Shoulder Instability (Shoulder dislocations & shoulder joint labral tears)

Acute Shoulder dislocation

 

The shoulder joint is the body's most mobile joint. It can turn in many directions. But, this advantage also makes the shoulder an easy joint to dislocate.

 

A partial dislocation (subluxation) means the head of the upper arm bone (humerus) is partially out of the socket (glenoid). A complete dislocation means it is all the way out of the socket. Both partial and complete dislocation cause pain and unsteadiness in the shoulder.

 

Symptoms to look for include:

  • Swelling

  • Numbness

  • Weakness

  • Bruising

 

 

 

 

Sometimes dislocation may tear ligaments or tendons in the shoulder or damage nerves.

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.

 

Diagnosis

The muscles may have spasms from the disruption, and this can make it hurt more. When the shoulder dislocates time and again, there is shoulder instability.

The doctor will examine the shoulder and may order an X-ray. It is important that the doctor know how the dislocation happened and whether the shoulder had ever been dislocated before.

 

Treatment

The doctor will place the ball of the upper arm bone (humerus) back into the joint socket. This process is called closed reduction. Severe pain stops almost immediately once the shoulder joint is back in place.

 

Rehabilitation

Your doctor may immobilize the shoulder in a sling or other device for several weeks following treatment. Plenty of rest is needed. The sore area can be iced 3 to 4 times a day.

After the pain and swelling go down, the doctor will prescribe rehabilitation exercises for you. These help restore the shoulder's range of motion and strengthen the muscles. Rehabilitation may also help prevent dislocating the shoulder again in the future. Rehabilitation will begin with gentle muscle toning exercises. Later, weight training can be added.

Shoulder instability - Shoulder joint tear (labrum tear)

 

Symptoms

 

The symptoms of a tear in the shoulder socket rim are very similar to those of other shoulder injuries. Symptoms include

 

  • Pain, usually with overhead activities

  • Catching, locking, popping, or grinding

  • Occasional night pain or pain with daily activities

  • A sense of instability in the shoulder

  • Decreased range of motion

  • Loss of strength


 

 

Anatomy

The shoulder joint has three bones: the shoulder blade (scapula), the collarbone (clavicle), and the upper arm bone (humerus). The head of the upper arm bone (humeral head) rests in a shallow socket in the shoulder blade called the glenoid. The head of the upper arm bone is usually much larger than the socket, and a soft fibrous tissue rim called the labrum surrounds the socket to help stabilize the joint. The rim deepens the socket by up to 50% so that the head of the upper arm bone fits better. In addition, it serves as an attachment site for several ligaments.

 

Risk Factors/Prevention

Injuries to the tissue rim surrounding the shoulder socket can occur from acute trauma or repetitive shoulder motion. Examples of traumatic injury include:

  • Falling on an outstretched arm

  • A direct blow to the shoulder

  • A sudden pull, such as when trying to lift a heavy object

  • A violent overhead reach, such as when trying to stop a fall or slide

  •  

Throwing athletes or weightlifters can experience glenoid labrum tears as a result of repetitive shoulder motion.

 

 

Diagnosis

Your doctor will take a history of your injury. You may be able to remember a specific incident or you may note that the pain gradually increased. The doctor will do several physical tests to check range of motion, stability, and pain. In addition, the doctor will request x-rays to see if there are any other reasons for your problems.

Because the rim of the shoulder socket is soft tissue, x-rays will not show damage to it. The doctor may order a computed tomography (CT) scan or magnetic resonance imaging (MRI) scan. In both instances, a contrast medium may be injected to help detect tears. Ultimately, however, the diagnosis will be made with arthroscopic surgery.

 

 

Treatment

Anti-inflammatory medication and rest to relieve symptoms. Rehabilitation exercises to strengthen the rotator cuff muscles may also be recommended. If these conservative measures are insufficient, your doctor may recommend arthroscopic surgery.

During arthroscopic surgery, the doctor will examine the rim and the biceps tendon. If the injury is confined to the rim itself, without involving the tendon, the shoulder is still stable. The surgeon will remove the torn flap and correct any other associated problems. If the tear extends into the biceps tendon or if the tendon is detached, the shoulder is unstable (Fig 2c &2d). The surgeon will need to repair and reattach the tendon using absorbable tacks, wires, or sutures (Figure 2e &2f).

Tears below the middle of the socket are also associated with shoulder instability. The surgeon will reattach the ligament and tighten the shoulder socket by folding over and "pleating" the tissues.

 

If there have been multiple episodes of dislocation, the bony edge of the socket might have been eroded, in which case an open surgery with bone transfer and reconstruction of the bony socket (Laterjet) procedure might be needed. 

 

Rehabilitation

After surgery, you will need to keep your shoulder in a sling for 3 to 4 weeks. Your physician will also prescribe gentle, passive, pain-free range-of-motion exercises. When the sling is removed, you will need to do motion and flexibility exercises and gradually start to strengthen your biceps. Athletes can usually begin doing sport-specific exercises 6 weeks after surgery, although it will be 3 to 4 months before the shoulder is fully healed.

 

 

Dr Vinod Kumar Abu Dhabi

Shoulder Surgeon Abu Dhabi

NMC Royal Hospital.

Anchors - suture tacks used for repair of the torn labrum- These can be metal ones or bio-absorbable ones

© 2013 by Shoulder-Surgeon. All rights reserved.

The treatments described are for information and educational purposes only. This is not to be taken as medical advice and they are in no way intended to replace a consultation with your doctor.