upper limb joints Flashcards
gleno-humeral joint
Classification:
Type: synovial
Subtype: ball and socket
Articular surfaces of gleno-humeral joint
Medially: glenoid cavity
Laterally: head of the humerus
Articular surfaces are covered by hyaline cartilage Articular cartilage doesn’t have perichondrium One of the most mobile joints of the body Mobility is at the cost of stability
Anatomically a weak joint
Stabilizing factors of gh joint
Coraco-acromial arch forms the secondary socket Musculotendinous cuff
Glenoidal labrum
Surrounding muscles
Coraco-acromial arch: gh j
Formed by coracoid process, acromion process and coraco-acromial ligament
Musculotendinous cuff (rotator cuff):
Formed by the capsular ligament, supraspinatus, infraspinatus, teres minor and
subscapularis muscles
Glenoidal labrum
Made up of white fibro-cartilage
Deepens the glenoid fossa
Muscles: gh j
Long head of biceps prevents upward displacement of head
Long head of triceps prevents downward displacement of the head
Ligaments of the joint: gh j
Capsular ligament (articular capsule)
- enforced by 3 glenohumeral lig
Coracohumeral ligament- Extends from the root of the coracoid process to the greater tubercle
Transverse humeral ligament- Bridges the gap between greater and lesser tubercles
Glenoidal labrum
Capsular ligament: gh j
Medial attachment:
To the glenoidal labrum
Supraglenoid tubercle is intracapsular
Lateral attachment:
To the anatomical neck of the humerus
Inferiorly it extends up to the surgical neck
Capsule is reinforced by 3 glenohumeral ligaments (superior, middle and inferior)
Capsule and surrounding 4 muscles (subscapularis, supraspinatus, infraspinatus and teres minor) form rotator cuff
Capsule has openings for tendon of long head of biceps and subscapular bursa
Tendon of long head of biceps at gh j
intracapsular but extrasynovial
Relations of shoulder joint:
Anterior:
Anterior fibres of deltoid, short head of biceps and coracobrachialis and subscapularis
Posterior:
Infraspinatus, teres minor and posterior fibres of deltoid
Superior:
Coracoacromial arch, subacromial bursa,deltoid and supraspinatus
Inferior:
Long head of triceps, axillary nerve and posterior circumflex humeral vessels
Blood supply: gh j
Anterior and posterior circumflex humeral vessels
Subscapular vessels
Suprascapular vessels
Nerve supply:
Axillary, musculocutaneous, suprascapular and lateral pectoral nerves
Scapular-humeral mechanism:
-Scapula and upper limb are suspended from the clavicle by coracoclavicular ligament
-Scapula can rotate on the chest wall to change the position of glenoid fossa
- Coracoclavicular ligament forms the axis of rotation of scapula
-180 degrees of abduction is possible
-For every 3 degrees of abduction, 2 degrees occurs at the shoulder joint and one degree by the rotation of scapula
-Scapula is rotated by the combined actions of serratus anterior and trapezius muscles
Applied anatomy: gh j
Dislocations:
-Most commonly dislocated large joint (antero-inferior)
-Axillary nerve can be damaged
Frozen shoulder (adhesive capsulitis):
- pain and loss of motion or stiffness in the shoulder
-in older athletes
-Due to Inflammation of the joint
-Movements are restricted and painful
Rotator cuff tendinitis:
AKA subacromial bursitis, suprspinatus tendinitis or pericapsulitis
Cause: excessive overhead activity
painful abduction
Can lead to rupture of supraspinatus tendon
Elbow joint type
Type: Synovial
Subtype: Hinge
It is a compound and an uniaxial joint
It has humero-radial and humero-ulnar components
The two components and superior radioulnar joint are collectively called ‘cubital articulation’