Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Semester 2 Musculoskeletal System > L10: The elbow and Forearm > Flashcards

L10: The elbow and Forearm Flashcards

1
Q

What type of joint is the elbow joint?

A

Complex hinge joint

Composed of 3 or more skeletal elements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the articulations within the elbow?

A

Humeroulnar joint

Humeroradial joint

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the articulations within the humeroulnar joint?

A 
Trochlear of the humerus
Trochlear notch (sigmoid nothc) of the ulna
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the articulations within the humeroradial joint?

A

Capitellum of the humerus

Radial head

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What other joint is found within the joint capsule but not part of the elbow joint?

A

Proximal radio-ulnar joint

Between the side of head of radius and the radial notch of the ulnar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe the anatomy of the distal humerus?

A

Medial and lateral condyles –>Trochlear and capitellum
Medial and lateral epicondyles–> attachment for forearm muscles
Radial fossa
Coronoid fossa
Posterior side–> olecranon fossa
Medial and lateral supracondyle ridge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What group of muscles attach to the medial condyle?

A

Flexor-pronator groups of anterior forearm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What groups of muscles attach to the lateral epicondyle?

A

Extensor muscles of posterior forearm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What accommodates the radial and coronoid fossae during flexion?

A

The radial head and coronoid porcess of ulnar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What accommodates the olecranon fossa during extension?

A

The olecranon on ulna

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe the anatomy of the proximal radius? Why?

A

Radial head–> concave articulating surface, thicker medially–> proximal radio-ulnar joint
Radial neck–> Inferior to head, thinner, at risk of fracture
Radial tuberosity–> bone projection, attachment of biceps brachii

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Describe the anatomy of the proximal ulnar?

A

Sigmoid (trochlear) notch–> formed by the olecranon and coronoid process–> articulates with the trochlear
Coronoid process–> ridge of bone projects outwards anteriorly
Olecranon–> large projection of bone proximally, ‘tip’ of elbow–> triceps attaches superior surface
Radial notch–> lateral surface
Tuberosity of ulna–> roughening immediatley distal to coronoid process–> brachialis attaches
Supinator crest–> anterior surface of ulnar–> supinator muscle attaches

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What strengthens the medial and lateral aspects of the elbow?

A

Radial (lateral) collateral ligaments

Ulnar (medial) collateral ligaments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the attachment sites radial collateral ligament? What does it do?

A

Radial–> lateral epicondyle of humerus and annular ligament of radius (fan shaped ligament)

Keeps head of radiua and capitellum in close association during pronation and supination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the attachment sites of the ulna collateral ligament?

A

Ulnar–> medial epicondyle of humerus and coronoid process and olecranon of ulnar (triangular shaped)
3 bands
Anterior–> strongest
Posterior–> fan like weakest
Inferior (Slender oblique)–> deepens the socket for the trochlear of humerus (transversely between the anterior and posterior ligaments)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What stabilies the proximal radio-ulna joint?

A

Annular ligament
Forms a collar around the radial head in which the radial head can rotate
Maintain contact with radial notch on ulna

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What movements are possible at the elbow?

A

Flexion and extension

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the carrying angle?

A

The angle at which the ulnar makes with the long axis of humerus at full extension
Usually around 5-10 in men and 10-15 degrees in women

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the point of the carrying angle?

A

Allows the arm to clear the hips in swinging movements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are deviations to the carrying angle known as?

A

Cubital valgus–> angle greater than 5-10/10-15 degrees

Cubital varus–> angle less than 5-10/10-15 degrees

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the main muscles that flex the elbow?

A

Brachialis
Biceps brachii
Brachioradialis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the main muscles that extend the elbow?

A

Triceps brachii

Anconeus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the main muscles involved in supination?

A

No resistance- Supinator

Resistance- Biceps brachii

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the main muscles in involved in pronation?

A

Pronator quadratus

Pronator teres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are the important bursae in the elbow joint? Where are they located?

A

Olecranon bursae–> subcutaneous CT overlying the olecranon

Subtendinous bursae–> between the triceps tendon and tip of olecranon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What type of joint is the distal radio-ulna joint?

A

Pivot joint
Located immediately proximal to the wrist
Ulnar notch of radius rotates anteriorly around the ulna head

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Where does the axis of rotation for supination/pronation pass?

A

Longitudinally through the head of radius proximally and through the styloid process of the ulna distally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What keeps the radius and ulnar together at the distal radioulnar joint? What else does this structure do?

A

Triangular fibrocartilage complex

Also separates the distal radioulnar joint from the wrist joint

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What other structure also helps to keep the radius and ulnar together during the movements of pronation and supination?

A

The interosseous membrane
Fibrous joint
Fibres run diagonally from the radius proximally to the ulnar more distally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is a good way of remembering the anterior forearm muscles?

A 
4-1=3
4 superficial 
(pass, fail, pass, fail--> thumb on medial epicondyle)
1 intermediate
3 deep
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What are the 4 superficial muscles of the anterior compartment?

A 
Pass, Fail, Pass, Fail
Pronator Teres
Flexor carpi radialis 
Palmaris longus
Flexor carpi ulnaris
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is the origin, insertion, innervation and function of the pronator teres?

A

O:

  • -> Humeral head–> medial epicondyle
  • -> Ulna head–> coronoid process of ulna

I: Mid-shaft of the radius

F: Pronation

Innervation: Median nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is the origin, insertion, innervation and function of the Flexor carpi radialis?

A

O: Median epicondlye

I: Base of 2nd and 3rd metacarpals

F: Flexion and abduction at wrist

Innervation: Median nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is the origin, insertion, innervation and function of the Palmaris longus?

A

O: Median epicondyle

I: Flexor retinaculum of wirst and palmar aponeurosis

F: Weak flexor

Innervation: Median nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

How can the palmaris longus be located?

A

Flex the wrist
Oppose the thumb and little finger
Tendon will protrude

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What lies immediately deep to the Palmaris Longus?

A

The median nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is the origin, insertion, innervation and function of the Flexor carpi ulnaris?

A

O:

  • -> Humeral head–> Median epicondlye
  • -> Ulnar head—> Medial margin of the olecranon

I: Pisiform bone, hook of hamate and base of 5th metacarpal bone

F: Flexes and adducts at the wrist

Innervation: Ulnar nerve
(nerve passes between the two heads)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What is the common flexor origin?

A

Superficial flexor muscles all have a common tendon form the medial epicondyle of humerus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What is the intermediate muscle of the forearm?

A

Flexor digitorum superficialis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What is the origin, insertion, innervation and function of the flexor digitorum superficialis?

A

O:
–>Humeroulnar head–> Medial epicondyle of humerus, ulnar collateral ligament and cornonoid process
–> Radial head–> anterior surface of the radius
Not discrete origins form a continuous tendinous arch

I: Base of middle phalanges of the finger digits

F: Flexes metacarpophalangeal joints and proximal interphalangeal joints, flexion of wrist

Innervation: Median nerve

(median nerve and ulnar artery pass between the two heads)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What is the origin, insertion, innervation and function of the Flexor digitorum profundus?

A

O: proximal 2/3 of shaft of ulna and associated interosseous membrane

I: 4 tendons onto base of distal phalanges of four fingers

F: Flex distal interphalangeal joints, flexes metacaropophalangeal joint and flexes wrist

Innervation: Ulnar half (medial half) --> ulnar nerve
Radial half (lateral half)--> anterior interosseous branch of median nerve
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What is the origin, insertion, innervation and function of the Flexor pollicis longus?

A

O: Middle of anterior surface of radial shaft and adjacent interosseous membrane

I: Base of distal phalanx of thumb

F: Flexes interphalangeal joint and metacarpophalangeal of the thumb

Innervation: Anterior interosseous branch of median nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What is the origin, insertion, innervation and function of the pronator quadratus?

A

O: Anterior surface of the distal ulnar

I: Anterior surface of distal radius

F: Pronates the forearm

Innervation: Anterior interosseous branch of the median nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What is the root values of the median nerve?

A

C6-T1

Input from medial and lateral cords of brachial plexus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What is the motor innervation of the median nerve?

A

Anterior flexor and pronator muscles of the forearm
Except flexor carpi ulnaris and 1/2 flexor digitorum profundus
Also 1 1/2 LOAF
1 1/2 lumbricals (lateral)
Opponens pollicis
Abductor pollicis brevis
Flexor Pollicis Brevis (not deep head)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What is the sensory innervation of the median nerve?

A

Small and confined to hand
Palmar cutaneous branch–> radial (lateral) aspect of hand
Digital cutaneous branch–> radial 3.5 fingers on palmar surface and dorsum of their respective distal phalanages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What is the anatomical course of the median nerve?

A
  • Orginated in the axilla
  • Descend the arm lateral to the brachial artery
  • Halfway down crosses over to be situated medially
  • Enter anterior forearm through the cubital fossa
  • Travels between the heads of the pronator teres and deep to tendious arch of flexor digitorum superficialis
  • Distally passes betwen the FDS and FDP
  • Gives off anterior interosseous branch
  • Gives off palmnar cutaneous branch–> Passes superficial to the carpal tunnel to suplly skin of lateral palm
  • Median nerve enters hand via the carpal tunnel
  • Terminates by dividing into two branches
  • -> Recurrent branch–> thenar muslces (expect Adductor pollicis and deep head of FPB)
  • -> Palmar digital branch–> palmar surface and fingertips of radial (lateral) 3.5 digits and lateral two lumbricals
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What is the root value of the ulnar nerve?

A

C8 and T1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What is the motor innervation of the ulna nerve?

A

Flexor carpi ulnaris
1/2 flexor digitorum profundus
Intrinsic muscle of the hand EXCEPT (1.5 LOAF)
–> Opponens Pollicis
–> Abductor Pollicis brevis
–> Flexor Pollicis brevis (superficial head)
–> Lateral 2 lumbicals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

What is the sensory innervation of the ulnar nerve?

A

Palmar and dorsal surface of the ulna (medial) one and a half fingers and ulnar aspect of palm and dorsum of the hand

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

What is the anatomical course of the ulnar nerve?

A
  • Medial aspect of arm
  • Posterior to medial epicondyle of humerus
  • Cubital tunnel –> articular branch supplied elbow
  • Between two heads of FCU into forearm
  • Deeps to FCU muscles adjacent to ulna
  • 3 branches in forearm
  • -> Muscular branch–> FCU and 1/2 FDP
  • -> Palmar cutaneous branch–> ulnar (medial) 1/3 palm
  • -> Dorsal cutaneous branch–> dorsal surface of ulna (medial) one and half fingers and associated dorsal area of the hand
  • At wrist travels superiorly to flexor retinaculum and medial to ulnar artery
  • Enters the hand via the ulnar canal
  • Terminated by giving rise to superficial and deep branches
  • -> Deep branch innervates majority of intrinsic muscles -hypothenar muscles, PADs, DABs, ulnar (medial) lumbricals, adductor pollicis, palmaris brevis, deep head of flexor pollicis brevis
  • -> Superficial arises in the palm and innervates the palmar surface of ulna (medial) one and half fingers via palmar digital nerves
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What is Froment’s sign?

A

Test for ulnar nerve palsy
Paralysis of adductor pollicis
Pt hold piece of paper between the thumb and index finger
Paper is pulled away
Negative sign–> pt holds paper with no difficulty
Positive sign–> pt flex the thumb at the interphalangeal joint to maintain hold on paper

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What is the root values of the musculocutaneous nerve?

A

C5, 6 and 7

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

What is the motor innervation of the musculocutaneous nerve?

A

Muscle of the anterior arm BBC muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

What is the sensory innervation of the musculocutanous nerve?

A

Becomes the lateral cutaneous nerve of the forearm supplying the lateral surface of the forearm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

What is the course of the musculocutaneous nerve?

A
  • Leaves the axilla
  • Pierces the coracobrachialis muscle supplying it
  • Passes down arm superficial to bracialis, deep to biceps brachii
  • Pierces deep fascia lateral to biceps brachii
  • Emerges lateral to biceps tendon and brachioradialis
  • Continues as lateral cutaneous nerve of the forearm close to cephalic vein
  • Sensory innervation to the lateral forearm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

Which dermatome is the cutaneous distribution of the musculocutaneous nerve found?

A

Within the C6 dermatome

58
Q

What is the clinical presentation of damage to the musculocutaneous nerve?

A

Injury uncommon
Motor function: paralysis to coracobrachialis, biceps brachii and brachialis muscle
- flexion weakened and supination weakened
Sensory function: Loss of sensation over radial (lateral) side of the forearm

59
Q

What is the medial cutaneous nerve of the arm?

A

Arises from the medial cord of the brachial plexus
Contains T1 fibres
Skin on distal medial side of arm as far as the elbow

(Communicates with intercostobrachial nerve (T2)
hence overlap with T1 and T2 dermatomes)

60
Q

What is the medial cutaneous nerve of the forearm?

A

Arises from medial cord of brachial plexus
Fibres from C8 and T1 nerves
Supplies skin on distal anterior surface of the arm and ulnar (medial) side of the forearm to the wrist

61
Q

What is the vascular supply to the forearm?

A

Radial and ulnar arteries
Bifurcation of the brachial artery in the cubital fossa
Radial artery–> posterolateral aspect of forearm, anastomotic networks surrounding the elbow joint and carpal bones
Ulnar artery–> anteromedial aspect of forearm, anastomotic network surrounding elbow joint and gives rise to anterior and posterior interosseous arteries–> deep structures of the forearm
Radial and ulnar arteries anastomose in the hand forming two arches–> superficial palmar arch and deep palmar arch

62
Q

Which pulses can be palpated in the forearm?

A

Brachial pulse–> cubital fossa, medial to bicep brachii tendon
Radial pulse–> radial (lateral) to tendon of FCR at wrist
Ulnar pulse–> radial (lateral) to FCU, proximal to pisiform bone

63
Q

What is the venous system in the forearm?

A

Superficial–>
Cephalic vein - Dorsal venous network of hand, anterolateral aspect of limb, passes anteriorly at elbow
Basillic vein - dorsal venous network of hand, medial aspect of limb, at inferior border of teres major moves deep into arm

Deep—>
Deep to deep fascia, formed by venae comitantes (paired veins that lie either side of an artery)
Brachial veins situated either side of brachial artery
Radial and ulnar venae comitantes (accompanying veins) to the respective arteries
Porforating veins run between superfical and deep veins

64
Q

What is the cubital fossa?

A

Triangular depression anterior to the elbow joint

65
Q

What are the borders of the cubital fossa?

A

Lateral border: Medial border of brachioradialis
Medial border: Lateral border of pronator teres
Superior border: Hypothetical line between the epicondyles of the humerus
Floor: Proximally brachialis, distally supinator
Roof: Skin and fascia, reinforced by bicipital aponeurosis

66
Q

What runs in the roof of the cubital fossa?

A

Median cubital vein (venepuncture)
Medial cutaneous nerve of forearm
Lateral cutaneous nerve of forearm

67
Q

What is contained within the cubtial fossa?

A

Lateral to medial
Radial nerve–> between brachioradialis and brachialis muscle
Biceps tendon–> inserts onto radial tuberosity
Brachial artery–> bifurcates in the cubital fossa into radial and ulnar arteries
Median nerve–> exits by passing between two heads of pronator teres

‘Really Need, Beer To, Be At, My Nicest’

68
Q

What are the posterior arm muscles commonly known as?

A

Extensor muscles

69
Q

What are the superficial muscles of the posterior forearm?

A 
Brachioradialis
Extensor Carpi radialis longus 
Extensor Carpi radialis brevis 
Extensor digitorum 
Extensor digiti minimi
Extensor carpir ulnaris 
Anconeus
70
Q

What is the common extensor origin? Which muscles does it apply to?

A 
Lateral epicondyle 
Extensor carpi radialis brevis
Extensor digitorum 
Extensor digit minimi
Extensor carpi ulnaris
71
Q

What is the origin, insertion, innervation and function of the brachioradialis?

A

O: Lateral supracondylar ridge of humerus

I: distal end of radius, proximal to radial styloid process

F: Flexion of elbow in midprone position, supinated position assists flexion

Innervation: Radial nerve

(Paradoxical muscle–> O and I characteristic of extensor muscles but assists in flexion)

72
Q

What is the origin, insertion, innervation and function of the Extensor carpi radialis longus?

A

O: Lateral supracondylar ridge of humerus

I: Dorsal (posterior) surface of the base of second metacarpal bone

F: Extension and abduction at the wrist

Innervation: Radial nerve

73
Q

What is the origin, insertion, innervation and function of the Extensor carpi radialis brevis?

A

O: Lateral epicondyle

I: Dorsal (posterior) surface of the base of third metacarpal bone

F: Extension and adbuction of the wrist

Innervation: Deep branch of radial nerve (innervated after the radial nerve has branched)

74
Q

What is the origin, insertion, innervation and function of the extensor digitorum?

A

O: Lateral epicondyle

I: Splits into 4 tendons that insert onto the extensor hood onto the phalanges

F: Extends the fingers at metacarpophalangeal and interphalangeal joints

Innervation: Posterior interosseous branch of the radial nerve

75
Q

What links the tendons of the extensor digitorum? What does this prevent?

A

Tendons are linked by fibrous bands on the dorsum called the juncturae tendinum
Prevents full extension of middle and ring finger if other fingers are flexed

76
Q

What is the origin, insertion, innervation and function of the extensor digiti minimi?

A

O: Lateral epicondyle

I: Ulnar side of extensor digitorum tendon (extensor hood of little finger)

F: Extends the little finger and extension of wrist

Innervation: Posterior interosseous branch of radial nerve

77
Q

What is the origin, insertion, innervation and function of the extensor carpi ulnaris?

A

O:

  • -> Humeral head: Lateral epicondyle
  • -> Ulnar head: Olecranon, posterior surface of proximal ulna and deep fascia

I: Base of 5th metacarpal

F: Adduction and extension of wrist

Innervation: Posterior interosseous branch of radial nerve

78
Q

What is the origin, insertion, innervation and function of the Anconeus?

A

O: Lateral epicondyle

I: Radial (lateral) side of olecranon and posterior surface of proximal ulna

F: Weak extensor of elbow, stabilised the elbow joint
-In pronation it abducts the ulna preventing impingement of the joint capsule

Innervation: Radial nerve

79
Q

What are the deep muscles of the posterior compartment?

A 
Supinator
Abductor pollicis longus 
Extensor pollicis brevis 
Extensor pollicis longus 
Extensor indicies
80
Q

What is the origin, insertion, innervation and function of the supinator?

A

O:

  • -> Humeral head- Lateral epicondyle
  • ->Ulnar head: Supinator crest on radial border of ulna

I: Wrap around radial (lateral) border of radius to insert onto proximal radial (lateral) border of radius, extending distally to pronator teres insertion

F: Supination (main in absence of resistance)

Innervation: Deep branch of radial nerve

81
Q

What is the origin, insertion, innervation and function of the abductor pollicis longus?

A

O: Interosseous membrane and adjacent posterior surface of radius and ulna

I: Radial and lateral side of base of 1st metacarpal

F: Abducts the thumb and assists in extension of the carpometacarpal joint

Innervation: Posterior interosseous branch of radial nerve

(Lateral border of anatomical snuffbox)

82
Q

What is the origin, insertion, innervation and function of the extensor pollicis brevis?

A

O: Posterior surface of the radius and interosseous membrane

I: Base of proximal phalanx of the thumb

F: Extends the metacarpophalangeal and carpometacarpal joints of the thumb

Innervation: Posterior interosseous branch of radial nerve

(Lateral border of anatomical snuffbox)

83
Q

What is the origin, insertion, innervation and function of the extensor pollicis longus?

A

O: Middle third of posterior surface of ulnar and interosseous membrane

I: Distal phalanx of thumb

F: Extends all the joints of the thumb: carpometacarpal, metacarpophalangeal and interphalangeal joints

Innervation: Posterior interosseous branch of radial nerve

84
Q

What is the origin, insertion, innervation and function of the extensor indicis?

A

O: Posterior surface of ulna and interosseous membrane
(distal to origin of EPL)

I: Extensor hood of the index finger, ulnar (medial) side of tendon of extensor digitorum

F: Extends the index finger

Innervation: Posterior interosseous branch of radial nerve

85
Q

What is the root value of the radial nerve?

A

C5-T1

86
Q

What is the motor innervation of the radial nerve?

A

Triceps brachii and the extensor muscles of the forearm

87
Q

What is the sensory innervation of the radial nerve?

A

Majority of skin of posterior forearm, the lower lateral arm, the posterior forearm, dorsal surface of radial (lateral) hand, dorsal surface of radial (lateral) three and a half digits apart from skin over distal phalanges

88
Q

What is the course of the radial nerve?

A
  • Posterior compartment of arm gives off branches to:
  • -> long and lateral head of the triceps brachii
  • -> posterior cutaneous nerve of the arm- innervated posterior surface
  • Radial (spiral) groove of humerus with profunda brachii artery between triceps heads, inferolateral direction
  • -> branch to medial head of triceps
  • ->Two further branches
  • -> lower (inferior) lateral cutaneous nerve of the arm (lateral aspect of arm inferior to insertion of deltoid muscle)
  • -> posterior cutaneous nerve of the forearm (strip of skin down middle of posterior forearm
  • Emerges from radial groove on lateral surface of arm 5cm below deltoid tuberosity
  • ->Gives off branches to brachioradialis and ECRL (occasionally branch to brachialis)
  • Pierces lateral intermuscular septum to reach anterior compartment, anterior to lateral epicondyle, through cubital fossa
  • In cubital fossa terminate
  • -> Deep branch (motor) -posterior arm muscle
  • -> Superficial branch (sensory)
  • Exits the cubital fossa between two heads of supinator into posterior compartment
  • Deep branch changes its name to posterior interosseous nerve
89
Q

Where does the deep branch travel?

A
  • Supplies ECRB
  • Exits cubital fossa posteriorly between supinator heads (innervates it)
  • Becomes posterior interosseous nerve
  • Supplies:
  • -> Extensor digitorum
  • -> Extensor digiti minimi
  • -> Extensor carpi ulnaris
  • -> Abductor pollicis longus
  • -> Extensor pollicis brevis
  • -> Extensor pollicis longus
  • -> Extensor indicis
90
Q

What is supracondylar fracture of the distal humerus?

A

Fracture line is usually extra-articular
Distal fragment is usually displaced
75% of all elbow injuries

Fracture above the condyle

91
Q

How do supracondylar fractures normally occur?

A

Fall from a heigt onto an outstretched arm with the elbow hyperextended
Most common-90% fractures seen in children

Elderly-> fall onto flexed elbow

92
Q

What do patient with supracondylar fracture present with?

A

Pain, deformation ad loss of function

93
Q

What are the complications that can arise from supracondylar fractures?

A

Malunion—> results in cubitis varus (distal end (radius and ulna) point medially)
—> aka gunstock deformity (resembles barrel of gun)

Damage to nerve—> median most common, radial an ulnar nerve damage also possible

Ischaemic contracture: brachial artery passes closely can be damage or occluded by the displaced fracture–> ischaemia of muscles in anterior compartment–> odeme–> rise in compartment pressure (compartment syndrome)–> futher exacerbates the problem–> muscle belly infarction–> dead tissue replaced by fibrous tissue (scar)–> fibrotic tissue contracts (myofribroblast activity)–> Flexion contraction–> Volkmann’s ischaemic contracture

94
Q

Why is ischaemia contracture a result of supracondylar fracture?

A
  1. Damage to brachial artery
  2. Causes ischaemia to muscle (if reflex spasm of collateral circulation)
  3. Increased hydrostatic pressure—> Oedema
  4. Increased compartment pressure—> compartment syndrome
  5. Left untreated exacerbates the ischaemia—> infarction of muscle bellies
  6. Repair phase—> dead tissue replaced by scar tissue
  7. Fibrotic tissue contracts (myofibroblast activity)–> flexion contracture–> Volkmann’s ischaemic contracture
95
Q

What is the characteristic presentation of Volkmann’s ischaemic contracture?

A 
Wrist is typically flexed 
Fingers extended at metacarpophalangeal joints
Flexed interphalangeal joints
Forearm pronated
Elbow flexed
96
Q

How are the complications from supracondylar fracture minimised?

A

Prompt through neurovascular examination

Compromised—> emergency reduction and fixation of fracture

97
Q

When is elbow dislocation most likely to occur? Why?

A

Child falls on outstretched hand with elbow partially flexed
Elbow joint most stable—> fully flexed or extended
Mid-flexion its weakest—> more reliant on ligaments

98
Q

How common is elbow dislocation?

A

Most common in children

Second most common in adults (shoulder first)

99
Q

What is the most common type of elbow dislocation? What other complications occur alongside?

A

90% posterior dislocation
Ulnar and radius displaced backwards
Distal end of humerus driven though joint capsule anteriorly
Ulnar collateral ligament is usually torn
Associated fracture
Ulnar nerve involvement

100
Q

What are anterior fractures a result of?

A

10% (radius and ulnar displaced anteriorly)
Direct blow to posterior aspect of flexed elbow
Associated with fractures of olecranon —> usually requires a lot of force to dislocate

101
Q

What is a pulled elbow? How does it occur?

A

Subluxation of the radial head—> partial dislocation
Children aged 2-5 years
Longitudinal traction of the arm with forearm in pronated position (tugging a child or swinging children by arms)
Falls
Over reaching for an object
Traction tears the distal attachment of the annular ligament where it is loosely attached to the neck of the radius
Radial heads then displaced distally through the torn ligament
Children age –>annular ligament natural strengthens–> less likely to happen

102
Q

Why does pulled elbow normally occur with the forearm in the pronated position?

A

Annular ligament is relaxed in pronation

Taut in supination

103
Q

What are the symptoms of a pulled elbow?

A

Reduced movement of elbow
Pain over lateral aspect of proximal forearm
Parents state—> not using their arm

104
Q

How do radial head and neck fractures occur?

A

Fall onto outstretched hand

Radial head impacts on the capitellum of the humerus

105
Q

How does the patient with a radial head or neck fracture present?

A 
Pain in lateral aspect of proximal forearm
Loss in range of movement 
Swelling modest (compared to supracondylar fractures)
106
Q

How are X-rays used to detect radial head and neck fractures?

A

Fracture difficultly to see on x-ray
Fat pad sign (sail sign) usually more visible
—> effusion probably due to haemarthrosis (blood in the joint)—> secondary to intra-articulation fracture

107
Q

What is fat pad sign or ‘sail sign’? What causes it?

A

Sail sign due to resemblance of sail
Caused by displacement of anterior fat pad
Relatively radiolucent—> shows up as black on X-ray
Usually due to blood in the joint (haemarthrosis) secondary to intra-articular fracture
Posterior fat pad can be present—>displacement of crescent of fat in olecranon fossa

108
Q

Why is osteoarthritis of the elbow uncommon?

A

Relatively uncommon—> well matched joint surfaces with strong stabilising ligaments
Elbow can therefore tolerate large forces with out becoming unstable—> less wear and tear

109
Q

Who is osteoarthritis of the elbow most commonly seen in?

A

Men> women (4:1)
Manual workers
Athletes—> throwing sports

110
Q

What are the types of osteoarthritis of the elbow?

A

Cartilage surface of joint is worn out
Primary
Secondary—> post traumatic —> fracture, dislocation

111
Q

In osteoarthritis of the elbow what do patients normally present with? How is it treated?

A

Grating sensation (crepitus)
Locking of elbow (loose fragments of cartilage)
Swelling (due to effusion)
Paraesthesia +/- muscle weakness —> osteophyte impingement on ulnar nerve
Stiffness to elbow—> tolerated relatively well, loss of extension—> little limitation to activities

Injections
Surgical debridement
Rare—> total elbow replacement

112
Q

What is rheumatoid arthritis?

A

Autoimmune disease
Autoantibodies- Rheumatoid factor –> attack the synovial membrane
Inflamed cells proliferate to form a pannus (abnormal layer of fibrovascular tissue)
Penetrates through cartilage an adjacent bone–> joint erosion and deformity

113
Q

What joints are commonly affected by rheumatoid arthritis?

A 
Metacarpophalangeal joints
Proximal interphalangeal joints
Feet
Cervical spine
Can involve larger joint such as the elbow
114
Q

What other structures (other than bone) are affected by rheumatoid arthritis?

A 
Other organ 
Eyes
Skin
Lungs
Heart
Blood vessels 
Kidneys
Usually suffer from anaemia of chronic disease
Weight loss 
Fatigue 
Low grade fever
115
Q

What are the key x-ray features of rheumatoid arthritis?

A 
Joint space narrowing 
Periarticular osteopenia 
Juxta-articular (marginal) bony erosion—> non cartilaginous protected bones
Subluxation and gross deformity
Soft tissue swelling
116
Q

How common is rheumatoid arthritis?

A

1% population affected
Peak age 40-50 years
Juvenile form that affects children
Women>men (2:1 or 3:1) ratio

117
Q

How is rheumatoid arthritis managed?

A 
Medically rather than surgery 
Disease modifying medication:
Corticosteroid (prednisolone)
DMARDs: methotrexate, hydroxychloroquine
Biological—> Anti-TNF alpha
(- Adalimumab (monoclonal antibody)
- Infliximab (monoclonal antibody)
- Etanerceptr (TNF receptor blocker))
Surgery—> joint replacement
118
Q

What is lateral elbow tendinopathy?

A

Tennis elbow
Chronic overuse of tendon—> inflammation and pain
Approx 3% of 40-60yr olds
Pain at site of commons extensor origin at lateral epicondyle

119
Q

What causes lateral elbow tendinopathy?

A

Extensor carpi radialis brevis (ECRB) (posterior forearm muscle)—> usually helps to stabilise the wrist when the elbow is straight
Weakened by overuse (repetitive action)—> microscopic tears form in the tendon
Inflammation and pain

120
Q

When do patients experience pain in lateral elbow tenidopathy?

A

Over lateral epicondyle when the wrist is extended

Especially against resistance

121
Q

How is lateral elbow tendionpathy treated?

A

Modification of activities
Rest
Sometimes physiotherapy and bracing are required
Small number need injections and surgery

122
Q

What is medial elbow tendinopathy?

A

Golfer’s elbow
10 times less common than lateral elbow tendinopathy
Affects the common flexor origin at the medial epicondyle

123
Q

What causes medial elbow tendinopathy?

A

Associated with golfing and throwing sport

Places valgus stresses on the elbow

124
Q

What is the most common site for medial elbow tendinopathy? (Between which muscles)

A

Interface between Pronator Teres and flexor carpi radialis (FCR) origins

125
Q

When does the patient experience pain in medial elbow tendinopathy?

A

Acceleration phase of throwing
Resisted flexion or pronation of the wrist
Ulnar nerve symptoms usually present (close proximity to medial epicondyle)

126
Q

What are three common swelling conditions that occur around the elbow?

A

Olecranon bursitis (students elbow)
Rheumatoid nodules
Gouty tophi

127
Q

What is olecranon bursitis?

A

Students elbow
Inflammation in the olecranon bursae
(Between skin and olecranon process)
Repeated microtrauma—> leaning on elbow etc

128
Q

What is the clinical presentation of olecranon bursitis?

A

Swelling on olecranon process
Soft, cystic (fluid filled) and trans illuminates (shine light through it)
Not painful but aesthetically not appealing

129
Q

How is olecranon bursitis treated? What is the treatment for olecranon bursitis that has result from infection?

A

Compression bandage
Aspiration (if necessary)
Hydrocortisone injection sometimes needed

Infection—> aspiration, compression and antibiotics
Occasionally—> surgical drainage ad washout under anaesthetics will be needed

130
Q

What are rheumatoid nodules?

A

Commonest extra-articular presentation
Affects 20% patients
Firm subcutaneous lumps under the skin
Usually in smokers, aggressive joint disease
These patients prone to other extra-articulations manifestation of rheumatoid disease—> vasculitis and lung disease

131
Q

Where do rheumatoid nodules normally appear?

A

Exposed regions subject to microtrauma

Elbow region, fingers, forearms, back of the heel

132
Q

What is the treatment for Rheumatoid nodules?

A

Non-tender—> overlying skin can sometimes ulcerate and become infected
Treatment—> improve control of rheumatoid disease
doesn’t always improve existing nodules

133
Q

What is Gout?

A

Inflammatory conditions
Defective purine metabolism —> increase uric acid production
Supersaturation and precipitation occurs
Crystal of monosodium urate in synovial joint cavity, tendons and surrounding tissue form
Urate crystals trigger an immune response—> acute inflammation

134
Q

How is gout treated?

A

Medically with non-steroidal anti-inflammatory drugs —> acute phase
Once acute phase resolves—> xanthine oxidase inhibitors (allopurinol) —> reduce production of uric acid

135
Q

What are gout tophi?

A

Tophi—> nodular masses of monosodium urate crystals deposited in the soft tissues
Contains white ‘pasty’ material—> enlarge making their way towards the skin surface to drain—> form sinus tract or continuously draining ulcer
Late complication of hyperuricaemia (untreated gout)
Usually painless but can include pain, soft tissue damage and deformity, joint destruction and nerve compression

136
Q

Where does Gouty tophi normally occur?

A

Fingers and ears

Can be—> olecranon bursa, subcutaneous tissue of elbow

137
Q

What is cubital tunnel syndrome? How does it occur?

A

Ulnar nerve compression
Ulnar nerve posterior to medial epicondyle of humerus
Flexor Carpi Ulnaris —> two muscle heads united by tendinopathy arch
- Common flexor origin
- Medial margin of olecranon
Ulnar nerve passes beneath the tendinous arch to enter the cubital tunnel

138
Q

What is a minor form of cubital tunnel syndrome?

A

Hitting your funny bone

Sharp transient pain radiating from elbow to cutaneous nerve territory

139
Q

What does compression of the ulnar nerve in the cubital tunnel result in?

A

Paraesthesia in cutaneous territory of the ulnar nerve

Weakness in muscles supplied by the ulnar nerve

140
Q

How is cubital tunnel syndrome treated?

A

Decompress the nerve

Surgically release it and transpose it anteriorly to the medial epicondyle

Semester 2 Musculoskeletal System (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions