Osteology of clavicle

Inferior surface of clavicle

Clavicle is the collar bone. It is situated at the root of the neck and transfers the weight of upper limb to the axial skeleton

Specialties of clavicle:

1)It is a modified long bone.

2)It is the only long bone that is situated in horizontal direction.

3)First bone to start ossification .

4)Last bone to complete ossification 

5) Mo medullary cavity

6)only long bone which has 2 primary ossification Centers.

7)Only long bone to ossify in membrane.

Joints formed:1)Sterno clavicular joint.
2)Acromioclavicular joint.

Parts and features:

Clavicle has Medial end and lateral end and intervening shaft. The clavicle is divided into medial two thirds and lateral one third. The junction between the two parts is the weakest area of clavicle. 

Medial end is quadrangular, presents an articular facet for the manubrium. It presents four surfaces - anterior, superior, inferior and posterior.

Lateral end is flat from above downwards. It presents anterior and posterior border, superior and inferior surfaces. Inferior surface presents conoid tubercle and trapezoid ridge.

The inferior surface of the shaft of the clavicle presents subclavian fossa.

Attachments:

Superior surface of clavicle

Origin of 

• Pectoralis major from anterior surface of medial end.
• Sternocleidomastoid from superior surface of medial end.
• Sternohyoid from posterior surface of medial end.
• Deltoid from anterior border and adjacent surfaces of lateral end.

Insertion of 

• Trapezius to the posterior border and adjacent surfaces of lateral end.
• Subclavius to the subclavian groove.

Ligaments:

• Conoid and trapezoid part of the coracoclavicular ligament.
• Costoclavicular ligament.
• Fibrous capsule.
• Articular disc, interclavicular ligament.
• Clavipectoral fascia to the margins of the subclavian groove.