helpful for 1st year medical students and lecturer of medical college teaching first year medical student.

1. Presented by
Dr. Fahim Faisal
M.B.B.S. (DU)

3. 1. The clavicle is a modified long bone. (Latin “a small key”)
2. It supports the shoulder so that the arm can swing clearly away from
the trunk.
3. The clavicle transmits the weight of the limb to sternum.( Receives
weight of upper limb via lateral one third through coracoclavicular
ligament and transmit the weight to axial skeleton via medial two thirds.)
4. The bone has a cylindrical part called the shaft and two ends, lateral
and medial.
5. It is also called “colar bone” and “Beauty bone” in female.

4.  The lateral end is flat and the medial end is large and quadrilateral.
 The shaft is slightly curved, so that it is convex forwards in it’s medial
two-thirds and concave forwards in it’s lateral one-third.
 The inferior surface is grooved in it’s middle one-third
Superior surface Inferior surface

5.  Shaft : divisible into
A. The lateral one-third and
B. The medial two-thirds.
The lateral one third : this part of the shaft is flattened from above downwards. It has
2 borders, anterior and posterior, 2 surfaces superior and inferior. Superior surface is
subcutaneous and inferior surface has conoid tubercle and trapezoid ridge.
The medial two thirds: it is rounded and has 4 surfaces. Anterior surface is convex
forwards, the posterior surface is smooth, the superior surface is rough in its medial
part , the inferior surface has an oval impression in its medial end. The lateral half of
this surface has a longitudinal subclavian groove. Nutrient foramen lies at the lateral
end of the groove which transmits a branch of the suprascapular artery.

6. Inferior surface of clavicle

7.  Medial end
The medial or sternal end is
quadrangular and articulates with the
clavicular notch of the manubrium
sterni to form the sternoclavicular
joint. The articular surface extends to
the inferior aspect, for articulation
with the first costal cartilage.
 Lateral end
The lateral or acromial end is
flattened from above downwards it
bears a facet that articulates with the
acromion process of the scapula to
form acromioclavicular joint.

8. Medial end
Lateral end

9. 2. At the medial end, the margin of
the articular surface of the sternum
gives attachment to :
a. Fibrous capsule of sternoclavicular
joint all around.
b. Articular disc posterosuperiorly.
c. Interclavicular ligament superiorly.
1.At the lateral end, the margin of
the articular surface for it’s
acromioclavicular joint gives
attachment to the joint capsule.

11. 3. Lateral one-third of shaft :
a. The anterior border gives origin to the deltoid.
b. Posterior border provides insertion to the trapezius.
c. The conoid tubercle and trapezoid ridge give attachment to the conoid
and trapezoid parts of the coracoclavicular ligament.

12. 4. Medial two-thirds of the shaft:
a. Most anterior surface gives origin to the pectoralis major.
b. Half of the rough superior surface give origin to the clavicular head of
the sternocleidomastoid.
c. The oval impression on the inferior surface gives attachment to the
costoclavicular ligament.
d. The subclavian groove gives insertion to the subclavius muscle. The
margins of the groove give attachment to the clavipectoral fascia.
e. The posterior surface close to medial end gives origin to sternohyoid
muscle.
f. The subclavian vessels and cords of brachial plexus pass towards the
axilla lying between the inferior surface of the clavicle and upper surface
of the first rib. Subclavius muscle acts as a cushion.

13. 1. It is the only long bone that lies horizontally.
2. It is subcutaneous throughout.
3. It is the first bone to start ossifying.
4. It is the only long bone which ossifies in membrane.
5. It is the only long bone which has two primary centers of ossification.
6. There is no medullary cavity.
7. It is occasionally pierced by middle supraclavicular nerve.

14.  Primary centre : The two primary
centres appear in the shaft
between 5Th and 6th weeks of intra
uterine life and fuse about the 45
day.
 Secondary centre : the secondary
centre for the medial end appears
during 15-17 years, and fuses with
the shaft during 21-22 years .
Occasionally there may be a
secondary centre for the acromial
end.
 The clavicle is the first bone in the
body to ossify. Except for its
medial end, it ossifies in
membrane. It ossifies from two
primary centres and one
secondary centre.

15.  Fracture of clavicle :
The clavicle is commonly fractured by falling on the outstretched hand.
The most common site of fracture is the junction between the two
curvatures of the bone, which is the weakest point. The lateral segment is
displaced downwards by the weight of the limb as trapezius muscle alone
is unable to support the weight of the upper limb.

17.  Congenital anomaly :
The clavicles may be congenitally
absent or imperfectly developed
in a disease called cleidocranial
dysostosis. In this condition, the
shoulders droop, and can be
approximated anteriorly in front of
the chest.

18. Your friend “X” called you and said
that she/he had an accident earlier
that day when she/he was trying to
get down of the bus. Now she/he
having severe pain beside right
shoulder and movement of right arm
and shoulder is restricted. She/ He
also sent you a picture of her/his
current condition.
What advice will you give to your friend?