Clavicle bone -Anatomy

Hello friends,

Introduction-
The  clavicle or collar bone is a long bone. It supports the shoulder so that the arm can swing away from the trunk. It is palpable bone who have less fat in this region. clavicle transmits the body weight of the limb to the sternum.
It receives its name from the Latin word clavicula ("little key"). The clavicle is the most commonly broken bone. 

General features-

Shaft-

Shaft is divided into the lateral 1/3rd and medial 2/3rd.

The lateral end of the shaft is flattened from above downwards. 

It has:-

 2 borders- Anterior(concave forward) and posterior (convex backward).

 2 surfaces- Superior and Inferior.

Medial end-

The medial or sternal end is quadrangular . Articulated with the clavicle notch of the manubrium sterni to form sternoclavicular joint. 

It gives attachments to:

• fibrous capsule joint, all around
• articular disc, superoposteriorly
• interclavicular, ligament superiorly

Lateral end- 

The lateral or acromial end is flattened from above downwards . It articulate with the acromian process by facet present in it to form acromioclavicular joint. 

Side determination-

Side can be determine by the following features :-

1. lateral end is flat and medial end is large and quadrangular.

2. The shaft is slightly curved. medial 2/3rd is convex forward and lateral 1/3rd is concave forward.

3. Inferior surface is grooved longitudinally in it's medial 1/3rd.

Peculiarities-

1. It is the only long bone with lies horizontally.

2. It is subcutaneous throughout.

3. First bone to start ossifying.

4. Only long bone which ossifies in membrane.

5. It has 2 primary centers ossification.

6. generally have no medullary cavity but this is not always true.

sex determination-

In females- clavicle is shorter, lighter, thinner, smoother and less curved .

In males- The lateral end is either at the same level or slightly higher then the medial end.

osteology-

myology-

Clinical anatomy-

1. The clavicle is commonly fractured by falling on the outstretched hand. The most common site of fracture between the two curvature of bone, which is the weakest point.

2. The clavicle may congenitally absent, or imperfectly developed , this disease is called as cleidocraniel dysostosis. In this conditions the shoulders droop.