The sternum is connected to the clavicle by the sternoclavicular joint (articulatio sternoclavicularis).
This joint is formed between the articular surfaces on the clavicular notch of the manubrium of the sternum (incisura clavicularis manubrii sterni);
and the sternal end of the clavicle (extremitas sternalis claviculae).
The joint capsule is attached along the edge of the articular surfaces, it is dense and fibrous.
According to the classification, the joint is simple, plane, multiaxial, complex, and combined (with an acromioclavicular joint (articulatio acromioclavicularis)).
The following range of motions is possible in the joint:
Around the sagittal axis: lifting and lowering of the clavicle.
Around the vertical axis: back and forth motion of the clavicle.
Shifting from the sagittal plane to the vertical plane enables circumduction (circumductio) The fixing apparatus of the joint is represented by several ligaments:
Anterior sternoclavicular ligament (ligamentum sternoclaviculare anterius). It is a wide fibrous cord covering the anterior surface of the joint and running diagonally from the proximal part of the clavicle to the sternum.
The posterior sternoclavicular ligament (ligamentum sternoclaviculare posterius) runs from the posterior-superior surface of the sternal end of the clavicle to the posterior-superior surface of the manubrium of the sternum.
The costoclavicular ligament (ligamentum costoclaviculare) is a short, wide ligament that connects the inferior surface of the sternal end of the clavicle with the cartilage and bony part of the 1st rib.
The interclavicular ligament (ligamentum interclaviculare) connects two sternal ends of the right and left clavicles.
The additional structures of the joint consist of an articular disc (discus articularis) that fuses with the capsule and divides the articular cavity into two chambers.
The following vessels and nerves take part in the blood supply and innervation of the joint.
Blood supply and innervation.
Arteries: perforating and sternal branches of the internal thoracic artery (rr. perforantes et sternales a. thoracica interna), superior thoracic artery (a. thoracica superior), first intercostal artery (a. intercostalis I)
Veins: internal thoracic vein (v. thoracica interna), superior thoracic vein (v. thoracica superior), posterior intercostal veins (vv. intercostales posteriores)
- Sternoclavicular joint
- art. sternoclavicularis
- Clavicular notch of the manubrium of the sternum
- incisura clavicularis manubrii sterni
- Sternal end of the clavicle
- extremitas sternalis claviculae
- Acromioclavicular joint
- art. acromioclavicularis
- Anterior sternoclavicular ligament
- lig. sternoclaviculare anterius
- Posterior sternoclavicular ligament
- lig. sternoclaviculare posterius
- Costoclavicular ligament
- lig. costoclaviculare
- Interclavicular ligament
- lig. interclaviculare
- Articular disc
- discus articularis