Download The Humerus

Bones of the Upper Limb
Dr. Fadel Naim
Orthopedic Surgeon
Faculty of Medicine
IUG-Gaza
‫اَل ُأ ْق ِس ُم ِب اي ْو ِم الْ ِق ايا ام ِة{‪ }1‬او اَل ُأ ْق ِس ُم ِِبلن ْف ِس اللوا ام ِة{‪}2‬‬
‫َأ ا َْي اس ُب ْاَلن اس ُان َألن ا ْن اَم اَ ِِ اَا ام ُُ{‪ }3‬ب ا اَل قاا ِد ِر اين عا اَل‬
‫ِ‬
‫َأن ن ُّ اس ِو اي باناان ا ُُ{‪}4‬‬
Skeleton of the Upper Limb


Each upper limb has 32 bones
Two separate regions
– 1. The pectoral (shoulder) girdle (2 bones)
– 2. The free part (30 bones)
Upper Limb

The pectoral girdle consists of two bones:
– the scapula
– the clavicle

The free part has 30 bones
– 1 humerus (arm)
– 1 ulna (forearm)
– 1 radius (forearm)
– 8 carpals (wrist)
– 19 metacarpal and phalanges (hand)

Composition of the
upper limb
Pectoral Girdle
clavicle
scapula
humerus
Clavicle

The clavicle is an s-shaped bone that
attaches the trunk to the upper extremity

Medial 2/3 convex forward and lateral 1/3
concave forward
Clinical Connection – Fractured Clavicle




A fall on an outstretched arm (F.O.O.S.H.)
injury can lead to a fractured clavicle
The clavicle is weakest at the junction of the
two curves
Forces are generated through the upper limb
to the trunk during a fall
Therefore, most breaks occur approximately
in the middle of the clavicle

Acromial end
– is flat and has a small facet for articulation with the acromion

Sternal end
– has a large facet for articulation with the manubrium, and first costal
cartilage

Conoid tubercle
– Attachment of conoid ligament of the coracoclavicular ligament

Trapezoid line
– Attachment of trapezoid portion of the coracoclavicular ligament
Clavicle: Ligament Attachments

Sternal end of clavicle to first costal cartilage:
Costoclavicular ligament

Conoid tubercle:
Conoid portion of coracoclavicular ligament

Trapezoid line:
Trapezoid portion of coracoclavicular ligament
Clavicle: Muscle Attachments





Deltoid
Pectoralis major
Trapezius
Sternocleidomastoid
Subclavius
Muscular, ligamentous, and fascial attachments to the clavicle
Scapula



Flat triangular bone
On the posterior thoracic wall
Between 2nd and 7th rib
Anterior Scapula
 Borders:
– Superior
– Medial
– lateral
 Angles:
• Superior
• inferior
 coracoid process
 acromion
 neck of scapula
Anterior Scapula
coracoid process
acromion
process
glenoid cavity
superior angle
subscapular fossa
inferior angle
Posterior Scapula

Spine of scapula
– Divides the supraspinous and
infraspinous fossae
– Serves as attachment for the
deltoid and trapezius

Acromion:
– Lateral extension of spine of
scapula;
– Articulate with clavicle

Greater scapular notch
– Point at which the spine of the
scapula ends, but the acromion
continues;

Coracoid process
– Partially seen as it projects
anteriorly;

Supraspinous fossa
– Origin of the supraspinatus
muscle

Infraspinous fossa
– Origin of the infraspinatous
muscle

Lateral border
– Attachment of:
• Teres major
• The long head of the triceps
brachii
• Teres minor
Posterior
Scapula
acromion process
supraspinous fossa
infraspinous fossa
spine
lateral border
medial border
Lateral Scapula

Supraglenoid tubercle
– Attachement of the long
head of the biceps
brachii

Infraglenoid tubercle
– Attachement of the long
head of the triceps
brachii
Lateral Scapula

Acromion:
– Articulates with the clavicle
– Attachment for the trapezius and
deltoid muscles;


Superior and inferior angles
Coracoid process:
– Attachment point for:
• The short head of the biceps
brachii
• Corachobrachialis
• Pectoralis minor
The Humerus



Longest and largest bone of the free part
of the upper limb
The proximal ball-shaped end articulates
with the glenoid cavity of the scapula
The distal end articulates at the elbow with
the radius and ulna
The Humerus

The proximal end consists of:
– The head
– Anatomical neck
– Greater and lesser tubercles separated from each
other by an intertubercular groove (bicipital groove)
The head



The head, nearly hemispherical in form
Articulates with the glenoid cavity of the scapula .
The circumference of its articular surface is slightly
constricted and is termed the anatomical neck
The anatomical neck


The anatomical neck of the humerus is an
indentation no suremuh eht fo daeh eht ot latsid
eht hcihwarticular capsule attaches.
Fracture of the anatomical neck rarely.srucco
The Greater Tubercle
 The greater tubercle is situated lateral to the head and lesser
tubercle, and just lateral to the anatomical neck
 Its upper surface is rounded and marked by three flat
impressions:
– the highest for insertion of the suprasinatus muscle
– the middle for the infraspinatus muscle
– the lowest one, and the body of the bone for teres muscle
The Lesser Tubercle


The lesser tubercle is more prominent than the
greater tubercle
Above and in front it presents an impression for the
insertion of the tendon of the subscapularis muscle
The Intertubercular (Bicipital) Groove

The tubercles are separated from
each other by a deep groove, the
intertubercular groove (bicipital
groove gnol eht segdol hcihw ,)
iihcarb specib eht fo nodnet
elcsum
The surgical neck


The surgical neck is the point distal to the
tubercles at which the superior portion of the
bone meets the shaft
The surgical neck is a common site of fracture .

The body of the humerus has
two prominent features:
– The deltoid tuberosity, laterally,
for attachment of the deltoid
muscle
Distal Humerus

Medial epicondyle:
– The pronator and flexor muscles
of the forearm originate here

Lateral epicondyle:
– The extensor and supinator
muscles of the forearm originate
here



Medial supracondylar ridge
Lateral supracondylar ridge
Trochlea (medial condyle):
– Articulates with the trochlear
notch of the ulna

Capitulum (lateral condyle):
– Articulates with the radial head
•Distal Humerus

Coronoid fossa:
– Accommodates the coronoid
process of the ulna during
flexion.
– A fat pad is situated here

Radial fossa:
– Accommodates the head of the
radius during flexion.
– A fat pad is situated here

Olecranon fossa:
– Accommodates the olecranon.
– A fat pad is situated here

Groove for ulnar nerve
Anterior Humerus
medial epicondyle
trochlea
coronoid fossa
capitulum
lateral epicondyle
deltoid
tuberosity
intertubercular
groove
lesser
tubercle
greater
tubercle
Humerus: Anterior
•Greater tubercle
•Clavicle
•Acromion process
•Coracoid process
•Lesser tubercle
•Humerus
•Deltoid tuberosity
•Scapula
•Glenoid fossa
•Coronoid fossa
•Medial epicondyle
•Lateral epicondyle
•Capitulum
•Radius
•Click R Button for Slideshow
•Trochlea
•Ulna
Humerus: Anterior2
•Greater tubercle
•Clavicle
•Acromion process
•Coracoid process
•Lesser tubercle
•Humerus
•Deltoid tuberosity
•Scapula
•Glenoid fossa
•Coronoid fossa
•Medial epicondyle
•Lateral epicondyle
•Capitulum
•Radius
•Trochlea
•Ulna
Humerus: Posterior
•Acromion of scapula
•Spine of scapula
•Scapula
•Glenoid fossa of scapula
•Head of humerus
•Greater tubercle
•of humerus
•Deltoid tuberosity
•of humerus
•Humerus
•Medial epicondyle
•of humerus
•Lateral epicondyle
•of humerus
•Olecranon process of ulna
•Ulna
•Radius
•Right Arm, Posterior
Radius


The radius is the lateral and shorter of the two
forearm bones.
Its proximal end consists of:
1. A short cylindrical (or thick disc like) head
• The smooth superior aspect of the head of the radius is concave
for articnlation with the capitulum of the hnmerus during flexion
and extension of the elbow joint.
• The head also articulates peripherally with the radial notch of the
ulna
• The head is covered with articular cartilage.
2. A neck
• Relatively constricted between the head and the tuberosity.
3. A medially directed tuberosity
• The oval radial tuberosity separates the proximal end of the radius
from the body.
Radius
The distal end of the radius



Its medial aspect forms a
concavity, the ulnar notch,
which accommodates the
head of the ulna.
Extending from its lateral
aspect is the radial styloid
process.
The dorsal tubercle,
(Lister’s) projecting dorsally
lies between grooves for the
passage of the tendons of
forearm muscles


The radial styloid process is much
larger than the ulnar styloid
process and extends
approximately a finger's breadth
further distally
This relationship is of clinical
importance when the ulna and/or
the radius are fractured
Radius
•radial tuberosity
•head
•styloid process
Ulna


The stabilizing bone of the
forearm is the medial and
longer of the two forearm
bones
Its proximal end has two
prominent projections:
– The olecranon:
• projects proximally from its
posterior aspect
– The coronoid process
• Projects anteriorly.
The olecranon

The olecranon is the most proximal
posterior eminence of the ulna

It is on the dorsal subcutaneous
border and contains broad
attachments for the triceps
posteriorly

Anteriorly, the olecranon forms the
trochlear notch of the ulna, which
articulates with the trochlea

The radial notch
– On the lateral side of the
coronoid process is a smooth,
rounded concavity, which
articulates with the head of the
radius.
Ulna




Inferior to the coronoid process
is the tuberosity of the ulna for
attachment of the tendon of the
Brachialis muscle.
Inferior to the radial notch on the
lateral surface of the ulna is a
prominent ridge (the supinator
crest)
Between it and the distal part of
the coronoid process is a
concavity (the supinator fossa)
The deep part of the supinator
muscle attaches to the
supinator crest and fossa.

At the narrow distal end of the ulna is a abrupt
enlargement forming a disclike head and a
small, conical styloid process.
•styloid
process
Ulna
•trochlear notch
•coronoid process
•head
•radial notch
•olecranon process
•styloid process
•Ulna
•olecranon
•Trochlear notch
•Coronoid process
•Ulnar tuberosity
•Head of ulna
•styloid process
•Proximal end
•Distal end
Bones of the Hand
The skeleton of the carpus is
composed of eight carpal bones
(carpals) arranged in two rows of four
each
 The pisiform is set on a plane anterior
to the others and behaves as a
sesamoid in the tendon of flexor
carpi ulnaris, rather than participating
in movements at the wrist


The carpus is markedly convex
posteriorly and concave anteriorly
From lateral to medial, the bones in the
proximal row of carpals are:

1.
Scaphoid
2.
3.
4.
Lunate
Triquetrum
Pisiform
From lateral to medial, the four bones in
` distal row of carpals are the:
the

1.
2.
3.
4.
Trapezium:
Trapezoid:
Capitate:
Hamate:
•She Likes To Play
•Scaphoid
•Lunate
•In the moonlight
•A boat
•Triquetrum
•The third T Bone
Mnemonic
for
Learning
Carpals
•Pisiform
•Pea-shaped
•Hamate
•A hambone
•With a hook
•Trapezium:
•“It’s by the thumb”
•Capitate
•Trapezoid
•“Is by its side”
•Try To Catch Her
Metacarpals

The first element of each ray is its metacarpal.

The proximal end of a metacarpal is expanded to form a
base that articulates with the carpus.

The distal end of a metacarpal is expanded to form a
rounded head that articulates with the proximal phalanx of
the digit to form the knuckles of the fist
Phalanges

Each of the four fingers contains a:
– Proximal phalanx
– Middle phalanx
– Distal phalanx.

The thumb has only :
– A proximal phalanx
– A distal phalanx.
Naming of Digits





1
2
3
4
5





Thumb
Index
Middle
Ring
Little
Manus (Hand)
•Carpals (8)
•3
•1 •pollex
•Metacarpals (5)
•Digits
(5)