treated conservatively using a sling. Need surgical fixation when:
Complete displacement
Severe displacement causing tenting of the skin, with the risk of puncture
Floating shoulder - clavicle fracture with ipsilateral fracture of glenoid neck.
Mid-clavicular fracture:
sternocleiodomastoid muscle elevates the medial segment
Lateral segment drops as trapezoid cannot hold it up.
Shoulder drops, adduction(pec major).
Complications:
pneumothorax
suprascapular nerve damage
supraclavicular nerves (C3,4) damage so parasthesia of upper chest.
Rotator cuff tears notion
Tear of one or more of the tendons of the 4 muscles.
Usually supraspinatus - tears at insertion into G tubercle.
Cause:
Microtrauma +Age-related degeneration - poor blood supply so small tears do not heal so full tear.
Repetitive movements - lifting eg painters.
Sports eg tennis - overhead
Symptoms:
Asympto or otherwise anterolateral pain radiates down the arm.
Leaning on elbow - pushes humeral head up
Shoulder flexion
weakness of shoulder abduction
Impingement syndrome notion
supraspinatus tendon rubs or catches on the coraco-acromial arch.
Cause:
Anything that narrows the space - inflammation of the tendon, thickening of coracoacromial ligament, subacromial osteophytes.
Symptoms:
Pain(acute due to injury or insidious and dull) weakness and reduced range of motion when shoulder is abducted or flexed, overhead movement (brush hair or getting stuff from shelves) and lying on it while sleeping.
Grinding or popping sensation during movement.
Painful arc - between 60-120degrees of abduction.
Calcific supraspinatus tendinopathy
Notion
deposits of hydroxyapatite in the tendon of supraspinatus.
Cause:
Hypoxia —> tenocytes converted to chondrocytes—> endochondral ossification means calcium deposits.
Or
Metaplasia of mesenchymal stem cells to osteogenic cells in the tendon.
Symptoms:
pain (due to reabsorption by phagocytes) - abducting or flexing the arm (by lying on the shoulder).
Stiffness
Snapping
Catching
Reduced range of movement
Adhesive capsulitis (“Frozen shoulder”)
Notion
capsule of the glenohumeral joint becomes inflamed and stiff
Symptoms:
Restricted movement
chronic pain - worse at night and exacerbated by movement and cold weather.
Risk factors:
Female
Trauma
Diabetes Mellitus
Long periods of inactivity
Complications:
sleep deprivation
severe interference with work and activities
depression
Treatment:
Physio, analgesia, anti- inflammatory medication
Surgery to break up adhesions and scar tissue in the joint
Osteoarthritis
commonly affects the acromioclavicular joint
Over 50
Treatment:
activity modification, analgesia, and NSAIDs.
nutritional supplements e.g. glucosamine
Steroid injections into the joint to reduce swelling
Hyaluronic acid injections into the joint may increase lubrication
Arthroscopy to remove loose pieces of damaged cartilage from the glenohumeral joint
hemiarthroplasty (replacement of the humeral head)
Total shoulder replacement
Upper brachial plexus injuries - Erb’s palsy
Brachial plexus - anterior rami of spinal nerve roots of C5-T1.
Upper means C5 and C6 nerve roots damaged.
Symptoms:
This causes sensory loss in dermatomes supplied by these spinal nerves
paralysis of muscles predominantly supplied by these spinal nerves. Include - deltoid (axillary nerve), biceps brachii, brachioradialis etc.
Loss of function in myotome so upper limb is adducted, internally rotated, elbow extended and wrist flexed- waiter’s tip position
Causes:
Stretching of angle between neck and shoulder so trauma
Or when giving birth baby’s shoulders are impacted on pelvis and head is being pulled - shoulder dystocia
Lower brachial plexus injury - Klumpke’s palsy
Injury to nerve roots C8-T1
Causes:
forced hyperextension or hyperabduction
Example - falling from a height and grabbing onto tree branch
Or baby’s arm delivered first so traction applied on arm to deliver rest.
Symptoms:
claw hand’ with hyperextension of all of the metacarpophalangeal joints (not just the ring and little finger seen in an ulnar nerve injury)
flexion of the interphalangeal joints
abduction of the thumb
wasting of the interossei.
Winging of the Scapula
Medial border of scapula is no longer held against chest wall so protrudes posteriorly as serratus anterior is paralysed due to LTN damage.
Causes:
Traction injuries eg Blunt trauma to shoulder/neck or heavy backpack
Surgical trauma during mastectomy with axillary clearance.
Tests:
Push arms straight against wall
Pull unaffected shoulder forwards with affected limb
Fracture of the surgical neck of the humerus
blunt trauma to the shoulder or from falling on an outstretched hand.
Axillary nerve damage will result in paralysis of the deltoid and teres minor muscles.
The patient will have difficulty performing abduction of the affected limb.
This nerve also innervates the skin over insertion of deltoid (regimental badge area), and sensation in this region will be impaired.
Posterior circumflex humeral artery damage - avascular necrosis.
Rupture of the Biceps Tendon
patients over the age of 50 years following quite minimal trauma.
snap” in the shoulder whilst lifting.
flexion of the arm at the elbow produces a firm lump in the lower part of the arm - this is the unopposed contracted muscle belly of the biceps and is called the ‘Popeye sign’.
Supination and brachialis still intact so conservative management.
