1. Shoulder Joint Glenohumeral Joint Dr M Idris Siddiqui Glenohumeral Joint Dr M Idris Siddiqui

2. SHOULDER JOINT The Glenohumeral Joint is Synovial ball and socket articulation – Between The head of the humerus andhumerus The glenoid cavity of the scapula.scapula It is the major joint connecting the upper limb to the trunk.

3. SHOULDER JOINT SHOULDER JOINT is component of SHOULDER GIRDLE which comprises of five linkages. 1.Glenohumeral 2.Suprahumeral articulation: Coracoacromial arch above with head of humerus below with subdeltoid bursa in between. 3.Acromioclavicular 4.Sternoclavicular 5.Scapulothoracic (muscular)

5. TYPE The shoulder joint is a ball-and-socket type of synovial joint. The head of humerus is the ball. The glenoid cavity of the scapula is socket. – A dense fibrocartilagenous lip, called labrum glenoidale is attached to the rim of the glenoid cavity and makes it wider & deeper.

6. SHOULDER JOINT The shoulder joint has the following characteristics. – It has a very wide range of movements. The shoulder joint is the most movable joint of the body. – It is not a stable or a secure joint. It is most commonly dislocated large joint in the body.

7. The Intertubercular Sulcus of humerus is a vertical groove between lesser and greater tubercles. It contains of (a) long head of biceps, wrapped in the synovial sheath (b) ascending branch of anterior circumflex humeral artery. Three muscles are connected (inserted) in the region of this groove: 1.Pectoralis major on the lateral lip of the groove. 2.Teres major on the medial lip of the groove. 3.Latissimus dorsi in the floor of the groove

8. LIGAMENTS The ligaments of the shoulder joint are as follows: 1. Capsular ligament (joint capsule): 2. Glenohumeral ligaments: There are three thickenings in the anterior part of the fibrous capsule; to strengthen it. – Superior, – Middle, – Inferior glenohumeral ligaments. 3. Coracohumeral ligament: It is a strong band of fibrous tissue that passes from the base of the coracoid process to the anterior part of the greater tubercle of the humerus.Coracohumeral ligament 4. Transverse humeral ligament: It is a broad fibrous band, which spans the bicipital groove between the greater and lesser tubercles changing it the groove into a canal. – It provides passage to the tendon of long head of biceps surrounded by a synovial sheath.

10. ACCESSORY LIGAMENTS 1.Coracoacromial ligament: It extends between coracoid and acromion processes. It protects the superior component of the joint.Coracoacromial ligament Coracoacromial arch: The coracoacromial arch is formed by coracoid process, acromion process, and coracoacromial ligament between them. – This strong triangular band forms a protective arch for the head of humerus above and prevents its superior displacement above the glenoid cavity. – The supraspinatus muscle passes under this arch and exists deep to the deltoid where its tendon mixes with the joint capsule.deltoid

12. The joint capsule The joint capsule is a fibrous sheath which encloses the structures of the joint. It extends from the anatomical neck of the humerus to the border of the glenoid fossa. The synovial membrane lines the inner surface of the joint capsule, and produces synovial fluid to reduce friction between the articular surfaces. Several synovial bursae are present. – A bursa is a synovial fluid filled sac, which acts as a cushion between tendons and other joint structures.

14. Joint capsule The synovial cavity of the joint shows the following features: – It forms tubular sheath around the tendon of biceps brachii where it is located in the bicipital groove of the humerus. – It communicates with subscapular and infraspinatus bursae, around the joint. Thus there are three apertures in the joint capsule.

15. Three apertures in the joint capsule 1.An opening between the tubercles of the humerus for the passage of tendon of long head of biceps brachii. 2.An opening located anteriorly inferior to the coracoid process to allow interaction between the synovial cavity and subscapular bursa. 3.An opening located posteriorly to allow communication between synovial cavity and infraspinatus bursa.

17. BURSAE RELATED TO THE SHOULDER JOINT Subscapular bursa: – It lies between the tendon of subscapularis and the neck of the scapula; and protects the tendon from friction from the neck. This bursa normally communicates with the joint cavity.subscapularis Subacromial bursa: – lies between the coracoacromial ligament and acromion process above, and supraspinatus tendon and joint capsule below. It continues downwards beneath the deltoid, hence it is sometimes also described as subdeltoid bursa. It is the biggest synovial bursa in the body. Infraspinatus bursa: – It lies between the tendon of infraspinatus and posterolateral aspect of the joint capsule. It may sometime communicate with the joint cavity.

19. Important Relations Anteriorly The subscapularis muscle Deltoid The axillary vessels and brachial plexus Posteriorly The infraspinatus Teres minor muscles Superiorly The supraspinatus muscle, Subacromial bursa, Coracoacromial ligament, Deltoid muscle Inferiorly The long head of the triceps muscle, The axillary nerve The posterior circumflex humeral vessels The tendon of the long head of the biceps muscle passes through the joint and emerges beneath the transverse ligament

20. Neurovascular Supply Arterial supply to the glenohumeral joint is via – The anterior and posterior circumflex humeral arteries, and – The suprascapular artery. Branches from these arteries form an anastomotic network around the joint. The joint is supplied by the nerves: – The axillary, – The suprascapular and – The lateral pectoral nerves. These nerves are derived from roots C5 and C6 of the brachial plexus.brachial plexus – An upper brachial plexus injury (Erb’s palsy) will affect shoulder joint function.

22. Movements at the shoulder Two types of movements: 1.Movements of the shoulder joint: – Take place between humerus & scapula 2.Movements of the shoulder girdle: – Involve clavicle & scapula together and occur at the shoulder joint

23. Movements of the shoulder joint flexion Pectoralis major(clavicular head) Anterior fibers of the deltoid Coracobrachialis Biceps Extension Pectoralis major(sternocostal head) Posterior fibers of the deltoid Teres major Latissimus dorsi Abduction Supraspinatus (up to 15⁰) Deltoid middle fibres (up to 90⁰) Trapezius & serratus anterior(above head) Adduction Pectoralis major Teres major latissimus dorsi Coracobrachialis Subscapularis

24. Movements of the shoulder joint Medial rotation Pectoralis major Teres major Latissimus dorsi Anterior fibers of the deltoid Subscapularis Lateral rotation Infraspinatus Teres minor Posterior fibers of the deltoid Circumduction Circumduction is a cone-shaped movement of a limb that includes flexion, abduction, extension, and adduction.

25. Shoulder Girdle Movements Elevation Depression Abduction Adduction UpwardRotation DownwardRotation

26. Movements Elevation – Upward or superior movement, as in shrugging shoulders Depression – Downward or inferior movement, as in returning to normal position

28. Movements Abduction (protraction) – Scapula moves laterally away from spinal column Adduction (retraction) – Scapula moves medially toward spinal column

30. Movements Upward rotation – Turning glenoid fossa upward & moving inferior angle superolaterally away from spinal column Downward rotation – Returning inferior angle inferomedially toward spinal column & glenoid fossa to normal position

31. Glenoid faces upGlenoid faces down

32. Movements of the shoulder girdle Elevation(shrugging shoulders) Upper Trapezius Levator Scapula Depression(drooping shoulders)Pectoralis Major Pectoralis Minor Latissimus Dorsi Upward rotation(glenoid faces up)Lower Trapezius Upper Trapezius Serratus Anterior(lower part) Downward rotation (glenoid faces down) Levator Scapula Rhomboids Latissimus Dorsi Protraction (pulling forwards)Serratus Anterior Pectoralis Minor Retraction (pulling backwards)Middle Trapezius Rhomboids

33. Mobility and Stability The shoulder joint is one of the most mobile in the body, at the expense of stability. Factors that contribute to mobility: – Type of joint – It is a ball and socket joint. – Bony surfaces – Shallow glenoid cavity and large humeral head There is a 1:4 disproportion in surfaces. – Laxity of the joint capsule.

34. Mobility and Stability Factors that contribute to stability: – Rotator cuff muscles: – Glenoid labrum: – Ligaments: The ligaments act to reinforce the joint capsule, and forms the coraco-acromial arch.

36. Clinical Relevance: Common Injuries Dislocation of the Shoulder Joint: – Dislocations at the shoulder are described by where the humeral head lies in relation to the infraglenoid tubercle. An anterior dislocation is 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.humerus The axillary nerve runs in close proximity to the shoulder joint, and can be damaged in the dislocation. Injury to

37. CLINICAL CORRELATION A portion of epiphyseal line of proximal humerus is intracapsular, Septic arthritis of the shoulder joint may occur following metaphyseal osteomyelitis.arthritis

38. Rotator Cuff

39. Rotator Cuff Tendonitis Tendonitis refers to inflammation of the muscle tendons – usually due to overuse. This may cause degenerative changes in the subacromial bursa, and the supraspinatus tendon. – This increases friction between the structures of the joint. The characteristic sign of rotator cuff tendonitis is the ‘painful arc’ – pain in the middle of abduction, where the affected area comes into contact with the acromion.

40. Subacromial bursitis, supraspinatus tendinitis, or pericapsulitis showing the painful arc in the middle range of abduction, when the diseased area impinges on the lateral edge of the acromion.

41. Adhesive Capsulitis of the Glenohumeral Joint(FROZEN SHOULDER) A frozen shoulder is one that has become stuck and limited in movement. Frozen shoulder is often caused by inflammation of the capsule, tissue surrounding the shoulder joint. Diagnosing frozen shoulder requires a physical examination and possible X- rays or additional tests to rule out other causes of symptoms.X- rays Adhesive fibrosis and scarring between the inflamed joint capsule of the glenohumeral joint, rotator cuff, subacromial bursa, and deltoid usually cause adhesive capsulitis, a condition seen in individuals 60 years of age. A person with this condition has difficulty abducting the arm and can obtain an apparent abduction of up to 45° by elevating and rotating the scapula. Because of the lack of movement of the glenohumeral joint, strain is placed on the AC joint, which may be painful during other movements (e.g., elevation, or shrugging, of the shoulder). – Injuries that may initiate acute capsulitis are glenohumeral dislocations, calcific supraspinatus tendinitis, partial tearing of the rotator cuff, and bicipital tendinitis