Acromioclavicular joint

The acromioclavicular joint , articulatio acromioclavicularis. Is formed by the articular surface of the shoulder end of the clavicle and the articular surface of the acromion of the scapula . The joint is simple. Joint articular surfaces The joint cavity is divided into two parts by an articular disc.

The joint is multiaxial, but with a sharply limited volume of movements, which results in flat joints.

The joint capsule is attached to the edge of the articular surfaces, it is strengthened by the following ligaments:

1. Acromioclavicular ligament, lig. Acromioclaviculare, which is stretched between the acromial end of the clavicle and the acromion of the scapula.

2. The biliary-clavicular ligament, lig. Coracoclaviculare, connecting the lower surface of the acromial end of the clavicle and the coracoid scapula of the scapula.

In the coracoid-clavicular ligament there are two parts: 1) trapezoidal ligament, lig. Trapezoideum, which occupies the lateral position and extends from the trapezoidal line, the acromial end of the clavicle to the coracoid scapula of the scapula; Has the form of a quadrangle; 2) conical bundle, lig. Conoideum, which lies medial, is stretched between the cone-shaped tubercle of the acromial end of the clavicle and the coracoid scapula of the scapula; Has the form of a triangle.

Both ligaments converge at the coracoid process at an angle and limit the groove formed on top of the clavicle and filled with loose fiber. Sometimes here lies a slimy bag.

In addition, the scapula carries a series of fibrous bundles - ligaments that connect its individual formations. These include:

1. The beak-acromial ligament, lig. Coracoacromiale, is the most powerful bundle of scapula. Tightened in the form of a four-holonon plate between the acro-myion and the coracoid process of the scapula.

2. Upper transverse ligament of the scapula, lig. Transversum scapulae superius, is thrown over the scrap of the scapula, limiting the hole with it.

3. Lower transverse ligament of the scapula, tig. Transversum scapulae inferius, - the weakest of the ligament bundles. It extends along the back surface of the scapula from the root of the acromion through the neck of the scapula to the outer surface of the articular cavity, interlacing part of its bundles in the capsule of the shoulder joint .