What Is the Sternoclavicular Joint?

The sternoclavicular joint is a saddle joint that connects the upper limbs to the trunk. It consists of the articular surface of the sternal end of the clavicle and the clavicle notch of the sternal stem. There are joint discs in the joint cavity (some statistics, 44% are complete, and 40% are absent). The joint capsule is tough and reinforced by ligaments around it. The articular surface resembles a saddle shape. Because of the joint disk, it changes into a ball-and-socket joint. There are three motion axes, which can be moved up and down around the sagittal axis (about 10 cm of motion, such as shrugging). Movement (movement range of about 12 cm, such as chest movement, chest expansion exercise); orbital movement around the frontal axis (such as shoulder movement around the back and forth). The sternal end of the clavicle is easily accessible because it is located above the sternal stem.

The sternoclavicular joint is a saddle joint that connects the upper limbs to the trunk. It consists of the articular surface of the sternal end of the clavicle and the clavicle notch of the sternal stem. There are joint discs in the joint cavity (some statistics, 44% are complete, and 40% are absent). The joint capsule is tough and reinforced by ligaments around it. The articular surface resembles a saddle shape. Because of the joint disk, it changes into a ball-and-socket joint. There are three motion axes, which can be moved up and down around the sagittal axis (about 10 cm of motion, such as shrugging). Movement (movement range of about 12 cm, such as chest movement, chest expansion exercise); orbital movement around the frontal axis (such as shoulder movement around the back and forth). The sternal end of the clavicle is easily accessible because it is located above the sternal stem.

Chinese name

Sternoclavicular joint

Foreign name

articulationes sternoclavicularis

Sternoclavicular joint auxiliary structure

1. The fibrous portion of the sternoclavicular joint capsule The fibrous portion of the sternoclavicular joint wraps the sternoclavicular joint, including the epiphysis of the sternal end of the clavicle, and is attached to the edge of the articular surface, including the periphery of the joint disc. The synovium is lined on the inner surface of the fibrous capsule and covers the joint disc and the joint surface.

2. Ligament of sternoclavicular joint The sternoclavicular ligament increases the stability of the joint capsule from the front and back sides. The interclavicular ligament is strengthened above the joint capsule. The ligament spans from the sternum end of the clavicle on one side to the sternum end of the clavicle on the other side, and is also attached between the upper edges of the sternal stem. The costoclavicular ligament is located below the sternal end of the clavicle and is attached to the first rib and the first rib cartilage, limiting the lifting of the shoulder strap.

3. Movement of the sternoclavicular joint Although the sternoclavicular joint is very firm, it still has good mobility to allow movement of the shoulder straps and upper limbs. With the upper limb fully raised, the clavicle is lifted approximately 60 °. The sternoclavicular joint moves in the following directions: forward, backward, down, and up 25 ° to 30 ° along the long axis.

4. The blood supply of the sternoclavicular joint is provided by the internal thoracic artery and the superior scapular artery.

5. The nerve of the sternoclavicular joint innervates the medial branch of the supraclavicular nerve and the subclavian nerve that innervates the sternoclavicular joint.

Sternoclavicular Joint Related Diseases and Treatment

1. Sternoclavicular joint dislocation is relatively rare in clinical practice, because of its acuteness and severe long-term complications, it has attracted more and more attention from clinicians. After dislocation of the sternoclavicular joint, the surrounding stable structure is destroyed, and the joint is unstable after reduction, and it is easy to dislocate again, which requires surgical treatment.

2. Imaging diagnosis of sternoclavicular joint dislocations For sternoclavicular joint dislocations, especially posterior dislocations, X-ray films often have overlapping bone images, which cannot clearly show whether the joints are dislocated and missed diagnosis. CT can better show the anatomical relationship of the bone and the mediastinal anatomy. It can determine whether the joint is dislocated and the degree of dislocation, whether the adjacent structure is compressed, whether it is accompanied by a clavicle or sternal fracture, and whether there are fracture fragments and fragment displacement.

3. Treatment: The previous point of view is that conservative treatment is recommended for patients with acute dislocation of the sternoclavicular joint without serious complications. The sternoclavicular joint is easy to reset, but because the joint stability is damaged, such as the pectoralis major, sternocleidomastoid and trapezius muscles attached to the clavicle, it is easy to cause joint dislocation and fracture relocation, and it is difficult to maintain reduction. The sternoclavicular joint is not easy to reset and the joint can not be maintained after the reduction and pain, should be treated with surgery. Posterior dislocation of the sternoclavicular joint is more likely to cause serious injury than anterior dislocation. Early surgical treatment is also recommended.

Surgical treatment methods: Reconstruction of sternoclavicular joint, resection of medial end of clavicle, internal fixation of sternoclavicular joint, Kirschner wire tension band fixation, T-shaped and oblique T-shaped steel plate of distal radius, clavicle hook plate, sternoclavicular hook Steel plates and other internal fixation technologies. Some new internal fixation technologies are also used in the treatment of sternoclavicular joint dislocation, including steel cable "8" fixation, distal clavicle lock plate, L-shaped lock reconstruction plate, contralateral shoulder lock hook plate, fibula. Anatomical steel plate, etc. However, the clinical application of the above internal fixation technology is relatively small, and further cases need to be accumulated, and biomechanical experimental research needs to be increased.

Sternoclavicular joint attention

Early diagnosis of sternoclavicular joint disease should be emphasized. After biopsy, conservative treatment or local curettage can have a good effect on lesions with less bone destruction and low invasiveness. If the disease is acute, serious, and highly invasive, such as Tumors, septic arthritis, and tuberculosis should be removed early to prevent lesions from invading important surrounding tissues. According to the scope of the lesion resection, the reconstruction can be properly performed, and the stability of the stump can be increased by repairing the joint capsule and ligaments or by covering with soft tissue, but excessive reconstruction is not necessary.