2. The Pectoral Girdle
Signs and symptoms:
- Abnormally long arm - Humeral head positioned in the axilla - Pain - Dysfunction - Acromium becomes most palpable lateral bony prominence
Each half of the pectoral girdle consists of two bones:
1) Anterior clavicle 2) Posterior scapula
What are the 4 main types of shoulder stiffness:
1) Idiopathic 2) Diabetic 3) Post-surgical 4) Post-traumatic
(4) joints of the shoulder:
1) Sternoclavicular 2) Acromioclavicular 3) Glenohumeral 4) Scapulo-thoracic
The humerus is a long bone that has 2 what ends?
2 epiphyseal ends
The posterior surface divides into what?
2 unequal fossa by the spine of the scapula Projects shelf-like and posteriorly Angling upwards from the medial border
The sternoclavicular joint is capable of movements in the anterior-posterior plane movement of;
20 degrees
The acromioclavicuar joint is covered by what?
A cartilage-like fibrous tissue
What type of joint is a sternoclavicular joint?
A complicated synovial joint
The fibrous portion of the joint capsule in the upper arm forms what?
A connective tissue layer across the intertubular sulcus and converts it into an osteofibrous canal
Acromioclavicular joint is what type?
A synovial gliding
Shoulder dislocation occurs due to what movement?
Abduction & External-rotation- the joint is weakened inferiorly
Lateral end: flattened in the horizontal plane, with a small posterolateral facet which articulates with the acromion process of the scapula-->
Acromioclavicular joint
Capsule has a strengthened ligament on its superior surface-->
Acromioclavicular ligament
Sheila's Frozen Shoulder is what?
Adhesive capsulitis
The scapula has 2 surfaces:
Anterior Posterior
Most common form of GHJ dislocation?
Anterior dislocation--> limb is placed antero-inferiorly.
The proximal end forms what surface for the shoulder joint?
Articular surface for the shoulder joint
It is more suited as what?
Ball and socket type
Where is the inferior glenohumeral ligament located?
Between the SUBSCAPULARIS and the TERES MINOR
The long head of what muscle sits in the groove?
Biceps Brachii
The sternoclavicular joint is capable of movements in the superior- inferior plane:
Bof upto 60 degrees
What is it called when the head of the upper arm is completely out of the socket?
COMPLETE
Some people are born without a clavicle; this is called what?
Cleidocranial Dysplasia
How common?
Common in people aged 40-60. Affects 1 million people in the UK
What happens in posterior dislocation?
Direct blow to the front of the shoulder Partial dislocation--> head of upper arm is partially out of the socket
The articular disk does what?
Divides the space of the joint cavity in 2
More common in females or males?
Females 2:1
The socket is enlarged by what?
Fibrocartilaginous tip- the glenoidal tip
The capsule must be weak in order to permit what?
Free movement
The superior and anterior part of the capsule are thickened by what?
Glenohumeral ligaments
Exhibits what in temperature?
Increase in temperature
Diabetic how?
Increased vascularity of the capsule
The scapula has 3 angles:
Inferior Superior Lateral
Clavicles are interconnected by what ligaments?
Interclavicular ligaments
In the adducted position, the capsule hangs dependent into the what?
Into the axilla
The Glenohumeral joint cavity-->
Is a bony socket
The coracoclavicular ligament can be divided into anterolateral and posteromedial parts-->
Lateral part: the trapezoid ligament arises from the upper medial margin of the coracoid process and extends to the trapezoid line Medial part: The conoid ligament, arises from the base of the coracoid process
What is Adhesive Capsulitis?
Loss of range of motion in shoulder
It is occasionally pierced by what nerve?
Middle Supraclavicular Nerve
Do the ligaments provide stability for the shoulder?
NO! It's weak
Nerve supply to the sternoclavicular joint:
Nerve to subclavius and anterior (medial) supraclavicular nerve
Do any other bones ossify from 2 primary centres?
No
Do any other bones ossify into a membrane?
No
Does the clavicle have a medullary cavity?
No
X-Rays show what in Adhesive Capsulitis?
No arthritis/ Calcium deposits
However, it sits outside what?
Outside the synovial lining of the joint and is therefore extra-synovial
The scapula lies on the posterior thoracic wall between which ribs?
Ribs 2 & 7
What is it called when the head of the upper arm is partially out of the socket/
Subluxation
The scapula has 3 margins:
Superior Medial Lateral
The sternoclavicular joint is sometimes described as what?
Synovial saddle-joint
The costoclavicular ligament extends between what?
The 1st rib and the clavicle
The capsule of the glenohumeral joint attaches laterally to what?
The ANATOMICAL NECK OF THE HUMERUS
What is the lesion called if the glenoid labrum is torn
The Bankart lesion
The shaft of the humerus has a prominent V-shaped tuberosity on its lateral side, called what?
The Deltoid Tuberosity
The capsule of the glenohumeral joint attaches proximally to what?
The GLENOID LABRUM
This is called what???
The Subscapular Bursa
What passes between the humeral tubercles?
The TRANSVERSE HUMERAL LIGAMENT
The clavicle and scapula articulate with each other at what joint?
The acromioclavicular joint
The bone has 2 necks:
The anatomical neck which lies below the head The surgical neck at the top of the shaft Anatomical is above surgical
The capsule is slack and thick and strengthened by what?
The anterior and posterior sternoclavicular ligaments
The greater and lesser tubercle are separated by what?
The bicipital groove
The foramen between the superior and middle GH ligaments is present. It allows what?
The bursa to protrude anteriorly, which aids movement of subscapularis tendon
The acromion articulates with what??
The clavicle
Acromioclavicular joint is between what?
The clavicle and the scapula
Sternoclavicular joint is between what?
The clavicle and the sternum
Blood supply to the sternoclavicular joint:
The clavicular branch of the thoracoacromial artery
The upper portion of the GHJ capsule is partly strengthened by what?
The coracohumeral ligament and three (333333) weak GLENOHUMERAL ligaments
The coracoclavicular ligament is between what?
The coracoid process and the clavicle
The transverse humeral ligament attaches superiorly to what?
The epiphyseal line
The articular part is called what?
The head
The glenohumeral joint is between what?
The head of the humerus and the glenoid cavity of the scapula
Which ligament is largest and strongest?
The inferior glenohumeral ligament is the largest and strongest of the three
The transverse humeral ligament converts what into what?
The inter tubercular groove into a canal, and acts as a retinaculum for the short tendon of the biceps
The greater tuberosity has 3 facets for the attachment of 3 separate muscles from the scapula
The lesser tuberosity also receives a scapular muscle (subscapularis)
The medial end of the clavicle is expanded to form a large, oval facet which articulates with what?
The manubrium sterni- at the sternoclavicular joint
Posteriorly, the anterior surface of the scapula forms a connection with what?
The posterior aspect of the ribs
Posteriorly, there is a spiral groove in which what runs?
The radial nerve and the profound brachii artery
The scapulo-thoracic joint is between what?
The scapula and the rib-cage
This is called what?
The scapulo-thoracic joint
The medial end of the clavicle articulates with the manubrium of the sternum to form what joint?
The sternoclavicular joint
Anteriorly, bones are separated by what?
The sternum
The anterior (costal) surface of the scapula is taken up with the broad CONCAVE surface of what?
The sub-scapular fossa
Above the spine is what?
The supraspinous fossa
There is a gap between the glenohumeral ligaments anteriorly-->
The synovium membrane is able to escape from the confines of the capsule and form a BURSA in front of the SUBSCAPULARIS muscle
The tendon of what arises from inside the GH joint?
The tendon of the long head of the Biceps Brachii
The superior segment of the GH capsule and the CH ligament contributes to what?
The vertical stability of the humeral head
Posteriorly, there is a gap because?
They do not articulate with each other or with the vertebral column
The hyaline carriage covering the gleaned cavity is thicker where?
Thicker at the MARGINS than at the centre
Is the capsule of the glenohumeral joint WEAK or STRONG?
Weak
Is the clavicle subcutaneous?
Yes
Is the clavicle the first bone to ossify?
Yes
Is the clavicle the only long bone to lie horizontally?
Yes
