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JOINTS OF THE UPPER LIMB 06-08. 01. 2014 Kaan Yücel M.D., Ph.D. http://yeditepeanatomy1.org Dr.Kaan Yücel http://yeditepeanatomy1.org Joints of the upper limb Movement of the pectoral girdle involves the sternoclavicular, acromioclavicular, and glenohumeral joints, usually all moving simultaneously. Functional defects in any of the joints impair movements of the pectoral girdle. Mobility of the scapula is essential for free movement of the upper limb. The clavicle forms a strut that holds the scapula, and hence the glenohumeral joint, away from the thorax so it can move freely. Sternoclavicular joint: the only articulation between the upper limb and the axial skeleton. The sternal end of the clavicle articulates with the manubrium and a small part of the 1st costal cartilage. Saddle type, but functions as a ball-and-socket joint. Acromioclavicular joint: The acromial end of the clavicle articulates with the acromion of the scapula. Plane type. Glenohumeral (Shoulder) joint: More freedom of movement than any other joint in the body. Humeral head articulates with the relatively shallow glenoid cavity of the scapula, which is deepened slightly but effectively by the glenoid labrum (L., lip). Ball-and-socket type of synovial joint. Elbow joint: The spool-shaped trochlea and spheroidal capitulum of the humerus articulate with the trochlear notch of the ulna and the slightly concave superior aspect of the head of the radius, respectively; therefore, there are humeroulnar and humeroradial articulations. Hinge type Proximal (Superior) radio-ulnar joint: The head of the radius articulates with the radial notch of the ulna. Pivot type. Distal (Inferior) radio-ulnar joint: The head of the ulna articulates with the ulnar notch on the medial side of the distal end of the radius.Pivot type. Wrist (Radiocarpal) joint: The wrist (carpus), the proximal segment of the hand, is a complex of eight carpal bones, articulating proximally with the forearm via the wrist joint and distally with the five metacarpals. The ulna does not participate in the wrist joint. The distal end of the radius and the articular disc of the distal radio-ulnar joint articulate with the proximal row of carpal bones, except for the pisiform. Condyloid (ellipsoid) type. Intercarpal joints: Carpal bones (the intercarpal joints interconnect the carpal bones). Plante type. Carpometacarpal joints: The distal surfaces of the carpals of the distal row articulate with the carpal surfaces of the bases of the metacarpals. The important carpometacarpal joint of the thumb is between the trapezium and the base of the 1st metacarpal; it has a separate articular cavity. Like the carpals, adjacent metacarpals articulate with each other. The carpometacarpal and intermetacarpal joints are the plane type of synovial joint, except for the carpometacarpal joint of the thumb, which is a saddle joint. The metacarpophalangeal joints are the condyloid type of synovial joint that permit movement in two planes: flexion-extension and adduction-abduction. The interphalangeal joints are the hinge type of synovial joint that permit flexion-extension only.The heads of the metacarpals articulate with the bases of the proximal phalanges, and the heads of the phalanges articulate with the bases of more distally located phalanges. http://www.youtube.com/yeditepeanatomy 2 Dr.Kaan Yücel http://yeditepeanatomy1.org Joints of the upper limb 1. JOINTS OF THE UPPER LIMB Joints of the pectoral girdle Proximal (Superior) and Distal (Inferior) radio- Acromioclavicular joint & Sternoclavicular joint ulnar joints Glenohumeral (Shoulder) joint Radiocarpal (Wrist) joint Elbow joint Intercarpal joints Carpometacarpal and intermetacarpal joints Figure 1. Joints of the upper limb http://home.comcast.net/~wnor/lesson5jointsofupperlimb.htm The three joints in the shoulder complex are the sternoclavicular, acromioclavicular, and glenohumeral joints. The sternoclavicular joint and the acromioclavicular joint link the two bones of the pectoral girdle to each other and to the trunk. The combined movements at these two joints enable the scapula to be positioned over a wide range on the thoracic wall, substantially increasing "reach" by the upper limb. The glenohumeral joint (shoulder joint) is the articulation between the humerus of the arm and the scapula. 3 http://twitter.com/yeditepeanatomy Dr.Kaan Yücel http://yeditepeanatomy1.org Joints of the upper limb STERNOCLAVICULAR JOINT 1. Articulation between Sternum and clavicle 2. Distinct feature of the joint the only articulation between the upper limb and the axial skeleton. It can be readily palpated because the sternal end of the clavicle lies superior to the manubrium of the sternum. 3. Synovial joint type Saddle type, but functions as a ball-and-socket joint 4. Articular disc Yes. The articular disc divides the sternoclavicular joint into two compartments. 5. Articular surfaces The sternoclavicular joint occurs between the sternal end of the clavicle and the clavicular notch of the manubrium of sternum together with a small part of the first costal cartilage. 6. Ligaments of the sternoclavicular joint The sternoclavicular joint is surrounded by a joint capsule and is reinforced by four ligaments: Anterior and posterior sternoclavicular ligaments Costoclavicular ligament Interclavicular ligament The anterior and posterior sternoclavicular ligaments are anterior and posterior, respectively, to the joint. The interclavicular ligament links the ends of the two clavicles to each other and to the superior surface of the manubrium of sternum. The costoclavicular ligament is positioned laterally to the joint and links the proximal end of the clavicle to the first rib and related costal cartilage. Anterior and posterior sternoclavicular ligaments reinforce the joint capsule anteriorly and posteriorly. The interclavicular ligament strengthens the capsule superiorly. The costoclavicular ligament anchors the inferior surface of the sternal end of the clavicle to the 1st rib and its costal cartilage, limiting elevation of the pectoral girdle. The strength of the sternoclavicular joint depends on ligaments and its articular disc. The disc is firmly attached to the anterior and posterior sternoclavicular ligaments, thickenings of the fibrous layer of the joint capsule, as well as the interclavicular ligament. The great strength of the sternoclavicular joint is a consequence of these attachments. Thus, although the articular disc serves as a shock absorber of forces transmitted along the clavicle from the upper limb, dislocation of the clavicle is rare, whereas fracture of the clavicle is common. 7. Movements of the sternoclavicular joint Raising (60°) & rotating the clavicle Anterior and posterior movements of the clavicle The sternoclavicular joint allows movement of the clavicle, predominantly in the anteroposterior and vertical planes, although some rotation also occurs. Although the sternoclavicular joint is extremely strong, it http://www.youtube.com/yeditepeanatomy 4 Dr.Kaan Yücel http://yeditepeanatomy1.org Joints of the upper limb is significantly mobile to allow movements of the pectoral girdle and upper limb. During full elevation of the limb, the clavicle is raised to approximately a 60° angle. When elevation is achieved via flexion, it is accompanied by rotation of the clavicle around its longitudinal axis. Figure 2. Sternoclavicular joint http://www.daviddarling.info/encyclopedia/S/sternoclavicular_joint.html CLINICAL ANATOMY Sternoclavicular Joint Injuries The strong costoclavicular ligament firmly holds the medial end of the clavicle to the first costal cartilage. Violent forces directed along the long axis of the clavicle usually result in fracture of that bone, but dislocation of the sternoclavicular joint takes place occasionally. If the costoclavicular ligament ruptures completely, it is difficult to maintain the normal position of the clavicle once reduction has been accomplished. ACROMIOCLAVICULAR JOINT 1. Articulation between Acromion of scapulae and clavicle 2. Distinct feature of the joint Located 2-3 cm from the “point” of the shoulder formed by the lateral part of the acromion 3. Synovial joint type Plane type 4. Articular disc Yes. The articular surfaces are separated by an incomplete wedge-shaped articular disc. 5. Articular surfaces The acromial end of the clavicle articulates with the acromion of the scapula. The articular surfaces, covered with fibrocartilage. 6. Ligaments of the acromioclavicular joint 5 http://twitter.com/yeditepeanatomy Dr.Kaan Yücel http://yeditepeanatomy1.org Joints of the upper limb Intrinsic ligament of the acromioclavicular joint Acromioclavicular ligament Extrinsic ligament of the acromioclavicular joint Coracoclavicular ligament- conoid ligament and trapezoid ligament The acromioclavicular ligament is a fibrous band extending from the acromion to the clavicle that strengthens the acromioclavicular joint superiorly. However, the integrity of the joint is maintained by extrinsic ligaments, distant from the joint itself. The much larger coracoclavicular ligament is a strong pair of bands that unite the coracoid process of the scapula to the clavicle, anchoring the clavicle to the coracoid process. The coracoclavicular ligament is not directly related to the joint. However,it is an important strong accessory ligament, providing much of the weightbearing support for the upper limb on the clavicle. It maintains the position of the clavicle on the acromion. It spans the distance between the coracoid process of the scapula and the inferior surface of the acromial end of the clavicle. The coracoclavicular ligament consists of two ligaments, the conoid and trapezoid ligaments, which are often separated by a bursa. The vertical conoid ligament is an inverted triangle (cone), is attached to the root of the coracoid process. Its wide attachment (base of the triangle) is to the conoid tubercle on the inferior surface of the clavicle. The nearly horizontal trapezoid ligament is attached to the superior surface of the coracoid process and extends laterally to the trapezoid line on the inferior surface of the clavicle. In addition to augmenting the acromioclavicular joint, the coracoclavicular ligament provides the means by which the scapula and free limb are (passively) suspended from the clavicular strut. 7. Movements of the acromioclavicular joint The acromioclavicular joint allows movement in the anteroposterior and vertical planes together with some axial rotation. The acromion of the scapula rotates on the acromial end of the clavicle. These movements are associated with motion at the physiological scapulothoracic joint. http://www.youtube.com/yeditepeanatomy 6 Dr.Kaan Yücel http://yeditepeanatomy1.org Joints of the upper limb Figure 3. Acromioclavicular joint http://www.rahulgladwin.com/medimages/index.php?level=picture&id=96 CLINICAL ANATOMY Acromioclavicular Joint Dislocation A severe blow on the point of the shoulder, as is incurred during blocking or tackling in football or any severe fall, can result in the acromion being thrust beneath the lateral end of the clavicle, tearing the coracoclavicular ligament. This condition is known as shoulder separation. The displaced outer end of the clavicle is easily palpable. GLENOHUMERAL (SHOULDER) JOINT - ARTICULATIO HUMERI 1. Articulation between Humerus and scapula 2. Distinct feature of the joint Ball-and-socket type of synovial joint that permits a wide range of movement; however, its mobility makes the joint relatively unstable. The glenohumeral joint has more freedom of movement than any other joint in the body. 3. Synovial joint type Ball-and-socket type 4. Articular disc No. 5. Articular surfaces The large, round humeral head articulates with the relatively shallow glenoid cavity of the scapula, which is deepened slightly but effectively by the ring-like, fibrocartilaginous glenoid labrum (L., lip). Both articular surfaces are covered with hyaline cartilage. The glenoid cavity accepts little more than a third of the humeral head, which is held in the cavity by the tonus of the musculotendinous rotator cuff muscles. 7 http://twitter.com/yeditepeanatomy Dr.Kaan Yücel http://yeditepeanatomy1.org Joints of the upper limb 6. Ligaments of the glenohumeral joint Glenohumeral ligaments Coracohumeral ligament Transverse humeral ligament Coracoacromial ligament The fibrous membrane of the joint capsule is thickened: Glenohumeral ligaments three fibrous bands, evident only on the internal aspect of the capsule anterosuperiorly in three locations to form superior, middle, and inferior glenohumeral ligaments pass from the superomedial margin of the glenoid cavity to the lesser tubercle and inferiorly related anatomical neck of the humerus. strengthen the anterior aspect of the joint capsule of the joint. Coracohumeral ligament strong broad band passes from the base of the coracoid process to the anterior aspect of the greater tubercle of the humerus. strengthens the capsule superiorly. Transverse humeral ligament a broad fibrous band between the greater and lesser tubercles of the humerus, bridging over the intertubercular sulcus converts the groove into a canal, which holds the synovial sheath and tendon of the biceps brachii in place during movements of the glenohumeral joint. The coraco-acromial arch is an extrinsic, protective structure formed by the smooth inferior aspect of the acromion and the coracoid process of the scapula, with the coracoacromial ligament spanning between them. This osseoligamentous structure forms a protective arch that overlies the humeral head, preventing its superior displacement from the glenoid cavity. The coraco-acromial arch is so strong that a forceful superior thrust of the humerus will not fracture it; the humeral shaft or clavicle fractures first. Transmitting force superiorly along the humerus (e.g., when standing at a desk and partly supporting the body with the outstretched limbs), the humeral head presses against the coraco-acromial arch. Joint stability is provided by surrounding muscle tendons and a skeletal arch formed superiorly by the coracoid process and acromion and the coracoacromial ligament. 7. Movements of the glenohumeral joint http://www.youtube.com/yeditepeanatomy 8 Dr.Kaan Yücel http://yeditepeanatomy1.org Joints of the upper limb Flexion of the humerus Extension of the humerus Abduction of the humerus Adduction of the humerus Medial and lateral rotation of the humerus Circumduction The 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. The glenohumeral joint allows movements around three axes and permits flexion-extension, abduction-adduction, rotation (medial and lateral) of the humerus, and circumduction. Lateral rotation of the humerus increases the range of abduction. When the arm is abducted without rotation, available articular surface is exhausted and the greater tubercle contacts the coraco-acromial arch, preventing further abduction. If the arm is then laterally rotated 180°, the tubercles are rotated posteriorly and more articular surface becomes available to continue elevation. Circumduction at the glenohumeral joint is an orderly sequence of flexion, abduction, extension, and adduction—or the reverse. Unless performed over a small range, these movements do not occur at the glenohumeral joint in isolation; they are accompanied by movements at the two other joints of the pectoral girdle (sternoclavicular and acromioclavicular joints). 8. Bursae around the glenohumeral joint Several bursae (sac-like cavities), containing capillary films of synovial fluid secreted by the synovial membrane, are situated near the glenohumeral joint. Bursae are located where tendons rub against bone, ligaments, or other tendons and where skin moves over a bony prominence. The bursae around the glenohumeral joint are of special clinical importance because some of them communicate with the joint cavity (e.g., the subscapular bursa). Consequently, opening a bursa may mean entering the cavity of the glenohumeral joint. Subscapular Bursa: is located between the tendon of the subscapularis and the neck of the scapula. The bursa protects the tendon where it passes inferior to the root of the coracoid process and over the neck of the scapula. Subacromial Bursa (Subdeltoid bursa): is located between the acromion, coraco-acromial ligament, superiorly and joint capsule of the glenohumeral joint inferiorly. 9 http://twitter.com/yeditepeanatomy Dr.Kaan Yücel http://yeditepeanatomy1.org Joints of the upper limb Figure 4. Glenohumeral (shoulder) joint Figure 5. Bursae around the shoulder joint http://aftabphysio.blogspot.com/2010/08/joints-of-upper-limb.html http://www.shoulderdoc.co.uk/patient_info/shoulder-anatomy.asp CLINICAL ANATOMY Dislocations of the Shoulder Joint Anterior–Inferior Dislocations Sudden violence applied to the humerus with the joint fully abducted tilts the humeral head downward onto the inferior weak part of the capsule, which tears, and the humeral head comes to lie inferior to the glenoid fossa. Posterior Dislocations Posterior dislocations are rare and are usually caused by direct violence to the front of the joint. On inspection of the patient with shoulder dislocation, the rounded appearance of the shoulder is seen to be lost because the greater tuberosity of the humerus is no longer bulging laterally beneath the deltoid muscle. ARTICULATIO CUBITI ELBOW JOINT . 1. Articulation between Humerus, ulna and radius 2. Distinct feature of the joint Located 2-3 cm inferior to the epicondyles of the humerus 3. Synovial joint type Hinge type 4. Articular disc No. 5. Articular surfaces The elbow joint is a complex joint involving three separate articulations, which share a common synovial cavity. The joints between the trochlear notch of the ulna and the trochlea of the humerus and between the head of the radius and the capitulum of the humerus are primarily involved with hinge-like flexion and extension of the forearm on the arm and, together, are the principal articulations of the elbow joint. http://www.youtube.com/yeditepeanatomy 10 Dr.Kaan Yücel http://yeditepeanatomy1.org Joints of the upper limb The joint between the head of the radius and the radial notch of the ulna, the proximal radio-ulnar joint, is involved with pronation and supination of the forearm. The articular surfaces of the bones are covered with hyaline cartilage. The synovial membrane is separated from the fibrous membrane of the joint capsule by pads of fat in regions overlying the coronoid fossa, the olecranon fossa, and the radial fossa. These fat pads accommodate the related bony processes during extension and flexion of the elbow. 6. Joint capsule of elbow joint The fibrous layer of the joint capsule surrounds the elbow joint. The joint capsule is weak anteriorly and posteriorly but is strengthened on each side by collateral ligaments. These ligament support the flexion and extension movements of the elbow joint. In addition, the external surface of the joint capsule is reinforced laterally where it cuffs the head of the radius with a strong anular ligament of radius. Although this ligament blends with the fibrous membrane of the joint capsule in most regions, they are separate posteriorly. The anular ligament of radius also blends with the radial collateral ligament 7. Ligaments of the elbow joint Medial (ulnar) and lateral (radial) collateral ligaments The collateral ligaments of the elbow joint are strong triangular bands that are medial and lateral thickenings of the fibrous layer of the joint capsule. The lateral, fan-like radial collateral ligament extends from the lateral epicondyle of the humerus and blends distally with the anular ligament of the radius, which encircles and holds the head of the radius in the radial notch of the ulna. The anular ligament forms the proximal radio-ulnar joint and permits pronation and supination of the forearm. The medial, triangular ulnar collateral ligament extends from the medial epicondyle of the humerus to the coronoid process and olecranon of the ulna and consists of three bands: (1) the anterior cord-like band is the strongest, (2) the posterior fan-like band is the weakest, and (3) the slender oblique band deepens the socket for the trochlea of the humerus. The anular ligament of radius and related joint capsule allow the radial head to slide against the radial notch of the ulna and pivot on the capitulum during pronation and supination of the forearm. 8. Movements of the elbow joint Flexion and extension Flexion and extension occur at the elbow joint. The long axis of the fully extended ulna makes an angle of approximately 170° with the long axis of the humerus. This angle is called the carrying angle, named for the 11 http://twitter.com/yeditepeanatomy Dr.Kaan Yücel http://yeditepeanatomy1.org Joints of the upper limb way the forearm angles away from the body when something is carried. The obliquity of the ulna and thus of the carrying angle is more pronounced (the angle is approximately 10° more acute) in women than in men. It is said to enable the swinging limbs to clear the wide female pelvis when walking. In the anatomical position, the elbow is against the waist. 9. Bursae of the elbow joint Only some of the bursae around the elbow joint are clinically important. The three olecranon bursae are the: •Intratendinous olecranon bursa, which is sometimes present in the tendon of triceps brachii. •Subtendinous olecranon bursa, which is located between the olecranon and the triceps tendon, just proximal to its attachment to the olecranon. •Subcutaneous olecranon bursa, which is located in the subcutaneous connective tissue over the olecranon. Figure 6. Elbow joint http://www.aaos75th.org/stories/patient_story.htm?id=11 Figure 7. Bursae around the elbow joint http://www.joint-pain-expert.net/olecranon-bursitis.html http://www.youtube.com/yeditepeanatomy 12 Dr.Kaan Yücel http://yeditepeanatomy1.org Joints of the upper limb CLINICAL ANATOMY Stability of the Elbow Joint The elbow joint is stable because of the wrench-shaped articular surface of the olecranon and the pulley-shaped trochlea of the humerus; it also has strong medial and lateral ligaments. When examining the elbow joint, the physician must remember the normal relations of the bony points. In extension, the medial and lateral epicondyles and the top of the olecranon are in a straight line; in flexion, the bony points form the boundaries of an equilateral triangle. Dislocations of the Elbow Joint Elbow dislocations are common, and most are posterior. Posterior dislocation usually follows falling on the outstretched hand. Posterior dislocations of the joint are common in children because the parts of the bones that stabilize the joint are incompletely developed. Avulsion of the epiphysis of the medial epicondyle is also common in childhood because then the medial ligament is much stronger than the bond of union between the epiphysis and the diaphysis. PROXIMAL(SUPERIOR) RADIO-ULNAR JOINT 1. Articulation between Radius and ulna proximally 2. Distinct feature of the joint 3. Synovial joint type Pivot type 4. Articular disc No. 5. Articular surfaces The head of the radius articulates with the radial notch of the ulna. 6. Ligaments of the proximal radio-ulnar joint Annular ligament The radial head is held in position by the anular ligament of the radius. The strong anular ligament is attached to the ulna anterior and posterior to its radial notch. It surrounds the articulating bony surfaces and forms a collar that, with the radial notch, creates a ring that completely encircles the head of the radius. 7. Movements of the proximal radio-ulnar joint Supination & pronation The proximal (superior) radio-ulnar joint is a pivot type of synovial joint that allows movement of the head of the radius on the ulna. 13 http://twitter.com/yeditepeanatomy Dr.Kaan Yücel http://yeditepeanatomy1.org Joints of the upper limb During pronation and supination, it is the radius that rotates; its head rotates within the cup-shaped collar formed by the anular ligament and the radial notch on the ulna. Distally, the end of the radius rotates around the head of the ulna. Almost always, supination and pronation are accompanied by synergistic movements of the glenohumeral and elbow joints that produce simultaneous movement of the ulna, except when the elbow is flexed. Figures 8 & 9. Proximal radio-ulnar joint http://teachmeanatomy.net/upper-limb-2/joints-of-the-upper-limb/radioulnar-joints http://www.msdlatinamerica.com/ebooks/HandSurgery/sid484870.html DISTAL (INFERIOR) RADIO-ULNAR JOINT 1. Articulation between Radius and ulna distally 2. Distinct feature of the joint 3. Synovial joint type Pivot type 4. Articular disc Yes. A fibrocartilaginous, triangular articular disc of the distal radioulnar joint (sometimes referred to by clinicians as the “triangular ligament”) binds the ends of the ulna and radius together and is the main uniting structure of the joint. The articular disc separates the cavity of the distal radio-ulnar joint from the cavity of the wrist joint. 5. Articular surfaces The rounded head of the ulna articulates with the ulnar notch on the medial side of the distal end of the radius. 6. Ligaments of the distal radio-ulnar joint Anterior and posterior ligaments Anterior and posterior ligaments strengthen the fibrous layer of the joint capsule of the distal radio-ulnar joint. These relatively weak transverse bands extend from the radius to the ulna across the anterior and posterior surfaces of the joint. 7. Movements of the distal radio-ulnar joint http://www.youtube.com/yeditepeanatomy 14 Dr.Kaan Yücel http://yeditepeanatomy1.org Joints of the upper limb The radius moves around the relatively fixed distal end of the ulna. The distal radio-ulnar joint allows the distal end of the radius to move anteromedially over the ulna. During pronation of the forearm and hand, the distal end of the radius moves (rotates) anteriorly and medially, crossing over the ulna anteriorly. During supination, the radius uncrosses from the ulna, its distal end moving (rotating) laterally and posteriorly so the bones become parallel. Figure 10. Distal radio-ulnar joint http://en.wikipedia.org/wiki/File:Gray334.png CLINICAL ANATOMY Radioulnar Joint Disease The proximal radioulnar joint communicates with the elbow joint, whereas the distal radioulnar joint does not communicate with the wrist joint. In practical terms, this means that infection of the elbow joint invariably involves the proximal radioulnar joint. The strength of the proximal radioulnar joint depends on the integrity of the strong anular ligament. Rupture of this ligament occurs in cases of anterior dislocation of the head of the radius on the capitulum of the humerus. In young children, in whom the head of the radius is still small and undeveloped, a sudden jerk on the arm can pull the radial head down through the anular ligament. 15 http://twitter.com/yeditepeanatomy Dr.Kaan Yücel http://yeditepeanatomy1.org Joints of the upper limb WRIST JOINT (RADIOCARPAL JOINT) 1. Articulation between Radius and carpal bones 2. Distinct feature of the joint 3. Synovial joint type Condyloid (ellipsoid) type 4. Articular disc Yes. 5. Articular surfaces The wrist (carpus), the proximal segment of the hand, is a complex of eight carpal bones, articulating proximally with the forearm via the wrist joint and distally with the five metacarpals. The ulna does not participate in the wrist joint. The distal end of the radius and the articular disc of the distal radio-ulnar joint articulate with the proximal row of carpal bones, except for the pisiform. 6. Ligaments of the wrist joint Dorsal and palmar radiocarpal ligaments Ulnar collateral ligament Radial collateral ligament The fibrous layer of the joint capsule is strengthened by strong dorsal and palmar radiocarpal ligaments. The palmar radiocarpal ligaments pass from the radius to the two rows of carpals. They are strong and directed so that the hand follows the radius during supination of the forearm. The dorsal radiocarpal ligaments take the same direction so that the hand follows the radius during pronation of the forearm. The joint capsule is also strengthened medially by the ulnar collateral ligament, which is attached to the ulnar styloid process and triquetrum. The joint capsule is also strengthened laterally by the radial collateral ligament, which is attached to the radial styloid process and scaphoid. 7. Movements of the wrist joint Flexion Extension Abduction (Radial deviation) Adduction (Ulnar deviation) Circumduction The movements at the wrist joint may be augmented by additional smaller movements at the intercarpal and midcarpal joints. The movements are flexion—extension, abduction—adduction (radial deviation-ulnar deviation), and circumduction. The hand can be flexed on the forearm more than it can be extended; these movements are accompanied (actually, are initiated) by similar movements at the midcarpal joint between the proximal and the distal rows of carpal bones. Adduction of the hand is greater than abduction. Most adduction occurs at the wrist joint. Abduction from the neutral position occurs at the http://www.youtube.com/yeditepeanatomy 16 Dr.Kaan Yücel http://yeditepeanatomy1.org Joints of the upper limb midcarpal joint. Circumduction of the hand consists of successive flexion, adduction, extension, and abduction. 8. Surface anatomy of the wrist joint The position of the joint is indicated approximately by a line joining the styloid processes of the radius and ulna, or by the proximal wrist crease. Figure 11. Wrist (Radiocarpal) joint http://teachmeanatomy.net/upper-limb-2/joints-of-the-upper-limb/wrist-joint CLINICAL ANATOMY Wrist Joint Injuries A fall on the outstretched hand can strain the anterior ligament of the wrist joint, producing synovial effusion, joint pain, and limitation of movement. These symptoms and signs must not be confused with those produced by a fractured scaphoid or dislocation of the lunate bone, which are similar. Falls on the Outstretched Hand In falls on the outstretched hand, forces are transmitted from the scaphoid to the distal end of the radius, from the radius across the interosseous membrane to the ulna, and from the ulna to the humerus; thence, through the glenoid fossa of the scapula to the coracoclavicular ligament and the clavicle, and finally, to the sternum. If the forces are excessive, different parts of the upper limb give way under the strain. The area affected seems to be related to age. In a young child, for example, there may be a posterior displacement of the distal radial epiphysis; in the teenager the clavicle might fracture; in the young adult the scaphoid is commonly fractured; and in the elderly the distal end of the radius is fractured about 1 in. (2..5 cm) proximal to the wrist joint (Colles’ fracture). INTERCARPAL JOINTS 1. Articulation between carpal bones (the intercarpal joints interconnect the carpal bones) 17 http://twitter.com/yeditepeanatomy Dr.Kaan Yücel http://yeditepeanatomy1.org Joints of the upper limb 2. Distinct feature of the joint 3. Synovial joint type Plane type 4. Articular disc No. 5. Articular surfaces Joints between the carpal bones of the proximal row. Joints between the carpal bones of the distal row. The midcarpal joint, a complex joint between the proximal and distal rows of carpal bones. The pisotriquetral joint, formed from the articulation of the pisiform with the palmar surface of the triquetrum. 6. Ligaments of the intercarpal joints Anterior, posterior, and interosseous ligaments 7. Movements of the intercarpal joints Gliding Flexion & extension of the hand Abduction & adduction of the hand The gliding movements possible between the carpals occur concomitantly with movements at the wrist joint, augmenting them and increasing the overall range of movement. Flexion and extension of the hand are actually initiated at the midcarpal joint, between the proximal and the distal rows of carpals. Most flexion and adduction occur mainly at the wrist joint, whereas extension and abduction occur primarily at the midcarpal joint. Movements at the other intercarpal joints are small, with the proximal row being more mobile than the distal row. CARPOMETACARPAL & INTERMETACARPAL JOINTS 1. Articulation between carpal bones & metacarpals, between metacarpals 2. Distinct feature of the joint 3. Synovial joint type Plane type plane except for the carpometacarpal joint of the thumb, which is a saddle joint. 4. Articular disc No. 5. Articular surfaces The distal surfaces of the carpals of the distal row articulate with the carpal surfaces of the bases of the metacarpals at the carpometacarpal joints. The important carpometacarpal joint of the thumb is between the trapezium and the base of the 1st metacarpal; it has a separate articular cavity. Like the carpals, adjacent metacarpals articulate with each other; intermetacarpal joints occur between the radial and ulnar aspects of the bases of the metacarpals. http://www.youtube.com/yeditepeanatomy 18 Dr.Kaan Yücel http://yeditepeanatomy1.org Joints of the upper limb 6. Ligaments of the carpometacarpal and intermetacarpal joints Palmar and dorsal carpometacarpal and palmar and dorsal intermetacarpal ligaments Interosseus metacarpal ligaments Superficial and deep transverse metacarpal ligaments The bones are united in the region of the joints by palmar and dorsal carpometacarpal and palmar and dorsal intermetacarpal ligaments and by interosseous intermetacarpal ligaments. In addition, the superficial and deep transverse metacarpal ligaments (the former part of the palmar aponeurosis), associated with the distal ends of the metacarpals, play a role in limiting movement at these two joints as they limit separation of the metacarpal heads. 7. Movements of the carpometacarpal and intermetacarpal joints The carpometacarpal joint of the thumb permits angular movements in any plane (flexion-extension, abduction-adduction, or circumduction) and a restricted amount of axial rotation. Most important, the movement essential to opposition of the thumb occurs here. Almost no movement occurs at the carpometacarpal joints of the 2nd and 3rd digits, that of the 4th digit is slightly mobile, and that of the 5th digit is moderately mobile, flexing and rotating slightly during a tight grasp. When the palm of the hand is “cupped” (as during pad-to-pad opposition of thumb and little finger), two thirds of the movement occur at the carpometacarpal joint of the thumb, and one third occurs at the carpometacarpal and intercarpal joints of the 4th and 5th fingers. METACARPOPHALANGEAL & INTERPHALANGEAL JOINTS 1. Articulation between metacarpals and phalanges and between phalanges 2. Distinct feature of the joint 3. Synovial joint type The metacarpophalangeal joints are the condyloid type of synovial joint that permit movement in two planes: flexion-extension and adduction-abduction. The interphalangeal joints are the hinge type of synovial joint that permit flexion-extension only. 4. Articular disc No. 5. Articular surfaces The heads of the metacarpals articulate with the bases of the proximal phalanges in the metacarpophalangeal (MP) joints, and the heads of the phalanges articulate with the bases of more distally located phalanges in the interphalangeal (IP) joints. 6. Ligaments of the carpometacarpal and intermetacarpal joints Medial and lateral collateral ligaments 19 http://twitter.com/yeditepeanatomy Dr.Kaan Yücel http://yeditepeanatomy1.org Joints of the upper limb Palmar ligaments The fibrous layer of each MC and IP joint capsule is strengthened by two (medial and lateral) collateral ligaments. These ligaments have two parts: • Denser cord-like parts pass distally from the heads of the metacarpals and phalanges to the bases of the phalanges. • Thinner fan-like parts pass anteriorly to attach to thick, densely fibrous or fibrocartilaginous plates, the palmar ligaments (plates), which form the palmar aspect of the joint capsule. The fan-like parts of the collateral ligaments cause the palmar ligaments to move like a visor over the underlying metacarpal or phalangeal heads. The palmar ligaments of the 2nd-5th MP joints are united by deep transverse metacarpal ligaments that hold the heads of the metacarpals together. 7. Movements of the carpometacarpal and intermetacarpal joints Flexion-extension, abduction-adduction, and circumduction of the 2nd-5th digits occur at the 2nd-5th MP joints. Movement at the MP joint of the thumb is limited to flexion-extension. Only flexion and extension occur at the IP joints. http://www.youtube.com/yeditepeanatomy 20