Anatomy_Gray

Anatomy_Gray. The second palmar interosseous muscle originates from the medial surface of metacarpal II and inserts into the medial side of the extensor hood of the index finger. The third and fourth palmar interossei originate from the lateral surfaces of metacarpals IV and V and insert into the lateral sides of the respective extensor hoods. Like the tendons of the dorsal interossei, the tendons of the palmar interossei pass dorsal to the deep transverse metacarpal ligaments. The palmar interossei adduct the thumb, index, ring, and little fingers with respect to a long axis through the middle finger. The movements occur at the metacarpophalangeal joints. Because the muscles insert into the extensor hoods, they also produce complex flexion and extension movements of the digits (Table 7.15).


Anatomy_Gray

Anatomy_Gray. The adductor pollicis is a large triangular muscle anterior to the plane of the interossei that crosses the palm (Fig. 7.106). It originates as two heads: a transverse head from the anterior aspect of the shaft of metacarpal III, and an oblique head, from the capitate and adjacent bases of metacarpals II and III. The two heads converge laterally to form a tendon, which often contains a sesamoid bone, that inserts into both the medial side of the base of the proximal phalanx of the thumb and into the extensor hood. The radial artery passes anteriorly and medially between the two heads of the muscle to enter the deep plane of the palm and form the deep palmar arch. The adductor pollicis is a powerful adductor of the thumb and opposes the thumb to the rest of the digits in gripping (Table 7.15).


Anatomy_Gray

Anatomy_Gray. The adductor pollicis is a powerful adductor of the thumb and opposes the thumb to the rest of the digits in gripping (Table 7.15). The three thenar muscles (the opponens pollicis, flexor pollicis brevis, and abductor pollicis brevis muscles) are associated with opposition of the thumb to the fingers and with delicate movements of the thumb (Fig. 7.107) and are responsible for the prominent swelling (thenar eminence) on the lateral side of the palm at the base of the thumb. The thenar muscles are innervated by the recurrent branch of the median nerve. The opponens pollicis muscle is the largest of the thenar muscles and lies deep to the other two (Fig. 7.107). Originating from the tubercle of the trapezium and the adjacent flexor retinaculum, it inserts along the entire length of the lateral margin and adjacent lateral palmar surface of metacarpal I. The opponens pollicis rotates and flexes metacarpal


Anatomy_Gray

Anatomy_Gray. The opponens pollicis rotates and flexes metacarpal I on the trapezium, so bringing the pad of the thumb into a position facing the pads of the fingers (Table 7.15). The abductor pollicis brevis muscle overlies the opponens pollicis and is proximal to the flexor pollicis brevis muscle (Fig. 7.107). It originates from the tubercles of the scaphoid and trapezium and from the adjacent flexor retinaculum, and inserts into the lateral side of the base of the proximal phalanx of the thumb and into the extensor hood. The abductor pollicis brevis abducts the thumb, principally at the metacarpophalangeal joint. Its action is most apparent when the thumb is maximally abducted and the proximal phalanx is moved out of line with the long axis of the metacarpal bone (Table 7.15).


Anatomy_Gray

Anatomy_Gray. The flexor pollicis brevis muscle is distal to the abductor pollicis brevis (Fig. 7.107). It originates mainly from the tubercle of the trapezium and adjacent flexor retinaculum, but it may also have deeper attachments to other carpal bones and associated ligaments. It inserts into the lateral side of the base of the proximal phalanx of the thumb. The tendon often contains a sesamoid bone. The flexor pollicis brevis flexes the metacarpophalangeal joint of the thumb (Table 7.15). The hypothenar muscles (the opponens digiti minimi, abductor digiti minimi, and flexor digiti minimi brevis) contribute to the swelling (hypothenar eminence) on the medial side of the palm at the base of the little finger (Fig. 7.107). The hypothenar muscles are similar to the thenar muscles in name and in organization. Unlike the thenar muscles, the hypothenar muscles are innervated by the deep branch of the ulnar nerve and not by the recurrent branch of the median nerve.


Anatomy_Gray

Anatomy_Gray. Unlike the thenar muscles, the hypothenar muscles are innervated by the deep branch of the ulnar nerve and not by the recurrent branch of the median nerve. The opponens digiti minimi muscle lies deep to the other two hypothenar muscles (Fig. 7.107). It originates from the hook of the hamate and from the adjacent flexor retinaculum and it inserts into the medial margin and palmar surface of metacarpal V. Its base is penetrated by the deep branches of the ulnar nerve and ulnar artery. The opponens digiti minimi rotates metacarpal V toward the palm; however, because of the simple shape of the carpometacarpal joint and the presence of a deep transverse metacarpal ligament, which attaches the head of metacarpal V to that of the ring finger, the movement is much less dramatic than that of the thumb (Table 7.15).


Anatomy_Gray

Anatomy_Gray. The abductor digiti minimi muscle overlies the opponens digiti minimi (Fig. 7.107). It originates from the pisiform bone, the pisohamate ligament, and the tendon of the flexor carpi ulnaris, and inserts into the medial side of the base of the proximal phalanx of the little finger and into the extensor hood. The abductor digiti minimi is the principal abductor of the little finger (Table 7.15). The flexor digiti minimi brevis muscle is lateral to the abductor digiti minimi (Fig. 7.107). It originates from the hook of the hamate bone and the adjacent flexor retinaculum and inserts with the abductor digiti minimi muscle into the medial side of the base of the proximal phalanx of the little finger. The flexor digiti minimi brevis flexes the metacarpophalangeal joint. There are four lumbrical (worm-like) muscles, each of which is associated with one of the fingers. The muscles originate from the tendons of the flexor digitorum profundus in the palm:


Anatomy_Gray

Anatomy_Gray. There are four lumbrical (worm-like) muscles, each of which is associated with one of the fingers. The muscles originate from the tendons of the flexor digitorum profundus in the palm: The medial two lumbricals are bipennate and originate from the flexor digitorum profundus tendons associated with the middle and ring fingers and the ring and little fingers, respectively. The lateral two lumbricals are unipennate muscles, originating from the flexor digitorum profundus tendons associated with the index and middle fingers, respectively. The lumbricals pass dorsally around the lateral side of each finger, and insert into the extensor hood (Fig. 7.108). The tendons of the muscles are anterior to the deep transverse metacarpal ligaments. The lumbricals are unique because they link flexor tendons with extensor tendons. Through their insertion into the extensor hoods, they participate in flexing the metacarpophalangeal joints and extending the interphalangeal joints.


Anatomy_Gray

Anatomy_Gray. The medial two lumbricals are innervated by the deep branch of the ulnar nerve; the lateral two lumbricals are innervated by digital branches of the median nerve (Table 7.15). The blood supply to the hand is by the radial and ulnar arteries, which form two interconnected vascular arches (superficial and deep) in the palm (Fig. 7.109). Vessels to the digits, muscles, and joints originate from the two arches and the parent arteries: The radial artery contributes substantially to the supply of the thumb and the lateral side of the index finger. The remaining digits and the medial side of the index finger are supplied mainly by the ulnar artery.


Anatomy_Gray

Anatomy_Gray. The remaining digits and the medial side of the index finger are supplied mainly by the ulnar artery. The ulnar artery and ulnar nerve enter the hand on the medial side of the wrist (Fig. 7.110). The vessel lies between the palmaris brevis and the flexor retinaculum and is lateral to the ulnar nerve and the pisiform bone. Distally, the ulnar artery is medial to the hook of the hamate bone and then swings laterally across the palm, forming the superficial palmar arch, which is superficial to the long flexor tendons of the digits and just deep to the palmar aponeurosis. On the lateral side of the palm, the arch communicates with a palmar branch of the radial artery.


Anatomy_Gray

Anatomy_Gray. One branch of the ulnar artery in the hand is the deep palmar branch (Figs. 7.109 and 7.110), which arises from the medial aspect of the ulnar artery, just distal to the pisiform, and penetrates the origin of the hypothenar muscles. It curves medially around the hook of the hamate to access the deep plane of the palm and to anastomose with the deep palmar arch derived from the radial artery. Branches from the superficial palmar arch include: a palmar digital artery to the medial side of the little finger, and three large, common palmar digital arteries, which ultimately provide the principal blood supply to the lateral side of the little finger, both sides of the ring and middle fingers, and the medial side of the index finger (Fig. 7.110); they are joined by palmar metacarpal arteries from the deep palmar arch before bifurcating into the proper palmar digital arteries, which enter the fingers.


Anatomy_Gray

Anatomy_Gray. The radial artery curves around the lateral side of the wrist and passes over the floor of the anatomical snuffbox and into the deep plane of the palm by penetrating anteriorly through the back of the hand (Figs. 7.109 and 7.111). It passes between the two heads of the first dorsal interosseous muscle and then between the two heads of the adductor pollicis to access the deep plane of the palm and form the deep palmar arch. The deep palmar arch passes medially through the palm between the metacarpal bones and the long flexor tendons of the digits. On the medial side of the palm, it communicates with the deep palmar branch of the ulnar artery (Figs. 7.109 and 7.111).


Anatomy_Gray

Anatomy_Gray. Before penetrating the back of the hand, the radial artery gives rise to two vessels: a dorsal carpal branch, which passes medially as the dorsal carpal arch, across the wrist and gives rise to three dorsal metacarpal arteries, which subsequently divide to become small dorsal digital arteries, which enter the fingers; and the first dorsal metacarpal artery, which supplies adjacent sides of the index finger and thumb. Two vessels, the princeps pollicis artery and the radialis indicis artery, arise from the radial artery in the plane between the first dorsal interosseous and adductor pollicis. The princeps pollicis artery is the major blood supply to the thumb, and the radialis indicis artery supplies the lateral side of the index finger.


Anatomy_Gray

Anatomy_Gray. The deep palmar arch gives rise to: three palmar metacarpal arteries, which join the common palmar digital arteries from the superficial palmar arch; and three perforating branches, which pass posteriorly between the heads of origin of the dorsal interossei to anastomose with the dorsal metacarpal arteries from the dorsal carpal arch. As generally found in the upper limb, the hand contains interconnected networks of deep and superficial veins. The deep veins follow the arteries; the superficial veins drain into a dorsal venous network on the back of the hand over the metacarpal bones (Fig. 7.112). The cephalic vein originates from the lateral side of the dorsal venous network and passes over the anatomical snuffbox into the forearm. The basilic vein originates from the medial side of the dorsal venous network and passes into the dorsomedial aspect of the forearm.


Anatomy_Gray

Anatomy_Gray. The basilic vein originates from the medial side of the dorsal venous network and passes into the dorsomedial aspect of the forearm. The hand is supplied by the ulnar, median, and radial nerves (Figs. 7.113 to 7.115). All three nerves contribute to cutaneous or general sensory innervation. The ulnar nerve innervates all intrinsic muscles of the hand except for the three thenar muscles and the two lateral lumbricals, which are innervated by the median nerve. The radial nerve only innervates skin on the dorsolateral side of the hand. The ulnar nerve enters the hand lateral to the pisiform and posteromedially to the ulnar artery (Fig. 7.113). Immediately distal to the pisiform, it divides into a deep branch, which is mainly motor, and a superficial branch, which is mainly sensory.


Anatomy_Gray

Anatomy_Gray. The deep branch of the ulnar nerve passes with the deep branch of the ulnar artery (Fig. 7.113). It penetrates and supplies the hypothenar muscles to reach the deep aspect of the palm, arches laterally across the palm, deep to the long flexors of the digits, and supplies the interossei, the adductor pollicis, and the two medial lumbricals. In addition, the deep branch of the ulnar nerve contributes small articular branches to the wrist joint. As the deep branch of the ulnar nerve passes across the palm, it lies in a fibro-osseous tunnel (Guyon’s canal) between the hook of the hamate and the flexor tendons. Occasionally, small outpouchings of synovial membrane (ganglia) from the joints of the carpus compress the nerve within this canal, producing sensory and motor symptoms.


Anatomy_Gray

Anatomy_Gray. The superficial branch of the ulnar nerve innervates the palmaris brevis muscle and continues across the palm to supply skin on the palmar surface of the little finger and the medial half of the ring finger (Fig. 7.113). The median nerve is the most important sensory nerve in the hand because it innervates skin on the thumb, index and middle fingers, and lateral side of the ring finger (Fig. 7.115). The nervous system, using touch, gathers information about the environment from this area, particularly from the skin on the thumb and index finger. In addition, sensory information from the lateral three and one-half digits enables the fingers to be positioned with the appropriate amount of force when using precision grip. The median nerve also innervates the thenar muscles that are responsible for opposition of the thumb to the other digits.


Anatomy_Gray

Anatomy_Gray. The median nerve also innervates the thenar muscles that are responsible for opposition of the thumb to the other digits. The median nerve enters the hand by passing through the carpal tunnel and divides into a recurrent branch and palmar digital branches (Fig. 7.115). The recurrent branch of the median nerve innervates the three thenar muscles. Originating from the lateral side of the median nerve near the distal margin of the flexor retinaculum, it curves around the margin of the retinaculum and passes proximally over the flexor pollicis brevis muscle. The recurrent branch then passes between the flexor pollicis brevis and abductor pollicis brevis to end in the opponens pollicis.


Anatomy_Gray

Anatomy_Gray. The palmar digital nerves cross the palm deep to the palmar aponeurosis and the superficial palmar arch and enter the digits. They innervate skin on the palmar surfaces of the lateral three and one-half digits and cutaneous regions over the dorsal aspects of the distal phalanges (nail beds) of the same digits. In addition to skin, the digital nerves supply the lateral two lumbrical muscles. Superficial branch of the radial nerve The only part of the radial nerve that enters the hand is the superficial branch (Fig. 7.116). It enters the hand by passing over the anatomical snuffbox on the dorsolateral side of the wrist. Terminal branches of the nerve can be palpated or “rolled” against the tendon of the extensor pollicis longus as they cross the anatomical snuffbox.


Anatomy_Gray

Anatomy_Gray. The superficial branch of the radial nerve innervates skin over the dorsolateral aspect of the palm and the dorsal aspects of the lateral three and one-half digits distally to approximately the terminal interphalangeal joints. Tendons, muscles, and bony landmarks in the upper limb are used to locate major arteries, veins, and nerves. Asking patients to maneuver their upper limbs in specific ways is essential for performing neurological examinations. Tendons are used to test reflexes associated with specific spinal cord segments. Vessels are used clinically as points of entry into the vascular system (for collecting blood and administering pharmaceuticals and nutrients), and for taking blood pressure and pulses. Nerves can become entrapped or be damaged in regions where they are related to bone or pass through confined spaces. Bony landmarks and muscles of the posterior scapular region


Anatomy_Gray

Anatomy_Gray. Nerves can become entrapped or be damaged in regions where they are related to bone or pass through confined spaces. Bony landmarks and muscles of the posterior scapular region The medial border, inferior angle, and part of the lateral border of the scapula can be palpated on a patient, as can the spine and acromion. The superior border and angle of the scapula are deep to soft tissue and are not readily palpable. The supraspinatus and infraspinatus muscles can be palpated above and below the spine, respectively (Fig. 7.117). The trapezius muscle is responsible for the smooth contour of the lateral side of the neck and over the superior aspect of the shoulder. The deltoid muscles form the muscular eminence inferior to the acromion and around the glenohumeral joint. The axillary nerve passes posteriorly around the surgical neck of the humerus deep to the deltoid muscle.


Anatomy_Gray

Anatomy_Gray. The latissimus dorsi muscle forms much of the muscle mass underlying the posterior axillary skin fold extending obliquely upward from the trunk to the arm. The teres major muscle passes from the inferior angle of the scapula to the upper humerus and contributes to this posterior axillary skin fold laterally. Visualizing the axilla and locating contents and related structures The axillary inlet and outlet and walls of the axilla can be established using skin folds and palpable bony landmarks (Fig. 7.118). The anterior margin of the axillary inlet is the clavicle, which can be palpated along its entire length. The lateral limit of the axillary inlet is approximated by the tip of the coracoid process, which is palpable immediately below the lateral third of the clavicle and deep to the medial margin of the deltoid muscle. The inferior margin of the anterior axillary wall is the anterior axillary skin fold, which overlies the lower margin of the pectoralis major muscle.


Anatomy_Gray

Anatomy_Gray. The inferior margin of the anterior axillary wall is the anterior axillary skin fold, which overlies the lower margin of the pectoralis major muscle. The inferior margin of the posterior axillary wall is the posterior axillary skin fold, which overlies the margins of the teres major muscle laterally and latissimus dorsi muscle medially. The medial wall of the axilla is the upper part of the serratus anterior muscle overlying the thoracic wall. The long thoracic nerve passes vertically out of the axilla and down the lateral surface of the serratus anterior muscle in a position just anterior to the posterior axillary skin fold. The lateral boundary of the axilla is the humerus. The floor of the axilla is the dome of skin between the posterior and anterior axillary skin folds. Major vessels, nerves, and lymphatics travel between the upper limb and the trunk by passing through the axilla.


Anatomy_Gray

Anatomy_Gray. Major vessels, nerves, and lymphatics travel between the upper limb and the trunk by passing through the axilla. The axillary artery, axillary vein, and components of the brachial plexus pass through the axilla and into the arm by traveling lateral to the dome of skin that forms the floor. This neurovascular bundle can be palpated by placing a hand into this dome of skin and pressing laterally against the humerus. The cephalic vein travels in superficial fascia in the cleft between the deltoid muscle and the pectoralis major muscle and penetrates deep fascia in the clavipectoral triangle to join with the axillary vein. Locating the brachial artery in the arm The brachial artery is on the medial side of the arm in the cleft between the biceps brachii and triceps brachii muscles (Fig. 7.119). The median nerve courses with the brachial artery, whereas the ulnar nerve deviates posteriorly from the vessel in distal regions. The triceps brachii tendon and position of the radial nerve


Anatomy_Gray

Anatomy_Gray. The triceps brachii tendon and position of the radial nerve The triceps brachii muscle forms the soft tissue mass posterior to the humerus, and the tendon inserts onto the olecranon of the ulna, which is readily palpable and forms the bony protuberance at the “tip” of the elbow (Fig. 7.120). The brachioradialis muscle is also visible as a muscular bulge on the lateral aspect of the arm. It is particularly prominent when the forearm is half pronated, flexed at the elbow against resistance, and viewed anteriorly. The radial nerve in the distal arm emerges from behind the humerus to lie deep to the brachioradialis muscle. The cubital fossa lies anterior to the elbow joint and contains the biceps brachii tendon, the brachial artery, and the median nerve (Fig. 7.121).


Anatomy_Gray

Anatomy_Gray. The cubital fossa lies anterior to the elbow joint and contains the biceps brachii tendon, the brachial artery, and the median nerve (Fig. 7.121). The base of the cubital fossa is an imaginary line between the readily palpable medial and lateral epicondyles of the humerus. The lateral and medial borders are formed by the brachioradialis and pronator teres muscles, respectively. The margin of the brachioradialis can be found by asking a subject to flex the semipronated forearm against resistance. The margin of the pronator teres can be estimated by an oblique line extending between the medial epicondyle and the midpoint along the length of the lateral surface of the forearm. The approximate apex of the cubital fossa is where this line meets the margin of the brachioradialis muscle.


Anatomy_Gray

Anatomy_Gray. Contents of the cubital fossa, from lateral to medial, are the tendon of the biceps brachii, the brachial artery, and the median nerve. The tendon of the biceps brachii is easily palpable. Often the cephalic, basilic, and median cubital veins are visible in the subcutaneous fascia overlying the cubital fossa. The ulnar nerve passes behind the medial epicondyle of the humerus and can be “rolled” here against the bone. The radial nerve travels into the forearm deep to the margin of the brachioradialis muscle anterior to the elbow joint. Identifying tendons and locating major vessels and nerves in the distal forearm Tendons that pass from the forearm into the hand are readily visible in the distal forearm and can be used as landmarks to locate major vessels and nerves.


Anatomy_Gray

Anatomy_Gray. Tendons that pass from the forearm into the hand are readily visible in the distal forearm and can be used as landmarks to locate major vessels and nerves. In the anterior aspect of the distal forearm, the tendons of the flexor carpi radialis, flexor carpi ulnaris, and palmaris longus muscles can be easily located either by palpating or by asking a patient to flex the wrist against resistance. The tendon of flexor carpi radialis is located approximately at the junction between the lateral and middle thirds of an imaginary line drawn transversely across the distal forearm. The radial artery is immediately lateral to this tendon and this site is used for taking a radial pulse (Fig. 7.122A).


Anatomy_Gray

Anatomy_Gray. The tendon of the flexor carpi ulnaris is easily palpated along the medial margin of the forearm and inserts on the pisiform, which can also be palpated by following the tendon to the base of the hypothenar eminence of the hand. The ulnar artery and ulnar nerve travel through the distal forearm and into the hand under the lateral lip of the flexor carpi ulnaris tendon and lateral to the pisiform. The palmaris longus tendon may be absent, but when present, lies medial to the flexor carpi radialis tendon and is particularly prominent when the wrist is flexed against resistance. The median nerve is also medial to the flexor carpi radialis tendon and lies under the palmaris longus tendon. The long tendons of the digits of the hand are deep to the median nerve and between the long flexors of the wrist. Their position can be visualized by rapidly and repeatedly flexing and extending the fingers from medial to lateral.


Anatomy_Gray

Anatomy_Gray. In the posterior distal forearm and wrist, the tendons of the extensor digitorum (Fig. 7.122B) are in the midline and radiate into the index, middle, ring, and little fingers from the wrist. The distal ends of the tendons of the extensor carpi radialis longus and brevis muscles are on the lateral side of the wrist (Fig. 7.122C) and can be accentuated by making a tight fist and extending the wrist against resistance. The tendon of the extensor carpi ulnaris can be felt on the far medial side of the wrist between the distal end of the ulna and the wrist.


Anatomy_Gray

Anatomy_Gray. Hyperextension and abduction of the thumb reveals the anatomical snuffbox (Fig. 7.122D). The medial margin of this triangular area is the tendon of the extensor pollicis longus, which swings around the dorsal tubercle of the radius and then travels into the thumb. The lateral margin is formed by the tendons of the extensor pollicis brevis and abductor pollicis longus. The radial artery passes through the anatomical snuffbox when traveling laterally around the wrist to reach the back of the hand and penetrate the base of the first dorsal interosseous muscle to access the deep aspect of the palm of the hand. The pulse of the radial artery can be felt in the floor of the anatomical snuffbox in the relaxed wrist. The cephalic vein crosses the roof of the anatomical snuffbox, and cutaneous branches of the radial nerve can be felt by moving a finger back and forth along the tendon of the extensor pollicis longus muscle. Normal appearance of the hand


Anatomy_Gray

Anatomy_Gray. Normal appearance of the hand In the resting position, the palm and digits of the hand have a characteristic appearance. The fingers form a flexed arcade, with the little finger flexed the most and the index finger flexed the least (Fig. 7.123A). The pad of the thumb is positioned at a 90° angle to the pads of the fingers. A thenar eminence occurs at the base of the thumb and is formed by the underlying thenar muscles. A similar hypothenar eminence occurs along the medial margin of the palm at the base of the little finger. The appearance of the thenar and hypothenar eminences, and the positions of the fingers change when the ulnar and median nerves are compromised. Major superficial veins of the upper limb begin in the hand from a dorsal venous network (Fig. 7.123B), which overlies the metacarpals. The basilic vein originates from the medial side of the network and the cephalic vein originates from the lateral side.


Anatomy_Gray

Anatomy_Gray. Position of the flexor retinaculum and the recurrent branch of the median nerve The proximal margin of the flexor retinaculum can be determined using two bony landmarks. The pisiform bone is readily palpable at the distal end of the flexor carpi ulnaris tendon. The tubercle of the scaphoid can be palpated at the distal end of the flexor carpi radialis tendon as it enters the wrist (Fig. 7.124). An imaginary line between these two points marks the proximal margin of the flexor retinaculum. The distal margin of the flexor retinaculum is approximately deep to the point where the anterior margin of the thenar eminence meets the hypothenar eminence near the base of the palm. The recurrent branch of the median nerve lies deep to the skin and deep fascia overlying the anterior margin of the thenar eminence near the midline of the palm. Motor function of the median and ulnar nerves in the hand


Anatomy_Gray

Anatomy_Gray. Motor function of the median and ulnar nerves in the hand The ability to flex the metacarpophalangeal joints while at the same time extending the interphalangeal joints of the fingers is entirely dependent on the intrinsic muscles of the hand (Fig. 7.125A). These muscles are mainly innervated by the deep branch of the ulnar nerve, which carries fibers from spinal cord level (C8)T1. Adducting the fingers to grasp an object placed between them is caused by the palmar interossei muscles, which are innervated by the deep branch of the ulnar nerve carrying fibers from spinal cord level (C8)T1. The ability to grasp an object between the pad of the thumb and the pad of one of the fingers depends on normal functioning of the thenar muscles, which are innervated by the recurrent branch of the median nerve carrying fibers from spinal cord level C8(T1). Visualizing the positions of the superficial and deep palmar arches


Anatomy_Gray

Anatomy_Gray. Visualizing the positions of the superficial and deep palmar arches The positions of the superficial and deep palmar arches in the hand can be visualized using bony landmarks, muscle eminences, and skin creases (Fig. 7.126). The superficial palmar arch begins as a continuation of the ulnar artery, which lies lateral to the pisiform bone at the wrist. The arch curves laterally across the palm anterior to the long flexor tendons in the hand. The arch reaches as high as the proximal transverse skin crease of the palm and terminates laterally by joining a vessel of variable size, which crosses the thenar eminence from the radial artery in the distal forearm.


Anatomy_Gray

Anatomy_Gray. The deep palmar arch originates on the lateral side of the palm deep to the long flexor tendons and between the proximal ends of metacarpals I and II. It arches medially across the palm and terminates by joining the deep branch of the ulnar artery, which passes through the base of the hypothenar muscles and between the pisiform and hook of the hamate. The deep palmar arch is more proximal in the hand than the superficial palmar arch and lies approximately one-half of the distance between the distal wrist crease and the proximal transverse skin crease of the palm. Peripheral pulses can be felt at six locations in the upper limb (Fig. 7.127). Axillary pulse: axillary artery in the axilla lateral to the apex of the dome of skin covering the floor of the axilla. Brachial pulse in midarm: brachial artery on the medial side of the arm in the cleft between the biceps brachii and triceps brachii muscles. This is the position where a blood pressure cuff is placed.


Anatomy_Gray

Anatomy_Gray. Brachial pulse in the cubital fossa: brachial artery medial to the tendon of the biceps brachii muscle. This is the position where a stethoscope is placed to hear the pulse of the vessel when taking a blood pressure reading. Radial pulse in the distal forearm: radial artery immediately lateral to the tendon of the flexor carpi radialis muscle. This is the most common site for “taking a pulse.” Ulnar pulse in the distal forearm: ulnar artery immediately under the lateral margin of the flexor carpi ulnaris tendon and proximal to the pisiform. Radial pulse in the anatomical snuffbox: radial artery as it crosses the lateral side of the wrist between the tendon of the extensor pollicis longus muscle and the tendons of the extensor pollicis brevis and abductor pollicis longus muscles. Fig. 7.1 Upper limb. A. Anterior view of the upper limb. B. Superior view of the shoulder.


Anatomy_Gray

Anatomy_Gray. Fig. 7.1 Upper limb. A. Anterior view of the upper limb. B. Superior view of the shoulder. Spinous process of vertebra TINeckShoulderGlenohumeral jointArmElbow jointForearmWrist jointHandBAThoracic wallRib IRib IAxillaScapulaManubriumof sternumClavicle Fig. 7.2 Areas of transition in the upper limb. Fig. 7.3 Movements of the scapula. A. Rotation. B. Protraction and retraction. Fig. 7.4 Movements of the arm at the glenohumeral joint. Fig. 7.5 Movements of the forearm. A. Flexion and extension at the elbow joint. B. Pronation and supination. Fig. 7.6 Movements of the hand at the wrist joint. Fig. 7.7 Bones of the upper limb. Fig. 7.8 Movements of the metacarpophalangeal (A) and interphalangeal (B) joints. Fig. 7.9 Muscles of the shoulder. A. Posterior shoulder. B. Anterior shoulder. C. Rotator cuff muscles.


Anatomy_Gray

Anatomy_Gray. Fig. 7.8 Movements of the metacarpophalangeal (A) and interphalangeal (B) joints. Fig. 7.9 Muscles of the shoulder. A. Posterior shoulder. B. Anterior shoulder. C. Rotator cuff muscles. SupraspinatusSubscapularisHumerusAcromionSpine of scapulaInfraspinatusTeres minorCoracoid processTrapeziusDeltoidPectoralis majorTeres majorLatissimus dorsiABCTrapeziusLatissimus dorsiLevator scapulaeRhomboid minorRhomboid major Fig. 7.10 Muscle components in the arm and forearm. Fig. 7.11 Relationship of the upper limb to the neck. Axillary arteryAxillary veinAxillaMedial margin ofcoracoid processHumerusAxillary inletSuperior margin of scapulaNerves to upper limbLateral margin of rib I Fig. 7.12 Muscles of the back and thoracic wall. Fig. 7.13 Breast. Fig. 7.14 Innervation of the upper limb. Anterior ramiNervesMusculocutaneous nerve(C5 to C7)Radial nerve(C5 to C8,T1)Median nerve(C6 to C8,T1)Ulnar nerve(C[7], C8, T1)C5C6C7C8T1Brachial plexus


Anatomy_Gray

Anatomy_Gray. Fig. 7.14 Innervation of the upper limb. Anterior ramiNervesMusculocutaneous nerve(C5 to C7)Radial nerve(C5 to C8,T1)Median nerve(C6 to C8,T1)Ulnar nerve(C[7], C8, T1)C5C6C7C8T1Brachial plexus Fig. 7.15 Dermatomes and myotomes in the upper limb. A. Dermatomes. B. Movements produced by myotomes. T1T1T1T2T2C6C6C6C5C5C5C4C4C3C3C8C8C8C7C7C7AAbduction of armC5Flexion of elbowC(5)6Adduction and abduction of digitsT1Flexion of digitsC8BC(6)7(8) Fig. 7.16 Nerves of upper limb. A. Major nerves in the arm and forearm. B. Anterior and posterior areas of skin innervated by major peripheral nerves in the arm and forearm.


Anatomy_Gray

Anatomy_Gray. Radial nerve • All muscles in posterior compartment of arm and forearmUlnar nerve• Most intrinsic muscles in hand• Flexor carpi ulnaris and medial half of flexor digitorum profundus in forearmMusculocutaneous nerve• All muscles in anterior compartment of armMedian nerve• Most flexors in forearm• Thenar muscles in handABUlnar nerveMedian nerveRadial nerve• Inferior lateral cutaneous nerve of arm• Posterior cutaneous nerve of arm• Posterior cutaneous nerve of forearmMusculocutaneous nerve• Lateral cutaneous nerve of forearmRadial nerve• Superficial branchPosteriorT1T2Ulnar nerveMedian nerveRadial nerve• Inferior lateral cutaneous nerve of armAxillary nerve• Superior lateral cutaneous nerve of armAxillary nerve• Superior lateral cutaneous nerve of armMusculocutaneous nerve• Lateral cutaneous nerve of forearmRadial nerve• Superficial branchAnteriorT1T2 Fig. 7.17 Nerves related to the humerus.


Anatomy_Gray

Anatomy_Gray. Fig. 7.17 Nerves related to the humerus. Radial nerveUlnar nerveAxillary nerveRadial groove of humerusSurgical neck of humerusMedial epicondyle Fig. 7.18 Veins in the superficial fascia of upper limb. The area of the cubital fossa is shown in yellow. Clavipectoral triangleClavicleCephalic veinBiceps brachiiAxillary veinCephalic veinPectoralis majorBasilic veinMedian cubital veinDorsal venous network of handBasilic veinCubital fossaDeltoid Fig. 7.19 A to C. Movements of the thumb. Fig. 7.20 Right clavicle. LateralMedialSuperior viewSurface for articulationwith acromionAnterior viewSurface for articulation with manubrium of sternum andfirst costal cartilageTrapezoid lineInferior viewConoid tubercleConoid tubercle Fig. 7.21 Scapula. A. Posterior view of right scapula. B. Anterior view of costal surface. C. Lateral view.


Anatomy_Gray

Anatomy_Gray. Fig. 7.21 Scapula. A. Posterior view of right scapula. B. Anterior view of costal surface. C. Lateral view. Articular surface for clavicleCoracoidprocessSuperior borderAnterior view of scapulaSuperior angleMedial borderSubscapular fossaAcromionGlenoid cavityLateral borderInfraglenoid tubercleInferior angleAAcromionSupraglenoid tubercleSuperior angleCoracoid processGlenoid cavityInfraglenoid tubercleInferior angleLateral borderSpinous processLateral viewCMedial borderLateral borderSuperior borderSuperior angleInferior angleArticular surface for clavicleCoracoid processPosterior viewAcromionGlenoid cavityInfraglenoid tubercleSupraspinousfossaSuprascapular notchGreater scapular notch (or spinoglenoid notch)InfraspinousfossaSpine of scapulaB Fig. 7.22 Proximal end of right humerus.


Anatomy_Gray

Anatomy_Gray. Fig. 7.22 Proximal end of right humerus. HeadSuperior facet on greater tubercle(supraspinatus)GreatertubercleIntertubercularsulcusIntertubercularsulcusLesser tubercle(subscapularis)Lateral lip, floor,and medial lip ofintertubercularsulcus (pectoralismajor, latissimusdorsi, and teresmajor, respectively)Deltoid tuberosity(deltoid)Deltoid tuberosity(deltoid)Anatomical neckSurgical neckLateral viewAnterior viewAttachmentfor pectoralis majorAttachment forcoracobrachialisGreatertubercleSuperior facet(supraspinatus)Middle facet(infraspinatus)Inferior facet(teres minor)Surgical neckAnatomicalneckPosterior view Fig. 7.23 Sternoclavicular joint. A. Bones and ligaments. B. Volume-rendered reconstruction using multidetector computed tomography.


Anatomy_Gray

Anatomy_Gray. Fig. 7.23 Sternoclavicular joint. A. Bones and ligaments. B. Volume-rendered reconstruction using multidetector computed tomography. CostoclavicularligamentInterclavicularligamentClavicular notchAnteriorsternoclavicularligamentManubrium ofsternumSternal angleArticular disc(capsule and ligamentsremoved anteriorlyto expose joint)Attachment sitefor rib IIFirst costalcartilageRib IVertebral body of TIILeft clavicleSternalangleRib IRib IIManubriumof sternumAB Fig. 7.24 Right acromioclavicular joint. Fig. 7.25 Glenohumeral joint. A. Articular surfaces of right glenohumeral joint. B. Radiograph of a normal glenohumeral joint. Tendon of longhead of bicepsbrachii muscleGlenoid cavityABGlenoid labrumTransverse humeral ligamentClavicleAcromionGlenoid cavityHead of humerusHead ofhumerus Fig. 7.26 Synovial membrane and joint capsule of right glenohumeral joint.


Anatomy_Gray

Anatomy_Gray. Fig. 7.26 Synovial membrane and joint capsule of right glenohumeral joint. Synovial sheathSynovial membraneRedundant synovial membrane in adductionSubtendinous bursa of subscapularisLong head of biceps brachii tendonCoracohumeralligamentLong head of biceps brachiitendonFibrous membrane of joint capsule Fig. 7.27 Capsule of right glenohumeral joint. Superior glenohumeral ligamentMiddle glenohumeral ligamentInferiorglenohumeralligamentCoracohumeral ligamentTransversehumeral ligamentSynovialsheathTendon oflong headof bicepsbrachiiRedundant capsuleAperture for subtendinousbursa of subscapularis Fig. 7.28 Lateral view of right glenohumeral joint and surrounding muscles with proximal end of humerus removed.


Anatomy_Gray

Anatomy_Gray. Fig. 7.28 Lateral view of right glenohumeral joint and surrounding muscles with proximal end of humerus removed. SupraspinatusInfraspinatusTeres minorTeres majorSynovial membraneSubtendinous bursaof subscapularisLong head of biceps brachii tendonLong head of tricepsbrachiiShort head of biceps brachiiand coracobrachialisLatissimus dorsiPectoralis majorGlenoid labrum Fibrous membraneSubscapularisDeltoidAcromionCoracoid processCoraco-acromial ligamentGlenoid cavitySubacromial bursa (subdeltoid) Fig. 7.29 Magnetic resonance image (T1-weighted) of a normal glenohumeral joint in the sagittal plane. SupraspinatusInfraspinatusPosteriorAnteriorClavicleAcromionTeres minorHead of humerusCoracoid processSubscapularis Fig. 7.30 There is an oblique fracture of the middle third of the right clavicle. Fracture of clavicleAcromioclavicular joint


Anatomy_Gray

Anatomy_Gray. Fig. 7.30 There is an oblique fracture of the middle third of the right clavicle. Fracture of clavicleAcromioclavicular joint Fig. 7.31 Radiographs of acromioclavicular joints. A. Normal right acromioclavicular joint. B. Dislocated right acromioclavicular joint (shoulder separation). Acromioclavicular jointAcromionClavicle Head of humerusClavicleAcromionHumerusAB Fig. 7.32 Radiograph showing an anteroinferior dislocation of the shoulder joint. AcromionGlenoid cavityClavicleHead of humerus Fig. 7.33 Magnetic resonance image of a full-thickness tear of the supraspinatus tendon as it inserts onto the greater tubercle of the humerus. Fig. 7.34 Ultrasound of shoulder showing needle placement into the subdeltoid/subacromial bursa. DeltoidHead of humerusNeedleSubacromial-subdeltoid bursa Fig. 7.35 Lateral view of trapezius and deltoid muscles. AcromionSpine of thescapulaTrapeziusDeltoidDeltoid tuberosity of humerusClavicle


Anatomy_Gray

Anatomy_Gray. DeltoidHead of humerusNeedleSubacromial-subdeltoid bursa Fig. 7.35 Lateral view of trapezius and deltoid muscles. AcromionSpine of thescapulaTrapeziusDeltoidDeltoid tuberosity of humerusClavicle Fig. 7.36 Attachments and neurovascular supply of the trapezius and deltoid muscles. AcromionSpine of scapulaTrapeziusDeltoidDeltoid tuberosity of humerusRhomboid minorRhomboid majorClavicleSuperior nuchal lineExternal occipitalprotuberanceMastoid processLigamentum nuchaeSpinous processes and interspinous ligaments to TXIIAccessory nerve (XI)Levator scapulaeAxillary nervePosterior circumflex humeral arteryLine of attachment of trapeziusLine of attachment of deltoid Fig. 7.37 Right posterior scapular region.


Anatomy_Gray

Anatomy_Gray. Fig. 7.37 Right posterior scapular region. Suprascapular notch (foramen) SupraspinatusInfraspinatusCut edge of trapeziusCut edge of deltoidSurgical neck of humerusMedial lip of intertubercular sulcusTriangular intervalTriangular spaceOlecranonLong head of triceps brachiiTeres majorTeres minorQuadrangular spaceCut edge of lateral head of triceps brachii Fig. 7.38 Arteries and nerves associated with gateways in the posterior scapular region. Posterior circumflex humeral arteryCircumflex scapular arterySuperior transverse scapular ligamentSuprascapular nerveSuprascapular arteryAxillary nerveProfunda brachii arteryRadial nerveTo deltoidTo skin on lateral part of deltoidCut edge of lateral head of triceps brachii Fig. 7.39 Arterial anastomoses around the shoulder.


Anatomy_Gray

Anatomy_Gray. Fig. 7.39 Arterial anastomoses around the shoulder. ClaviclePosterior circumflexhumeral arteryAnterior circumflexhumeral arterySubscapular arteryCircumflex scapular arterySuprascapular arteryAxillary arteryProfunda brachii arteryBrachial arteryRight subclavian arteryDeep branch of transversecervical arteryTransverse cervical arteryRib IRight common carotid arteryThyrocervical trunk Fig. 7.40 Axilla. A. Walls and transition between neck and arm. Axilla. B. Boundaries. C. Continuity with the arm. Lateral wallAnterior wallPosterior wallSkinMedial wallCoracoid processAnterior scalene muscleMiddle scalene muscleClavicleLateral margin of rib IA


Anatomy_Gray

Anatomy_Gray. Axilla. B. Boundaries. C. Continuity with the arm. Lateral wallAnterior wallPosterior wallSkinMedial wallCoracoid processAnterior scalene muscleMiddle scalene muscleClavicleLateral margin of rib IA Axillary sheathsurroundingarteries, veins, nerves, and lymphaticsApex of inletInletAxillaSkin of armSkin on floor of axillaPosterior wall• Subscapularis, teres major, and latissimus dorsi muscles, and long head of triceps brachii muscleLateral wall• Intertubercular sulcusInlet• Lateral margin of rib I• Clavicle• Superior margin of scapula to coracoid processAnterior wall• Pectoralis major and minor muscles• Subclavius muscle• Clavipectoral fasciaMedial wall• Upper thoracic wall • Serratus anterior muscleFloor • Skin of armpit• Opens laterally into armBC Fig. 7.41 Pectoralis major muscle. Fig. 7.42 Pectoralis minor and subclavius muscles and clavipectoral fascia.


Anatomy_Gray

Anatomy_Gray. Fig. 7.41 Pectoralis major muscle. Fig. 7.42 Pectoralis minor and subclavius muscles and clavipectoral fascia. Pectoralis majorPectoralis majorPectoralis minorClavipectoral fasciaCephalic veinLateral pectoral nerveMedial pectoralnervesPectoral branch of thoraco-acromial arterySubclaviusAttachment of fasciato floor of axilla Fig. 7.43 Medial wall of the axilla. A. Lateral view. B. Lateral view with lateral angle of scapula retracted posteriorly. C. Anterior view. IIIIIIIVVVIVIILong thoracic nerveLong thoracic nerveLateral angle ofscapula pulledposterolaterallyaway from thethoracic wallIntercostobrachial nerve (lateral cutaneousbranch of T2)Serratus anteriorSerratus anteriorSerratus anteriorABC Fig. 7.44 Lateral wall of the axilla. Fig. 7.45 Posterior wall of the axilla.


Anatomy_Gray

Anatomy_Gray. Fig. 7.44 Lateral wall of the axilla. Fig. 7.45 Posterior wall of the axilla. Teres majorLatissimus dorsiLong head of triceps brachiiSubscapularisSuprascapular foramen• Suprascapular nerveTriangular interval • Radial nerve • Profunda brachii arteryTriangular space • Circumflex scapular arteryQuadrangular space • Axillary nerve • Posterior circumflex humeral artery and vein Fig. 7.46 Magnetic resonance image of the glenohumeral joint in the transverse or horizontal plane. Glenoid cavityBiceps tendon in intertubercular sulcusSubscapularisGlenoid labrumTeres minor and infraspinatus musclesHead of humerusAnteriorPosterior Fig. 7.47 Floor of the axilla. Axillary sheathArmDome of skin onfloor of axillaAnterior axillary skin foldPosterior axillaryskin fold Fig. 7.48 Contents of the axilla: muscles. Long head of biceps brachiiShort head of biceps brachiiTendon of biceps brachiiCoracobrachialisBicipital aponeurosisTransverse humeral ligament


Anatomy_Gray

Anatomy_Gray. Fig. 7.48 Contents of the axilla: muscles. Long head of biceps brachiiShort head of biceps brachiiTendon of biceps brachiiCoracobrachialisBicipital aponeurosisTransverse humeral ligament Fig. 7.49 Contents of the axilla: the axillary artery. Lower border of teres majorPectoralis minorLateral margin of rib ISubclaviusSubclavian artery1st part2nd part3rd partBrachial arteryAxillary artery Fig. 7.50 Branches of the axillary artery. Posterior circumflex humeral artery(quadrangular space)Anterior circumflex humeral arteryProfunda brachii artery(triangular interval)Long head of triceps brachiiThoraco-acromial arterySubclaviusPectoralis minorSubscapular arterySubscapularisSuperior thoracic arteryLateral thoracic arteryCircumflex scapular branch(triangular space)Thoracodorsal arteryLatissimus dorsiTeres major Fig. 7.51 Axillary vein. Fig. 7.52 Brachial plexus. A. Major components in the neck and axilla. B. Schematic showing parts of the brachial plexus.


Anatomy_Gray

Anatomy_Gray. Fig. 7.51 Axillary vein. Fig. 7.52 Brachial plexus. A. Major components in the neck and axilla. B. Schematic showing parts of the brachial plexus. TerminalnervesCordsDivisionsTrunksRoots(anterior rami)C5C6C7C8T1SuperiorMiddleInferiorLateralPosteriorPosteriorPosteriorPosteriorMedialAnteriorAnteriorAnterior Arrangedaround 2nd part of axillary arteryBSuperior cervical sympathetic ganglionInferior cervical sympathetic ganglionMiddle cervical sympathetic ganglionGray ramuscommunicansRoots (anterior rami of C5 to T1)Trunks (superior, middle, inferior)Divisions (anterior, posterior)Cords (medial, lateral, posterior)C8C7C6C5T1Middle scalene muscleAnterior scalene tendonA Fig. 7.53 Brachial plexus. A. Schematic showing branches of the brachial plexus. B. Relationships to the axillary artery.


Anatomy_Gray

Anatomy_Gray. Terminal nervesCordsDivisionsTrunksRoots (anterior rami)C5C6C7C8T1SuperiorMiddleInferiorLateralPosteriorPosteriorPosteriorPosteriorMedialAnteriorAnteriorAnterior ALateral pectoral nerveMedial pectoral nerveMedial cutaneous nerve of armMedial cutaneous nerve of forearmMusculocutaneousMedianRadialUlnarAxillaryLong thoracicnerveSuprascapular nerveDorsal scapular nerveContribution to phrenic nerveNerve to subclaviusSuperiorsubscapular nerveThoracodorsal nerveInferior subscapular nerveDorsal scapular nerveC5C6C7C8T1T2Suprascapular nerveLateral pectoral nerveMedial cordPosterior cordLateral cordMedial pectoral nerveSecond part of axillary arteryMusculocutaneous nerveAxillary nerveMedian nerveC7 fibersRadial nerveUlnar nerveSuperior subscapular nerveThoracodorsal nerveInferior subscapular nerveMedial cutaneous nerve of armMedial cutaneous nerve of forearmLong thoracic nerveIntercostobrachial nerve (lateral cutaneous branch of T2)Nerve to subclaviusB


Anatomy_Gray

Anatomy_Gray. Fig. 7.54 Branches of the roots and trunks of the brachial plexus. Dorsal scapular nerveMiddle scalene muscleAnterior scalene tendonT1 intercostal nerveC5 branch to phrenic nervePhrenic nerveSubclavian veinNerve to subclaviusAxillary arteryLong thoracic nerveSerratus anteriorSuprascapular foramenSuprascapular nerve Fig. 7.55 Branches of the lateral and medial cords of the brachial plexus. Lateral pectoral nerveMedial pectoral nerveAxillary arteryMusculocutaneous nerveMedian nerveUlnar nerveLateral cutaneousnerve of armMedial cutaneous nerve of forearmMedial cutaneous nerve of armLateral cordMedial cordPectoralis minorT1 intercostal nerve Fig. 7.56 Branches of the posterior cord of the brachial plexus. Axillary nerveSuperior subscapular nerveThoracodorsal nerveInferior subscapular nerveRadial nervePosterior cutaneousnerve of arm Fig. 7.57 Lymph nodes and vessels in the axilla.


Anatomy_Gray

Anatomy_Gray. Axillary nerveSuperior subscapular nerveThoracodorsal nerveInferior subscapular nerveRadial nervePosterior cutaneousnerve of arm Fig. 7.57 Lymph nodes and vessels in the axilla. Humeral nodesCentral nodesPectoral nodesApical nodesInfraclavicular nodesSubscapular nodesAnterior scaleneMost of upper limbSome of upper limbAnterolateral body wall and centrolateral part of mammary glandRight subclavian trunkSuperior part of mammary gland Fig. 7.58 Axillary process of the breast. Fig. 7.59 Arm. A. Proximal and distal relationships. B. Transverse section through the middle of the arm. AxillaCubitalfossaLateral intermuscular septumMedial intermuscular septumHumerusAnterior (flexor) compartmentPosterior (extensor) compartmentDeep fasciaForearmABArmLine of section Fig. 7.60 Humerus. Posterior view. Fig. 7.61 Distal end of the humerus. Fig. 7.62 A. Anterior view of the proximal end of the radius. B. Radiograph of the elbow joint (anteroposterior view).


Anatomy_Gray

Anatomy_Gray. Fig. 7.60 Humerus. Posterior view. Fig. 7.61 Distal end of the humerus. Fig. 7.62 A. Anterior view of the proximal end of the radius. B. Radiograph of the elbow joint (anteroposterior view). BTrochleaCapitulumLateral epicondyleMedial epicondyleRadiusHead of radiusHumerusUlnaOblique lineHeadRadial tuberosityNeckLateralMedialA Fig. 7.63 A. Lateral, anterior, medial, and posterior views of the proximal end of the ulna. B. Radiograph of the elbow joint (lateral view). Fig. 7.64 Coracobrachialis, biceps brachii, and brachialis muscles. Long head of bicepsbrachii muscleShort head of bicepsbrachii muscleCoracobrachialis muscleTransverse humeral ligamentBrachialis muscleTuberosity of ulnaBicipital aponeurosis (cut )Radial tuberosity Fig. 7.65 Triceps muscle. OlecranonLong head of triceps brachiiLateral head of triceps brachiiMedial head of triceps brachiiLateral head of triceps brachiiRadial groove of humerus Fig. 7.66 Brachial artery. A. In context. Brachial artery. B. Branches.


Anatomy_Gray

Anatomy_Gray. Fig. 7.66 Brachial artery. A. In context. Brachial artery. B. Branches. Fig. 7.67 Veins of the arm. Axillary veinCoracobrachialisInferior margin of teres majorPaired brachial veinsBasilic veinBrachialisBasilic vein (subcutaneous superficial vein)Basilic vein penetratesdeep fasciaDeep veins accompanying arteriesCephalic veinBiceps brachii Fig. 7.68 Musculocutaneous, median, and ulnar nerves in the arm. Median nerveUlnar nerveMedial epicondyleLateral cutaneous nerve of forearmMusculocutaneous nerveMusculocutaneous nerveMedial cordLateral cordRadial nerveMedial intermuscular septum Fig. 7.69 Radial nerve in the arm. Ulnar nerveProfunda brachii arteryTriangular intervalInferior lateral cutaneous nerve of armPosterior cutaneous nerve of forearmRadial nerve (in radial groove)Medial epicondyleBranch to medial head of triceps brachii Fig. 7.70 Radiograph of the humerus demonstrating a midshaft fracture, which may disrupt the radial nerve.


Anatomy_Gray

Anatomy_Gray. Fig. 7.70 Radiograph of the humerus demonstrating a midshaft fracture, which may disrupt the radial nerve. Fig. 7.71 Components and movements of the elbow joint. A. Bones and joint surfaces. B. Flexion and extension. C. Pronation and supination. D. Radiograph of a normal elbow joint (anteroposterior view). Fig. 7.72 Synovial membrane of elbow joint (anterior view). Fig. 7.73 Elbow joint. A. Joint capsule and ligaments of the right elbow joint. B. Magnetic resonance image of the elbow joint in the coronal plane. RadialcollateralligamentAUlnarcollateralligamentAnular ligamentof radiusSacciform recessof synovialmembraneBUlnar collateralligamentRadial collateral ligamentHead of radiusHumerusMedial epicondyleUlna Fig. 7.74 Radiograph of an elbow showing a fracture of the olecranon and involving the insertion of the triceps brachii muscle. Fig. 7.75 Radiographs of elbow joint development. A. At age 2 years. B. At age 5 years. C. At age 5–6 years. D. At age 12 years.


Anatomy_Gray

Anatomy_Gray. Fig. 7.75 Radiographs of elbow joint development. A. At age 2 years. B. At age 5 years. C. At age 5–6 years. D. At age 12 years. Fig. 7.76 MRI of right elbow showing swelling of the ulnar nerve in the cubital tunnel posterior to the medial epicondyle, consistent with nerve compression. Fig. 7.77 Cubital fossa. A. Margins. B. Contents. C. Position of the radial nerve. D. Superficial structures.


Anatomy_Gray

Anatomy_Gray. Fig. 7.77 Cubital fossa. A. Margins. B. Contents. C. Position of the radial nerve. D. Superficial structures. Ulnar nerveRadial arteryUlnar arteryPronator teres (humeral head)Pronator teres(ulnar head)Median nerveMedian cubitalveinUlnar nerveMedian nerveBasilic veinBasilic veinMedial cutaneousnerve of forearmLateral cutaneousnerve of forearmForearm extensorsLine betweenlateral and medialepicondylesForearm flexorsBrachioradialisBrachialisRadial nerveRadial nerveCephalic veinMusculocutaneous nerveBrachioradialis(pulled back )Deep branchof radial nerveSupinatorSuperficial branch of radial nerveTendon (biceps brachii)Biceps brachiiRadial arteryUlnar arteryTriceps brachiiABCDPronator teres Artery(brachial)Nerve(median)BicipitalaponeurosisMedial intermuscularseptumCubital fossaMedialepicondyleLateralepicondyleTendon (biceps)Artery (brachial)Nerve (median)Ulnar nerveRadial nerve Fig. 7.78 Digital subtraction angiograms of forearm demonstrating a surgically created radiocephalic fistula.


Anatomy_Gray

Anatomy_Gray. Fig. 7.78 Digital subtraction angiograms of forearm demonstrating a surgically created radiocephalic fistula. A. Anteroposterior view. B. Lateral view. Fig. 7.79 Forearm. A. Proximal and distal relationships of the forearm. B. Transverse section through the middle of the forearm. Cubital fossaCarpal tunnelUlnaMedian nerveLong flexortendons of digitsBiceps tendonBrachial arteryMedian nerveUlnaRadiusRadiusPosteriorcompartmentDeep fasciaBALateral intermuscular septumAnterior compartmentInterosseous membraneArmElbow jointForearmWrist jointHand Fig. 7.80 Radius. A. Shaft and distal end of the right radius. B. Radiograph of the forearm (anteroposterior view). Fig. 7.81 Shaft and distal end of right ulna.


Anatomy_Gray

Anatomy_Gray. Fig. 7.80 Radius. A. Shaft and distal end of the right radius. B. Radiograph of the forearm (anteroposterior view). Fig. 7.81 Shaft and distal end of right ulna. AnteriorsurfaceAnterior border(rounded)Posterior border(sharp)Anterior surfaceInterosseousborderMedialsurfaceAnterior borderPosterior surfaceUlnar styloid processRougheningfor attachmentof pronator quadratusAttachment ofarticular discInterosseousborderTrochlearnotchTuberosity of ulnaCoronoidprocessRadial notchOlecranonAnterior viewDistal view Fig. 7.82 Distal radio-ulnar joint and the interosseous membrane. Fig. 7.83 Pronation and supination. PronatedSupinatedSupinatorBiceps brachiiPronator teresPronator teresand pronatorquadratuscontractSupinator andbiceps brachiicontractPronator quadratusSupinatedAxis of movement Fig. 7.84 Abduction of the distal end of the ulna by the anconeus during pronation. Abduction ofulna by anconeusduring pronationAxis of movementwith abduction of ulnaAnconeus


Anatomy_Gray

Anatomy_Gray. Fig. 7.84 Abduction of the distal end of the ulna by the anconeus during pronation. Abduction ofulna by anconeusduring pronationAxis of movementwith abduction of ulnaAnconeus Fig. 7.85 Superficial layer of forearm muscles. A. Superficial muscles (flexor retinaculum not shown). B. Flexor carpi ulnaris muscle. Median nerveFlexor carpi radialisPalmaris longusFlexor carpi ulnaris Palmar aponeurosisPisometacarpal ligamentPisiformUlnar head offlexor carpi ulnarisABHumeral head ofpronator teresUlnar head ofpronator teresHumeral head offlexor carpi ulnarisUlnar nerveUlnar nerveBrachial arteryUlnar arteryRadial arteryPronator teres (cut )Pisohamate ligamentHook of hamate Fig. 7.86 Intermediate layer of forearm muscles. Median nerveFlexor digitorumsuperficialisUlnar nerve Ulnar arteryFlexor retinaculumHumero-ulnarhead of flexordigitorumsuperficialisUlnar arteryRadial head of flexordigitorumsuperficialisMedian nerve Fig. 7.87 Deep layer of forearm muscles.


Anatomy_Gray

Anatomy_Gray. Fig. 7.87 Deep layer of forearm muscles. Fig. 7.88 Arteries of the anterior compartment of the forearm. Fig. 7.89 Nerves of anterior forearm. Fig. 7.90 Superficial layer of muscles in the posterior compartment of the forearm. A. Brachioradialis muscle (anterior view). B. Superficial muscles (posterior view). Fig. 7.91 Deep layer of muscles in the posterior compartment of the forearm. Fig. 7.92 Posterior interosseous artery and radial nerve in posterior compartment of forearm. Posteriorinterosseous nerve(continuation ofdeep branch ofradial nerve)Commoninterosseous arteryAnteriorinterosseous arteryUlnar arteryPosteriorinterosseous arteryInterosseous membraneSuperficial branchDeep branchRadial nerveBranch tobrachioradialisBranch to extensorcarpi radialis brevisBranch to extensorcarpi radialis longusAnteriorinterosseous arteryPosteriorinterosseous arteryAnterior viewPosterior view


Anatomy_Gray

Anatomy_Gray. Fig. 7.93 Right hand. The fingers are shown in a normal resting arcade in which they are flexed. In the anatomical position, the digits are straight and adducted. Carpal bonesThumbLittleRingIndexFingersRadiusWrist jointUlnaProximal skin creaseDistal skin creaseMetacarpalsDigits ofthe handAdductionAdductionAbductionAbductionMiddle Fig. 7.94 Right hand and wrist joint. A. Bones. Right hand and wrist joint. B. Radiograph of a normal hand and wrist joint (anteroposterior view). C. Magnetic resonance image of a normal wrist joint in the coronal plane. RadiusWrist jointIIIIIIIVVScaphoidTrapezoidLunateUlnaTriquetrumTriquetrumPisiformPisiformHook ofhamateHamateHamatePhalangesAMetacarpalsCarpal bonesCapitateCapitateTrapeziumTrapeziumProximalMiddleDistalProximalCarpal bonesCarpal archCarpal archDistalTubercle of trapeziumTrapezoidTubercle of scaphoidTubercle Fig. 7.95 Deep transverse metacarpal ligaments, right hand.


Anatomy_Gray

Anatomy_Gray. Fig. 7.95 Deep transverse metacarpal ligaments, right hand. Fig. 7.96 Wrist radiographs (posteroanterior view). A. Normal. B. Scaphoid fracture. Fig. 7.97 Radiograph of wrist showing sclerosis in the lunate consistent with avascular necrosis (Kienbock’s disease). Fig. 7.98 Carpal tunnel. A. Structure and relations. B. Magnetic resonance image of a normal wrist in the axial plane. C. Magnetic resonance image of a normal wrist in the coronal plane. Fig. 7.99 Palmar aponeurosis, right hand. Fig. 7.100 Anatomical snuffbox, left hand. Fig. 7.101 Fibrous digital sheaths and synovial sheaths of the right hand. Fig. 7.102 MRI of the wrist showing fluid and inflammation associated with the first extensor compartment, consistent with De Quervain’s tenosynovitis. Fig. 7.103 Extensor hood. A and B. Middle finger, left hand. C. Function of extensor hoods and intrinsic muscles.


Anatomy_Gray

Anatomy_Gray. Fig. 7.103 Extensor hood. A and B. Middle finger, left hand. C. Function of extensor hoods and intrinsic muscles. Extensor hoodExtensordigitorum tendonDorsal interosseousmuscleFlexor digitorumprofundus tendonFulcrum ofmetacarpophalangeal jointABCContraction of intrinsicmuscles (lumbricals andinterossei muscles)Deep transversemetacarpal ligamentMiddle fingerFulcrums ofinterphalangeal jointsExtension ofinterphalangeal jointsFlexion ofmetacarpophalangeal jointExtendedFlexedUpstrokePalmar ligamentLumbrical muscle Fig. 7.104 Dorsal interossei (palmar view), right hand. Fig. 7.105 Palmar interossei (palmar view), right hand. AdductionAdductionFirst palmarinterosseous(rudimentary: whenpresent is oftenconsidered part ofeither adductorpollicis or flexorpollicis brevis)Insertion intodorsal expansion Fig. 7.106 Adductor pollicis, right hand. Oblique head of adductor pollicisTransverse head of adductor pollicisRadial artery(deep palmar arch)Sesamoid bone


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Anatomy_Gray. Fig. 7.106 Adductor pollicis, right hand. Oblique head of adductor pollicisTransverse head of adductor pollicisRadial artery(deep palmar arch)Sesamoid bone Fig. 7.107 Thenar and hypothenar muscles, right hand. Flexor retinaculumMedian nerveFlexor carpi ulnarisOpponens digiti minimiAbductor digiti minimiFlexor digiti minimi brevisDeep branch ofulnar artery and nerveRecurrent branch of median nerveAdductor pollicis and first palmarinterosseous insert into medialside of extensor hoodFlexor pollicis brevis and abductorpollicis brevis insert into lateral side of extensor hoodExtensor hoodFlexor pollicis brevisThree thenar musclesThree hypothenar musclesOpponens pollicisAbductor pollicis brevis Fig. 7.108 Lumbrical muscles, right hand.


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Anatomy_Gray. Fig. 7.108 Lumbrical muscles, right hand. Flexor retinaculumFlexor digitorumsuperficialis tendon (cut )Flexor digitorumprofundus tendonAttached to dorsal hoodFirst and second lumbricals(unipennate)Third and fourth lumbricals(bipennate)Flexor pollicislongus tendonDeep transversemetacarpal ligament Fig. 7.109 Arterial supply of the right hand. Fig. 7.110 Superficial palmar arch, right hand. Fig. 7.111 Deep palmar arch, right hand.


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Anatomy_Gray. Fig. 7.109 Arterial supply of the right hand. Fig. 7.110 Superficial palmar arch, right hand. Fig. 7.111 Deep palmar arch, right hand. Radial arteryUlnar arteryUlnar nerveDeep branchof ulnar arteryPerforatingarteryPalmarmetacarpalarteriesDeep palmar archAdductorpollicismuscleRadialis indicisarteryPrincepspollicis arteryFirst dorsalinterosseous muscleFirst dorsalmetacarpalarteryMainly radial arteryDorsalmetacarpalarteriesDorsal carpalnetworkDorsalcarpal archDorsaldigitalarteriesDorsalcarpal branchof ulnar arteryPosteriorinterosseousarteryDorsal viewarcharteryExtensordigitorumtendons(cut)DorsalmetacarpalarteriesFirst dorsalmetacarpalarteryDorsal carpalDorsal carpalbranch of ulnarExtensor pollicis brevisAbductor pollicis longusExtensor pollicis longusExtensor retinaculumExtensor carpiradialis longusRadial artery inanatomical snuffboxExtensor carpiradialis brevisDorsal interosseiDorsal digitalarteriesDorsal branches of properpalmar digital arteries


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Anatomy_Gray. Fig. 7.112 Dorsal venous arch of the right hand. Fig. 7.113 Ulnar nerve in the right hand. Palmar viewDorsal viewMedial twolumbricalmusclesPalmar branch of ulnarnerve from forearmArea of distribution ofsuperficial branch of ulnarnerve in handDorsal branch of ulnarnerve from forearmUlnar nerveDeep branch(of ulnar nerve)Superficial branch(of ulnar nerve)Ulnar artery Fig. 7.114 Typical appearance of a “clawed hand” due to a lesion of the ulnar nerve. Fig. 7.115 Median nerve in the right hand. Recurrent branch(of median nerve)Lateral twolumbrical musclesPalmar branch of mediannerve from forearmDigital nervesMedian nervePalmar branch(of median nerve)Abductor pollicis brevisFlexor pollicis brevisPalmar viewDorsal view Fig. 7.116 Radial nerve in the right hand. Fig. 7.117 Bony landmarks and muscles of the posterior scapular region. Posterior view of shoulder and back.


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Anatomy_Gray. Fig. 7.116 Radial nerve in the right hand. Fig. 7.117 Bony landmarks and muscles of the posterior scapular region. Posterior view of shoulder and back. Teres major muscleTrapezius muscleDeltoid muscleAxillary nerveLatissimus dorsi muscleSpine of scapulaAcromionSupraspinatus muscleInfraspinatus muscleTeres minor musclePosterior axillary skin fold Fig. 7.118 Visualizing the axilla and locating its contents and related structures. A. Anterior shoulder showing folds and walls of the axilla. B. Anterior shoulder showing outlet and floor of the axilla. C. Anterior view showing the axillary neurovascular bundle and long thoracic nerve. D. Anterior view of the shoulder showing the clavipectoral triangle with the cephalic vein.


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Anatomy_Gray. ClavicleCoracoid processHumerusAnterior axillaryskin foldAnterior wallPosterior wallMedial wallLateral wallNeurovascular bundleSerratus anteriormuscleLong thoracic nerveAxillaDeltoid musclePectoralis major muscleCephalic veinClavipectoral triangleFloor of axillaOpening ofaxilla into armAnterior axillary skin foldPosterioraxillary skin foldABCD Fig. 7.119 Locating the brachial artery in the right arm (medial view of arm with brachial artery, median nerve, and ulnar nerve). Fig. 7.120 Triceps brachii tendon and position of the radial nerve (posterior view of right arm). Fig. 7.121 Cubital fossa (anterior view, right arm). A. Anterior view. B. Boundaries and contents. C. Showing radial and ulnar nerves, and veins. Fig. 7.122 Identifying tendons and locating major vessels and nerves in the distal right forearm. A. Anterior distal forearm and wrist. B. Posterior distal forearm and wrist. C. Lateral view of posterior wrist and forearm. D. Anatomical snuffbox.


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Anatomy_Gray. Fig. 7.123 Normal appearances of the right hand. A. Palmar view with the thenar and hypothenar eminences and finger arcade. B. Dorsal view with dorsal venous network. Fig. 7.124 Anterior view of left hand to show the position of the flexor retinaculum and recurrent branch of the median nerve. Recurrent branch of the median nervePisiform Tubercle ofthe scaphoidFlexor carpiradialis tendonMedian nerveFlexor carpiulnaris tendonFlexor retinaculumHypothenar eminenceThenar eminence Fig. 7.125 Motor function of the ulnar and median nerves in the hand. A. Flexing the metacarpophalangeal joints and extending the interphalangeal joints: the “ta-ta” position. B. Grasping an object between the fingers. C. Grasping an object between the pad of the thumb and pad of the index finger.


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Anatomy_Gray. Fig. 7.126 Visualizing the positions of the superficial and deep palmar arches, left hand. The proximal transverse skin crease of the palm and distal wrist crease are labeled and the superficial and deep palmar arches shown in overlay. This also shows the position of the pisiform and the hook of the hamate. Distal transverseskin crease of palmPisiform Distal wrist creaseProximal transverseskin crease of palmProximalwrist creaseUlnar arteryRadial arteryHook of hamateDeep palmar archSuperficial palmar arch Fig. 7.127 Where to take peripheral artery pulses in the upper limb. A. Pulse points. B. Placement of blood pressure cuff and stethoscope. ABBrachial pulse in midarmBrachial pulse in the cubital fossaUlnar pulse in distal forearmRadial pulse in the anatomical snuffboxRadial pulse in distal forearmAxillary pulse eFig. 7.128 Ultrasound showing a completely torn supraspinatus tendon with fluid in the subacromial subdeltoid bursa.


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Anatomy_Gray. Deltoid muscleTear in supraspinatus tendonNormal supraspinatus tendonHead of humerusHead of humerus eFig. 7.129 The radiograph, anteroposterior view, demonstrates an anteroinferior dislocation of the humeral head at the glenohumeral joint. Table 7.1 Muscles of the shoulder (spinal segments in bold are the major segments innervating the muscle) Table 7.2 Muscles of the posterior scapular region (spinal segments in bold are the major segments innervating the muscle) Table 7.3 Muscles of the anterior wall of the axilla (spinal segments in bold are the major segments innervating the muscle) Table 7.4 Muscle of the medial wall of the axilla (spinal segment in bold is the major segment innervating the muscle) Table 7.5 Muscles of the lateral and posterior wall of the axilla (spinal segments in bold are the major segments innervating the muscle; spinal segments in parentheses do not consistently innervate the muscle)


Anatomy_Gray

Anatomy_Gray. Table 7.6 Muscles having parts that pass through the axilla (spinal segments in bold are the major segments innervating the muscle) Table 7.7 Branches of brachial plexus (parentheses indicate that a spinal segment is a minor component of the nerve or is inconsistently present in the nerve) Table 7.8 Muscles of the anterior compartment of the arm (spinal segments in bold are the major segments innervating the muscle) Table 7.9 Muscle of the posterior compartment of the arm (spinal segment indicated in bold is the major segment innervating the muscle) Table 7.10 Superficial layer of muscles in the anterior compartment of the forearm (spinal segments indicated in bold are the major segments innervating the muscle) Table 7.11 Intermediate layer of muscles in the anterior compartment of the forearm (spinal segment indicated in bold is the major segment innervating the muscle)


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Anatomy_Gray. Table 7.11 Intermediate layer of muscles in the anterior compartment of the forearm (spinal segment indicated in bold is the major segment innervating the muscle) Table 7.12 Deep layer of muscles in the anterior compartment of the forearm (spinal segments indicated in bold are the major segments innervating the muscle) Table 7.13 Superficial layer of muscles in the posterior compartment of the forearm (spinal segments indicated in bold are the major segments innervating the muscle) Table 7.14 Deep layer of muscles in the posterior compartment of the forearm (spinal segments indicated in bold are the major segments innervating the muscle) Table 7.15 Intrinsic muscles of the hand (spinal segments indicated in bold are the major segments innervating the muscle) In the clinic Fracture of the proximal humerus


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Anatomy_Gray. Table 7.15 Intrinsic muscles of the hand (spinal segments indicated in bold are the major segments innervating the muscle) In the clinic Fracture of the proximal humerus It is extremely rare for fractures to occur across the anatomical neck of the humerus because the obliquity of such a fracture would have to traverse the thickest region of bone. Typically fractures occur around the surgical neck of the humerus. Although the axillary nerve and posterior circumflex humeral artery may be damaged with this type of fracture, this rarely happens. It is important that the axillary nerve is tested before relocation to be sure that the injury has not damaged the nerve and that the treatment itself does not cause a neurological deficit. In the clinic Fractures of the clavicle and dislocations of the acromioclavicular and sternoclavicular joints


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Anatomy_Gray. In the clinic Fractures of the clavicle and dislocations of the acromioclavicular and sternoclavicular joints The clavicle provides the only bony connection between the upper limb and trunk. Given its relative size and the potential forces that it transmits from the upper limb to the trunk, it is not surprising that it is often fractured. The typical site of fracture is the middle third (Fig. 7.30). The medial and lateral thirds are rarely fractured. The acromial end of the clavicle tends to dislocate at the acromioclavicular joint with trauma (Fig. 7.31). The outer third of the clavicle is joined to the scapula by the conoid and trapezoid ligaments of the coracoclavicular ligament.


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Anatomy_Gray. A minor injury tends to tear the fibrous joint capsule and ligaments of the acromioclavicular joint, resulting in acromioclavicular separation on a plain radiograph. More severe trauma will disrupt the conoid and trapezoid ligaments of the coracoclavicular ligament, which results in elevation and upward subluxation of the clavicle. The typical injury at the medial end of the clavicle is an anterior or posterior dislocation of the sternoclavicular joint. Importantly, a posterior dislocation of the clavicle may impinge on the great vessels in the root of the neck and compress or disrupt them. In the clinic Dislocations of the glenohumeral joint The glenohumeral joint is extremely mobile, providing a wide range of movement at the expense of stability. The relatively small bony glenoid cavity, supplemented by the less robust fibrocartilaginous glenoid labrum and the ligamentous support, make it susceptible to dislocation.


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Anatomy_Gray. Anterior dislocation (Fig. 7.32) occurs most frequently and is usually associated with an isolated traumatic incident (clinically, all anterior dislocations are anteroinferior). In some cases, the anteroinferior glenoid labrum is torn with or without a small bony fragment. Once the joint capsule and cartilage are disrupted, the joint is susceptible to further (recurrent) dislocations. When an anteroinferior dislocation occurs, the axillary nerve may be injured by direct compression of the humeral head on the nerve inferiorly as it passes through the quadrangular space. Furthermore, the “lengthening” effect of the humerus may stretch the radial nerve, which is tightly bound within the radial groove, and produce a radial nerve paralysis. Occasionally, an anteroinferior dislocation is associated with a fracture, which may require surgical reduction.


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Anatomy_Gray. Posterior dislocation is extremely rare; when seen, the clinician should focus on its cause, the most common being extremely vigorous muscle contractions, which may be associated with an epileptic seizure caused by electrocution. Treatment of recurrent instability can be challenging. The aims of treatment are to maintain function and range of movement while preventing instability (subluxation, dislocation, and the “feeling” of dislocation). This can be achieved through physical therapy and shoulder “re-education.” If this fails, capsular tightening and stabilization of the labrum can be achieved arthroscopically. If the problem persists, the coracoid process can be divided at the base, maintaining continuity of the muscular attachments. The process is transferred and a screw fixed to the anterior inferior border of the glenoid to form a buttress to prevent future dislocations. In the clinic


Anatomy_Gray

Anatomy_Gray. In the clinic The two main disorders of the rotator cuff are impingement and tendinopathy. The muscle most commonly involved is supraspinatus as it passes beneath the acromion and the acromioclavicular ligament. This space, beneath which the supraspinatus tendon passes, is of fixed dimensions. Swelling of the supraspinatus muscle, excessive fluid within the subacromial/subdeltoid bursa, or subacromial bony spurs may produce significant impingement when the arm is abducted. The blood supply to the supraspinatus tendon is relatively poor. Repeated trauma, in certain circumstances, makes the tendon susceptible to degenerative change, which may result in calcium deposition, producing extreme pain. The calcium deposits can be extracted through a needle under image guidance and often have the consistency of toothpaste.


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Anatomy_Gray. When the supraspinatus tendon has undergone significant degenerative change, it is more susceptible to trauma, and partialor full-thickness tears may develop (Fig. 7.33). These tears are most common in older patients and may result in considerable difficulty in carrying out normal activities of daily living such as combing hair. However, complete tears may be entirely asymptomatic. In the clinic Inflammation of the subacromial (subdeltoid) bursa Between the supraspinatus and deltoid muscles laterally and the acromion medially, there is a bursa referred to clinically as the subacromial or subdeltoid bursa. In patients who have injured the shoulder or who have supraspinatus tendinopathy, this bursa may become inflamed, making movements of the glenohumeral joint painful. These inflammatory changes may be treated by injection of a corticosteroid and local anesthetic agent (Fig. 7.34). In the clinic


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Anatomy_Gray. In the clinic Hypertrophy of the quadrangular space muscles or fibrosis of the muscle edges may impinge on the axillary nerve. Uncommonly, this produces weakness of the deltoid muscle. Typically it produces atrophy of the teres minor muscle, which may affect the control that the rotator cuff muscles exert on shoulder movement. In the clinic ”Winging” of the scapula Because the long thoracic nerve passes down the lateral thoracic wall on the external surface of the serratus anterior muscle, just deep to skin and subcutaneous fascia, it is vulnerable to damage. Loss of function of this muscle causes the medial border, and particularly the inferior angle, of the scapula to elevate away from the thoracic wall, resulting in characteristic “winging” of the scapula, on pushing forward with the arm. Furthermore, normal elevation at the arm is no longer possible. In the clinic Imaging the blood supply to the upper limb


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Anatomy_Gray. In the clinic Imaging the blood supply to the upper limb When there is clinical evidence of vascular compromise to the upper limb, or vessels are needed to form an arteriovenous fistula (which is necessary for renal dialysis), imaging is required to assess the vessels. Ultrasound is a useful tool for carrying out a noninvasive assessment of the vessels of the upper limb from the third part of the subclavian artery to the deep and superficial palmar arteries. Blood flow can be quantified and anatomical variants can be noted.


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Anatomy_Gray. Angiography is carried out in certain cases. The femoral artery is punctured below the inguinal ligament and a long catheter is placed through the iliac arteries and around the arch of the aorta to enter either the left subclavian artery or the brachiocephalic trunk and then the right subclavian artery. Radiopaque contrast agents are injected into the vessel and radiographs are obtained as the contrast agents pass first through the arteries, then the capillaries, and finally the veins. In the clinic Trauma to the arteries of the upper limb The arterial supply to the upper limb is particularly susceptible to trauma in places where it is relatively fixed or in a subcutaneous position. Fracture of rib I


Anatomy_Gray

Anatomy_Gray. The arterial supply to the upper limb is particularly susceptible to trauma in places where it is relatively fixed or in a subcutaneous position. Fracture of rib I As the subclavian artery passes out of the neck and into the axilla, it is fixed in position by the surrounding muscles to the superior surface of rib I. A rapid deceleration injury involving upper thoracic trauma may cause a first rib fracture, which may significantly compromise the distal part of the subclavian artery or the first part of the axillary artery. Fortunately, there are anastomotic connections between branches of the subclavian artery and the axillary artery, which form a network around the scapula and proximal end of the humerus; therefore, even with complete vessel transection, the arm is rarely rendered completely ischemic (ischemia is poor blood supply to an organ or a limb). Anterior dislocation of the humeral head


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Anatomy_Gray. Anterior dislocation of the humeral head Anterior dislocation of the humeral head may compress the axillary artery, resulting in vessel occlusion. This is unlikely to render the upper limb completely ischemic, but it may be necessary to surgically reconstruct the axillary artery to obtain pain-free function. Importantly, the axillary artery is intimately related to the brachial plexus, which may be damaged at the time of anterior dislocation. In the clinic There are a number of routes through which central venous access may be obtained. The “subclavian route” and the jugular routes are commonly used by clinicians. The subclavian route is a misnomer that remains the preferred term in clinical practice. In fact, most clinicians enter the first part of the axillary vein.


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Anatomy_Gray. There are a number of patients that undergo catheterization of the subclavian vein/axillary vein. Entering the subclavian vein/axillary vein is a relatively straightforward technique. The clavicle is identified and a sharp needle is placed in the infraclavicular region, aiming superomedially. When venous blood is aspirated, access has been obtained. This route is popular for long-term venous access, such as Hickman lines, and for shorter-term access where multiple-lumen catheters are inserted (e.g., intensive care unit).


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Anatomy_Gray. The subclavian vein/axillary vein is also the preferred site for insertion of pacemaker wires. There is, however, a preferred point of entry into the vein to prevent complications. The vein should be punctured in the midclavicular line or lateral to this line. The reason for this puncture site is the course of the vein and its relationship to other structures. The vein passes anterior to the artery, superior to the first rib, and inferior to the clavicle as it courses toward the thoracic inlet. Beneath the clavicle is situated the subclavius muscle. Should the puncture of the vein enter where the subclavius muscle is related to the axillary vein, the catheter or wire may become kinked at this point. Moreover, the constant contraction and relaxation of this muscle will induce fatigue in the line and wire, which may ultimately lead to fracture. A fractured pacemaker wire or a rupture in a chemotherapy catheter can have severe consequences for the patient. In the clinic


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Anatomy_Gray. In the clinic Injuries to the brachial plexus The brachial plexus is an extremely complex structure. When damaged, it requires meticulous clinical history taking and examination. Assessment of the individual nerve functions can be obtained by nerve conduction studies and electromyography, which assess the latency of muscle contraction when the nerve is artificially stimulated. Brachial plexus injuries are usually the result of blunt trauma producing nerve avulsions and disruption. These injuries are usually devastating for the function of the upper limb and require many months of dedicated rehabilitation for even a small amount of function to return. Spinal cord injuries in the cervical region and direct pulling injuries tend to affect the roots of the brachial plexus. Severe trauma to the first rib usually affects the trunks. The divisions and cords of the brachial plexus can be injured by dislocation of the glenohumeral joint. In the clinic


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Anatomy_Gray. In the clinic Lymphatic drainage from the lateral part of the breast passes through nodes in the axilla. Significant disruption to the normal lymphatic drainage of the upper limb may occur if a mastectomy or a surgical axillary nodal clearance has been carried out for breast cancer. Furthermore, some patients have radiotherapy to the axilla to prevent the spread of metastatic disease, but a side effect of this is the destruction of the tiny lymphatics as well as the cancer cells. If the lymphatic drainage of the upper limb is damaged, the arm may swell and pitting edema (lymphedema) may develop. In the clinic Rupture of biceps tendon


Anatomy_Gray

Anatomy_Gray. If the lymphatic drainage of the upper limb is damaged, the arm may swell and pitting edema (lymphedema) may develop. In the clinic Rupture of biceps tendon It is relatively unusual for muscles and their tendons to rupture in the upper limb; however, the tendon that most commonly ruptures is the tendon of the long head of the biceps brachii muscle. In isolation, this has relatively little effect on the upper limb, but it does produce a characteristic deformity—on flexing the elbow, there is an extremely prominent bulge of the muscle belly as its unrestrained fibers contract—the “Popeye” sign. Distal biceps tendon rupture also occurs. It is important to determine the site of the rupture, whether it’s at the musculotendinous junction, midtendon, or at the insertion because this will determine the surgical approach for repair. In the clinic


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Anatomy_Gray. In the clinic Blood pressure measurement is an extremely important physiological parameter. High blood pressure (hypertension) requires treatment to prevent long-term complications such as stroke. Low blood pressure may be caused by extreme blood loss, widespread infection, or poor cardiac output (e.g., after myocardial infarction). Accurate measurement of blood pressure is essential.


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Anatomy_Gray. Most clinicians use a sphygmomanometer and a stethoscope. The sphygmomanometer is a device that inflates a cuff around the midportion of the arm to compress the brachial artery against the humerus. The cuff is inflated so it exceeds the systolic blood pressure (greater than 120 mm Hg). The clinician places a stethoscope over the brachial artery in the cubital fossa and listens (auscultates) for the pulse. As the pressure in the arm cuff of the sphygmomanometer is reduced just below the level of the systolic blood pressure, the pulse becomes audible as a regular thumping sound. As the pressure in the sphygmomanometer continues to drop, the regular thumping sound becomes clearer. When the pressure in the sphygmomanometer is less than that of the diastolic blood pressure, the audible thumping sound becomes inaudible. Using the simple scale on the sphygmomanometer, the patient’s blood pressure can be determined. The normal range is 90–120/60–80 mm Hg (systolic blood pressure/diastolic


Anatomy_Gray

Anatomy_Gray. sound becomes inaudible. Using the simple scale on the sphygmomanometer, the patient’s blood pressure can be determined. The normal range is 90–120/60–80 mm Hg (systolic blood pressure/diastolic blood pressure).


Anatomy_Gray

Anatomy_Gray. In the clinic Radial nerve injury in the arm The radial nerve is tightly bound with the profunda brachii artery between the medial and lateral heads of the triceps brachii muscle in the radial groove. If the humerus is fractured, the radial nerve may become stretched or transected in this region, leading to permanent damage and loss of function. This injury is typical (Fig. 7.70) and the nerve should always be tested when a fracture of the midshaft of the humerus is suspected. The patient’s symptoms usually include wrist drop (due to denervation of the extensor muscles) and sensory changes over the dorsum of the hand. In the clinic Median nerve injury in the arm In the arm and forearm the median nerve is usually not injured by trauma because of its relatively deep position. The commonest neurological problem associated with the median nerve is compression beneath the flexor retinaculum at the wrist (carpal tunnel syndrome).


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Anatomy_Gray. On very rare occasions, a fibrous band may arise from the anterior aspect of the humerus beneath which the median nerve passes. This is an embryological remnant of the coracobrachialis muscle and is sometimes called the ligament of Struthers; occasionally, it may calcify. This band can compress the median nerve, resulting in weakness of the flexor muscles in the forearm and the thenar muscles. Nerve conduction studies will demonstrate the site of nerve compression. In the clinic Supracondylar fracture of the humerus


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Anatomy_Gray. In the clinic Supracondylar fracture of the humerus Elbow injuries in children may result in a transverse fracture of the distal end of the humerus, above the level of the epicondyles. This fracture is termed a supracondylar fracture. The distal fragment and its soft tissues are pulled posteriorly by the triceps muscle. This posterior displacement effectively “bowstrings” the brachial artery over the irregular proximal fracture fragment. In children, this is a relatively devastating injury: the muscles of the anterior compartment of the forearm are rendered ischemic and form severe contractions, significantly reducing the function of the anterior compartment and flexor muscles (Volkmann’s ischemic contracture). In the clinic


Anatomy_Gray

Anatomy_Gray. In the clinic Pulled elbow is a disorder that typically occurs in children under 5 years of age. It is commonly caused by a sharp pull of the child’s hand, usually when the child is pulled up a curb. The not-yet-developed head of the radius and the laxity of the anular ligament of the radius allow the head to sublux from this cuff of tissue. Pulled elbow is extremely painful, but can be treated easily by simple supination and compression of the elbow joint by the clinician. When the radial head is relocated the pain subsides immediately and the child can continue with normal activity. In the clinic Fracture of the olecranon Fractures of the olecranon can result from a direct blow to the olecranon or from a fall onto an outstretched hand (Fig. 7.74). The triceps inserts into the olecranon and injuries can cause avulsion of the muscle. In the clinic Developmental changes in the elbow joint


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Anatomy_Gray. In the clinic Developmental changes in the elbow joint The elbow joint can be injured in many ways; the types of injuries are age dependent. When a fracture or soft tissue trauma is suspected, a plain lateral and an anteroposterior radiograph are obtained. In an adult it is usually not difficult to interpret the radiograph, but in children additional factors require interpretation.


Anatomy_Gray

Anatomy_Gray. As the elbow develops in children, numerous secondary ossification centers appear before and around puberty. It is easy to mistakenly interpret these as fractures. In addition, it is also possible for the epiphyses and apophyses to be “pulled off” or disrupted. Therefore, when interpreting a child’s radiograph of the elbow, the physician must know the child’s age (Fig. 7.75). Fusion occurs at around the time of puberty. An understanding of the normal epiphyses and apophyses and their normal relationship to the bones will secure a correct diagnosis. The approximate ages of appearance of the secondary ossification centers around the elbow joint are: capitulum—1 year, head (of radius)—5 years, medial epicondyle—5 years, trochlea—11 years, olecranon—12 years, and lateral epicondyle—13 years. In the clinic Fracture of the head of the radius


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Anatomy_Gray. In the clinic Fracture of the head of the radius A fracture of the head of the radius is a common injury and can cause appreciable morbidity. It is one of the typical injuries that occur with a fall on the outstretched hand. On falling, the force is transmitted to the radial head, which fractures. These fractures typically result in loss of full extension, and potential surgical reconstruction may require long periods of physiotherapy to obtain a full range of movement at the elbow joint.


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Anatomy_Gray. A lateral radiograph of a fracture of the head of the radius typically demonstrates the secondary phenomenon of this injury. When the bone is fractured, fluid fills the synovial cavity, elevating the small pad of fat within the coronoid and olecranon fossae. These fat pads appear as areas of lucency on the lateral radiograph—the “fat pad” sign. This radiological finding is useful because fracture of the head of the radius is not always clearly visible. If there is an appropriate clinical history, tenderness around the head of the radius, and a positive fat pad sign, a fracture can be inferred clinically even if no fracture can be identified on the radiograph, and appropriate treatment can be instituted. In the clinic


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Anatomy_Gray. In the clinic It is not uncommon for people who are involved in sports such as golf and tennis to develop an overuse strain of the origins of the flexor and extensor muscles of the forearm. The pain is typically around the epicondyles and usually resolves after rest and physical therapy. It may also be treated with injection of the patient’s own plasma, rich in platelets, into the tendon to promote tendon healing and repair. If pain and inflammation persist, surgical division of the extensor or flexor origin from the bone may be necessary. Typically, in tennis players this pain occurs on the lateral epicondyle and common extensor origin (tennis elbow), whereas in golfers it occurs on the medial epicondyle and common flexor origin. In the clinic


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Anatomy_Gray. In the clinic Osteoarthritis is extremely common and is usually most severe in the dominant limb. From time to time an arthritic elbow may undergo such degenerative change that small bone fragments appear in the articular cavity. Given the relatively small joint space, these fragments can result in an appreciable reduction in flexion and extension, and typically lodge within the olecranon and coronoid fossae. In the clinic Ulnar nerve injury at the elbow Posterior to the medial epicondyle of the humerus the ulnar nerve is bound in a fibro-osseous tunnel (the cubital tunnel) by a retinaculum. Older patients may develop degenerative changes within this tunnel, which compresses the ulnar nerve when flexed. The repeated action of flexion and extension of the elbow may cause local nerve damage, resulting in impaired function of the ulnar nerve. Accessory muscles and localized neuritis in this region secondary to direct trauma may also produce ulnar nerve damage (Fig. 7.76).


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Anatomy_Gray. In the clinic Construction of a dialysis fistula Many patients throughout the world require renal dialysis for kidney failure. The patient’s blood is filtered and cleaned by the dialysis machine. Blood therefore has to be taken from patients into the filtering device and then returned to them. This process of dialysis occurs over many hours and requires considerable flow rates of 250–500 mL per minute. To enable such large volumes of blood to be removed from and returned to the body, the blood is taken from vessels that have a high flow. As no veins in the peripheral limbs have such high flow, a surgical procedure is necessary to create such a system. In most patients, the radial artery is anastomosed (joined) to the cephalic vein (Fig. 7.78) at the wrist, or the brachial artery is anastomosed to the cephalic vein at the elbow. Some surgeons place an arterial graft between these vessels.


Anatomy_Gray

Anatomy_Gray. After six weeks, the veins increase in size in response to their arterial blood flow and are amenable to direct cannulation or dialysis. In the clinic Fractures of the radius and ulna The radius and ulna are attached to the humerus proximally and the carpal bones distally by a complex series of ligaments. Although the bones are separate, they behave as one. When a severe injury occurs to the forearm it usually involves both bones, resulting in either fracture of both bones or more commonly a fracture of one bone and a dislocation of the other. Commonly, the mechanism of injury and the age of the patient determine which of these are likely to occur. There are three classic injuries to the radius and ulna: Monteggia’s fracture is a fracture of the proximal third of the ulna and an anterior dislocation of the head of the radius at the elbow.


Anatomy_Gray

Anatomy_Gray. There are three classic injuries to the radius and ulna: Monteggia’s fracture is a fracture of the proximal third of the ulna and an anterior dislocation of the head of the radius at the elbow. Galeazzi’s fracture is a fracture of the distal third of the radius associated with subluxation (partial dislocation) of the head of the ulna at the wrist joint. Colles’ fracture is a fracture, and posterior displacement, of the distal end of the radius. Whenever a fracture of the radius or ulna is demonstrated radiographically, further images of the elbow and wrist should be obtained to exclude dislocations. In the clinic Transection of the radial or ulnar artery


Anatomy_Gray

Anatomy_Gray. In the clinic Transection of the radial or ulnar artery Adult patients may transect the radial or ulnar artery because these vessels are relatively subcutaneous. A typical method of injury is when the hand is forced through a plate glass window. Fortunately, the dual supply to the hand usually enables the surgeon to tie off either the ulnar or the radial artery, without significant consequence. In the clinic Fracture of the scaphoid and avascular necrosis of the proximal scaphoid The commonest carpal injury is a fracture across the waist of the scaphoid bone (Fig. 7.96). It is uncommon to see other injuries. In approximately 10% of individuals, the scaphoid bone has a sole blood supply from the radial artery, which enters through the distal portion of the bone to supply the proximal portion. When a fracture occurs across the waist of the scaphoid, the proximal portion therefore undergoes avascular necrosis. It is impossible to predict which patients have this blood supply.


Anatomy_Gray

Anatomy_Gray. In the clinic Interruption of the blood supply to the lunate can lead to avascular necrosis of the lunate, known as Kienbock’s disease (Fig. 7.97). This can cause pain and stiffness and arthritis in the longer term. In the clinic A large median artery is an anatomical variant found in some individuals, where a persistent artery runs alongside the median nerve in one or both forearms and through the carpal tunnel. Individuals are at risk from heavy bleeding from deep cuts to the wrist. In the clinic


Anatomy_Gray

Anatomy_Gray. In the clinic Carpal tunnel syndrome is an entrapment syndrome caused by pressure on the median nerve within the carpal tunnel. The etiology of this condition is often obscure, though in some instances the nerve injury may be a direct effect of increased pressure on the median nerve caused by overuse, swelling of the tendons and tendon sheaths (e.g., rheumatoid arthritis), and cysts arising from the carpal joints. Increased pressure in the carpal tunnel is thought to cause venous congestion that produces nerve edema and anoxic damage to the capillary endothelium of the median nerve itself. Patients typically report pain and pins-and-needles sensations in the distribution of the median nerve. Weakness and loss of muscle bulk of the thenar muscles may also occur. Gently tapping over the median nerve (in the region of the flexor retinaculum) readily produces these symptoms (Tinel’s sign).