Clinical - Frozen Shoulder Flashcards
What is the most common cause of shoulder pain, especially as you get older?
Rotator cuff disease
What are the 4 joints of the shoulder?
- Glenohumeral 2. Acromioclavicular 3. Sternoclavicular 4. Scapulothoracic
What is the glenohumeral joint?
Arguably the true shoulder joint - between the glenoid fossa of the scapula and the head of the humerus
What is the acromioclavicular (AC) joint?
Joint between the acromion of the scapula and the clavicle
What is the sternoclavicular joint?
Joins shoulder to axial skeleton - joint between sternum and clavicle
What is the scapulothoracic joint?
Arguably not a true joint but acts like one - gathers the sternoclavicular and AC joints at the junction between the anterior surface of the scapula and the thoracic cage. Where anterior surface of scapula comes into communication with posterior part of chest wall.
Diagram of head of humerus and tuberosities
What runs in the bicipital groove?
Bicep tendon
Diagram of glenoid fossa
What is the glenoid labrum? What is its function?
Fibrocartilage rim attached around the margin of the glenoid cavity - function is to deepen the shallow gleniod fossa, but depsite this it is still not a true ball and socket joint
What is the glenoid fossa deepend by?
Glenoid labrum
What encloses the strucutres of the glenohumeral joint?
The joint capsule - a fibrous sheath that extends from the anatomical neck of the humerus to the border or ‘rim’ of the glenoid fossa.
What lines the inner surface of the joint capsule of the glenohumeral joint?
Synovial membrane
What does the synovial membrane produce? What is purpose of this?
Synovial fluid - reduces friction between the articular surfaces.
What type of joint is the glenohumeral joint?
Synovial joint
What is a synovial joint?
Joins bones or cartilage with a fibrous joint capsule
Why is the glenohumeral joint so unstable?
Due to large head of humerus and small glenoid fossa –> poor fit for ball and socket joint
The capsule of the glenohumeral joint is lax. What does this allow?
Relaxed - allows rotation and elevation (greater mobility)
What is highlighted in blue?
Joint capsule
The joint capsule of the glenohumeral is thicker anteriorly. Why is this?
Risk of anterior dislocation - main source of stability for the shoulder, holding it in place and preventing it from dislocating anteriorly.
What are the ligaments of the shoulder?
- Glenohumeral
- Coracohumeral
- Transverse humeral
- Coracoacromial ligament
- Acromioclavicular ligament
- Coraco–clavicular ligament
What are the glenohumeral ligaments?
Superior, middle and inferior
Function of glenohumeral ligaments?
They are the main source of stability for the shoulder, holding it in place and preventing it from dislocating anteriorly. They act to stabilise the anterior aspect of the joint.
What do the 3 glenohumeral ligaments form?
Joint capsule - ligaments connect the humerus to the glenoid fossa
Where does the coraco-acromial ligament run? What is its function?
Running between the acromion and coracoid process of the scapula, it forms the coraco-acromial arch
What ligaments support the AC joint?
- Acromioclavicular ligament
- Coracoclavicular ligament
Where does the acromioclavicular ligament run? What is its function?
Runs horizontally from the acromion to the lateral clavicle. It covers the joint capsule, reinforcing its superior aspect.
Reinforce the joint capsule and serves as the primary restraint to posterior translation and posterior axial rotation at the AC joint
Where does the coraco–clavicular ligament run? What is it composed of?
- Composed of the trapezoid and conoid ligaments
- Runs from the clavicle to the coracoid process of the scapula
What is function of coracoclavicular ligament?
Work alongside the acromioclavicular ligament to maintain the alignment of the clavicle in relation to the scapula.
They have significant strength but large forces can rupture these ligaments as part of an acromio-clavicular joint (ACJ) injury.
Does the AC joint have much movement?
Little movement; full abduction, adduction + flex
What structure has to slide underneath coracoacromial ligament? What problem can this cause?
Part of rotator cuff - supraspinatus
Can cause impingement
How is the sternoclavicular able to move? How does this help with movement?
Rotates with elevation 30-40 degrees
Allows wider range of movement of humerus
What muscles does scapula serve as origin for?
Rotator cuff muscles, deltoid and trapezius
What are the 4 rotator cuff muscles?
- Supraspinatus
- Infraspinatus
- Subscapularis
- Teres minor
Which rotator cuff is found anteriorly? What is its function?
Subscapularis - originates from the subscapular fossa and attaches to the lesser tubercle of the humerus.
Medially rotates arm.
Which rotator cuff muscles are found posteriorly?
Supraspinatus, infraspinatus, teres minor
What are attachments of supraspinatus?
Originates from the supraspinous fossa of the scapula (above spine of scapula), attaches to the greater tubercle of the humerus.
Actions of supraspinatus?
Abducts the arm 0-15 degrees, and assists deltoid for 15-90
Attachments of infraspinatus?
Originates from the infraspinous fossa of the scapula (below spine of scapula), attaches to the greater tubercle of the humerus.
Actions of infraspinatus?
Laterally rotates arm
Attachments of the teres minor?
Originates from the posterior surface of the scapula, adjacent to its lateral border. It attaches to the greater tubercle of the humerus.
Actions of the teres minor?
Laterally rotates the arm.
What is the collective function of the rotator cuff muscles?
Originate from the scapula and attach to the humeral head.
Collectively, the resting tone of these muscles acts to ‘pull’ the humeral head into the glenoid fossa. This gives the glenohumeral joint a lot of additional stability.
What are the extrinsic muscles of the shoulder?
Trapezius, Latissimus Dorsi, Levator Scapulae, Rhomboid Major and Rhomboid Minor
What are the intrinsic muscles of the shoulder?
Deltoid, teres major, and the four rotator cuff muscles (supraspinatus, infraspinatus, subscapularis and teres minor).
Where do the extrinsic muscles of the shoulder originate and attach?
Originate from the torso, and attach to the bones of the shoulder (clavicle, scapula or humerus).
Where do the instrinsic muscles of the shoulder originate and attach?
Originate from the scapula and/or clavicle, and attach to the humerus.
What muscle allows the first 20 degrees of abduction of the arm?
Supraspinatus
What muscle allows the next 20-90 degrees of abduction of the arm?
Deltoid
What muscle allows the final 90-180 degrees of abduction of the arm?
Past 90 degrees, the scapula needs to be rotated to achieve abduction – that is carried out by the trapezius and serratus anterior
What movement of the clavicle & scapula does abduction of the arm require?
30-40 degrees clavicle rotation (SCJ and some ACJ)
Lateral slide of scapula on thorax
What can the extrinsic muscles of the shoulder be further divided into?
Superficial (lat dorsi and trapezius) and deep (levator scapulae and rhomboids) layers
What is a force couple?
A force couple is a system that exerts a resultant movement, but no resultant force. Two equal and opposite forces exert a purely rotation force.
How is a force couple formed between rotator cuff muscles and deltoid?
Deep muscles depress humeral head preventing unopposed deltoid action (toward acromion)
Deltoid and supraspinatus both contribute to abduction equally:
As the arm is abducted the resultant joint reaction force is directed towards the Glenoid. This ‘compresses’ the humeral head against the Glenoid and improves the stability of the joint when the arm is abducted and overhead.
Describe what is involved in the early vs late phases of abduction
Early phase 30-40 degrees - most comes from shoulder itself (glenohumeral joint)
Later phase - clavicle and scapula engage more and more
GHJ and STJ (scapulothoracic joint) movement must be synchronous
What happens to the involvement of the scapula the more you abduct your arm?
More and more involved
What is scapulohumeral rhythm?
The coordinated motion of the scapula and humerus experienced during shoulder movement
What muscles are involved in adduction?
Pec major and lat dorsi
What muscles are involved in flexion?
Pec major and anterior deltoid
What muscles are involved in extension?
Lat dorsi, teres major and posterior deltoid
What muscles are involved in lateral rotation?
Infraspinatus
What muscles are involved in medial rotation?
Pec major, lat dorsi and anterior deltoid
Describe what happens during impingement of rotator cuff?
Tendon gets trapped between acromion and humerus (underneath coracoacromial ligament)
What are bursae?
Small fluid-filled sacs that reduce friction between moving parts in your body’s joints.
What bursae are clinically important in the shoulder?
- Subacromial
- Subscapular
What is function of subacromial bursae?
Located deep to the deltoid and acromion, and superficial to the supraspinatus tendon and joint capsule.
The subacromial bursa reduces friction beneath the deltoid, promoting free motion of the rotator cuff tendons.
What is the function of the subscapular burase?
Located between the subscapularis tendon and the scapula. It reduces wear and tear on the tendon during movement at the shoulder joint.
What innervates the deltoid muscle?
Axillary nerve
What is the teres major innervated by?
Lower subscapular nerve
What innervates the supraspinatus?
Suprascapular nerve
What innervates the infraspinatus?
Suprascapular nerve
What innervates the teres minor?
Axillary nerve
What innervates the subscapularis?
Upper and lower subscapular nerves.
Where is the suprascapular nerve derived from?
Derived from upper trunk of brachial plexus
What does the suprascapular nerve innervate?
Supra and infraspinatus, superior and posterior parts of joint and capsule
What does the axillary nerve innervate?
Deltoid, teres minor
Sensory: upper lateral cutaneous surface, anterior aspect of joint and capsule
What is the prime mover of the GH joint?
Deltoid with cuff
What is important in preventing impingement in shoulder?
Scapular movement increases >90 degrees
Why can diabetes lead to ‘frozen shoulder’ / adhesive capsulitis?
Long term complications of diabetes may include changes in connective tissue that occur as a result of high glucose levels
What is a heart disease-related cause of shoulder pain?
Pericarditis - inflammation of the membrane that surrounds heart
Angina - pain can spread to shoulder
What is adhesive capsulitis?
A painful condition in which the movement of the shoulder becomes limited. Frozen shoulder occurs when the strong connective tissue surrounding the shoulder joint (called the shoulder joint capsule) become thick, stiff, and inflamed
Name the location of different pains
Green: ACJ (pain well localised to joint)
Black: STJ (pain well localised to joint)
Grey: Rotator cuff, outer upper arm, deltoid
Red: C spine referred
Pink: Scapular
What is a longhead bicep rupture?
When the tendon which connects the biceps muscle on the front of the upper arm with the shoulder blade tears completely - causes shoulder pain and is normally visually obvious
What are you looking for during inspection of shoulder?
- Anterior, posterior and lateral
- Swelling, deformity
- Neck position
- Muscle wasting
- Asymmetry of scapulohumeral rhythm
- Scapula winging
- Tendon rupture-biceps
As a ball and socket synovial joint, what movements are permitted?
- Extension (upper limb backwards in sagittal plane)
- Flexion (upper limb forwards in sagittal plane)
- Abduction (upper limb away from midline in coronal plane)
- Adduction (upper limb towards midline in coronal plane)
- Internal rotation (rotation towards the midline, so that the thumb is pointing medially)
- External rotation (rotation away from the midline, so that the thumb is pointing laterally)
Which muscles contribute to adduction?
pectoralis major, latissimus dorsi and teres major
What muscles contribute to internal rotation?
subscapularis, pectoralis major, latissimus dorsi, teres major and anterior deltoid.
What factors contribute to the mobility of the shoulder joint?
Type of joint – ball and socket
Bony surfaces – shallow glenoid cavity and large humeral head
Inherent laxity of the joint capsule.
What factors contribute to the stability of the shoulder joint?
- Rotator cuff muscles - the resting tone of these muscles act to compress the humeral head into the glenoid cavity.
- Glenoid labrum - It deepens the cavity and creates a seal with the head of humerus, reducing the risk of dislocation.
- Ligaments - act to reinforce the joint capsule, and form the coraco-acromial arch.
- Biceps tendon - it acts as a minor humeral head depressor, thereby contributing to stability.
Where is dislocation of the shoulder joint most prevalent?
Anterior dislocations (95%), posterior (4%), inferior (1%)
What is superior displacement of the humeral head prevented by?
Coraco-acromial arch
What is anterior dislocation usually caused by?
Excessive extension and lateral rotation of the humerus. The humeral head is forced anteriorly and inferiorly – into the weakest part of the joint capsule.
What nerve is at risk of being damaged with the dislocation of the shoulder joint?
The axillary nerve - runs in close proximity to the shoulder joint and around the surgical neck of the humerus
What muscle can damage to the axillary nerve cause paralysis of?
Deltoid
What is subacromial bursitis? What can it cause?
Inflammation of the subacromial bursae - can cause shoulder pain
Where does the clavicle meet the scapula?
At the arcomion - this is the AC joint
What should muscles of the shoulder and neck be palpated for?
Trigger and tendon points; typically present with myofascial syndromes and fibromyalgia
Also consider calcific tendonitis if tender
Possible cause of;
1) Pain and stiffness that does not go away over months or yearsf
2) Pain that’s often worse while using your arm or shoulder
3) Tingling, numb, weak, feels like it’s clicking or locking
4) Sudden very bad pain, cannot move your arm (or it’s difficult), sometimes changes shape
5) Pain on top of the shoulder (where the collarbone and shoulder joint meet)
1) Frozen shoulder, arthritis (osteoarthritis or rheumatoid arthritis)
2) Tendonitis, bursitis, impingement
3) Shoulder instability, sometimes because of hypermobility
4) Dislocated shoulder, broken bone (such as the upper arm or collarbone), torn or ruptured tendon
5) Problems in the acromioclavicular joint, like dislocation or stretched or torn ligaments
What is active vs passive movement of the shoulder during examination?
Active - patient moves e.g. arm themselves
Passive - you move e.g. arm for them
What does active movement of the shoulder test?
Tests joint/capsule and muscles/tendons
What does passive movement of the arm/shoulder test?
Joint/capsule
How would you typically expect ‘frozen shoulder’ to present during clinical examination?
- Reduction in the range of both active and passive movement.
- Palpation of the joint does not typically cause pain
- Risk factors include; surgery, prolonged immobility and trauma.
How would you typically expect axillary nerve palsy to present during clinical examination?
Typically caused by shoulder dislocation.
- Loss of sensation over the lateral deltoid region (known as the regimental patch)
- Deltoid muscle weakness (loss of shoulder abduction)
- Biceps and brachialis weakness (loss of elbow flexion).
If you want to look at the rotator cuff moving independently, what msut you stabilise?
The scapula
If both active and passive movements are reduced, what may this suggest there is a problem with?
Joint/capsule
What diagnoses can cause problems with the joint/capsule?
Arthritis, capsulitis, frozen shoulder
What diagnoses can cause problems with the tendons?
Rotator cuff tendinopathy, bicipital tendinopathy, calcific tendinopathy
A few differential diagnoses for shoulder pain;
Joint/Capsule - arthritis, capsulitis, ‘frozen shoulder’
Tendons - Rotator cuff tendinopathy, bicipital tendinopathy, calcific tendinopathy
SCJ, ACJ
Instability
Referred - cervical, thorax, abdomen, brachial
Regional pain syndrome
What disease may predispose ‘frozen shoulder’?
- Diabetes
- Thyroid disease
- Lung disease (TB, Ca.)
- Cardiac disease/surgery
What are the clinical features of frozen shoulder?
- Ache
- Night pain
- Spasm
- Stiffness
- Increased restriction
What can be given to temp reduce symptoms of ‘frozen shoulder’?
Corticosteroids
What is rotator cuff tendonopathy?
Common cause of shoulder pain where degeneration of tendon leads to dysfunction and impingement
