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Radiology Anatomy > Narrow upper limb > Flashcards

Narrow upper limb Flashcards

1
Q

Acromioclavicular joint - description

A

• The AC joint is a plane synovial joint of the pectoral girdle

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2
Q

Acromioclavicular joint - articular features

A
  • Lateral end of the clavicle

* Medial border of the acromion

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3
Q

Acromioclavicular joint - capsule +ligaments

A

Capsule:
• Weak joint capsule
• Thickening of the superior fibres constitutes the acromioclavicular ligament
Ligaments:
• Coracoclavicular ligament (main stabiliser)
o conoid ligament: coracoid process to the conoid tubercle
o trapezoid ligament: coracoid process to the trapezoid line
o ligaments attach to each other posteriorly
• Superior and inferior acromioclavicular ligaments

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4
Q

Acromioclavicular joint - Relations

A

• Surrounded by the trapezius, deltoid and supraspinatus

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5
Q

Acromioclavicular joint - neurovasculature

A 
Arterial supply:
•	Suprascapular artery
•	Thoraco-acromial artery
Innervation:
•	Axillary nerve
•	Suprascapular nerve 
•	Lateral pectoral nerve
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6
Q

Acromioclavicular joint - variation

A
  • AC joint configuration can be horizontal (normal), low lying or inferolateral (both associated with impingement of the supraspinatus tendon)
  • Sometimes joint is in two synovial joints separated by a meniscus
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7
Q

Arterial Supply - description

A

• Derived via the subclavian artery which receives blood from the brachiocephalic artery which is the first of the branches from the aortic arch
• Subclavian artery gives off several branches for the head, neck and chest as well as scapular branches before it becomes the axillary artery at the level of the first rib
• Axillary artery turns into the brachial artery just below the axilla as it exits from beneath teres major
o it supplies blood to the shoulder, including the scapula via several smaller branches
• Brachial artery travels medially towards the elbow and gives off a deep branch and collateral branches that supply the arterial anastomosis at the elbow before terminating distal to the elbow and bifurcating into the radial artery and ulnar artery
• Radial and ulnar arteries extend along either side of the forearm to the wrist

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8
Q

Axillary artery -

A

• Origin: continuation of the subclavian artery as it passes under the midpoint of the clavicle on the outer edge of the first rib
• Termination: continues as the brachial artery beneath the teres major
• Divided into three parts by the pectoralis minor
o first part lies proximal to pectoralis minor (branches: superior thoracic artery)
o second part lies posterior to pectoralis minor (branches: thoracoacromial artery, lateral thoracic artery)
o third part distal to pectoralis minor (branches: subscapular artery, anterior circumflex artery, posterior circumflex artery)
• Relations:
o axillary vein is anterior to the artery
o first and second part: posterior, lateral and medial cords embrace the artery
o third part: the cords becomes branches

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9
Q

Brachial artery

A
  • Origin: continuation of the axillary artery distal to teres major
  • Terminal branches: radial and ulnar arteries
  • Initially lies medial to the humerus, biceps brachii and medial head of the triceps
  • Accompanied by the basilic vein and the median nerve (median nerve crosses from lateral to medial)
  • Profunda brachii is the first, and main, branch which arises above the midpoint of the arm
  • Courses medially and gives off superior and inferior ulnar collateral arteries as it approaches the elbow
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10
Q

Radial and ulnar arteries

A
  • Give rise to recurrent arteries that complete the arterial anastomosis at the elbow
  • Ulnar artery gives off an intraosseous branch that trifurcates to form anterior, posterior and recurrent branches
  • Ulnar artery is continuous as the superficial palmar arch
  • Radial artery continues as the deep palmar arch
  • Both give off branches that provide blood to the thumbs and fingers
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11
Q

Arterial Supply - variations

A

• Axillary artery
o high origin of the subscapular artery from the second part
o common trunk for subscapular artery and posterior circumflex humeral artery
o common trunk for subscapular artery, posterior circumflex humeral artery and profunda brachii
• Brachial artery
o duplicated (20%)
o superficial brachial artery: courses anteriorly rather than posteriorly to the median nerve
o accessory brachial artery: duplication that unites before the cubital fossa
• Arteries of the forearm
o persistent median artery: arises from the ulnar artery, travels with the median nerve, associated with bifid median nerve

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12
Q

Arterial supply of the hand -

A
  • Can be divided into palmar and dorsal components

* Palmar arterial supply can be divided into superficial and deep components

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13
Q

Palmar supply

A

• Superficial component
o superficial palmar arch
 superficial branch of the ulnar artery, distal to flexor retinaculum
 two-thirds of cases the palmar arch is incomplete
 arch lies across the centre of the palm
o common palmar digital arteries
 branches off the superficial palmar arch
 run in the webs between fingers, splitting into two proper palmar digital arteries that supply adjacent fingers
o proper palmar digital arteries
 branches off the common palmar digital arteries
 runs on either side of each finger
o superficial palmar branch
 branch off the the radial artery
 one-third of cases the superficial palmar branch joins the superficial palmar arch to form a true arcade
• Deep component
o princeps pollicis artery
 branch off the radial artery
 travels along the first metacarpal then divides into two palmar digital branches at the metacarpal head
o radial indices artery
 branch off the radial artery
 supplies radial aspect of the index finger
o deep palmar arch
 continuation of the radial artery that anastomoses with the deep branch of the ulnar artery
 often the arch is complete (unlike the superficial arch)
o palmar metacarpal arteries
 branches off the deep palmar arch
 anastamose with the common palmar digital branches and perforate the interosseous spaces to anastomose with the dorsal metacarpal arteries
o deep palmer branch
 of the ulnar artery
o palmar carpal branches

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14
Q

Dorsal supply

A

• Dorsal carpal arch
o anastomosis between the radial, ulnar, and anterior interosseous arteries
• Dorsal metacarpal arteries
o branches off the posterior carpal arch
o anastomose with the deep palmar arch via the palmar metacarpal arteries

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15
Q

Variations

A 
•	Variations of complete arch
o	radioulnar type
o	medianulnar type
o	radiomedianulnar type
•	Variations of incomplete arch
o	variable number of common palmar digital arteries off the radial, ulnar and median arteries
•	Variations of dorsal arch
o	radioulnar type
o	radiointerosseusulnar type
o	interosseusulnar type
o	no dorsal arch
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16
Q

Axilla - boundaries

A
  • Superiorly: outer border of first rib, superior border of scapula, and posterior border of clavicle
  • Medially: serratus anterior, ribcage
  • Anteriorly: pectoralis major, pectoralis minor
  • Posteriorly: subscapularis, teres major, latissimus dorsi
  • Laterally: humerus
  • Inferiorly: axillary fascia (extends between the chest wall (at the level of the 4th rib), arm and the posterior boundary)
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17
Q

Axilla contents

A
  • Axillary artery and its branches
  • Axillary vein and its tributaries
  • Infraclavicular part of the brachial plexus
  • Five groups of axillary lymph nodes and the associated lymphatics
  • The long thoracic and intercostobrachial nerves
  • Axillary fat and areolar tissue
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18
Q

Axillary artery branches

A

Axillary artery is from the lateral margin of the first rib to the inferior border of the teres major

Parts:
• First part: medial to pectoralis minor
• Second part: posteriorly to pectoralis minor
• Third part: lateral to pectoralis minor
Branches: She Tastes Like Sweet Apple Pie:
• First part (1 branch)
o Superior thoracic artery
• Second part (2 branches)
o Thoraco-acromial artery
o Lateral thoracic artery
 variant branching from: (1) thoracoacromial, (2) third part of axillary artery, (3) suprascapular artery, (4) subscapular artery
• Third part (3 branches)
o Subscapular artery
o Anterior humeral circumflex artery
o Posterior humeral circumflex artery
 variable eg. the posterior and anterior circumflex arteries often have a common trunk

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19
Q

Axillary Nerve - origin

A
  • Arises from the posterior cord of the brachial plexus

* Fibres from C5-C6

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20
Q

Axillary Nerve - course

A
  • Lies posteriorly to the axillary artery in the axilla
  • Passes inferiorly to the shoulder joint, exiting the axilla through the quadrangular space with the posterior circumflex humeral artery
  • Divides into an anterior and a posterior branch
  • Anterior branch winds around the surgical neck of the humerus, beneath the deltoid with the posterior humeral circumflex vessels
  • Posterior branch is continued as the lateral brachial cutaneous nerve
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21
Q

Axillary Nerve - supply

A
  • Muscular branches: deltoid, teres minor
  • Articular branches to the glenohumeral joint
  • Superior lateral cutaneous nerve of the arm (skin overlying the deltoid muscle)
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22
Q

Collateral Ligaments of the Elbow - Description

A

• Medial (ulna) collateral ligament (MCL/UCL) complex is a major stabiliser of the elbow joint and resists valgus stress
• MCL complex runs from the humerus to the ulna and is composed of three parts
o anterior bundle
 inferior medial epicondyle to the sublime tubercle of the medial coronoid process
 cord-like
o posterior bundle
 medial epicondyle to medial olecranon
 thickening of the joint capsule
o transverse / oblique bundle (Cooper’s ligament)
 runs between the inferior fibres of the anterior and posterior bands (ie. medial olecranon to medial coronoid process)
 almost no role in elbow stabilisation
• Lateral (radial) collateral ligament (LUCL/RCL) complex is a major lateral stabiliser of the elbow joint and resists varus stress
• LCL is a Y-shaped ligamentous complex composed of three parts
o annular ligament
 from sigmoid notch to supinator crest of the ulna bone
 forms a sling around the radial head
o radial collateral ligament
 anterior lateral epicondyle to annular ligament and supinator muscle fascia
o lateral ulnar collateral ligament
 lateral epicondyle to supinator crest of the ulna

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23
Q

Collateral Ligaments of the Elbow - Variants

A
  • Accessory lateral collateral ligament - runs from annular ligament to supinator crest
  • Absence of lateral ulna collateral ligament
  • Accessory ligament - posterior joint capsule to transverse ligament (25%)
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24
Q

Cubital Fossa

A

Contents (lateral to medial):
• Proximal: imaginary horizontal line connecting the medial and lateral epicondyles of the humerus
• Medial: lateral border of pronator teres
• Lateral: medial border of brachioradialis muscle
• Distal: meeting point of the lateral and medial boundaries
• Roof: superficial fascia containing the median cubital vein, lateral and medial cutaneous nerve of the forearm, bicipital aponeurosis
• Floor: brachialis, supinator
• Radial nerve
• Biceps brachii tendon
• Brachial artery and vein
• Median nerve

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25
Q

Cubital Tunnel - Boundaries

A
  • Roof: cubital tunnel retinaculum (Osborne ligament) extends from the olecranon to the medial epicondyle
  • Laterally: olecranon process
  • Medially: medial epicondyle
  • Floor: elbow joint capsule, posterior band of MCL of the elbow joint
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26
Q

Cubital Tunnel - Contents

A
  • Ulnar nerve
  • Superior ulnar collateral artery
  • Fat
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27
Q

Elbow joint - Articulation

A
  • Radiohumeral: capitellum of the humerus with the radial head
  • Ulnohumeral: trochlea of the humerus with the trochlear notch of the ulna
  • Radioulnar: radial head with the radial notch of the ulna
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28
Q

Elbow joint - ligaments/capsule

A

Ligaments:
• Lateral collateral ligament complex of the elbow:
o radial collateral ligament: thickening of the lateral aspect of the capsule
o annular ligament: encircles the head of the radius being attached to the anterior and posterior margins of the radial notch
o lateral ulnar collateral ligament
• Medial collateral ligament complex of the elbow:
o ulnar collateral ligament: thickening of the medial aspect of the capsule
 anterior, posterior and transverse bundles
Capsule:
• The joint capsule has two layers, deep and superficial
• Attaches proximally to the radial, coronoid and olecranon fossae
• Distally it attaches to the annular ligament of the radius and coronoid process of the ulna

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29
Q

Elbow joint - fat pads

A

• Three fat pads of the elbow sit between the two layers of the joint capsule, making them extra-synovial:
o coronoid fossa fat pad (anterior)
o radial fossa fat pad (anterior)
o olecranon fossa fat pad (posterior)

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30
Q

Elbow joint - bursae

A
  • Superficial olecranon bursa: lies between the olecranon and the subcutaneous tissue
  • Subtendinous olecranon bursa: lies between olecranon and triceps brachii tendon
  • Intratendinous olecranon bursa: variably lies in the triceps brachii tendon
  • Bicipitoradial bursa: completely or partially envelopes the distal biceps brachii tendon, preventing friction against the proximal radius
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31
Q

Elbow joint - relations

A

Movements:
• Combination hinge and pivot joint:
o the hinge component (allowing flexion-extension) is formed by the ulnohumeral articulation
o the pivot component (allowing pronation-supination) is formed by the radiohumeral articulation and the proximal radioulnar joint
Relations:
• Anterior: brachialis, cubital fossa (biceps brachii tendon, median nerve, brachial artery)
• Posterior: triceps brachii, olecranon bursae
• Lateral: supinator, common extensor origin
• Medial: common flexor origin, ulna nerve

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32
Q

Elbow joint - neurovasculature

A

Arterial supply:
• Arterial supply is via anastomotic arcades formed by branches of the radial, ulna and brachial arteries
Nerve supply:
• Articular branches of the radial, ulna, median and musculocutaneous nerves

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33
Q

Elbow joint - variants

A

• Synovial folds
o thin projections of synovial membrane (inner layer of joint capsule)
o may be confused for intra-articular loose bodies on MRI
• Capitellar and olecranon pseudodefects
o normal areas devoid of articular cartilage
o can be mistaken on MRI for impaction injuries or osteochondral defects
• Accessory ossicles
o os supratrochlear dorsale
o patella cubiti

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34
Q

Extensor tendons at the wrist

A
  • Remember longus, brevis, longus, brevis, longus for compartment 1, 2, 3
  • All tendons pass under extensor retinaculum, but different compartments are enclosed in their own synovial tendon sheath
  • Compartment 1: APL, EPB
  • Compartment 2: ECRL, ECRB
  • Listers tubercle
  • Compartment 3: EPL
  • Compartment 4: extensor indices, extensor digitorum
  • Compartment 5: extensor digiti minimi
  • Compartment 6: ECU
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35
Q

Glenohumeral joint - description and articular surfaces

A

• Ball and socket, synovial joint
• Reinforced by the rotator cuff, except inferiorly where it is weakest
Articular surfaces:
• Head of humerus
• Glenoid fossa of the scapula
• Glenoid labrum increases the surface area for the humeral head

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36
Q

Glenohumeral joint - capsule/ligaments

A

Capsule:
• Capsule of the joint is attached to the scapula at the margins of the labrum
• Attached to the humeral head at the anatomical neck except inferiorly where it is attached to the surgical neck
• Synovial membrane lines the capsule and invests the long head of the biceps in a tubular sleeve
• Synovial membrane continues under the subscapularis muscle as the subscapular bursa (communicates via foramen of Weitbrecht)
Ligaments:
• Glenohumeral ligaments are 3 thickened bands from glenoid labrum to humerus that reinforce the anterior capsule
o superior attaches to just above lesser tubercle
o middle attaches to lower part of lesser tubercle
o inferior attaches to surgical neck ?anterior and posterior parts
• Coracohumeral ligament runs from the coracoid process to the anterior aspect of the greater tubercle
• Transverse humeral ligament is part of the capsule that bridges the gap between lesser and greater tubercles

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37
Q

Glenohumeral joint - movements

A

• Arm flexion, extension, adduction, abduction, internal rotation, external rotation, circumduction

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38
Q

Glenohumeral joint - relations

A
  • Superior: Supraspinatus
  • Inferior: Long Head of the Triceps brachii
  • Anterior: Subscapularis
  • Posterior: Infraspinatus and Teres minor
  • Within: Tendon of Long Head of Biceps brachii
  • Deltoid covers the articulation in front, behind, and laterally
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39
Q

Glenohumeral joint - neurovasculature

A

Arterial supply:
• Anterior / Posterior Circumflex Humeral
• Suprascapular Arteries
Nerve supply:
• Suprascapular, Axillary and Lateral Pectoral Nerves

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40
Q

Intrinsic muscles of the hand

A 
Lateral to medial in the palm
A: abductor pollicis brevis
F: flexor pollicis brevis
O: opponens pollicis
A: adductor pollicis (oblique and transverse heads)
O: opponens digiti minimi
F: flexor digiti minimi
A: abductor digiti minimi
Palmar and dorsal interossei: PAd, DAb
P: palmar interossei
Ad: adduction
D: dorsal interossei
Ab: abduction
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41
Q

Lunate - description

A
  • Lunate is one of the carpal bones and forms part of the proximal carpal row
  • Crescent-shape with a proximal convex articular facet and a distal concave articular facet
  • Medial surface is a square-shaped facet and the lateral surface is a semilunar facet
42
Q

Lunate - articulations

A

• Radius (along with the scaphoid and triquetrum)
• Scaphoid (lateral)
• Capitate (distal)
• Triquetrum (medial)
• Hamate (distal and medial)
• Triangular fibrocartilage complex
o this is composed of the triangular disc, distal radioulnar ligaments and the ulnocarpal ligaments

43
Q

Lunate - attachments

A
  • Scapholunate ligament
  • Lunotriquetral ligament
  • Palmar radiocarpal ligament
  • Dorsal radiocarpal ligament
44
Q

Lunate - relations

A

• Structures in the carpal tunnel pass over it (4 tendons of FDP, 4 tendons of FDS, 1 tendon of FPL, median nerve)

45
Q

Lunate - variants

A

• Lunate morphology
o type I lunates: single distal articular facet for the capitate
o type II lunates: additional distal articular facet medially for the hamate
• Lunotriquetral coalition: congenital fusion of the lunate and triquetral
• Associated accessory ossicles: os epilunatum, os hypotriquetrum

46
Q

Upper limb lymph drainage

A

Description/Course/Relations:
• Lymph glands of the upper extremity divided into superficial and deep
o only a few small superficial nodes - supratrochlear (above medial epicondyle of humerus) and deltopectoral (beside cephalic vein between pectoralis major and deltoid)
o deep lymph nodes mainly located in axilla - 5 subtypes
 lateral / humeral lymph nodes
 anterior / pectoral axillary lymph nodes
 posterior / subscapular axillary lymph nodes
 central lymph nodes
 apical lymph nodes
o axillary lymph nodes drain lymph from the arms, breast, chest wall and upper abdomen
• Lymphatic vessels also divided into superficial and deep
o superficial lymphatic vessels form a network mesh, then group together into median, ulnar and radial groups which follow the median cubital, basilic and cephalic veins respectively
 few drain into supratrochlear nodes, but majority drain into lateral axillary nodes
o deep lymphatic vessels accompany deep arteries (radial, ulnar, anterior and posterior interosseus arteries)
 mostly also pass to lateral axillary nodes
o there is communication between superficial and deep lymph channels

47
Q

Median Nerve - Description +origin

A

• One of five main nerves that arise from brachial plexus
• Only one to pass through carpal tunnel
• Carpal tunnel syndrome is due to pressure on the median nerve
origin
• Lateral and medial cords of the brachial plexus (fibres from C5-T1)

48
Q

Median Nerve - course/relations

A
  • It lies at first lateral to the brachial artery then crosses about the level of the insertion of the Coracobrachialis to its medial side
  • Descends in the arm between Biceps brachii and Triceps brachii muscles
  • Enters the cubital fossa
  • In the forearm it passes between the two heads of the Pronator teres and crosses the ulnar artery
  • It descends beneath the Flexor digitorum superficialis, and superficial to the Flexor digitorum profundus
  • Travels with four tendons of FDS, four tendons of FDP, tendon of FHL through the carpal tunnel
49
Q

Median Nerve - Major branches

A

• Anterior interosseous nerve
o supplies all the flexor muscles of the forearm apart from flexor carpi ulnaris and the ulnar half of flexor digitorum profundus
• Motor branch in the hand (recurrent branch to thenar, palmar digital to lumbricals)
o supplies thenar muscles and the radial two lumbricals (LOAF muscles)
• Palmar cutaneous branch
o cutaneous innervation to the palmar aspect of the thumb, index and middle fingers and the radial half of the ring finger
• Articular branches to the elbow, wrist, carpal and phalangeal joints

50
Q

Median Nerve - variants

A

• May pass under the Struthers’ ligament (exists in 10-15% people) which extends between a bony process from humeral shaft to the medial epicondyle (passes under here with the brachial artery) - potential site of compression (supracondylar process syndrome)
• High division or bifid median nerve
o bifurcation of the median nerve typically occurs after the nerve exits the carpal tunnel
o 5%-10% individuals the median nerve bifurcates more proximal in the carpal tunnel, wrist or forearm
• During gestation, a median artery that serves the hand retracts. However, in some individuals the median artery does not retract and follows the course next to the median nerve into the hand
• Martin-Gruber anastomoses can occur when branches of the median nerve cross-over in the forearm and merge with the ulnar nerve to innervate portions of the forearm
• Riche-Cannieu anastomoses can occur when there is connection between recurrent branch of the median nerve and deep branch of the ulnar nerve of the hand
• The median nerve or either of its branches may pass behind the axillary artery or brachial artery instead of in front of it
• The site of union between the lateral and medial cords is quite variable and has been found as far down as the elbow
• The two cords (lateral and medial) may enclose the axillary vein as well as the axillary artery

51
Q

Musculocutaneous N - origin

A
  • Lateral cord of the brachial plexus

* Fibres from C5-C7

52
Q

Musculocutaneous N - course

A
  • In the axilla, the musculocutaneous nerve courses laterally away from the axillary artery
  • Pierces (and supplies) the coracobrachialis muscle and descends towards the elbow between biceps brachii and brachialis muscles
  • In the cubital fossa, it courses lateral to the biceps tendon as the lateral cutaneous nerve of the forearm
53
Q

Musculocutaneous N - supply

A
  • Muscular branches: anterior compartment of the arm (coracobrachialis, biceps brachii and brachialis muscles)
  • Articular branches: shoulder and elbow joints
  • Lateral cutaneous nerve of the forearm (lateral aspect of the forearm)
54
Q

Quadrangular space - general

A
  • Quadrangular space is an axillary space in the arm
  • The axillary nerve and posterior circumflex humeral artery can be compressed or damaged due to space-occupying lesions / trauma
55
Q

Quadrangular space - borders

A
  • Superiorly: subscapularis muscle, teres minor muscle
  • Medially: long head of triceps brachii muscle
  • Laterally: surgical neck of humerus
  • Inferiorly: teres major muscle
56
Q

Quadrangular space - contents

A
  • Axillary nerve

* Posterior circumflex humeral artery and vein

57
Q

Radial Nerve - description

A
  • One of five main branches of the brachial plexus

* Provides motor and sensory innervation to the arm and forearm and sensory innervation to the hand

58
Q

Radial Nerve - origin

A
  • One of two terminal branches of the posterior cord of the brachial plexus (other being axillary)
  • Fibres from C8-T1
59
Q

Radial Nerve - course/relations

A
  • Lies posterior to the axillary artery in the axilla
  • Enters the posterior compartment of the arm under teres major muscle
  • Winds around the radial groove of the humerus (between lateral and medial heads of the triceps) accompanying profunda brachii artery
  • Passes through the triangular space with profunda brachii
  • Pierces the lateral intermuscular septum to enter the anterior compartment of the arm
  • Passes to the forearm by coursing anterior to the lateral epicondyle at the level of the elbow joint
  • Enters the cubital fossa, where it divides into superficial and deep branches
  • Superficial branch courses towards the wrist lateral to the radial artery and enters the hand, dividing into the dorsal digital cutaneous branches
  • Deep branch of the radial nerve winds to the back of the forearm around the lateral side of the radius between the two heads of the supinator and continues downward between superficial and deep layers of muscles to the middle of the forearm as the posterior interosseus nerve
60
Q

Radial Nerve - branches/ supply

A

• Muscular twigs in the arm:
o medial and lateral heads of the triceps brachii
o anconeus muscles
o brachioradialis
o extensor carpi radialis longus
• Superficial branch of the radial nerve supplies cutaneous sensation to the:
o dorsal aspect of the hand
o dorsal aspect of the first to third digits
o dorsal lateral aspect of the fourth finger
• Deep branch of the radial nerve (continues as the posterior interosseous nerve):
o extensor carpi radialis brevis
o supinator
o extensor digitorum
o extensor digiti minimi
o extensor carpi ulnaris
o abductor pollicis longus
o extensor pollicis brevis
o extensor pollicis longus
o extensor indicis
• Articular twigs to the elbow and wrist joints
• Posterior cutaneous nerve of the forearm

61
Q

Radial Nerve - variants

A
  • The radial nerve may communicate with the ulnar nerve in the arm
  • The radial nerve may supply the entire dorsum of the hand including the dorsal aspect of all the fingers
62
Q

Rotator Cuff - description

A
  • Group of muscles and their tendons that act to stabilize the shoulder
  • Supraspinatus, infraspinatus, teres minor, subscapularis
63
Q

Rotator Cuff - origin

A
  • Supraspinatus - supraspinous fossa of the scapula
  • Infraspinatus - infraspinous fossa of the scapula
  • Teres minor - middle half of the lateral border of the scapula
  • Subscapularis - subscapular fossa of the scapula
64
Q

Rotator Cuff - insertion

A
  • Supraspinatus - superior and middle facet of the greater tubercle
  • Infraspinatus - posterior facet of the greater tubercle
  • Teres minor - inferior facet of the greater tubercle
  • Subscapularis - lesser tubercle (60%) or humeral neck (40%)
65
Q

Rotator Cuff - action

A
  • Supraspinatus - abducts the humerus
  • Infraspinatus - externally rotates the humerus
  • Teres minor - externally rotates the humerus
  • Subscapularis - internally rotates the humerus
66
Q

Rotator Cuff - relations

A

• Supraspinatus tendon closely associated to the coracoacromial arch
o may lead to shoulder impingement syndrome
• All tendons run outside capsule, and the glenohumeral ligaments
• Coracohumeral ligament helps support rotator cuff

67
Q

Rotator Cuff - neurovasculature

A

Nerve supply:
• Supraspinatus - suprascapular nerve (C4-6)
• Infraspinatus - suprascapular nerve (C4-6)
• Teres minor - axillary nerve (C5-6)
• Subscapularis - subscapular nerve (C5-6)
Blood supply:
• Supraspinatus - suprascapular artery
• Infraspinatus - suprascapular artery and circumflex scapular artery
• Teres minor - circumflex scapular artery and posterior circumflex humeral artery
• Subscapularis - subscapular artery

68
Q

Scaphoid - Features/location

A
  • The scaphoid is the largest bone of the proximal carpal row
  • Boat shaped
  • It is situated at the radial side of the carpus
  • The scaphoid can be divided into proximal and distal poles separated by the waist
  • The scaphoid tubercle is a bony prominence on the ventral surface of the lateral portion of the distal pole
69
Q

Scaphoid - articulation

A
  • Scaphoid articulates with five bones
  • Proximal surface: radius
  • Distal surface: laterally with the trapezoid and trapezium; medially with the capitate
  • Ulnar surface: lunate
70
Q

Scaphoid - attachments

A
  • Dorsal radiocarpal ligament
  • Palmar radiocarpal ligament
  • Radial collateral ligament
  • Scapholunate ligament
  • Radioscapholunate ligament
  • Scaphocapitate ligament
  • Short ligaments to trapezoid and trapezium
71
Q

Scaphoid - relations

A
  • The radial artery crosses the dorsal surface of the scaphoid (snuff box)
  • The scaphoid forms the radial portion of the carpal tunnel and is therefore related to the structures that pass through it (fibres from flexor digitorum produndus and superficialis, the median nerve, flexor pollicis longus), flexor carpi radialis runs within retinaculum
  • Muscles of the thumbs and associated tendons are located in the vicinity
72
Q

Scaphoid - variant anatomy

A
  • Approximately 75% of blood supply is from branches of the radial artery through vascular perforations on the dorsal surface near the tubercle and waist
  • Mainly retrograde vascular supply to the proximal pole
73
Q

Scaphoid - blood supply

A
  • Bipartite scaphoid
  • Coalition with neighbouring bones (rare)
  • Scaphoid hypoplasia
74
Q

Scapula - description

A

• It is a flat triangular bone
• The upper border slants laterally and downwards to the scapular notch
• The lateral border of the scapula extends from the glenoid cavity to the inferior angle
• The glenoid cavity forms part of the shoulder joint and presents superior and inferior tubercles for attachment of biceps and triceps respectively
• The dorsal surface of the scapula is divided by the spine into supraspinous and infraspinous fossae
• Anteriorly, on the costal surface, is the shallow subscapular fossa
• The spine extends laterally over the shoulder joint as the acromion
• The coracoid process is a thick curved process attached by a broad base to the upper part of the neck of the scapula
• There are multiple ossification sites in the scapula
o an ossification centre appears in the coracoid process in the first year and fuses by 15

75
Q

Scapula - articulations

A
  • Acromion: clavicle (forming the acromioclavicular joint)

* Glenoid cavity: humeral head (forming the glenohumeral joint)

76
Q

Scapula - attachments

A

• Musculotendinous
o supraspinous fossa: supraspinatus muscle
o infraspinous fossa: infraspinatus muscle
o subscapular fossa: subscapularis muscle, serratus anterior
o acromion: acromial part of deltoid muscle, trapezius
o scapular spine: spinous part of deltoid muscle, trapezius
o lateral border: teres minor muscle, teres major muscle
o medial border: levator scapulae, rhomboid minor, rhomboid major
o inferior angle: teres major muscle, latissimus dorsi (small slip)
o supraglenoid tubercle: long head of biceps muscle
o infraglenoid tubercle: long head of triceps muscle
o coracoid process: pectoralis minor, short head of biceps brachii, coracobrachialis
• Ligamentous
o superior transverse scapular ligament: crosses suprascapular notch, with the suprascapular nerve below (within the resulting foramen) and the suprascapular vessels above
o coracoacromial ligament
o coracoclavicular ligament: conoid to the conoid tubercle, trapezoid ligament to the trapezoid line
o coracohumeral ligament
o glenohumeral ligaments: superior, middle, inferior
o acromioclavicular ligament: superior, inferior

77
Q

Scapula - blood supply

A

The scapula is a site of arterial anastomosis between many arteries
o suprascapular artery
o dorsal scapular artery
o branches of subscapular artery (ie. circumflex scapular artery)

78
Q

Scapula - variants

A
  • The coracoid process may exist as a separate bone
  • Sprengel deformity: congenital elevation of the scapula
  • Suprascapular notch: absent, V-shaped, U-shaped, superior transverse scapular notch is ossified making it a foramen
79
Q

Snuff box - borders

A
  • Medial: extensor pollicis longus
  • Lateral: extensor pollicis brevis, abductor pollicis longus (more laterally)
  • Floor: scaphoid, trapezium bones, base of 1st metacarpal (distally), radial styloid process (proximally)
80
Q

Snuff box - contents

A
  • Radial artery
  • Superficial branch of the radial nerve
  • Cephalic vein (variable)
81
Q

Subclavian Artery - description

A

• Subclavian artery supplies blood to the upper limb with some supply to the neck and thorax

82
Q

Subclavian Artery - origin/end

A

• Right subclavian artery is a terminal branch of the brachiocephalic trunk
o arises posterior to the right sternoclavicular joint
• Left subclavian artery arises from the arch of the aorta (T3/ T4) and enters the root of the neck by passing superiorly
o arises posterior to the left sternoclavicular joint
• Ends at the lateral margin of the first rib where it becomes the axillary artery
• Subclavian is divided into three parts based on its relation to scalenus anterior
o 1st part = medial to the anterior scalene
o 2nd part = posterior to the anterior scalene
o 3rd part = lateral to the anterior scalene

83
Q

Subclavian Artery - relations

A
  • Anterior: IJV, subclavian vein, subclavius, clavicle, vagus nerve, phrenic nerve, thoracic duct, right lymph duct, anterior scalene
  • Inferior: rests in a depression on the first rib (subclavian groove) and upon the pleura
  • Posterior: sympathetic trunk, longus colli, scalenus medius, inferior trunk of brachial plexus
  • Superior: brachial plexus
  • Right RLN winds around the right subclavian
84
Q

Subclavian Artery - Branches

A

• 5 branches (VITamin C & D)
o vertebral artery (1st part)
 surrounded by a plexus of nerve fibers derived from the inferior cervical ganglion of the sympathetic trunk
 ascends through the foramina in the transverse process of C6
o internal thoracic artery (1st part)
 passes inferomedially into the thorax
o thyrocervical trunk (1st part)
 gives off the the inferior thyroid, suprascapular and transverse cervical arteries
 ascending cervical artery is a branch of the inferior thyroid
o costocervical trunk (2nd part)
 divides into the superior intercostal and deep cervical arteries
 supply the first two intercostal (posteriorly) spaces and the muscles of the neck
o dorsal scapular (3rd part)
 follows the nerve to rhomboids, deep to the levator scapulae

85
Q

Subclavian Artery - variants

A

• Right subclavian artery may arise directly from the arch of the aorta
o if it arises as the last branch, it may course behind the trachea (retrotrachea) or both the trachea and esophagus (retroesophageal) to reach the groove on the first rib
• Subclavian artery divides in some cases at the medial border of scalenus anterior muscle, with the two branches continuing through the axilla and down the arm to become the radial and ulnar arteries
• If a cervical rib is present, the artery may run above this extra rib
• Many different branching patterns
o examples: internal thoracic as a branch of thyrocervical trunk, costocervical trunk may give off inferior thyroid/vertebral/suprascapular arteries
• Left subclavian originates from a left brachiocephalic artery

86
Q

Ulnar nerve - Description

A

• Ulnar nerve is one of the terminal branches of the brachial plexus and has motor and sensory supply to the forearm and hand

87
Q

Ulnar nerve - origin

A

• Terminal branch of the medial cord of the brachial plexus with nerve root fibres from C8-T1

88
Q

Ulnar nerve - course/relations

A

• Arm
o runs medial to the axillary artery and subsequently the brachial artery on the coracobrachialis muscle in the anterior compartment
o posterior to the basilic vein and medial to the medial head then long head of the triceps brachii
o passes posterior to the medial epicondyle of the humerus in the superficial condylar groove in the cubital tunnel (under ligament of Osborne)
• Forearm
o enters the forearm between the two heads of flexor carpi ulnaris
o lies superficial to flexor digitorum profundus, deep to flexor carpi ulnaris, with the ulnar artery
o at the wrist, the ulnar nerve runs lateral to the tendon of flexor carpi ulnaris
• Hand
o enters the hand superficial to the flexor retinaculum and inside Guyon’s canal
o divides into its terminal branches at the level of the pisiform bone

89
Q

Ulnar nerve - branches

A
  • Muscular branches: arise near the elbow to supply flexor carpi ulnaris and the ulnar half of the flexor digitorum profundus
  • Palmar cutaneous branch: supplies skin of the hypothenar eminence
  • Dorsal cutaneous branch: arises above the wrist, supplies the dorsum of the hand and the ulnar one and a half fingers
  • Superficial branch: supplies palmaris brevis, and the remainder of the skin of the ulnar one and a half fingers
  • Deep branch: supplies the three hypothenar muscles and adductor pollicis, all the interossei, the third and fourth lumbricals
90
Q

Ulnar nerve - supply

A

• Motor:
o FDP, FCU
o hypothenar muscles, adductor pollicis
o all interossei, third and fouth lumbricals
• Sensory:
o articular innervation to elbow, wrist, carpal and phalangeal joints
o cutaneous innervation to ulnar aspect of the hand, 5th finger, medial 4th finger

91
Q

Ulnar nerve - variants

A

• The branch to the dorsum of the hand may be deficient, and this is compensated for by the radial or the medial antebrachial cutaneous nerves

92
Q

Cephalic Vein

A

o begins in the radial part of the dorsal venous network of the hand and winds upward around the radial border of the forearm
o ascends between the brachioradialis and the biceps brachii
o continues along the lateral border of the biceps brachii
o in the upper third of the arm it passes between the pectoralis major and deltoid, where it is accompanied by the deltoid branch of the thoracoacromial artery
o pierces the clavipectoral fascia and empties into the axillary vein

93
Q

Basilic Vein

A

o begins in the ulnar part of the dorsal venous network
o runs up the posterior surface of the ulna
o runs upward along the medial border of the biceps brachii
o perforates the deep fascia just below the middle of the arm
o then ascends on the medial side of the brachial artery
o at the lower border of the teres major, is continued onward as the axillary vein

94
Q

Median cubital vein

A

o superficial vein which connects basilic vein and cephalic vein

95
Q

Brachial vein

A

o ulnar and radial veins form the brachial veins
o brachial veins are placed on either side of the brachial artery
o they empty into the axillary vein

96
Q

Axillary vein

A

o begins at the lower border of the teres major as the continuation of the basilic vein
o ends at the outer border of the first rib as the subclavian vein

97
Q

Subclavian vein

A

o is the continuation of the axillary vein
o extends from the outer border of the first rib to the sternal end of the clavicle, where it unites with the internal jugular to form the brachiocephalic vein

98
Q

Wrist Joint - Description

A
  • Along with the carpus, forms the wrist
  • Wrist joint is a synovial condyloid articulation
  • Note: triangular fibrocartilage = triangular articular disc + ulnar collateral ligament + radioulnar ligaments
99
Q

Wrist Joint - articular surfaces

A
  • Distal radius
  • Triangular articular disc: lies between head of ulna and radius, separates distal radioulnar joint from wrist joint
  • Scaphoid
  • Lunate
  • Triquetrum
100
Q

Wrist Joint - ligaments

A
  • Palmar radiocarpal ligament: radius to the volar surfaces of the scaphoid, lunate, and triquetrum
  • Dorsal radiocarpal ligament: radius to the dorsal surfaces of the scaphoid, lunate, and triquetrum
  • Ulnar collateral ligament: styloid process of the ulna and triquetrium / pisiform
  • Radial collateral ligament: styloid process of the radius to the scaphoid
  • Palmar radioulnar ligament
  • Dorsal radioulnar ligament

Radiology Anatomy (14 decks)

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