6: Bones Of Forearm Flashcards
1
Q
The forearm skeleton is formed by …(a)…. (shorter bone) and …(b)…. (longer bone)
A
(a) radius (lateral)
(b) ulna (medial)
2
Q
The ……. rotates medially over the ulna to produce pronation
A
radius
3
Q
Joints between radius and ulna
A
- proximal radio ulnar joint
- interosseous membrane
- distal radio ulnar joint
4
Q
The stabilizing bone of the forearm which has a bulky proximal end which gradually tapers distally
A
Ulna
5
Q
Proximal end of ulna has an …….. process and a …… process, between them lie the trochlear notch
A
olecranon process and a coronoid process
6
Q
The distal end of ulna has:
A
- head
- posteromedial extension called styloid process
7
Q
Describe distal end of radius
A
- the distal end it is quadrangular in outline
- distal end presents ulnar notch for the ulnar head, and a styloid process
8
Q
Where is the radial notch?
A
Superior end of ulna laterally shows the radial notch, supinator crest and fossa and tuberosity
9
Q
Tubercle of lister, where?
A
The dorsal surface of inferior end of radius shows a dorsal tubercle of radius (of Lister) and grooves for tendons of extensor muscles.
(Know the muscles in picture attached)
10
Q
What bones articulate to form the wrist joint?
A
radius articulates with scaphoid and lunate
(Note: inferior surface of ulna is also articular but does not articulate with any bone, instead with a fibrous articular disc)
11
Q
The radius and ulna have three borders and three surfaces each (what are the surfaces of each?)
A
- ulna: anterior, posterior, medial surfaces
- radius: anterior, posterior, lateral surfaces
12
Q
The fracture of one bone (radius or ulna) is bound to be associated with dislocation of a nearby joint. Explain why?
A
Bcz Radius and ulna are bound together by the interosseous membrane
13
Q
How many carpal bones we have? How are they arranged?
A
Eight carpal bones arranged in proximal and distal rows of 4 bones each form the carpus, which is concave anteriorly and convex posteriorly
14
Q
The concave anterior surface of the carpus forms the floor of the ……?
A
carpal tunnel (canal)
15
Q
Carpal bones proximally articulate with the …(a)….. (scaphoid and lunate) but not with the ulna.
Carpal bones distally articulate with ….(b)….
A
(a) radius
(b) metacarpals
16
Q
What is the largest carpal bone?
A
Capitate
17
Q
What carpal bone is seen anteriorly only?
A
Pisiform bone
(Note: Pisiform bone is a sesamoid bone developing in the tendon of flexor carpi ulnaris and sitting on the palmar surface of triquetral)
18
Q
A. …….. has a tubercle
B. …….. has a hook
C. ……… has a head
A
A. Scaphoid
B. Hamate
C. Capitate
19
Q
What forms the knuckles?
A
The distal ends (heads) of metacarpals articulate with proximal phalanges to form metacarpophalangeal joints (knuckles)
20
Q
Which metacarpal also has a styloid process projecting from its base?
A
Third
21
Q
……. has two phalanges, and the four fingers have three phalanges each
A
Thumb
22
Q
What is boxer’s fracture?
A
Fifth metacarpal fracture is called ‘boxer’s fracture’ as it happens in someone who punches with closed abducted fist & extended wrist (at neck of 5th metacarpal)
23
Q
Phalangeal fractures are usually due to ……………, the distal phalanx fracture is highly painful as the tip of the finger has highly developed sensation
A
crushing injuries
24
Q
Do Metacarpals heal quickly or not & why?
A
Metacarpals have rich blood supply, so fractures heal quickly
25
When ……. fractures, there will be pain in anatomical snuffbox
Scaphoid
26
What type of joint is the interosseous membrane?
Syndesmosis
27
Type of joint between carpals?
Plane synovial
28
Ulna doesn’t articulate with any carpal bone. Why?
Bcz there is an articular disc formed by fibrous cartilage between it and the pisiform & triquetral bones
29
What parts of carpals are not seen posteriorly?
Pisoform, hook of hamate, tubercle of trapezium
30
How are the metacarpals numbered?
Lateral to medial
31
What type of joint is metacarpophalangeal joint?
Condyloid
32
What type of joint is interphalangeal joint?
Hinge
33
What type of joints are the carpometacarpal?
plane synovial joint except the joint between the first metacarpal and the trapezium and it is a saddle joint.
34
Elbow joint (Type & articulations)
- Elbow joint is a hinge joint consisting of humero-ulnar and
humero-radial joints
- Superior articular surfaces are provided by trochlea and capitulum on humerus, whereas the inferior articular surfaces are formed by the trochlear notch on ulna and radial head
35
Why is the elbow joint capsule weaker anteriorly and posteriorly?
Bcz on either side it’s supported by the collateral ligaments
36
RCL vs UCL
- The radial collateral ligament (RCL) extends from the lateral epicondyle and has two bands which merge with the anular ligament
- The (UCL) is stronger than the RCL
It has a stronger anterior band, a weaker posterior band and an oblique band which deepens the trochlear notch
37
What is the carrying angle?
The carrying angle is formed between the long axis of humerus and ulna (forearm), which is about 10-15
degrees in males and more than 15 degrees in females
38
Why is forearm in females more deviated than in males?
The more deviated forearm in females allows clearance of the upper limbs while swinging from the pelvis which is wider in females
39
What makes the carrying angle disappear?
Pronation of the forearm makes the angle to disappear
40
prime flexors of the elbow joint
Brachialis and biceps brachii
41
chief extensor of the elbow joint
Triceps brachii
42
Flex in absence of resistance?
Brachioradialis can also flex in the absence of resistance, but when there is resistance, brachioradialis and supinator help the prime flexors in flexing
43
What type of joint is superior radio-ulnar joint?
synovial pivot
44
The periphery of radial head articulates with the radial notch on ulna & held in place by …..
the anular ligament
45
The anular ligament is attached to ……. anterior and
posterior to ……..
ulna anterior and posterior to the radial notch
46
What movements happen at radio-ulnar joint?
Supination and pronation are the movement at this joint during which head of radius rotates
47
What happens to radius at supination vs pronation?
- During supination, the lower end of radius rotates laterally
- During pronation, the radius rotates medially over the ulna
48
What muscle responsible for supination?
supinator muscle (but biceps brachii takes part in this action when more power is required )
49
Two muscles for pronation?
- Pronator quadratus (main)
- pronator teres
50
What muscle helps in supination and pronation when the forearm is in mid-prone position?
Brachioradialis
51
What is subluxation of the radial head how & why it happens?
In children, the annular ligament is not strong and the head of the radius is not completely developed.
So, if you lift a child from one hand or both hands, the radius head can dislocate from the annular ligament and this is very painful.
This is know as subluxation of the radial head which means moving the radial head out of the annular ligament.
52
Direction of fibers of Middle radioulnar joint?
direction of fibers descend from radius distomedially to the ulna (weight transfer from radius to ulna)
53
What type of joint is distal radioulnar joint ?
pivot
54
What forms distal radioulnar joint?
ulna articulates with the ulnar notch on the medial aspect of lower end of radius
55
What holds the bones together at the distal radioulnar joint?
The two bones are held together by a fibrocartilaginous
articular disc which is triangular (clinically- triangular ligament)
56
distal radioulnar joint nerve & blood supply?
anterior and posterior interosseous arteries and nerves
57
dinner fork deformity is seen in what fracture?
Colles fracture
58
In colles fracture, complete transverse fracture of distal 2 cm of radius is displaced …... ? (What direction??)
Dorsally (posteriorly)
59
Colles fracture is often
associated with avulsion fracture of …..?
ulnar styloid process
60
More about colles fracture
61
What is the most fractured hand bone, which results from a fall on abducted hand?
Scaphoid
62
How can scaphoid fracture happen (hand orientation?) and where is the pain felt?
Scaphoid bone fractures at its narrow part, and pain occurs primarily on the lateral side when hand is extended and abducted (felt at anatomical snuff box*)
63
Complications of scaphoid fracture?
The proximal fragment undergoes avascular necrosis as this part of the bone has very poor blood supply
64
What parts of hamate can be fractured? Which type is more common?
Hamate fractures:
- at its hook (type 1- common)
- at its body (type 2)
65
Is hamate fracture easily healed or not and why?
Healing is difficult because muscles pull the fractured
fragments away from one another
66
Complications of hamate fracture?
Because the ulnar nerve and artery are closely related, both can be injured, ulnar nerve injury causes weak grip of the hand
67
The elbow joint is innervated by …?
articular branches of radial, median, ulnar and musculocutaneous nerves
68
The blood supply to the elbow joint is by…?
by anastomosis around the joint formed by the branches of radial, ulnar, brachial and deep brachial arteries
69
What are the bursas around elbow joint?
70
In cases of increased use or action of the elbow joint, for example in tennis players, what happens?
these bursa get inflamed leading to a conduction known as bursitis and it is very painful.
71
Around the elbow joint there are three important nerves passing to the forearm:
1- medially = the ….. nerve.
2- anteriorly = the …… nerve.
3- laterally = the ….. nerve.
1- medially = ulnar nerve.
2- anteriorly = median nerve.
3- laterally = radial nerve.
72
Elbow is commonly dislocated… (what direction) ?
Posteriorly
73
A ……….. can cause elbow dislocation
fall on outstretched hand
74
Elbow dislocations may be accompanied by fractures of …?
the medial epicondyle of humerus, olecranon (ulna), radial head, or coronoid process of the ulna
75
Nerves affected or injured accompanying elbow dislocation?
- ulnar nerve (most common)
- or median nerve
76
What is a divergent dislocation of elbow?
Humerus enters between ulna and radius
77
Fractures of the proximal radius often involve what parts
Either …. Or …..
the head or the neck of the radius
78
Fractures of Proximal Radius results from …?
fall on an outstretched hand or a direct blow to the elbow
79
Fracture of the radial ……. is more common in adults, whereas fracture of the …… is more common in children
Head @adults
Neck @children
80
How can orthopedic doctor indicate existance of fragments in case of Fractures of Proximal Radius?
81
What is essex-lopresti fracture?
1- Comminuted fracture of radial head
2- dislocation of distal radio-ulnar joint
3- proximal migration of radius
4- tear of interosseous membrane
82
Anatomy of Fractures of Proximal Radius (slide)
83
Elbow Dislocation (slide)
84
Styloid process clinical importance
85
Mcq: 1.What type of joint is the elbow joint?
a. Plane gliding joint
b. Condyloid joint
c. Hinge joint
d. Ball and socket joint
c. Hinge joint
86
Mcq: Which bones form the surface that articulates with the radius at the wrist joint?
a. Triquitrium, Lunate, and Scaphoid
b. Trapezium, Hamate, and Scaphoid
c. Triquitrium, Hamate, and Scaphoid
d. Triquitrium, Pisiform, and Scaphoid
a. Triquitrium, Lunate, and Scaphoid
87
Mcq: If there’s dislocation of the olecranon process, what movement would likely be lost?
a. Extension of the elbow
b. Extension of the wrist and ulnar deviation
c. Extension of the wrist and radial deviation
a. Extension of the elbow
88
Mcq: Which structure of the humerus is most painful in a young man known to have tennis elbow?
a. Medial epicondyle
b. Lateral supracondylar ridge
c. Medial supracondylar ridge
d. Lateral epicondyle
d. Lateral epicondyle
89
Mcq: A patient falls on his hand. Which carpal bone, which forms the floor of the anatomical snuff box, is most likely to be fractured?
a. Scaphoid
b. Trapezoid
c. Capitate
d. Hamate
a. Scaphoid
90
Mcq: During a surface anatomy session, a student was palpating the distal tubercle of Lister of the radius and the tendon medial to it, which muscle tendon was she palpating?
a. adductor pollicis longus
b. brachioradialis
c. Extensor carpi radialis longus
d. Extensor digitorum
e. Extensor pollicis longus
E. Extensor pollicis longus
91
Mcq: What is the most fractured bone when a patient falls on an outstretched hand?
a. Scaphoid
b. Trapezoid
c. Hamate
d. Lunate
Scaphoid
92
Mcq: Injury to which carpal bone affects the ulnar nerve?
a. Hamate
b. Scaphoid
c. Pisiform
a. Hamate ✅
c. Pisiform
(Both, go for A)
93
Mcq:Which bone heals slowly due to less blood supply?
a. Hamate
b. Scaphoid
c. Pisiform
b. Scaphoid
94
Greys Q: A 25-year-old male athlete is admitted to the emergency department after a bad landing while performing the pole vault. Radiographic examination of his hand reveals a fractured carpal bone in the floor of the anatomic snuffbox. Which bone has most likely been fractured?
A. Triquetral
B. Scaphoid
C. Capitate
D. Hamate
E. Trapezoid
B. Scaphoid
95
Greys Q: A 54-year-old female marathon runner presents
with pain in her right wrist that resulted when she fell with force on her outstretched hand. Radiographic studies indicate an anterior dislocation of a carpal bone. Which of the following bones is most likely dislocated?
A. Capitate
B. Lunate
C. Scaphoid
D. Trapezoid
E. Triquetrum
B. Lunate (most commonly dislocated carpal bone)
Note: scaphoid most common fractured carbone
96
Greys Q: A 68-year-old woman is examined by the senior
resident in emergency medicine after she fell on a wet bathroom floor in the shopping center. Physical examination reveals a posterior displacement of the left distal wrist and hand. Radiographic examination reveals an oblique fracture of the radius. Which of the following is the most likely fracture involved in this case?
A. Colles’ fracture
B. Scaphoid fracture
C. Bennett’s fracture
D. Volkmann’s ischemic contracture
E. Boxer’s fracture
A. Colles’ fracture
97
Greys Q: A 7-year-old boy suffered the most common of
fractures of the carpal bones when he fell on his outstretched hand. Which bone would this be?
A. Trapezium
B. Lunate
C. Pisiform
D. Hamate
E. Scaphoid
E. Scaphoid
98
Greys Q: A 22-year-old male medical student was seen in
the emergency department with a complaint of pain in
his right hand. He confessed that he had hit a vending
machine in the hospital when he did not receive his
soft drink after inserting money twice. The medial side
of the dorsum of the hand was quite swollen, and one
of his knuckles could not be seen when he “made a
fist.” The physician made a diagnosis of a “boxer’s
fracture.” What was the nature of the impatient student’s injury?
A. Fracture of the styloid process of the ulna
B. Fracture of the neck of the fifth metacarpal
C. Colles’ fracture of the radius
D. Smith’s fracture of the radius
E. Bennett’s fracture of the thumb
B. Fracture of the neck of the fifth metacarpal
99
Greys Q: A 68-year-old woman fell when she missed the
last step from her motor home. Radiographic examination at the local medical care center reveals a fracture of the distal radius. The distal fragment of the radius is angled forward. What name is commonly applied to this type of injury?
A. Colles’ fracture
B. Scaphoid fracture
C. Bennett’s fracture
D. Smith’s fracture
E. Boxer’s fracture
D. Smith’s fracture
100
Greys Q: A 55-year-old female choreographer had been
treated in the emergency department after she fell from
the stage into the orchestra pit. Radiographs revealed
fracture of the styloid process of the ulna. Disruption
of the triangular fibrocartilage complex is suspected.
With which of the following bones does the ulna normally articulate at the wrist?
A. Triquetrum
B. Hamate
C. Radius and lunate
D. Radius
E. Pisiform and triquetrum
D. Radius
101
Greys Q: A 54-year-old woman presents with pain in her right wrist that resulted when she fell forcefully on her outstretched hand. Radiographic studies indicate an anterior dislocation of a carpal bone of the proximal row (see Fig. 6-4). Which of the following bones is most commonly dislocated?
A. Capitate
B. Lunate
C. Scaphoid
D. Pisiform
E. Triquetrum
B. The lunate bone is the most commonly dislocated carpal bone. Displacement is almost always anteriorly. Dislocation of the lunate bone can precipitate the signs associated typically with carpal tunnel syndrome.
102
Greys Q: A 56-year-old woman visits the emergency department after falling on a wet pavement. Radiographic examination reveals osteoporosis and a Colles’ fracture.
Which of the following carpal bones are often fractured
or dislocated with a Colles’ fracture?
A. Triquetrum and scaphoid
B. Triquetrum and lunate
C. Scaphoid and lunate
D. Triquetrum, lunate, and scaphoid
E. Triquetrum and pisiform
C. Scaphoid and lunate
103
Greys Q: A 54-year-old woman is admitted to the hospital after falling from a tree with an outstretched hand. Radiographic examination reveals a wrist dislocation. Which of the following carpal bones will most likely be involved?
A. Scaphoid-lunate
B. Trapezoid-trapezium
C. Hamate-lunate
D. Pisiform-triquetrum
E. Hamate-capitate
A. The hallmark fracture caused by a fall on an outstretched hand is a scaphoid-lunate fracture; the scaphoid and lunate are the two wrist bones most proximal to the styloid process of the radius. All the other wrist bones are less likely to be affected by this injury.
104
Greys Q: A 62-year-old man is admitted to the emergency
department after falling on wet pavement. Radiographic
examination reveals a carpometacarpal fracture at the base of the thumb. What is the term applied to the
described fracture?
A. Colles’ fracture
B. Scaphoid fracture
C. Bennett’s fracture
D. Smith’s fracture
E. Boxer’s fracture
C. Bennett’s fracture
(Not from this note)
105
Greys Q: 55-year-old woman is admitted to the emergency department after a car crash. Radiographic examination of her hand reveals a fractured carpal bone,
which lies in the floor of the anatomical snuffbox.
Which bone is fractured?
A. Triquetrum
B. Scaphoid
C. Capitate
D. Hamate
E. Trapezoid
B. Scaphoid
