Shoulder instability - traumatic & habitual dislocation

GENERAL INFORMATIONS

Voluntary dislocation of the shoulder in male 16 years old

The shoulder is the most moveable joint in your body. Direct or indirect violence can cause the humeral head to dislocate from the glenoid. A critical factor is whether the dislocation was caused by adequate trauma or a particular movement. Differentiating between a traumatic and nontraumatic etiology has an important bearing on further management.

Once a shoulder has dislocated, it is vulnerable to repeat episodes. When the shoulder is loose and slips out of place repeatedly, it is called chronic shoulder instability. The shoulder joint can dislocate forward, backward, or downward. A common type of shoulder dislocation is when the shoulder slips forward (anterior instability). This means the upper arm bone moved forward and down out of its joint. It may happen when the arm is put in a throwing position.

Lateral view of the right shoulder.  Anatomy

Cause

There are three common ways that a shoulder can become unstable:

Shoulder instability often follows an injury that caused the shoulder to dislocate. This initial injury is usually fairly significant, and the shoulder must be reduced. To reduce a shoulder means it must be manually put back into the socket. The shoulder may seem to return to normal, but the joint often remains unstable. The ligaments that hold the shoulder in the socket, along with the labrum (the cartilage rim around the glenoid), may have become stretched or torn. This makes them too loose to keep the shoulder in the socket when it moves in certain positions. An unstable shoulder can result in repeated episodes of dislocation, even during normal activities. Instability can also follow less severe shoulder injuries.

In some cases, shoulder instability can happen without a previous dislocation. People who do repeated shoulder motions may gradually stretch out the joint capsule. This is especially common in athletes such as baseball pitchers, volleyball players, and swimmers. If the joint capsule gets stretched out and the shoulder muscles become weak, the ball of the humerus begins to slip around too much within the shoulder. Eventually this can cause irritation and pain in the shoulder.

A genetic problem with the connective tissues of the body can lead to ligaments that are too elastic. When ligaments stretch too easily, they may not be able to hold the joints in place. All the joints of the body may be too loose. Some joints, such as the shoulder, may be easily dislocated. People with this condition are sometimes referred to as double-jointed.

Left:     Normal view
Right:  Anterior dislocation of right shoulder


Symptoms

Acute anterior dislocation
The arm is held in a position of slight abduction. The patient complains of very severe pain. The contour of the shoulder differ from the unaffected side.

Recurrent dislocation
The patient gives a prior history of an initial dislocation. It is important to establish whether the prior dislocation could be easily reduced or whether it required reduction under general anesthesia. The latter indicates a traumatic etiology of the initial dislocation

The nerves are very close to the shoulder joint.  The dislocation produce extremely pain.

CONSERVATIVE TREATMENT
THERAPY: 

Primary anterior dislocation

The initial treatment for traumatic anterior dislocation is nonsurgical. Confirmed close reduction, 3 weeks of immobilization and activity modification with supervised rehabilitation program are indicated.

Chronic instability

Once recurrent episodes of instability occur, nonsurgical emphasizes of at-risk activities and position and strengthening of the shoulder stabilizing musculature. Such a program can be effective for recurrent subluxation, but is usually less helpful for recurrent dislocation unless the patient is willing and able to drastically restrict activities.
Once conservative treatment has failed, surgical treatment is considered. The most modern arthroscopic surgery restore the normal glenohumeral anatomy with minimal invasive way.

REHABILITATION: 

The postoperative rehabilitation is determined by the primary stabilization procedure performed. In general a sling is worn for 4 weeks. Gentle passive range of motion exercises are started on the first day after surgery.

The 5th week until 8th week progressive active exercise and neuromuscular training. The sling is continued to use
After the 8th week is the final phase and consists of progressive range of motion exercises as tolerated, increasing resistance, neuromuscular training and aerobic conditioning.

Return to full active duty, contact sports and activities requiring overhead or heavy lifting is restricted until 4 months postoperatively.

OPERATIVE TREATMENT
THERAPY: 

Arthroscopic shoulder stabilization offers a number of advantages over traditional open repair. These include:

smaller incisions
less muscle dissection
less postoperative pain
better visualization of the entire glenohumeral joint

 

Anterior shoulder instability.

Indications

The primary reason to offer a surgical stabilization procedure is shoulder instability that interferes with activities of daily living or recreational sports. Recurrent dislocation or subluxation episodes can result an additional chondral or osteochondral damage.


Χ-ray.  Normal shoulder appearance

X-ray.  Anterior shoulder dislocation.


Normal shoulder anatomy (A).  Anterior shoulder dislocation (B).

Bankart lesion:  The labrum is detached from the glenoid rim.  This produce shoulder instability and recurrent dislocation.
Hill-Suchs lesion:  The posterior surface of the humeral head collapsed due to crash with the anterior glenoid rim during anterior dislocation.


MRI: Transverse view,  Bankart lesion.  The anterior labrum is completely detached from the glenoid rim.

Animation of labrum stabilization.  The labrum is one of the main shoulder stabilizer.

The glenoid rim preparation for special srew insertrion.

The screw insertion with special instrument under atrhroscopic visualization.

An arthroscopic knot is tied and pushed down to abut the tissue of labrum down to the glenoid rim.

The completed repair visualized from posterior arthroscopic portal.  The labrum is stable attached to the rim.  The patient can enjoy his stable shoulder.