Shoulder Dislocation
The shoulder is a ball and socket joint. The ball is the head of the upper arm bone and the socket is the shallow indentation in the shoulder blade. The shoulder is the most mobile joint in the body and the joint most commonly dislocated. The stabilizing tendons and muscles that make up the rotator cuff allow for this wide range of motion while firmly holding the ball of the upper arm bone in the shoulder socket. Additionally, the shoulder socket is shallow. To ensure stability, nature has provided a protective cuff of cartilage called the labrum which deepens the socket and works with the shoulder ligaments to hold the bones together. It requires a strong force to dislocate the shoulder.
What is a shoulder dislocation?
Dislocation occurs when the head of the upper arm bone is forcefully displaced out of its socket by trauma including auto accidents, falls, and contact sports injuries. Epileptic seizures can cause the muscles to contract and force the head of the upper arm bone out of its socket. When the head of the upper arm bone is only partially out of the socket it is called a subluxation.
A dislocated shoulder is a common occurrence among younger, active male athletes, and a common reason for emergency room visits. Twenty percent of shoulder dislocations occur in people younger than age 20. Most suffer anterior shoulder dislocation and studies show that recurrent anterior shoulder instability after the shoulder dislocation is as high as 26% in young patients.
Another 20% of all shoulder dislocations occur in people over the age of 60, mainly women, who are more likely to suffer recurrent instability and dislocation, and to sustain injuries of the rotator cuff and nerves. Dislocation in this group is often caused by a fall on the shoulder or an auto accident.
Complications may include torn muscles, ligaments and tendons, nerve and blood vessel damage, and shoulder instability.
What are the symptoms of a shoulder dislocation?
a visible deformity
swelling and bruising
severe pain
weakness, numbness and tingling at the site of dislocation or in the neck, hands and fingers
difficulty moving the shoulder
muscle spasms
Types of shoulder dislocation
Anterior shoulder dislocation
Traumatic anterior shoulder dislocation is the most common major joint dislocation that affects about 2% of the population. Anterior shoulder dislocation is often caused by a sudden and powerful outward rotation of the upper arm. It is associated with a high number of injuries of the shoulder joint including wear and tear on the labrum. Associated damage to the soft tissues, tendons, nerves, blood vessels and labrum is common.
Posterior shoulder dislocation
Posterior shoulder dislocation is rare accounting for only about 0.9% of all dislocations. It is caused by high energy auto accidents, violence and epileptic seizures. It typically affects people aged 30-55.
Repetitive strain and chronic shoulder instability
Repetitive strain from sports such as swimming, tennis and volleyball and heavy labor can stretch shoulder ligaments and cause instability that can result in a dislocated shoulder.
How is a shoulder dislocation diagnosed?
Dr. Johnston will ask how the shoulder was injured, your symptoms and whether you have had a previous shoulder dislocation which would suggest potential recurrent shoulder instability. He will conduct an evaluation of the shoulder and order x-rays and additional imaging to view the position of the bones.
How is a shoulder dislocation treated?
Treatment involves placing the head of the upper arm bone back into its socket. This is called a reduction. If it can be accomplished without surgery, it is called a closed reduction. It is very painful, so you will likely be offered pain medication to relax your muscles, but severe pain will resolve almost immediately after the reduction is complete. In some cases, surgery may be needed to place the head of the upper arm bone back in its socket. This is called an open reduction.
After reduction the arm will be held in a sling to immobilize the joint for a few weeks. Rest, icing and after the pain and swelling subside, physical therapy will help to strengthen the muscles, restore range of motion and prevent another dislocation.
When shoulder instability remains, dislocations can become a recurrent problem. In that case, Dr. Johnston may recommend using a brace to protect the shoulder. When therapy and bracing are insufficient to prevent dislocation or when there are torn ligaments or damage to the labrum surgery may be needed to restore the integrity of the joint. Recurrent dislocations can also damage the bones which must be surgically treated.
Contact Dr. Peter Johnston about all your shoulder problems. He is committed to and beloved by his patients who trust him to always provide compassionate expert class care.
