Clavicle (Collar Bone)

Last updated 20.05.13

 

Definition

-  Bone of upper limb which forms part of pectoral girdle

 

Clinical Relevance

-  Clavicle fracture

 

Orientation

-  2 bones bilaterally, 1 each side

-  Lies anterior to the anterior wall of the thorax on its most superior aspect

-  Serves as attachement of upper limb to axial skeleton (sternum to scapula)

-  Common site of fracture usually with fall injuries

 

Clavicle 1

Clavicle 2 

 

 

Anatomical Features

-  Most landmarks on inferior surface

-  Superior surface is mostly indistinct and quite smooth

-  Body curves anterioroly (convex) at its medial 2/3 & posteriorly (concave) at its lateral 1/3

-  Sternal Extremity (Medial Extremity)

-  Large more bulbous end

-  Attachment site of:

-   Interclavicular ligament

-   Anterior sternoclavicular ligament

-   Posterior sternoclavicular ligament

-   Clavicular head of sternocleidomastoid muscle

-  Articulates medially with the superiolateral surface of the manubrium of the sternum at the sternoclavicular joint

-  Is enclosed in joint capsule of the sternoclavicular joint

-  Forms the lateral borders of the jugular notch

-  Costal Tubercule

-  Located at sternal end of inferior surface of clavicle

-  Serves as the attachement site for the costoclavicular ligament from the 1st rib and its costal cartilage

-  Shaft

-  Attachment site of:

-   Deltoid muscle attaches to the lateral anterioinferior surface

-   Trapezius muscle (upper fibers) attaches to the lateral anteriorsuperior surface

-   Pectoralis muscle (clavicular head) attaches to the majority of the anterior surface

-   Platysma muscle attaches to the anteriosuperior surface

-  Subclavian Groove

-  Located on the inferior surface of the clavicle

-  Covers the middle third of the inferior surface

-  Serves as the elongated attachment site for the subclavius muscle

-  Conoid Tubercule

-  Located at the posterior inferior surface of the acromial end of the clavicle

-  Large rounded elevation

-  Serves as the attachment site for the conoid ligament of the coracoclavicular ligament

-  Trapezoid Line

-  Located immediately lateral to the conoid tubercule on the inferior surface of the acromial end of the clavicle

-  Roughened line extending laterally from the conoid tubercule

-  Serves as the attachment site for the trapezoid ligament of the coracoclavicular ligament

-  Acromial Extremity (Lateral Extremity)

-  Flatter more broad extremity

-  Attachment site of the acromioclavicular ligament

-  Articulates laterally with the medial surface of the acromium of the scapula at the acromioclavicular joint

-  Trapezius attaches to superior aspect

 

 

 

References

 

Moores Clinically Oriented Anatomy

Pic: thesebonesofmine.files.wordpress.com/2011/05/scal.jpg