Shoulder joint dislocation

　　Shoulder joint dislocation caused by indirect violence is more common. The patient falls to one side, with the palm of the hand landing, and the humerus bone is in a highly abductively and externally rotated position, with the external force transmitted from the palm to the humeral head. Another type is the lever action external force, when the upper limb is excessively externally rotated, overextended, and abducted, the humeral neck is impacted by the acromion to become the fulcrum of the lever, causing the humeral head to slip forward and downward. Direct violence is often due to the external force transmitted from the posterior part of the humeral head, causing the humeral head to dislocate forward, but it is less common.

　　What complications can shoulder joint dislocation easily lead to

　　What are the typical symptoms of shoulder joint dislocation

　　Shoulder joint dislocation, in the early stage, has symptoms such as shoulder pain, swelling, and dysfunction, as follows:

　　1. The injured shoulder is swollen and painful, with limited active and passive movement.

　　2. The affected limb is elastically fixed in a slight abduction position, often supported by the healthy hand, with the head and trunk tilting towards the affected side.

　　3. Shoulder deltoid atrophy, presenting as a square shoulder deformity, the displaced humeral head can be felt in the axilla, under the coracoid process, or below the clavicle, with the glenoid fossa empty.

　　Shoulder joint dislocation is caused by traumatic factors, with no specific preventive measures. The focus of clinical prevention and treatment is on early diagnosis and early treatment, which is simple, minimizes patient suffering, and results in good treatment outcomes. However, missed or misdiagnosis can transform a fresh dislocation into an old one, making treatment complex, with a long course, severe patient suffering, and poor treatment outcomes. Therefore, clinical orthopedic physicians should be vigilant about the possibility of posterior glenohumeral dislocation, take additional axillary or anteroposterior chest side X-ray films for suspected cases, and perform shoulder joint CT scans if necessary.

　　X-ray films, CT three-dimensional reconstruction, and MRI can clearly determine the dislocation and soft tissue injury of shoulder joint dislocation.

　　1. When the shoulder joint is posteriorly dislocated, the routine anteroposterior shoulder joint X-ray film report is often negative. Since the subacromial type of posterior dislocation is the most common, and the approximate position relationship between the humeral head, glenoid fossa, and acromion during the anteroposterior X-ray film of the shoulder joint still exists, the film report is often negative. However, careful film reading can still reveal the following abnormal features:

　　1. Due to the humeral head being in a forced internal rotation position, even when the forearm is in a neutral position, the humeral neck can still be found to be 'shortened' or 'disappeared', with the images of the greater and lesser tubercles overlapping.

　　2. The gap between the inner margin of the humeral head and the anterior margin of the glenoid fossa is widened, and it is usually considered abnormal when the gap is greater than 6mm.

　　3. The elliptical overlapping shadow of the normal humeral head and the glenoid fossa disappears.

　　4. The relationship between the humeral head and the glenoid fossa is asymmetric, manifested as higher or lower, and not parallel to the anterior margin of the fossa.

　　In cases of highly suspected posterior glenohumeral dislocation, axillary or anteroposterior chest side radiographs should be taken, which can reveal the humeral head protruding posterior to the glenoid fossa. If necessary, a bilateral shoulder CT scan can clearly show that the humeral head joint surface is posterior and the humeral head protrudes beyond the posterior margin of the glenoid fossa. Sometimes, a concave fracture of the humeral head can be found, forming a jam with the posterior margin of the glenoid fossa, affecting reduction, or there may be a fracture of the posterior margin of the glenoid fossa.

　　After the reduction of shoulder joint dislocation patients, it is best to eat more calcium-rich foods, especially dairy products are better for calcium supplementation. There are many foods that contain calcium, but dairy products, such as milk, ice cream, and cheese, which contain more calcium and have a suitable calcium-phosphorus ratio, are the best. Patients can supplement appropriate milk every day. To promote the absorption of calcium and phosphorus, it is necessary to expose to the sun frequently, ensuring about one hour a day, in order to achieve a good calcium supplementation effect.

　　Not only dairy products, but also seafood contains a lot of calcium, which can be eaten more. In seafood, such as fish and shrimp, which contain a lot of calcium and phosphorus, and the calcium and phosphorus ratio is reasonable, making it a high-quality source of calcium and phosphorus. Therefore, eating more seafood is beneficial for shoulder joint dislocation. When eating fish and shrimp, choose appropriate cooking methods, and eat the shell together, because these components contain more calcium. When cooking, do not make it too greasy and try to choose light flavors. In addition, for those patients with seafood allergies, it is better not to use this method.

　　Habitual anterior shoulder joint dislocation is more common in young and middle-aged adults. The cause is generally believed to be injury caused by the first traumatic dislocation, although it has been reduced, but it has not received appropriate and effective fixation and rest. Due to poor repair of joint capsule tear or avulsion and cartilage labrum and edge injury, as well as pathological changes such as posterior lateral condyle fracture, the joint becomes loose. Subsequently, dislocation may occur repeatedly under slight external force or certain movements, such as external abduction and external rotation of the upper limb and posterior extension. The diagnosis of habitual shoulder joint dislocation is relatively easy. During X-ray examination, in addition to taking the anterior and posterior radiographs of the shoulder, it is also necessary to take the anterior and posterior X-ray films of the upper arm within 60 to 70 degrees of internal rotation, so that the posterior defect of the humeral head can be clearly displayed.

　　For habitual shoulder joint dislocation, if dislocation occurs frequently, surgical treatment should be considered, aiming to strengthen the anterior joint capsule, prevent excessive external rotation and abduction, stabilize the joint, and avoid recurrence of dislocation. There are many surgical methods, among which the most commonly used are the subscapularis muscle joint capsule overlap suture technique and the subscapularis muscle insertion external shift technique.