The Shoulder Joint Flashcards
what physical signs can you see when someone has a shoulder dislocation
visibly deformed, visible swelling and/or bruising
How common are anterior dislocations
90-95% - head of humerus sits anterior to the glenoid fossa
two types of anterior shoulder dislocation
Subcoracoid location = 60%
Subglenoid = 30%
how to get an anterior shoulder dislocation
arm abducted and external roated , force arm posteriorly or direct blow to shoulder
Bankart lesion
force of humeral head popping out of socket in anterior dislocation can cause part of the gleniod labrum to be torn off
Hill Sachs Lesion
posterior aspect of the humeral head become jammed against the anterior lip of the glenoid fossa can cause a dent in the posterolateral humeral head
How common are postior disloactions
2-4%
posterior dislocations cause
violent muscle contractions due to epiletic seizures, electrocution or a lighting strike or blow to anterior shoulder or when the arm is flxed across the body and pushed posteriorly
How do patient hold arm with posterior disloaction
internally rotated and adducted, flattening/squaring of the shoulder
injuries common with posterior disloaction
fractures, rotator cuff tears and hill sachs lesions
how common are inferior dislocations
0.5% head of humerus sits inferior to the glenoid
mechanisms of getting an inferior dislocation
forceful traction on the arm when it is fully extended over the head
how common are nerve damage, rotator cuff tears and injury to blood vessels in inferior dislocation
nerve 60%
cuff tear 80%
blood vessel damage 3%
the most common complication of should dislocation in nay direction
recurrent dislocation
recurrent dislocation occures why?
recurrent dislocation due to damage to the stabilising tissues surrounding the
shoulder (glenoid labrum, capsule, ligaments etc.).
why does chance of further dislocation increase with age
as tissues lose elasticity
why does rick of osteoarthitsis increase each time you discloacte your shoulder
. Each dislocation results in further
damage to the humeral head and glenoid,
what arerty may be damanaged in dislocation and hpw common is it
axillary artery 2%
signs is axially artery damnage
haematoma, absent pulses and/or a cool limb
why is axially nerve damanage more common then axiaally artery damange
axillary
nerve wraps around the neck of the humerus, and supplies the deltoid muscle and
the skin overlying the insertion of deltoid (Apply Hilton’s law: the nerve supplying
the muscle [deltoid] also supplies the skin overlying the insertion of the muscle
[insertion of deltoid]). This is known as the regimental badge area as it corresponds
with where a shoulder badge would be worn on the sleeve of a jacket.
when are fracture likely to occur in a disloaction
first time dislocation or if a person is aged over 40
what bones are likely to break in a fracture
humeral
head, greater tubercle, clavicle and acromion
rotator cuff muscule tears are more common in what kind of disloaction
inferior
which 3rd do clavical fracture occur in most
middle third
most clavical fracture are treated conservatively with a sling but when do you have to intervene?
Complete displacement (so the bone ends are not in apposition and
cannot unite)
Severe displacement causing tenting of the skin, with the risk of
puncture (see below)
Open fractures (fracture associated with a break in the integrity of skin)
Neurovascular compromise
Fractures with interposed muscle
Floating shoulder: clavicle fracture with ipsilateral fracture of glenoid
neck
What will happen to the position of the arm and clavicular fragments in a
displaced mid-clavicular fracture (fracture at the mid-point of the clavicle)
The sternocleiodomastoid muscle elevates the medial segment
Because the trapezius muscle is unable to hold the lateral segment up,
and also because of the weight of the upper limb, the shoulder drops
The arm is pulled medially by pectoralis major (adduction)
rotator cuff tears
1 or more tears in the tendons of the 4 rotator cuff muscles
impingement syndrome
supraspinatus tendon impinges (rubs or
catches) on the coraco-acromial arch, leading to irritation and inflammation.
Impingement may be caused by anything that narrows
this space further
hickening of the coracoacromial ligament, inflammation of
the supraspinatus tendon, subacromial osteophytes (in osteoarthritis)
when do people with impingement syndrome experience pain
When the shoulder is abducted or flexed, the space becomes narrowed further, resulting in symptoms of pain, weakness and reduced range of motion.
most common form of impingement syndrome
common form is impingement of supraspinatus tendon under the
acromion during abduction of the shoulder. This creates a ‘painful arc’ between
60 and 120 degrees of abduction (below 60°and above 120°, patients experience
significantly less, or no, pain). Patients often report pain on reaching upwards to
brush their hair or to lift a food can from an overhead shelf. Treatment is directed
at the underlying cause.
Calcific supraspinatus tendinopathy
presence of macroscopic deposits of hydroxyapatite (a crystalline form of
calcium phosphate) in the tendon of supraspinatus. It can occur in any tendon of
the rotator cuff but is by far most commonly seen in supraspinatus.
frozen shoulder
painful and
disabling disorder in which the capsule of the glenohumeral joint becomes
inflamed and stiff, greatly restricting movement and causing chronic pain.
when is frozen shoulder pain at its worst
pain is usually constant, worse at night and exacerbated by movement and
cold weather
risk factors fro frozen shoulder
Risk factors include female
gender, epilepsy with tonic seizures (i.e. sudden muscle contractions), diabetes
mellitus (the theory is that glucose molecules bond to the capsular collagen),
trauma to the shoulder, connective tissue disease, thyroid disease (hypo and
hyperthyroidism), cardiovascular disease, chronic lung disease, breast cancer,
polymyalgia rheumatica (an inflammatory condition causing muscle pain and
weakness) and Parkinson’s disease [Note: You will only need to recall a couple
of these examples!]. Long periods of inactivity
how is frozen shoulder treated
Treatment usually involves physiotherapy, analgesia and anti-inflammatory
medication. Patients sometimes undergo manipulation under anaesthesia,
which breaks up the adhesions and scar tissue in the joint to help restore range
of motion. Intense post-operative physiotherapy then helps to maintain the
movement that has been gained
osteoarthritsis treatment
activity modification (avoiding activities that
precipitate symptoms), analgesia, and anti-inflammatories (NSAIDs). Some
patients report a benefit from taking nutritional supplements e.g. glucosamine
and chondroitin sulfate.
Steroid injections can be performed into the joint to reduce swelling and
thereby alleviate shoulder stiffness and pain. Hyaluronic acid injections into the
joint (viscosupplementation) may increase lubrication, although the evidence
for this is limited.
Arthroscopy (keyhole surgery)
can be performed to remove
loose pieces of damaged cartilage
from the glenohumeral joint
