Major Joints of the Upper Limb. Barbara Kraszpulska, Ph.D. West Virginia University, School of Medicine Department of Neurobiology and Anatomy

Typical features of synovial joints articular cartilage covers the bones ends: hyaline, avascular, aneural articular or joint capsule a) inner or synovial membrane: highly vascular, produces synovial fluid (nutrition and lubrication) b) outer or fibrous membrane: rich nerve/blood supply joint cavity – a potential space contains the small amount of synovial fluid

Glenohumeral = Shoulder Joint Bones: 1. Large, round head of the humerus 2. Shallow glenoid cavity of the scapula Glenoid cavity is slightly deepened by the fibrocartilage element – glenoid labrum! Joint capsule: Remarkably thin and loose, extends from the margin of the glenoid cavity to the anatomical neck of the humerus! What part of the joint capsule is the weakest one and why? The inferior part, because this is the only part, which is not reinforced by the rotator cuff muscles!

Ligaments of the Glenohumeral Joint coracoacromial lig. subacromial bursa coracohumeral lig. Intrinsic lig. glenohumeral lig. Intrinsic lig. transverse humeral lig. subscapular bursa tendon synovial sheet Bursae are closed, partially collapsed balloon containing synovial fluid.They are located between any two of bone, tendon, muscle or skin and they prevent these organs to rub against each other. They serve to reduce friction! Tendon sheaths are similar to bursae, but differ in shape. They look like sausage-shaped balloons that wrap around long tendons subjected to friction.

Movements of the Glenohumeral Joint This is multiaxial ball and socket joint Flexion - Extention Abduction - Adduction Rotation – Medial and Lateral Circumduction – combination of flexion, extension, abduction and adduction.

} Muscles moving the Glenohumeral Joint MM ATTACH HUMERUS TO AXIAL SKELETON 1. Latissimus Dorsi 2. Pectoralis Major MM ATTACH HUMERUS TO THE SCAPULA 1. Supraspinatus, Infraspinatus 2. Subscapularis 3. Teres Minor 4. Teres Major 5. Deltoid } rotator cuff MUSCLES OF THE ARM 1. Biceps brachii 2. Triceps brachii 3. Coracobrachialis

Muscles moving the Glenohumeral Joint FLEXION: Pectoralis major, Deltoid (ant.part), Coracobrachialis, Biceps EXTENSION: Latissimus dorsi, Deltoid (post.part), Teres major ABDUCTION: Deltoid (as a whole, but especially central part), Supraspinatus ADDUCTION: Pectoralis major, Latissimus dorsi, Teres major, Teres minor, Infraspinatus, Subscapularis LATERAL ROTATION: Infraspinatus, Teres minor, Deltoid (post.part) MEDIAL ROTATION: Subscapularis, Pectoralis major, Latissimus dorsi, Teres major, Deltoid (ant. part)

Innervation and Blood Supply of the Glenohumeral Joint General rule! Articular nerves are branches of nerves that supply the muscles that cross and move the joint. Nerves of the Shoulder Joint: * Suprascapular * Axillary * Lateral pectoral General rule! Joints receive their blood supply from articular arteries that arise from vessels around the joint, and often form a network. Arteries of the Shoulder Joint: * Anterior and posterior circumflex humeral a. (branches of Axillary a.) * Suprascapular a. (branch of Thyrocervical trunk or as direct branch of Subclavian a.)

Rotator Cuff Muscles S S I T Anterior view Posterior view S S S I S I T T The rotator cuff muscles work as a group in holding the head of the humerus in the glenoid cavity. They give stability to the shoulder joint. Rotator cuff is formed by the tendons of: Supraspinatus , Infraspinatus, Teres minor and Subscapularis (SITS) fuses with the joint capsule.

Rotator cuff injuries Causes: tendonitis bursitis falling lifting or pulling repetitive stress poor posture Signs and symptoms: pain and tenderness in the shoulder shoulder weakness loss of shoulder range of motion inclination to keep shoulder inactive Treatment: exercise therapy steroid injections surgery arthroplasty

Glenohumeral Joint has more freedom of movement than any other joint in the body! This freedom results from the laxity of its joint capsule and the large size of the humeral head compared with the small size of the glenoid cavity. Its mobility makes the joint relatively unstable!

Common injuries of the Shoulder Joint Shoulder dislocation – dislocation of the glenohumeral joint! During anterior dislocation the humeral head comes to lie inferior to the glenoid cavity and anterior to the infraglenoid tubercle.

Anterior Dislocation Which nerve is most commonly affected with the shoulder dislocation? The axillary nerve!

Elbow Joint Bones: 1. Humerus – trochlea and capitulum 2. Ulna – trochlear notch and radial notch 3. Radius – the head Portions of the joint: 1. Humeroulnar joint – hinge joint 2. Humeroradial joint – arthrodial joint 3. Proximal radioulnar joint – pivot joint Joint capsule: The joint capsule is weak anteriorly and posteriorly, but it is strengthened on each side by collateral ligaments!

Ligaments of the Elbow Joint The Ulnar Collateral Ligament is a thick triangular band consisting of two portions, an anterior (strongest) and posterior (weakest) united by a thinner intermediate portion. The Radial Collateral Ligament is a short and narrow fibrous band, less distinct than the ulnar collateral ligament. The Annular Ligament is a strong band of fibers, which encircles the head of the radius, and retains it in contact with the radial notch of the ulna.

Fat Pads Fat pads may act as a cushion to absorb forces generated across the joint. Fat pads may also help distribute lubricants in the joint cavity. Anterior view Posterior view Fat pads There are three masses of fat between the fibrous capsule and the synovial membrane: * the largest, over the olecranon fossa * the second, over the coronoid fossa * the third, over the radial fossa

Movements of the Elbow Joint Humeroulnar joint – hinge joint Flexion- extension Humeroradial joint - arthrodial joint Gliding Proximal radioulnar joint – pivot joint Pronation -supination

Muscles moving the Elbow Joint 1. Muscles of the anterior compartment of the arm: a. biceps brachii b. brachialis 2. Muscles of the posterior compartment of the arm: a. triceps brachii b. anconeus 3. Muscles of the anterior compartment of the forearm (only these which cross the elbow joint) 4. Muscles of the posterior compartment of the forearm (only these which cross the elbow joint!)

Muscles moving the Elbow joint FLEXION: Brachialis, Biceps brachii, Brachioradialis, Pronator teres EXTENSION: Triceps brachii, Anconeus Biceps brachii, Supinator SUPINATION: Pronator teres, Pronator quadratus PRONATION:

Innervation and Blood Supply of the Elbow Joint Nerves of the Elbow Joint: Mainly * Musculocutaneous * Radial Also * Ulnar * Median *Anterior interosseous Arteries of the Elbow Joint: The articular arteries are derived from the anastomosis around the elbow, which are formed by: * collateral branches of the Brachial artery * recurrent branches of the Ulnar and Radial arteries.

Common injuries of the Elbow Joint Dislocation of the Elbow Joint Because the joint is basically stable, it requires considerable force to dislocate the elbow.  For this reason, as many as one third of all elbow dislocations involve fractures of the elbow bones. Dislocation of the elbow is the most common type of dislocation injury in children.  The distal end of the humerus is driven through the weak anterior part of the joint capsule, as the radius and ulna dislocate posteriorly! The ulnar collateral ligament is often torn, and fracture of the head of radius, coronoid process or olecranon process may occur.

Common injuries of the Elbow Joint Dislocation of the radial head – “pulled elbow” The dislocation usually results from pulling the child's arm--even just to swing the youngster around. The sudden pulling of the upper limb tears the distal attachment of the anular ligament, the radial head then moves distally, partially out of the anular ligament.

Common injuries of the Elbow Joint Bursitis of the elbow Bursitis is the inflammation of the olecranon bursa. The olecranon bursa, covers the olecranon process and lies between the skin of the elbow and the bones of the forearm. Normally, the bursa acts as a cushion between the skin and the bone. The common symptoms of elbow bursitis include: Pain around the back of the elbow Swelling directly over the bony prominence of the tip of the Slightly limited motion of the

Radiocarpal = Wrist Joint Bones: 1. The distal end of the radius 2. Carpal bones: a. scaphoid (S) b. lunate (L) c. triquetrum (T) T L The ulna does NOT participate in the wrist joint! Articular disc together with the articular surface of the radius form a transversely elliptical concave surface, the receiving cavity.

Ligaments of the Wrist Joint The fibrous layer of the joint capsule is strengthened by 4 strong ligaments: Palmar radiocarpal ligament Dorsal radiocarpal ligament Ulnar collateral ligament Radial collateral ligament

Movements of the Wrist Joint This is the condyloid (ellipsoid) type of synovial joint! Flexion - Extension Abduction - Adduction Circumduction

Muscles moving the Wrist Joint 1. Muscles of the anterior compartment of the forearm (only these which cross the wrist!) Flexor carpi ulnaris, Flexor carpi radialis, Flexor digitorum superficialis, Flexor digitorum profundus, Flexor pollicis longus, palmaris longus 2. Muscles of the posterior compartment of the forearm (only these which cross the wrist!) Extensor carpi ulnaris, Extensor carpi radialis longus and brevis, Extensor digitorum, other extensors of the fingers and thumb

Muscles moving the Wrist Joint FLEXION: Flexor carpi ulnaris, Flexor carpi radialis, Flexor digitorum superficialis, Flexor digitorum profundus, Flexor pollicis longus, palmaris longus EXTENSION: Extensor carpi ulnaris, Extensor carpi radialis longus and brevis, Extensor digitorum, other extensors of the fingers and thumb ABDUCTION: Flexor carpi radialis, Extensor carpi radialis longus and brevis, Abductor pollicis longus Extensor carpi ulnaris, Flexor carpi ulnaris ADDUCTION:

Innervation and Blood Supply of the Wrist Joint Nerves of the Wrist Joint: Branches of: * Median (anterior interosseous) * Ulnar (dorsal and deep branch) * Radial (posterior interosseous) Arteries of the Wrist Joint: Branches of: * dorsal carpal arterial arch * palmar carpal arterial arch

Common injuries of the Wrist Joint With the dawn of the computer age, wrist and hand pain became the most common complaint involving the upper extremity. Fracture of the distal end of the radius – Colles’ fracture

Common injuries of the Wrist Joint A Smith's fracture, also sometimes known as a reverse Colles’ fracture, is a fracture of the distal radius caused by falling onto flexed wrists, as opposed to a Colles' fracture which occurs as a result of falling onto wrists in extension. Smith's fractures are less common than Colles' fractures.

Common injuries of the Wrist Joint Fracture of the scaphoid bone The scaphoid can be localized to just below the thumb tendons. A fracture of the scaphoid usually happens from a fall on an outstretched hand, with the weight landing on the palm. Fractures of the scaphoid occur in people of all ages, including children. The injury often happens during sports activities or a motor vehicle accident. Men aged 20 to 30 years are most often affected.