Common Shoulder Conditions Flashcards
What happens during an anterior shoulder dislocation in the subcoracoid location
This is the more common one. Glenoid fossa is shallow and is least supported from the inferior aspect and therefore dislocates at an anterior-inferior angle and ends up displaces anteriorly due to the pull of different muscles
What happen during anterior shoulder dislocation in the subglenoid location
Head of humerus may lie displaced anterior-inferior to the glenoid. This is is where head of humerus is seen to be much lower
Is which position is the arm held after anterior dislocation
Arm is held in a position of external rotation and slight abduction
Ways in which the shoulder can become anteriorly dislocated
When is position of abduction and external rotation (hand behind head) and injury forces shoulder more posteriorly
OR
Direct blow to the posterior shoulder
What is a bankart lesion
When the force of the numeral head popping out of the socket causes a part of the glenoid labrum to be torn off. Sometimes a small piece of bone can be torn off together with the labrum
What is a hill-Sachs lesion and what is it causes by
When the humeral head is dislocated and the infraspinatas and teres minor muscles mean that the humeral head becomes jammed against glenoid fossa causing a dent
When do posterior dislocations occur
Very rare. Happen during violent muscle contractions eg seizure, electrocution or lightening strike. When there is blow to anterior shoulder or when arm is flexed across body and pushed posteriorly
How is the posterior dislocated shoulder usually presented
The patients arm will be internallly rotated and addicted. The arm cannot be externally rotated into the anatomical position
What is an inferior dislocation and h dos it happen
Found underneath the glenoid fossa. Very traumatic. Happens during forceful traction on arm when its fully extended over the head - grasping over head to break fall for example
Injuries associated with inferior shoulder dislocation
60% nerve damage, 80% rotator cuff tears ad can also cause some injury to blood vessels
What is recurrent dislocation
Common complication of shoulder dislocation. Happens due to the damage to the stabilising tissues around the shoulder. Risk decreases the older you are when you dislocate your shoulder.
ALSO increases risk of secondary osteoarthritis in that shoulder
When does axillary artery damage occur
Damage to axillary artery as its in the same area. More common in old people as they have less elastic vessels. Patient may have haematoma/absent pulses or cool limb (less blood supply)
How nerve injuries occur after shoulder dislocation
Particularly the axillary nerve is easily damaged as is it wraps around the neck of the humerus and supplies and deltoi muscle and the skin overlying it. - regimental badge area. Sometimes this can be resolved when the shoulder is put back into position
Sometimes dislocation may cause damage to cords of brachial plexus or musculotaneous nerve (much more unlikely)
Discuss what happens when fracture occurs at the same time as a dislocation
Usually only happens when the injury happen in a traumatic way. More common during first time dislocation (because everything is a bit less flexible) or when the person is older. Affects bones; humeral head, greater tubercle, clavicle and acromion.
Discuss rotator cuff muscle tears in association with shoulder dislocation
Comply in older people and if its an inferior dislocation.
Function of the clavicle
Transmits force form the upper limb to the axial skeleton
Protection of brachial plexus, subclavian vesssels and top of lung .
Allows arm to have freedom of motion by acting as a strut between sternum and glenohumeral joint
How do you break your clavicle
Falling onto shoulder or outstretched hand
Treatment of clavicle fracture
Use sling Need surgical fixation if; Complete displacement Severe displacement causing tenting of the skin = risk of puncture and necrosis Open fracture Neurovascular compromise Fractures with muscles between. Floating shoulder - fracture is clavicle and of glenoid neck
What happens to arm posits in a mid-clavicular fracture
Sternocleiodomastoid muscle elevates the medial segment and trapezius cant hold lateral segment plus pulled down by the weight of the arm. Arm is pulled medically by pictorial is major
Complications that occur with clavicle fracture
Pneumothorax or injury to surrounding neurovascular structures - eg the suprascapular nerve may be damaged and/or the supracalvicular nerve may also be damaged
What is a rotator cuff tear
Tear of one or more of the tendons of the four rotator cuff muscles of the shoulder
Which tendons are in the rotator cuff and which are frequently torn
Supraspinatus, infraspinatus, subscapularis, an teres minor. Most commonly torn is the supraspinatus tearing at the site of its insertion into the greater tubercle of the humerus
Can acute tears of the rotator cuff occur
Can occur for example following shoulder dislocation but not that common
Can/when do chronic tears of rotator cuff occur
Results from extended use in combo with factors e.g poor biomechanics. Common causes;
Age related degeneration - less blood supply to raptor cuff so cant repair injuries as well
What is the degenerative-microtrauma model
Micro trauma + age-related degeneration is what causes partial tendon tears which develop into full rotator cuff tears. Inflammatory cells re recruited and oxidative stress leads to tenocyte (tendon cell) apoptosis leading to further damage.
Risk factors for rotator cuff tear
Repetitive over the head lifting e.g tennis or painters
Symptoms of rotator cuff tears
Often asymptomatic but most commonly presented as anterolateral shoulder pain radiating down arm. Patients also experience pain when;
Lean on elbows and push down - pushes head of humerus up and decreases space between humeral head ad coracoacromial arch
When reaching forward (shoulder flexion)
ALSO have weakness of shoulder abduction - usually only found on physical examination
What is impingement syndrome
When supraspinatus tendon impinges (rubs or catches) on the coraco-acromial arch leading to irritation and inflammation. May be caused by thickening of coracoacromial ligament, inflammation of supraspinatus lineament or subacromial ostephytes. Then when shoulder i abducted or flexed this space narrows further causing pain, weakness and reduced range of motion .
When does impingement syndrome cause the most pain
Shoulder overhead movement - abduction of shoulder e.g brushing hair
Treatment of impingement syndrome
Treat underlying cause
What is a calcific supraspinatus tendiopathy
It’s hydroxyapatite (calcium phosphate crystals) in the tendon of the supraspinatus. Can also occur in other rotator cuff tendons but less common.
How does calcific supraspinatus tendinopathy preset
Acute/chronic pain aggravated by abducting or flexing the arm above shoulder level. Mechanical symptoms e.g stiffness, catching, reduced range of movement occur due to presence of large deposit
Why does calcific tendinopathy occur
Multifactoral.
1 theory = regional hypoxia leads to tendocytes being transformed to chondrocytes and laying down cartilage and calcium.
Another theory = ectopic bone formation from metplasia of meshenchymal stem cells in tendons into osteogenic cells
What is seen on an X-ray of calcific tendinopathy
Calcific deposits seen on X-ray. They are crystalline in their resting phase and are eventually reabsorbed by phagocytes - look like tooth paste e.g cloudy- this is what causes the most pain
Treatment for calcific tendinopathy
Rest and analgesia. Surgery sometimes required for persistent symptoms
What is adhesive capsulitis (frozen shoulder)
Gelnohumeral joint becomes inflamed and stiff greatly reducing movement and causing chronic pain which is worse at night and exarcerbated by movement and cold weather
Cause/risk factors of frozen shoulder
Unknown cause. Some say it’s autoimmune. Risk factors; Female Epilepsy (seizures with lots of muscle contraction) Diabetes (glucose molecule bind to capsular collagen) Shoulder trauma Connective tissue disease Thyroid disease CVS disease Chronic lung disease Breast cancer Polymyalgia rheumatica (inflammatory muscle condition) Parkinson’s disease Long periods of inactivity
Treatment for frozen shoulder
Physiotherapist and anti inflammatory medication. Some go under anaesthesia to get adhesions broken up to restore range of motion. Postoperative physiotherapy helps to maintain the movement gained
Usually resolves with time and patients regain 90% of movement but may return in other shoulder.
Treatment of osteoarthritis of the shoulder
- activity modification, analgesia and antiinflammatories.
- Steroid injections to reduce swelling and alleviate shoulder stiffness and pain and hyalauronic acid injections to increase lubrication.
- Atheroscopy - (keyhole sugary) to remove loose cartelise and some patients then get total shoulder replacement
Places in the shoulder often affected by osteoarthritis
Acromiocalvicular joint
Glenhumeral joint
Effects of biceps tendon rupture
Patient usually hears something snap in the shoulder whilst lifting.
Flexion of elbow produces lump in lower arm = Popeye sign
Patient wont notice much weakness due to activation of other muscles and management is usually conservative.
Effects of fracture of surgical neck of humerus
Blunt trauma or falling on outstretched hand causes it.
Axillary neve and posterior circumflex artery at risk.
Axillary nerve damage = paralysis of deltoid and teres minor and will therefore have difficulty performing abduction. In regimental badge area skin is also affected
Effects of fracture of the scapula
Very uncommon usually due to severe trauma. Doesn’t need fixation as surrounding muscles hold the fragments into place whilst healing occurs
