Recurrent Dislocation/Instability

A dislocated shoulder is a common shoulder injury in contact sports such as cricket, football, basketball and martial arts. in our country it is also frequently seen after road traffic accident (RTA). A dislocated shoulder is characterized by severe shoulder pain and hospital treatment is required to restore normal shoulder anatomy. The shoulder is a ball-and-socket joint that has a large range of movement but not a lot of stability, which makes the shoulder joint prone to dislocation. The shoulder is particularly unstable when it is rotated outwards and the arm cocked back or 'abducted'. Any additional force in this position will cause the head of the Humerus (arm) bone to come out of the joint in a forward direction. This is referred to as an anterior dislocation.

             

The shoulder joint is enclosed by a fibrous capsule which is strengthened by ligaments that provide a reinforced thickening of the capsule. The joint also has a labrum - a fibro cartilage lip that increases the stability of the joint. In the case of a dislocation due to trauma (such as a fall or collision), the joint capsule and ligaments are usually torn, and the labrum may also be damaged. In patient of younger age going specially under 25 years of age once they have dislocated shoulder the torn tissue is likely to be heal fully and present as recurrent dislocation. The term recurrent dislocation means that a person has had two or more dislocation of shoulder. Recurrent dislocation can be very debilitating condition and due to recurrent dislocation in shoulder joint  surfaces can get badly damaged.


What is a dislocated shoulder?

The arm is normally held in the shoulder socket by the soft tissue capsule which fits over the joint like a socket. It is also held together and stabilized by fibrous ligaments that lie within the capsule, by the muscles and tendons that rotate the arm.

Instability is usually defined as a clinical syndrome which occurs when a shoulder is loose enough to produce symptoms. It can refer to either outright dislocation where the upper arm bone comes out of the socket or to a more subtle slipping of the humeral head within the socket, a condition known as subluxation.

What causes the shoulder to dislocate?
Shoulders can dislocate when a strong force, such as a traumatic injury, abnormally stretches the ligaments and tendons, causing the ball-shaped end of the humerus to pop out of its socket. A minority of people has shoulders that can sublux or even dislocate spontaneously. However, almost 95% of shoulder dislocations result from either a forceful collision or from a sudden wrenching movement as may occur during sport, from falling onto an outstretched arm, and from motor vehicle collision.

How does it feel to have a dislocated shoulder?

During the period when their shoulder is still out-of-joint. Bruising, swelling, weakness, tingling,numbness and/or loss of sensation typically occur.
Dislocated Shoulder Signs & Symptoms
The most obvious symptom is shoulder pain. A person with a dislocated shoulder will be unable to move the affected shoulder and will hold the arm protectively against the chest. The normal rounded appearance of the shoulder will be replaced by a more squared-off edge because the head of the Humerus bone drops downwards. If a dislocation is suspected, an x-ray should be taken to confirm the damage.
Common dislocated shoulder symptoms:
• The most obvious symptom is shoulder pain.
• Loss of shoulder movement.
• Holding the arm protectively against the chest.
• The normal rounded appearance of the shoulder will be replaced by a more squared-off edge.

Dislocated Shoulder Treatment
Consult a sports injury expert
Apply ice packs/cold therapy to relieve pain & reduce bleeding
Wear a shoulder support for reassurance

It is important that a shoulder dislocation is seen quickly by a doctor who can put the joint back in place. This is because the position of the Humerus in a dislocated shoulder joint can cause damage to the Axillary nerve. This can lead to a loss of sensation and muscle strength in the affected arm. Pain relieving medication prescribed by a doctor can help to relieve the shoulder pain.
Ice packs can be applied to the injured shoulder for 20 minutes every two hours (never apply ice directly to the skin). The ice packs relieve pain and reduce bleeding in the damaged tissue.
Once the shoulder has been put back in place it is immobilized using a sling. The sling is kept on for about 2 to 3 weeks, during which time it is important that the elbow, wrist and fingers are kept moving to prevent them stiffening up.
Active rehabilitation is started as soon as possible but overhead arm movement and sporting activity should be avoided for at least 6 weeks. Gentle range of movement exercises under the supervision of a Physiotherapy can be started once the sling is removed. Strengthening exercises for the Rotator Cuff muscles should be started as soon as they can be done without pain.
Because of the damage to the structures surrounding the shoulder, there is a high chance of recurrent dislocation. Surgery on an unstable shoulder is usually required after four dislocations or more.

Dislocated Shoulder Prevention
Once there has been a dislocation of the shoulder, the joint will have a degree of instability and will be more likely to dislocate again. This is because the ligaments, capsule and labrum are damaged and cannot restrain the humeral head and prevent dislocation. In order to prevent dislocation, the Rotator Cuff muscles that surround the humeral head should be strengthened.
The Rotator Cuff muscles (Subscapularis, Supraspinatus, Infraspinatus and Teres minor) are small muscles situated around the shoulder joint. Although they have individual actions, their main role is to work together to stabilize the humeral head (ball) in the shoulder socket. Exercises using a resistance band can be very effective at strengthening the Rotator Cuff and maintaining shoulder stability and prevent recurrent shoulder dislocation.

Clinical Evaluation of Unstable Shoulders
The diagnosis is largely based on the history. The main points that the sports injury Doctor at clinic will ask you are:
1. What symptoms do you have and how long have you had them?
2. What forces were involved in the original injury (if there was one)? What was the direction and the magnitude of the forces involved, and where did they have contact with your body? For example, were you hit at high speed front-on by a car, did your shoulder impact with the steering wheel, or did you fall onto your outstretched arm while walking, running, skating, or cycling?
3. How long was your shoulder out of place before it was put back into place?
4. Did you shoulder go back into place by itself or was it put back into place by someone?
5. Did you have numbness or tingling in your arm after you were injured?
6. Did the injury occur at work?
7. What body positions or activities cause or exacerbate pain and other symptoms?
8. Is this a recurrence of symptoms or of a previous injury? If so, were the forces involved similar or was less force required to produce similar symptoms?
9. Has your shoulder problem affected your daily living skills, sporting performance, training, etc.?
10. How many other times have you had shoulder injury? (Recurrence of shoulder dislocation).

11 Have had a history of epileptic seizures.

Clinical Tests for Shoulder Instability

Grade 0:	Little/no movement
Grade 1:	Shift to edge of glenoid
Grade 2:	hift over edge of glenoid, spontaneously relocates
Grade 3:	Shift over edge of glenoid doesn't spontaneously relocate

 
1 Sulcus Sign
2 Provocative Tests
3 Apprehension test
4 Relocation test

Non-surgical Management of the Instability/ Recurrent shoulder dislocation
Usually, the doctor at A⁺ Clinic will recommend resting your injured shoulder and applying ice packs 3-4 times daily. A sling may be recommended.
Doctor at A⁺ Clinic may suggest some gentle exercises to gradually increase the shoulder's range of motion. These start with passive movements where the arm is moved by another person, progressing to active-assisted, and then to active movements made by the patient alone. Rehabilitation is best if based on the principle of progressive resistance and avoidance of aggravating factors.
After the pain and swelling are under control, the doctor may give you a program to strengthen your shoulder. The reported success rates of shoulder strengthening protocols for the management of multidirectional instability are better than those reported for unidirectional instability.

6. Physiotherapy for the Instability/ Recurrent  shoulder dislocation

Rehabilitation of the unstable shoulder, be it with non-operative or post-operative management, should aim to optimise the performance of the shoulder muscles. When the arm is held out 90o at the side with the palm facing upwards, this is a position where the shoulder is at extreme risk of dislocation if a large force is applied to it. The aim for rehabilitation would be to strengthen the muscles which normally help to prevent inadvertent dislocation.
To achieve this, the physiotherapist must consider all parts of the shoulder; in particular, its muscles and tendons, ligaments, and neuromuscular control.
1. Muscles. The rotator muscles of the shoulder, i.e. the rotator cuff, must work together to keep the shoulder still while moving the arm. Weakness affecting the balance of these muscles needs to be identified and corrected from the outset of rehabilitation. This is achieved by various resistance exercises using a "Theraband".  Instability often occurs when the muscles responsible for stability tire. Hence, it is not only important to strengthen these muscles but also to improve endurance.
Two muscles at the back of the shoulder, the trapezius and serratus anterior muscles are involved in positioning the scapula correctly. Exercises which help to strengthen these muscles are push-ups and rowing. However, all muscles around the scapula should be assessed to ensure their optimal function.
2. Capsular length can be restored to some extent by specific stretching and mobilizing of the joint capsule. Where restoration of capsular length is crucial for preventing/rehabilitating anterior shoulder instability, surgery may be warranted.
3. Neuromuscular control: This is achieved by exercising the unstable shoulder in positions which maximally challenge the shoulder muscles. Messages relating to joint position awareness (proprioception) are fed back to the brain via receptors contained in the capsule and ligaments of the shoulder. When these receptors detect a situation of potential tissue damage, the brain sends a signal to the muscles to contract and thus reposition the joint to decrease the mechanical stress on the surrounding areas.

Surgery for the Unstable Shoulder / Recurrent Dislocation

In general, shoulder surgery pre recurrent shoulder dislocation can be done in two fundamentally different ways: using closed surgical techniques (arthroscopy or "keyhole" surgery) or using open surgical techniques. Arthroscopy is a microsurgical technique whereby the surgeon can use an endoscope to look through a small hole into a joint and repair the problem of recurrent shoulder dislocation. The endoscope is an instrument, the size of a pen, which essentially consists of a tube containing a light and/or a miniature video camera, which transmits an image of the joint interior to the examiner eye via a television monitor.

Traumatic Unidirectional Instability/Recurrent Dislocation

Bankart Lesion Repair

Recuurent Dislocation also known as Shoulder Instability be resulting from trauma usually involves a Bankart lesion; i.e., detachment of the anterior part of the labrum from the rim of the glenohumeral cavity. The most recent and successful surgical procedure for recurrent shoulder dislocation for unidirectional shoulder instability is an arthroscopic variation of open Bankart repair. In the arthroscopic procedure, the detached part of the labrum and the associated ligaments are reattached to bone along the rim of the glenohumeral cavity through a small "keyhole" incision. This is done with little disruption to the other shoulder structures; e.g., without the need to detach and reattach the overlying subscapularis muscle. Because it is less invasive than open surgery, the arthroscopic procedure tends to preserve the range of movement for external rotation, and to reduce the risk of osteoarthritis.

          

Arthroscopic techniques for Recuurent Dislocation of shoulder repair involves reattaching the labrum to the glenohumeral cavity and may use:

1. Sutures
2. Suture anchors or
3. biodegradable tacks

By way of comparison, in recurrent dislocation an open Bankart repair consists of detaching and later reattaching the humeral insertion of the subscapularis tendon, and also reattaching the labrum to the anterior glenoid cavity with sutures through the bone or with suture anchors. With the open technique,for addressing the recurrent dislocation  the shoulder loses on the average 12o of external rotation following anterior stabilization, probably because the subscapularis tendon is shortened after the detachment/reattachment process.

SLAP Lesion Repair

SLAP stands for "Superior Labrum Anterior Posterior". SLAP lesions occur less frequently than Bankart lesionsin recurrent dislocating of shoulder. In SLAP lesions, the labrum detaches from its usual location along the top margin of the shoulder cavity. This detachment is associated with clicking sounds, locking of the shoulder, and/or a feeling that the shoulder is "not right" but it is rarely associated with frank shoulder instability. Best diagnosed by arthroscopy, the labrum can be reattached using an arthroscopically delivered biodegradable tac or suture anchor.
Rotator Interval Closure
Normally there is a small gap between the subscapularis and supraspinatus muscles. In a preliminary study of patients with subluxation, some success was achieved in stabilizing the shoulder by closing this gap.

Multidirectional Instability Repair for recurrent shoulder dislocationn

Anterior Capsular Shift: The most commonly performed and the most successfully reported surgical procedure for tightening the capsule is the anterior capsular shift. This can be used for patients with a large amount of anterior instability but it is particularly useful for patients with multidirectional shoulder instability. For this, slack in the capsule is reduced by making a "T-shaped" cut through the capsule, overlapping the anterior and inferior margins of the cut, and then stitching the overlapped part of the capsule (Fig. 8f).
Capsular Shrinkage: Several studies have shown that heat applied to a loose capsule can cause local shrinkage and, therefore, tightening of the capsule to prevent recurrent shoulder dislocation. Heating an area of the shoulder capsule to 65-71o resulted in a shortening of capsule collagen fibres and a 15-40% reduction in capsule size [6]. Arthroscopic devices have been designed to deliver heat to the shoulder capsule so the loose capsule can be shrunk through a small incision. This procedure is still being developed and improved.