e posters of 2023-24 batch- cubital fossa

 CHAPTER 12

JOINTS OF THE UPPER LIMB :

JOINTS OF THE SHOULDER GIRDLE:

The joints of girdle are:

Sternoclavicular joint

Acromioclavicular joint

Sternoclavicular joint:

• Sternal end of the clavicle articulates with clavicular notch of manubrium sternii
• Saddle type of synovial joint

The ligaments are:

Capsular ligament

Anterior and posterior sternoclavicular ligaments

Articular disc

Interclavicular ligament

Costoclavicular ligament

Acromioclavicular joint:

• Plane type of synovial joint
• The lateral end of clavicle articulates with clavicular facet on the medial margin of the acromial process of scapula

The ligaments are:

Fibrous capsule

Coraco-clavicular ligament: Conoid part, Trapezoid part

Movements of shoulder girdle joints :

Elevation and depression of scapula

Protraction and retraction of scapula

Forward and backward rotation of scapula

SHOULDER JOINT:

FOR ANIMATED VIDEO OF ENTIE SHOULDER JOINT, WATCH THIS VIDEO:     

https://youtu.be/WA3oza7KGng

Or Glenohumeral joint

Type of Joint: Multiaxial spheroidal type

Articulating surfaces:

Proximally – pear shaped glenoid cavity of scapula

Distally – spheroidal head of humerus

Ligaments of shoulder joint:

          The shoulder joint presents the following ligaments:

• Fibrous capsule and synovial membrane
• Glenohumeral ligaments
• Glenoidal labrum
• Coracohumeral ligament
• Transverse humeral ligament

Fibrous capsule: 

It forms a loose envelope for the shoulder joint

Medially : it is attached to the peripheral margin of the glenoid cavity.

Laterally : it is attached around the anatomical neck of humerus except infero medially where it extends about 1 cm below to encroach the surgical neck of humerus

Synovial membrane:

It lines the capsule, a synovial sheath extends along the tendon of long head of biceps brachii up to the surgical neck of humerus

Glenohumeral ligaments:

Thickening of the anterior part of the fibrous capsule form gleno humeral ligaments – superior, middle and inferior.

All three ligaments are attached above to the supero medial margin of glenoid cavity blending with glenoid labrum

Below, superior and middle are attached to the lesser tubercle of humerus of anatomical neck of humerus.

Glenoidal labrum:

It is a fibrocartilaginous rim attached to the margin of the glenoidal labrum

It deepens the glenoid fossa

Coracohumeral ligament:

It is a thickening in the upper part of fibrous capsule

It extends from the lateral border of coracoids process to the anatomical neck of humerus between the greater and lesser tubercles.

Transverse humeral ligament:

It connects the two lips of the upper part of intertubercular sulcus and keeps the long tendon of biceps in position

Relations of the joint:

Above – supraspinatus, subacromial bursa, coracoacromial arch

Below – quadrangular space with axillary nerve and posterior circumflex humeral vessels, long head of triceps.

Infront- Subscapularis, coracobrachialis and short head of biceps.

Behind – infraspinatus and teres minor

Within the joint:

Tendon of long head of biceps

Deltoid muscle covers the joint in front, behind and laterally

 Bursae in relation to shoulder joint:

Subscapular bursa – communicates with the joint cavity.

Subacromial bursa- intervenes between the supraspinatus and coracoacromial arch

Infraspinatus bursa

Synovial sheath around the long tendon of biceps

Arterial supply:

Anterior circumflex humeral artery

Posterior circumflex humeral artery

Suprascapular arteries

Nerve Supply:

Axillary nerve

Suprascapular nerve

Lateral pectoral nerve

Movements of shoulder joint:

Flexion and extension: Take place at right angles to the plane of the body of scapula.

Adductions and abduction: Parallel to the plane of the body of scapula

Medial and lateral rotations: around a vertical axis which extends from the center of humeral head to the center of capitulum

Muscles producing movements:

Flexion: Clavicular head of pectoralis major anterior fibres of deltoid assisted by coracobrachialis and biceps brachii.

Extension: Posterior fibres of deltoid and teres major

Abduction: Initial abduction of 15⁰ by supraspinatus. From 15⁰ to 90⁰ by middle fibres of deltoid.

The abduction is only 60 degree when the humerus rotated medially. Its range is increased to about 90 degree when the humerus moves in the plane of the body of scapula.

The abduction range is increased to 120 degree when the humerus rotates laterally by the contraction of infraspinatus and teres minor.

Adduction: Anterior and posterior fibres of deltoid pectoralis major, teres major, latissimus dorsi, coracobrachialis and long head of triceps.

Medial rotation: Anterior fibres of deltoid, pectoralis major, latissimus dorsi, subscapularis.

Lateral rotation: Infraspinatus teres minor, and posterior fibres of deltoid.

APPLIED  ANATOMY :

Dislocation of shoulder joint:  is common, due to disproportionate articular surfaces and laxity of the ligaments and dislocation is initially inferior or sub glenoid and this is followed by sub coracoid or sub clavicular and others.

Some times, recurrent dislocation of shoulder takes places anterior through a tear in the antero inferior part of glenoidal labrum.

Painful arc syndrome: Thickening of supraspinatus tendon causes pain in abduction between 9000 to 120 due to the impingement of tendon against coracoacromial arch.

Frozen shoulder: Tendinitis of rotator cuff causes restriction of all shoulder movements due to adhesions

FOR RADIOLOGY OF SHOULDER JOINT, WATCH THIS VIDEO:

https://youtu.be/3tH_lzmx03I