Diagnosis and Treatment of Shoulder Dislocation
Shoulder dislocations often occur in young people and athletes. The younger the injury when the dislocation first occurs, the more likely it is that the dislocation will develop into a habitual shoulder dislocation, or recurrent shoulder dislocation, or more accurately, habitual shoulder instability. For example, patients who have their first shoulder dislocation in their teens have a 90% or greater chance of developing recurrent shoulder instability, while patients who have their first shoulder dislocation over the age of 40 are less than 10% likely to develop chronic shoulder instability.
I. Introduction of the disease
The shoulder joint consists of the articular pelvis, the humeral head, and the surrounding shoulder capsule and ligaments. Under normal circumstances, the humeral head is within the articular pelvis, but when trauma causes the humeral head to dislocate from the pelvis, the shoulder joint is dislocated. The common cause is anterior subluxation of the shoulder joint, which is caused by a fall on the arm that is abducted and strongly forced over the top, a direct blow to the shoulder, or a strong forced external rotation of the arm; the less common is posterior dislocation of the shoulder joint, which is often associated with seizures or electric shock, when the muscles of the shoulder forcefully contract to cause dislocation.
Habitual shoulder dislocation (or habitual shoulder instability) begins with the first shoulder dislocation, which damages the ligaments that support the shoulder joint (the middle glenohumeral ligament and the anterior bundle of the inferior glenohumeral ligament). The surface of the glenoid is relatively flat and is deepened by the glenoid labrum, a cartilaginous cup that can wrap around part of the humeral head.
The glenoid labrum acts as a bumper to hold the humeral head firmly in place on the glenoid, and it is also the attachment point for stabilizing the shoulder ligaments. When the glenoid labrum is torn from the glenoid, the support of these ligaments ceases to exist. The development of habitual shoulder instability is inextricably linked to the type and extent of damage to the glenoid labrum and surrounding ligaments.
II. Symptoms of the disease
The clinical manifestations of shoulder dislocation are very obvious.
1.Severe pain in the shoulder joint after injury
2.Severe limitation of shoulder joint movement
3.The shoulder joint drops down and forward, and there is a large depression under the shoulder peak (square shoulder deformity)
4.The head of the humerus can be seen in front of the shoulder or in the armpit, like a lump. Resetting the dislocated shoulder joint usually involves going to a hospital emergency department to find medical help, while some patients with recurrent shoulder dislocation are experienced enough to reset it themselves.
III. Disease diagnosis
Sudden dislocation of the shoulder joint is very characteristic. The patient usually holds the affected limb by hand because any movement causes pain; a large depression under the shoulder crest and swelling of the axilla suggest the direction of the shoulder dislocation. However, the diagnosis is more difficult after spontaneous repositioning of the shoulder dislocation. The patient may only feel that the shoulder joint “slid a little” before spontaneous repositioning.
Some patients reset themselves immediately at the site of injury. Once repositioned successfully, the pain is immediately relieved. In some cases, it is difficult to relax the shoulder muscles without medication, so the patient must go to the hospital for consultation and repositioning.
X-rays are taken to clarify the dislocation and its direction and to see if there are any associated fractures. Follow-up X-rays after repositioning can confirm the dislocation and identify other injuries, and X-rays can show a “bony Bankart injury”, which is an anterior inferior fracture of the articular glenoid. This type of fracture suggests that the anterior glenoid labrum and ligaments of the shoulder are no longer attached to the glenoid.
Bankart injury (separation of the anterior inferior glenoid labrum from the glenoid) is the most common cause of injurious shoulder instability.
IV. Treatment of disease
Initial repositioning of shoulder dislocation may be difficult. Spasm of the muscles around the shoulder joint can jam the humeral head. Gentle traction, sometimes with sedation, pain medication or the need for anesthesia can complete the reset. After the shoulder is repositioned, a sling is applied to protect the shoulder joint. Physical therapy helps the patient to regain joint mobility.
1.Non-surgical treatment
Early treatment of recurrent shoulder instability is based on physical therapy. Strengthening the rotator cuff muscles and the muscles around the scapula can stabilize the shoulder joint. The purpose of physical therapy is to help the muscles provide stability to the shoulder joint, a stability that was originally maintained by torn ligaments. Physical therapy programs should be carefully designed for each individual, as this shoulder instability often causes patients to feel intimidated by certain specific postures and exercise maneuvers. Physical therapy can often restore shoulder mobility, reduce fear, and restore shoulder function.
2.Surgical treatment
If physical therapy and activity modification cannot control shoulder instability, i.e., if habitual shoulder dislocation is formed, surgical treatment is usually required. The goal of surgical treatment is to restore stability while minimizing the loss of shoulder mobility. The current method of treating forward instability of the shoulder joint is to rebuild the normal anatomical form without over-tightening the ligaments. In some cases, such as young people with a high likelihood of re-dislocation and athletes with physical contact who wish to continue competing, surgical treatment should be undertaken after the first shoulder dislocation.
(1) Incisional surgery to repair the glenoid labrum
This procedure uses an anterolateral shoulder incision to repair the glenoid labrum and tighten the anterior joint capsule. The success rate is as high as 95%, but the procedure is more invasive and there is a possibility of joint adhesions.
(2) Minimally invasive arthroscopic surgery
Recently arthroscopic surgery and Bankant repair have been used to repair the glenoid labrum and reduce joint capsule laxity. The success rate of arthroscopic technique is no less than that of incisional surgery, and the operation is less traumatic, with rapid postoperative recovery and less chance of joint adhesions. The operation is performed through a small fiberoptic scope to visualize the shoulder joint and instruments are placed through 2-3 small incisions in the shoulder joint to repair the glenoid labrum.
V. Disease rehabilitation
1.Recovery of non-surgical treatment
Patients with a first shoulder dislocation that has not developed into recurrent instability can often regain shoulder mobility after 4-6 weeks of physical therapy.
Patients with recurrent shoulder instability have a longer rehabilitation period and should mainly focus on strengthening the shoulder muscles. Daily rehabilitation at home to avoid recurrence of shoulder instability
2.Recovery after surgical treatment
Principles of rehabilitation after arthroscopic or open repair and fixation.
Patients are usually suspended in a sling 4-6 weeks after surgery. This braking method protects the repaired glenoid labrum from healing smoothly. The glenoid labrum is held in place by sutures until healing occurs. During the braking period, the elbow and wrist joints are gently exercised.
Physical therapy is performed once the healing process is complete. Shoulder mobility exercises are performed approximately 8 weeks after surgery until strength is fully restored. Over-the-top sports such as baseball or tennis can be started 3 months after surgery, and body contact sports are limited for 6 months after surgery.