What is sternoclavicular joint dislocation?
The sternoclavicular joint is a saddle-like joint that connects the upper arm to the trunk, and the clavicle can move in different planes. Sternoclavicular dislocation is the displacement of the clavicle relative to the normal position of the sternum. Anterior dislocation can occur when the medial clavicle is pushed anteriorly and laterally away from the chest wall, and vice versa for posterior dislocation. With direct trauma to the medial clavicle, the clavicle can be dislocated posteriorly, damaging the trachea, esophagus, thoracic duct, lungs, or large blood vessels.
Traumatic sternoclavicular dislocation is often caused by indirect violence acting on the anterior shoulder joint, which is in an external booth. Sternoclavicular dislocations may also result from congenital, degenerative or inflammatory processes. Sternoclavicular dislocation or subluxation may also occur in the absence of trauma due to generalized ligamentous laxity.
The severity of the sternoclavicular joint is graded according to sternoclavicular and costoclavicular ligament injuries. The first degree of injury is most common and is a strain or partial tear of the sternoclavicular and/or costoclavicular ligaments; the second degree of injury is a complete rupture of the sternoclavicular ligament as well as a partial tear of the costoclavicular ligament, and the third degree of injury is a complete rupture of both ligaments and dislocation of the clavicle from the upper sternal stalk.
Epidemiology and incidence: Sternoclavicular dislocations are uncommon, accounting for only 3% of all shoulder injuries, with anterior dislocations being much more common than posterior dislocations, with a ratio of 20:1. They are most often seen in young males, such as falls, car accidents, or rival sports (rugby, field hockey, etc.). Non-traumatic sternoclavicular dislocations are mostly caused by ligamentous laxity and are most often seen in young women under 20 years of age.
Diagnosis.
History: A complete history includes a history of previous trauma, mechanism of injury, history of previous dislocation of the sternoclavicular joint, and previous office visits. Patients may complain of chest or shoulder trauma, with shoulder or chest pain that worsens with arm movement and is more pronounced when the arm is raised and in the supine position. Muscle strength in the affected shoulder/arm is reduced and the patient complains of popping when injured. Posterior sternoclavicular joint dislocation may present with difficulty breathing, difficulty swallowing, or abnormal arm sensation. If these symptoms are present, further examination of the cause is required.
Physical examination: The patient’s head may be tilted to the affected side with the upper arm crossed over the chest. Vital signs should be noted, including the presence of respiratory abnormalities (e.g., shortness of breath, wheezing) and the presence of vascular problems in the head, neck, and upper extremities. The sternoclavicular joint may be swollen and deformed as well as painful on pressure, which may be induced by the patient doing normal shoulder activities and shrugging the shoulder. Posterior dislocation of the sternoclavicular joint may be overlooked, especially when soft tissue swelling is more pronounced.
Ancillary examinations: CT examination can understand the position of the clavicle and compare it with the normal side, as well as detect concomitant chest injury. MRI can be used to assess the extent of soft tissue injury, and if posterior dislocation occurs with suspected damage to the esophagus or blood vessels, esophagoscopy or angiography is required.
Treatment.
Treatment of sternoclavicular dislocation depends on the mode of injury (anterior or posterior dislocation) and the severity of the injury (first, second, or third degree). First-degree dislocations are usually treated conservatively with NSAIDs to reduce pain and inflammatory response, rest, ice, and immobilization of the affected limb in a sling. In the case of second degree dislocation, immobilization with a figure-of-8 harness is required for 7-10 days.
Third-degree dislocation first requires repositioning, including closed repositioning by manipulation and surgical incisional repositioning. The principles of treatment after repositioning are the same as for second-degree dislocation. If surgical incisional repositioning is performed, a longer period of braking is required. Posterior dislocations are best repositioned by surgical incision under anesthesia because of the risk of vascular and thoracic injury. Fixation is usually not performed with a Clinique pin because of the fear of movement of the pin into the chest. Posterior dislocation requires emergency management in case of concomitant injury or complications.
Prognosis.
The prognosis is generally good for first- and second-degree dislocations after regular conservative treatment. The prognosis of third-degree dislocations is related to complications and associated injuries. The prognosis is better for anterior dislocations that do not require repositioning or are easily closed and repositioned than for patients who require surgical incision and repositioning. Posterior dislocations usually require incisional repositioning and are prone to complications and have a poorer prognosis.
Rehabilitation.
Rehabilitation exercises depend on the mode and severity of the dislocation and the accompanying soft tissue injury. Special care needs to be taken by the rehabilitator when performing exercises, especially in posterior dislocations, and the patient’s vital signs should be closely monitored.
The primary task is pain control as well as restoration of function. Care is taken to monitor the patient’s exercise during rehabilitation to help him or her be able to return to pre-injury status.
Ice and heat packs may be used alternately to control inflammation and pain. Exercises can be performed in all directions of shoulder mobility without pain. Pay attention to exercising the muscles around the shoulder joint and scapula.
It takes 12 weeks for the ligaments and soft tissues around the shoulder joint to heal. During this period, weight-bearing exercises and confrontational sports should be avoided depending on the direction of dislocation and the severity of the injury. After the soft tissues have healed, more aggressive strength training can be performed to return to pre-injury status.
Complications.
Anterior sternoclavicular dislocations usually do not cause serious complications, but may lead to joint degeneration and limited mobility. Posterior sternoclavicular dislocation has a complication rate of up to 25% and includes esophageal rupture, pneumothorax, superior vena cava tear, subclavian artery/vein occlusion, and recurrent dislocation. In the event of a missed diagnosis, life-threatening complications may occur.
The most common surgical complication is the displacement of an intra-orthopedic implant into a vital organ, which may lead to death. Therefore, muscle, tendon or synthetic substances are now increasingly used to reconstruct the sternoclavicular ligament. Complications from open surgery can be as high as 25%.