Acromioclavicular joint

The acromioclavicular ( Medical: acromioclavicular joint, acromioclavicular joint, anatomical (Latin ) Articulatio acromioclavicularis, also lateral clavicular joint ) is the pivotal connection between the outer end of the collarbone ( clavicle ) and the upper end of the shoulder blade ( scapula ), the so-called shoulder height ( acromion ). The acromioclavicular joint (ACG ) is one of the synovial joints ( Diarthrosen ), that is, it has a joint cavity, articular cartilage and connective tissue as a stabilizing sheath has a joint capsule.

Anatomy

Right and left clavicle are each anchored via the sternoclavicular joint ( articulatio sternoclavicularis ) at the breastbone ( sternum) and connected via the acromioclavicular joint with the shoulder blade. These two each V-shaped portions are symmetrical and are used for the shoulder girdle, which rests the upper thoracic wall are summarized. The entire upper extremity is connected to the shoulder girdle to the trunk and therefore needs all the forces that occur between arm and torso, fielding (eg when climbing, serve in tennis ).

The acromioclavicular joint has the stability to withstand these forces, but still supports raising the arm above shoulder height. Movements in ACG are, however, always run in sync with the sternoclavicular joint and the Skapulothorakalgelenk ( articulatio scapulothoracalis ). Clavicle and scapula are mechanically coupled to each other due to cross- strained ligaments. Horizontal stability is achieved primarily through the acromioclavicular ligaments ( ligament acromioclavicular ). Vertical stability offer coracoclavicular ligaments ( coracoclavicular ligament ). Here ( conoid ligament ) is a distinction between a front ( trapezoid ligament ) and a posterior part. With respect to the Reißfestikeit is described that the ligamentum coracoclavicular is more stable. The force that is necessary in order to provoke a complete demolition is indicated with about 1000 N.

The two articulating surfaces are covered with hyaline cartilage, but do not fit exactly. This mismatch is compensated mostly by a joint intermediate disc ( discus ) for protection against abrasion. However, this is worn from the age of 20 already stresses of daily life, so that in a majority of no washer over 40 years can be found more. It can be shown over 50 years of osteoarthritis in the acromioclavicular joint in almost all. Thus, the acromioclavicular joint is one of the most commonly affected by osteoarthritis joints. However, the majority of patients therefore has no complaints.

Diseases of the Schultereckgelenks

The most common violation of the ACG is the acromioclavicular joint dislocation or ACG - blowing. After Tossy (I -III), three different degrees of severity can be distinguished. Usually it comes by a fall on the shoulder to overstretching or tearing of one or more ligaments, which can lead to instability of the joint. As therapy, the short-term immobilization in a Gilchrist bandage is recommended in the majority of cases.

A painful limitation of movement may also be evidence of osteoarthritis, but also rare on a cyst near the joint. The treatment of ACG osteoarthritis is usually in physiotherapy and physical applications such as cold and electrotherapy. Therefore no success is achieved, a resection of the Schultereckgelenks may be considered to be the joint surfaces on both sides of the joint milled and then a kind of meniscus between the articular surfaces of these places from the body's own material to fill the gap. With optimum course the results are impressive, after about 2 months, the shoulder is again fully stress-resistant and largely pain-free. This method can be performed in a minimally invasive, but this OP is still performed frequently open. In the open method, the chance of success is higher, but the disadvantage is the higher risk of infection and wound pain.

• Joint of the upper extremity