Transcript Clinical Anatomy of Upper Limb: Bones and Superficial Structures

UPPER EXTREMITY
Lecture #1
Bones and superficial structures of
the upper limb
Associate Professor
Dr. Alexey Podcheko
Spring 2015
Intended Learning Outcomes
BONES OF UPPER LIMB
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Clavicle
Scapula
Humerus
Bones of Forearm
Bones of Hand
Surface Anatomy of Upper Limb Bones
FASCIA, EFFERENT VESSELS, CUTANEOUS INNERVATION,
AND MYOTOMES OF UPPER LIMB
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Fascia of Upper Limb
Venous Drainage of Upper Limb
Cutaneous Innervations of Upper Limb
UPPER LIMB
SEGMENTS
1.
2.
3.
4.
Shoulder
Arm
Forearm
Hand
Shoulder
• Proximal segment of the
limb that overlaps parts of
the trunk and lower lateral
neck
• Includes the pectoral,
scapular, and lateral supraclavicular regions and is built
on half of the pectoral girdle
•The pectoral girdle is a bony ring, incomplete
posteriorly, formed by the scapulae and clavicles and
completed anteriorly by the manubrium of the sternum
Arm (Latin - brachium)
• First segment of the free upper limb (more mobile part of
the upper limb independent of the trunk) and the longest
one
• Extends
between and
connects the
shoulder and
the elbow and is
centered around
the humerus
Forearm (Latin - antebrachium):
• Is the second
longest segment
of the limb
• Extends between
and connects the
elbow and the wrist
and contains the ulna
and radius
Hand (Latin - manus)
• part of the upper limb distal to the forearm that is formed
around the carpus, metacarpus, and phalanges.
• It is composed of the wrist, palm, dorsum of hand, and
fingers (including an opposable thumb) and is richly
supplied with sensory endings for touch, pain, and
temperature.
Bones of the Upper
Limb
1. Clavicle
2. Humerus
3. Radius
4. Ulna
5. Carpal bones (8)
6. Metacarpal bones (5)
7. Phalanges
•Sternal end
articulates with the
manubrium of the
sternum at the
sternoclavicular (SC)
joint.
•Acromial end
articulates with the
acromion of the
scapula at the
acromioclavicular
(AC) joint
•Serves as a cranelike strut, keeps
scapula and free
limb away from the
trunk so that the
limb has maximum
freedom of motion.
•Commonly
fractured
Clavicle
CLINICAL CORRELATES: Fracture of the Clavicle
-The weakest part of the
clavicle is the junction of its
middle and lateral thirds
-In children fractures often
caused by:
a) fall
b) by the obstetrician in
breech presentation
when the infant presses
against the maternal
pubic symphysis during
its passage through the
birth canal
CLINICAL CORRELATES: Fracture of the Clavicle
• Middle third fracture results in upward displacement of
the proximal fragment (sternocleidomastoid muscle) and
downward displacement of the distal fragment by the
deltoid muscle and gravity
• May cause injury to the brachial plexus:
-paresthesia (sensation of tingling, burning, and numbness)
in the area of the skin supplied by medial brachial and
antebrachial cutaneous
nerves
• May cause fatal hemorrhage from the subclavian vein
• May cause thrombosis of
the subclavian vein
(cause of pulmonary
embolism)
CLINICAL CORRELATES: Fracture of the Clavicle
A fracture may also result
from a fall directly on the
shoulder.
A fracture of the clavicle
is often incomplete in
younger children, which is
called ‘greenstick
fracture’, in which one
side of a bone is broken
and the other is bent.
CLINICAL CORRELATES: Clinical Signs of Fracture of
Clavicle
•Person support the sagging limb
with the other limb
•Lateral fragment of the clavicle
may be pulled toward the chest
•Clavicle looks shortened
(Overriding of the bone
fragments)
CLINICAL CORRELATES: Treatment of Fracture of
Clavicle
Ice pack, sling support for 6 weeks.
Sling
Figure of eight bandage
Surgical treatment:
plates and screws
are used
CLINICAL CORRELATES: Congenital disorders
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Clavicle is the first bone to
begin ossification during fetal
development, but it is the
one of the last to complete
ossifi cation, at approximately
21 years of age
Is the only long bone to be
ossified intramembranously
Cleidocranial dysplasia, a
disorder characterized by
patent fontanelles, delayed
closure of cranial sutures,
Wormian bones*, delayed
eruption of secondary teeth,
primitive clavicles, and short
height
Scapula - aka shoulder blade
• Overlying the 2nd-7th ribs
• Structures you should
know:
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2.
3.
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8.
9.
Spine of the scapula
Supraspinous fossa
Infraspinous fossa
Subscapular fossa
Acromion
Coracoid process
Glenoid cavity (glenohumeral joint )
Medial border of the scapula
Scapular notch (transmits the
suprascapular nerve)
Scapula: more details
1. Spine of the Scapula
• forms upper supraspinous and
lower infraspinous fossae , and
also provides an origin for the
deltoid and an insertion for the
trapezius
2. Acromion
• Is the lateral end of the spine
and articulates with the clavicle
• Provides an origin for the
deltoid and an insertion for the
trapezius
3. Coracoid Process: Provides the
origin of the
• coracobrachialis and biceps
brachii
• insertion of the pectoralis minor
• attachment site for the
coracoclavicular, coracohumeral,
and coracoacromial ligaments
and the costocoracoid
membrane
Clinical Correlates:Calcification of the
superior transverse scapular ligament
• Suprascapular notch is bridged by the
superior transverse scapular ligament
and transmits the suprascapular
nerve
• Calcification of the superior
transverse scapular ligament may trap
or compress the suprascapular nerve
as it passes through the scapular
notch affecting functions of the
supraspinatus and infraspinatus
muscles (rotator cuff muscles) –
affecting the abduction and external
rotation of arm
Scapula (Other structures)
Humerus (arm bone): Important Structures
• Forms glenohumeral joint
and articulates with radius
and ulna
• Structures:
1. Head
2. Greater tubercle (lateral
margin of the humerus)
3. Lesser tubercle ( anterior
margin of humerus)
4. The intertubercular
(bicipital) groove separates
the tubercles and provides
protected passage for the
slender tendon of the long
head of the biceps muscle
5. Surgical neck (narrow part
distal to the head and
tubercles)
6.
Anatomical neck (groove circumscribing the head and separating it
from the greater and lesser tubercles)
7. Deltoid tuberosity (for attachment of the deltoid muscle)
8. Oblique radial groove (groove for radial nerve and deep artery of
arm)
9. Medial epicondyle and the lateral epicondyle, providing for muscle
attachment.
10. Trochlea;
11. Capitulum; and
olecranon fossa
12. Coronoid and radial
fossa
Humerus (arm bone): more details
1. Head: Articulates with the
scapula at the glenohumeral
joint
2. Anatomic Neck: Is an indentation
distal to the head and provides
an attachment for the fibrous
joint capsule
3. Greater Tubercle: Lies just
lateral and distal to the
anatomic neck and provides
attachments for the
supraspinatus, infraspinatus,
and teres minor muscles
4. Surgical Neck: narrow area
distal to the tubercles that is a
common site of fracture and is
in contact with the axillary
nerve and the posterior
humeral circumflex artery
Clinical Correlations: Humerus fractures
• Fracture of the greater tubercle:
occurs by direct trauma or by
violent contractions of the
supraspinatus muscle. The bone
fragment has the attachments of
the supraspinatus, infraspinatus,
and teres minor muscles, whose
tendons form parts of the
rotator cuff.
• Fracture of the surgical neck may
injure the axillary nerve and the
posterior humeral circumflex
artery as they pass through the
quadrangular space.
Humerus (arm bone): more details
• Lesser Tubercle: Lies on the anterior medial side
of the humerus, just distal to the anatomic neck,
and provides an insertion for the subscapularis
muscle
• Intertubercular (Bicipital) Groove :Lies between
the greater and lesser tubercles, lodges the
tendon of the long head of the biceps brachii
muscle, and is bridged by the transverse
humeral ligament, provides insertions for the
pectoralis major on its lateral lip, the teres major
on its medial lip, and the latissimus dorsi on its
floor .
• Deltoid Tuberosity: Is a rough triangular
elevation on the lateral aspect of the midshaft
that marks the insertion of the deltoid muscle
• Spiral Groove: Contains the radial nerve,
separating the origin of the lateral head of the
triceps above and the origin of the medial head
below
Clinical Correlations: Humerus fractures
• Fracture of the shaft may injure
the radial nerve and deep
brachial artery in the spiral
groove.
• Supracondylar fracture (common
in children) is a fracture of the
distal end of the humerus:
occurs when the child falls on
the outstretched hand with the
elbow partially flexed and may
injure the median nerve.
• Fracture of the medial
epicondyle may damage the
ulnar nerve. This nerve may be
compressed in a groove behind
the medial epicondyle “funny
bone,” causing numbness.
• USMLE SCENARIO:
• A 24-year-old mountain climber presents to the emergency
room with right shoulder pain following a fall. He was
climbing a cliff at a nearby national park when he lost his
grip and fell approximately 5 meters onto the boulders
below. He says that he "landed on his right arm and heard
the bone snap”. Physical examination reveals total inability
to extend the right wrist X-ray reveals a fracture of the
right humeral shaft. Which of the following arteries is most
likely to be injured in this patient?
• A. Anterior circumflex humeral artery
• B. Brachial artery
• C. Common interosseous artery
• D. Deep brachial artery
• E. Radial collateral artery
Bones of the Forearm
• this unit is formed by two parallel bones, one
of which (the radius) can pivot about the
other (the ulna), supination and pronation are
possible. This makes it possible to rotate the
hand when the elbow is flexed.
Radius
• Situated lateral to the ulna
• Structures you need to identify:
• 1. Head (articulates with the capitulum of
the humerus and the radial notch of the
ulna and is surrounded by the annular
ligament)
• 2. Distal End (Articulates with the
proximal row of carpal bones -scaphoid,
lunate, and triquetral bones )
• 3. Radial Tuberosity (prominence just
distal to the neck and provides an
attachment site for the biceps brachii
tendon)
• 4. Styloid Process (distal end of the radius
and is approximately 1 cm distal to that of
the ulna and provides insertion of the
brachioradialis muscle - can be palpated in
the proximal part of the anatomic
snuffbox between the extensor pollicis
longus and brevis tendons
Radius
CLINICAL CORRELATES: RADIUS FRACTURES
• Colles’s fracture of the wrist
is a distal radius fracture in
which the distal fragment is
displaced (tilted) posteriorly,
producing a characteristic
bump described as dinner
(silver) fork deformity
because the forearm and
wrist resemble the shape of
a dinner fork.
• If the distal fragment is
displaced anteriorly, it is
called a reverse Colles’s
fracture (Smith’s fracture).
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Ulna
Medial and longer of the two forearm
bones
• Structures you need to identify:
1. Olecranon ( curved projection on the
back of the elbow that provides an
attachment site for the triceps tendon)
2. Coronoid Process (below the trochlear
notch, attachment site for the
m.brachialis)
3. Trochlear Notch (receives the trochlea
of the humerus)
4. Ulnar Tuberosity (prominence distal to
the coronoid process that provides an
attachment site for the m. brachialis)
5. Radial Notch (accommodates the head
of the radius at the proximal radioulnar
joint)
6. Head (articulates with the articular disk
of the distal radioulnar joint and has a
styloid process)
Bones of the Hand
• The wrist, or carpus, is
composed of eight carpal
bones (carpals) arranged
in proximal and distal rows
of four (lateral to medial):
scaphoid, lunate,
triquetrum, pisiform,
trapezium, trapezoid,
capitate, and hamate
(mnemonic: Sandra Likes
To Pat Tom’s Two Cold
Hands)- (Trapezium
precedes trapezoid
alphabetically!)
•Sandra Likes To Pat Tom’s Two Cold Hands)- (Trapezium
precedes trapezoid alphabetically!) –
•scaphoid, lunate, triquetrum, pisiform,
•trapezium, trapezoid, capitate, and hamate
USMLE SCENARIO
• A 34-year-old female presents to
the emergency room after failing
in the bathroom. She complains
of wrist pain and numbness in
her right palm. Based on her
symptoms, you suspect that she
has dislocated the lunate bone in
the wrist. Identify the lunate
bone on the X-ray below
A.A
B.B
C.C
D.D
E.E
CLINICAL
CORRELATES: Fractures of carpal bones
• The scaphoid is the most
frequently fractured carpal bone
• Fracture of the scaphoid occurs
after a fall on the outstretched
hand, shows a deep tenderness
in anatomical snuffbox, and
damages the radial artery and
cause avascular necrosis of the
bone and degenerative joint
disease of the wrist
• Fracture of the hamate may
injure the ulnar nerve and
artery because they are near
the hook of the hamate
CLINICAL CORRELATES: Guyon’s canal syndrome
• Guyon’s canal (ulnar tunnel) is
formed by the pisiform, hook of
the hamate, and pisohamate
ligament, deep to the palmaris
brevis and palmar carpal
ligament and transmits the ulnar
nerve and artery.
• Guyon’s canal syndrome is an
entrapment of the ulnar nerve in
the Guyon’s canal
• Symptoms: pain, numbness, and
tingling in the ring and little
fingers, followed by loss of
sensation and motor weakness.
• Dx: surgical decompression of
the nerve.
USMLE SCENARIO
• A 19-year-old female presents to your office
complaining of right hand clumsiness. Physical
examination reveals decreased sensation over
the fifth finger and a flattened hypothenar
eminence. The affected nerve is commonly
injured at which at the following locations?
• A. Carpal tunnel
• B. Hook of the hamate
• C. Surgical neck of the humerus
• D Head of the radius
• E. Coracobrachial muscle
Metacarpals & Phalanges
• Miniature long bones
consisting of bases
(proximal ends), shafts
(bodies), and heads
(distal ends).
• Metacarpal Heads form
the knuckles of the fist.
• Phalanges - occur in
fingers (three each) and
thumb (two)
CLINICAL
CORRELATES: Fractures of carpal bones
• Bennett’s fracture is a
fracture of the base of the
metacarpal of the thumb.
• Boxer’s fracture is a fracture
of the necks of the second
and third metacarpals, seen
in professional boxers, and
typically of the fifth
metacarpal in unskilled
boxers
Surface Anatomy of the Upper Limb Bones
Identify on your friend or
yourself:
•Clavicle
•Jugular notch
•Acromion
•Acromial angle
•The crest of the scapular
spine
•The medial border of the
scapula
•The inferior angle of the
scapula
•The head of the humerus (
push fingers into the armpit).
The greater tubercle of the
humerus
•The shaft of the humerus
The medial and lateral
epicondyles
•Styloid process of radius
and ulna
The coracoid process of the scapula can be felt by
palpating deeply at the lateral side of the clavipectoral
triangle
Superficial structures of the upper limb
1.
2.
3.
4.
Fascia of the Upper Limb
CUTANEOUS NERVES
SUPERFICIAL VEINS
LYMPHATIC VESSELS
Fascia of the Upper Limb
• Deep fascia of the upper limb
surrounds and contains the
structures of the upper limb
as an expansion-limiting
membrane deep to the skin
and subcutaneous tissue.
• Deep fascia forms fascial
compartments containing
individual muscles or muscle
groups of similar function
and innervation
• The compartments also
contain or direct the spread
of infection or hemorrhage
Axillary fascia
forms the floor
of the axilla
and is
continuous
with the
pectoral fascia
SUPERFICIAL VEINS OF THE UPPER LIMB (4)
• Cephalic Vein (arises from
dorsal venous network
along the lateral surface of
the biceps, lies in the
deltopectoral triangle, ends
in the axillary vein)
• Basilic Vein (arises from the
dorsal venous arch of the
hand and lies along the
ulnar border of the forearm
and passes anterior to the
medial epicondyle, joins
the brachial veins to form
the axillary vein)
SUPERFICIAL VEINS OF THE UPPER LIMB (4)
• Median Cubital Vein
(connects the cephalic
vein to the basilic vein
over the cubital fossa,
lies close to brachial
artery which is
vulnerable to being
punctured during IV
puncturess)
• Median Vein of Forearm
(arises in the palmar
venous network, ascends
on the front of the
forearm, and terminates
in the median cubital or
the basilic vein)
Superficial Veins
Venous Palmar arch
CUTANEOUS NERVES OF THE UPPER LIMB
1. Supraclavicular Nerve - cervical plexus (C3-4) and innervates
the skin over the upper pectoral, deltoid, and outer
trapezius areas
2. Medial Brachial Cutaneous Nerve: from the medial cord of the
brachial plexus (C8-T1) and innervates the medial side of the
arm
3. Medial Antebrachial Cutaneous Nerve: medial cord of the brachial
plexus and innervates the medial side of the forearm (C8-T1)
4. Lateral Brachial Cutaneous Nerve: from the axillary nerve(C5-6)
and innervates the lateral side of the arm
5. Lateral Antebrachial Cutaneous Nerve: from the
musculocutaneous nerve and innervates the lateral side of the
forearm (C5-C6)
6. Posterior Brachial and Antebrachial Cutaneous Nerves: from the
radial nerve and innervate the posterior sides of the arm and
forearm (C5-8)
7. Intercostobrachial Nerve: Lateral cutaneous branch of the second
intercostal nerve emerging from the second intercostal space
and may communicate with the medial brachial cutaneous nerve
(T12)
CUTANEOUS NERVES OF THE UPPER LIMB
Referred pain to the shoulder most probably indicates involvement of the phrenic
nerve (or diaphragm). The supraclavicular nerve (C3–C4), which supplies sensory
fi bers over the shoulder, has the same origin as the phrenic nerve (C3–C5), which
supplies the diaphragm!