The scapula is connected to the clavicle by the acromioclavicular joint (articulatio acromioclavicularis).

This joint is formed between the acromial facet (facies articularis acromialis) and the acromial end of the clavicle (extremitas acromialis 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 plane, multiaxial, simple, and combined (with a sternoclavicular joint (articulatio sternoclavicularis)).

The range of motion in the joint is insignificant, it is carried out around three axes. The main motion is the raising of the hand.

Notably, raising to the horizontal line is carried out in the shoulder joint, and above the horizontal line — due to movement around the sagittal axis in the sternoclavicular joint (articulatio sternoclavicularis). The scapula also rotates during this motion.

If the clavicle moves around the anterior-posterior axis, then the shoulder girdle shifts up or down. If the clavicle moves around the vertical axis, the shoulder girdle shifts anteriorly or posteriorly.

The ligamentous apparatus of the joint is composed of several ligaments:

• The acromioclavicular ligament (ligamentum acromioclaviculare), connecting the acromion and the acromial end of the clavicle.

  

  

  

• The coracoclavicular ligament (ligamentum coracoclaviculare),

  

  

  which consists of the trapezoid ligament (ligamentum trapezoideum) and the conoid ligament (ligamentum conoideum).

  

  

  

  

  The additional structures of the joint include the articular disc (discus articularis) in 1/3 of the cases.

  The following vessels and nerves take part in the blood supply and innervation of the joint.

• Arteries: acromial branches of the thoraco-acromial artery (rr. acromiales a. thoracoacromialis), suprascapular artery (a. suprascapularis)

• Veins: thoraco-acromial vein (v. thoracoacromialis), suprascapular vein (v. suprascapularis)

• Nerves: supraclavicular nerves (nn. supraclaviculares)

Dictionary

Acromioclavicular joint

Acromioclavicular joint

art. acromioclavicularis

Scapula

scapula

Clavicula

clavicula

Acromial facet

facies articularis acromialis

Acromial end

facies articularis clavicularis

Sternoclavicular joint

art. sternoclavicularis

Acromioclavicular ligament

lig. acromioclaviculare

Coracoclavicular ligament

lig. coracoclaviculare

Trapezoid ligament

lig. trapezoideum

Conoid ligament

lig. conoideum

Articular disc

discus articularis