Articulations of the clavicle

The sternoclavicular joint

• Synovial joint, structurally plane, but functionally ball and socket.
  
  
• Formed between the medial end of the clavicle, clavicular notch of manubrium and adjoining first costal cartilage.
  
  
• Bony surfaces are lined by fibrocartilage not the usual hyaline cartilage.
  
  
• The capsule is thickened by anterior and posterior sternoclavicular ligaments.
  
  
  
• The major stability factor is the costoclavicular and sternoclavicular ligaments
  
  
• The brachiocephalic vein is formed immediately behind the joint
  
  
• Movements at this joint contribute to the increase the range of movement of the upper limb.

More info on the sternoclavicular joint

• Synovial plane joint between lateral endms of the clavicle and the acromion.
  
  
• Articular surfaces are lined by fibrocartilage instead of hyaline cartilage.
  
  
• An incomplete intracapsular fibrocartilage disc hangs down into the upper part of the joint cavity.
  
  
• A capsule surrounds the articular surfaces, and is thickened superiorly by the acromioclavicular ligament
  
  
• Main stability factor is the coracoclavicular ligament, with its two parts conoid and trapezoid.
  
  
• The joint is innervated by the suprascapular nerve.
  
  
• Allows passive movements of prortraction/retraction; rotation; elevation/depression

More info on the acromioclavicular joint

Forces from the humerus are transmitted via the glenoid cavity to the clavicle by the trapezoid ligament and from the clavicle to the first rib through the costoclavicular ligament.

Thus a fall on the outstretched hand or elbow puts no strain on either end of the clavicle at the joints. If the clavicle fractures as a result, it always does so between these ligaments.

The clavicle receives blood supply from the clavicular [A] and acromial branches of the thoracoacromial [T.C]artery.

Note: Thoracoacromial trunk [T.C] and its branches :- Clavicular [A], Pectoral [B] and Deltoid

What is the pattern of blood supply to the clavicle and what the importance of this in clavicular fractures?

Applied Anatomy Of The Clavicle